diff options
Diffstat (limited to 'libX11/specs')
| -rw-r--r-- | libX11/specs/libX11/CH02.xml | 6983 |
1 files changed, 3489 insertions, 3494 deletions
diff --git a/libX11/specs/libX11/CH02.xml b/libX11/specs/libX11/CH02.xml index a00b7c283..f4ef1bcd8 100644 --- a/libX11/specs/libX11/CH02.xml +++ b/libX11/specs/libX11/CH02.xml @@ -1,3494 +1,3489 @@ -<?xml version="1.0" encoding="UTF-8" ?>
-<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
- "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd">
-<chapter id="display_functions">
-<title>Display Functions</title>
-<para>
-Before your program can use a display, you must establish a connection
-to the X server.
-Once you have established a connection,
-you then can use the Xlib macros and functions discussed in this chapter
-to return information about the display.
-This chapter discusses how to:
-</para>
-<itemizedlist>
- <listitem>
- <para>
-Open (connect to) the display
- </para>
- </listitem>
- <listitem>
- <para>
-Obtain information about the display, image formats, or screens
- </para>
- </listitem>
- <listitem>
- <para>
-Generate a
-<systemitem>NoOperation</systemitem>
-protocol request
- </para>
- </listitem>
- <listitem>
- <para>
-Free client-created data
- </para>
- </listitem>
- <listitem>
- <para>
-Close (disconnect from) a display
- </para>
- </listitem>
- <listitem>
- <para>
-Use X Server connection close operations
- </para>
- </listitem>
- <listitem>
- <para>
-Use Xlib with threads
- </para>
- </listitem>
- <listitem>
- <para>
-Use internal connections
- </para>
- </listitem>
-</itemizedlist>
-<sect1 id="Opening_the_Display">
-<title>Opening the Display</title>
-<!-- .XS -->
-<!-- (SN Opening the Display -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-To open a connection to the X server that controls a display, use
-<function>XOpenDisplay</function>.
-<indexterm significance="preferred"><primary>XOpenDisplay</primary></indexterm>
-</para>
-<para>
-<!-- .LP -->
-<!-- .sM -->
-</para>
-<para>
-AllPlanes()
-</para>
-<para>
-XAllPlanes
-</para>
-
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display_name</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the hardware display name, which determines the display
-and communications domain to be used.
-On a <acronym>POSIX</acronym>-conformant system, if the display_name is NULL,
-it defaults to the value of the DISPLAY environment variable.
-<indexterm><primary>Environment</primary><secondary>DISPLAY</secondary></indexterm>
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The encoding and interpretation of the display name are
-implementation-dependent.
-Strings in the Host Portable Character Encoding are supported;
-support for other characters is implementation-dependent.
-On <acronym>POSIX</acronym>-conformant systems,
-the display name or DISPLAY environment variable can be a string in the format:
-</para>
-<!-- .LP -->
-<!-- .sM -->
-<literallayout class="monospaced">
-<!-- .TA 1i -->
-<!-- .ta 1i -->
- <emphasis remap='I'>protocol</emphasis>/<emphasis remap='I'>hostname</emphasis>:<emphasis remap='I'>number</emphasis>.<emphasis remap='I'>screen_number</emphasis>
-</literallayout>
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>protocol</emphasis>
- </term>
- <listitem>
- <para>
-Specifies a protocol family or an alias for a protocol family. Supported
-protocol families are implementation dependent. The protocol entry is
-optional. If protocol is not specified, the / separating protocol and
-hostname must also not be specified.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>hostname</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the name of the host machine on which the display is physically
-attached.
-You follow the hostname with either a single colon (:) or a double colon (::).
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the number of the display server on that host machine.
-You may optionally follow this display number with a period (.).
-A single <acronym>CPU</acronym> can have more than one display.
-Multiple displays are usually numbered starting with zero.
-<indexterm><primary>Screen</primary></indexterm>
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the screen to be used on that server.
-Multiple screens can be controlled by a single X server.
-The screen_number sets an internal variable that can be accessed by
-using the
-<function>DefaultScreen</function>
-macro or the
-<function>XDefaultScreen</function>
-function if you are using languages other than C (see section 2.2.1).
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-For example, the following would specify screen 1 of display 0 on the
-machine named ``dual-headed'':
-</para>
-<para>
-<!-- .LP -->
-<literallayout class="monospaced">
-dual-headed:0.1
-</literallayout>
-</para>
-<para>
-<!-- .LP -->
-The
-<function>XOpenDisplay</function>
-function returns a
-<type>Display</type>
-structure that serves as the
-connection to the X server and that contains all the information
-about that X server.
-<function>XOpenDisplay</function>
-connects your application to the X server through <acronym>TCP</acronym>
-or DECnet communications protocols,
-or through some local inter-process communication protocol.
-<indexterm><primary>Protocol</primary><secondary><acronym>TCP</acronym></secondary></indexterm>
-<indexterm><primary>Protocol</primary><secondary>DECnet</secondary></indexterm>
-If the protocol is specified as "tcp", "inet", or "inet6", or
-if no protocol is specified and the hostname is a host machine name and a single colon (:)
-separates the hostname and display number,
-<function>XOpenDisplay</function>
-connects using <acronym>TCP</acronym> streams. (If the protocol is specified as "inet", <acronym>TCP</acronym> over
-IPv4 is used. If the protocol is specified as "inet6", <acronym>TCP</acronym> over IPv6 is used.
-Otherwise, the implementation determines which <acronym>IP</acronym> version is used.)
-If the hostname and protocol are both not specified,
-Xlib uses whatever it believes is the fastest transport.
-If the hostname is a host machine name and a double colon (::)
-separates the hostname and display number,
-<function>XOpenDisplay</function>
-connects using DECnet.
-A single X server can support any or all of these transport mechanisms
-simultaneously.
-A particular Xlib implementation can support many more of these transport
-mechanisms.
-</para>
-<para>
-<!-- .LP -->
-<indexterm><primary>Display</primary></indexterm>
-If successful,
-<function>XOpenDisplay</function>
-returns a pointer to a
-<type>Display</type>
-structure,
-which is defined in
-<filename class="headerfile"><X11/Xlib.h></filename>.
-<indexterm type="file"><primary><filename class="headerfile">X11/Xlib.h</filename></primary></indexterm>
-<indexterm><primary>Files</primary><secondary><filename class="headerfile"><X11/Xlib.h></filename></secondary></indexterm>
-<indexterm><primary>Headers</primary><secondary><filename class="headerfile"><X11/Xlib.h></filename></secondary></indexterm>
-If
-<function>XOpenDisplay</function>
-does not succeed, it returns NULL.
-After a successful call to
-<function>XOpenDisplay</function>,
-all of the screens in the display can be used by the client.
-The screen number specified in the display_name argument is returned
-by the
-<function>DefaultScreen</function>
-macro (or the
-<function>XDefaultScreen</function>
-function).
-You can access elements of the
-<type>Display</type>
-and
-<type>Screen</type>
-structures only by using the information macros or functions.
-For information about using macros and functions to obtain information from
-the
-<type>Display</type>
-structure,
-see section 2.2.1.
-</para>
-<para>
-<!-- .LP -->
-X servers may implement various types of access control mechanisms
-(see section 9.8).
-</para>
-</sect1>
-<sect1 id="Obtaining_Information_about_the_Display_Image_Formats_or_Screens">
-<title>Obtaining Information about the Display, Image Formats, or Screens</title>
-<!-- .XS -->
-<!-- (SN Obtaining Information about the Display, Image Formats, or Screens -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-The Xlib library provides a number of useful macros
-and corresponding functions that return data from the
-<type>Display</type>
-structure.
-The macros are used for C programming,
-and their corresponding function equivalents are for other language bindings.
-This section discusses the:
-</para>
-<itemizedlist>
- <listitem>
- <para>
-Display macros
- </para>
- </listitem>
- <listitem>
- <para>
-Image format functions and macros
- </para>
- </listitem>
- <listitem>
- <para>
-Screen information macros
- </para>
- </listitem>
-</itemizedlist>
-<para>
-<!-- .LP -->
-<indexterm ><primary>Display</primary><secondary>data structure</secondary></indexterm>
-All other members of the
-<type>Display</type>
-structure (that is, those for which no macros are defined) are private to Xlib
-and must not be used.
-Applications must never directly modify or inspect these private members of the
-<type>Display</type>
-structure.
-<!-- .NT Note -->
-The
-<function>XDisplayWidth</function>,
-<function>XDisplayHeight</function>,
-<function>XDisplayCells</function>,
-<function>XDisplayPlanes</function>,
-<function>XDisplayWidthMM</function>,
-and
-<function>XDisplayHeightMM</function>
-functions in the next sections are misnamed.
-These functions really should be named Screen<emphasis remap='I'>whatever</emphasis>
-and XScreen<emphasis remap='I'>whatever</emphasis>, not Display<emphasis remap='I'>whatever</emphasis> or XDisplay<emphasis remap='I'>whatever</emphasis>.
-Our apologies for the resulting confusion.
-<!-- .NE -->
-</para>
-<sect2 id="Display_Macros_">
-<title>Display Macros </title>
-<!-- .XS -->
-<!-- (SN Display Macros -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-Applications should not directly modify any part of the
-<type>Display</type>
-and
-<type>Screen</type>
-structures.
-The members should be considered read-only,
-although they may change as the result of other operations on the display.
-</para>
-<para>
-<!-- .LP -->
-The following lists the C language macros,
-their corresponding function equivalents that are for other language bindings,
-and what data both can return.
-</para>
-<para>AllPlanes()</para>
-<para>XAllPlanes()</para>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>AllPlanes</primary></indexterm>
-<indexterm significance="preferred"><primary>XAllPlanes</primary></indexterm>
-Both return a value with all bits set to 1 suitable for use in a plane argument to
-a procedure.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-Both
-<function>BlackPixel</function>
-and
-<function>WhitePixel</function>
-can be used in implementing a monochrome application.
-These pixel values are for permanently allocated entries in the default
-colormap.
-The actual <acronym>RGB</acronym> (red, green, and blue) values are settable on some screens
-and, in any case, may not actually be black or white.
-The names are intended to convey the expected relative intensity of the colors.
-<!-- .sM -->
-</para>
-<para>
-BlackPixel(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XBlackPixel</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>BlackPixel</primary></indexterm>
-<indexterm significance="preferred"><primary>XBlackPixel</primary></indexterm>
-Both return the black pixel value for the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-WhitePixel(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XWhitePixel</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>WhitePixel</primary></indexterm>
-<indexterm significance="preferred"><primary>XWhitePixel</primary></indexterm>
-Both return the white pixel value for the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ConnectionNumber(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XConnectionNumber</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ConnectionNumber</primary></indexterm>
-<indexterm significance="preferred"><primary>XConnectionNumber</primary></indexterm>
-Both return a connection number for the specified display.
-On a <acronym>POSIX</acronym>-conformant system,
-this is the file descriptor of the connection.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultColormap(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Colormap <function>XDefaultColormap</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultColormap</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultColormap</primary></indexterm>
-Both return the default colormap ID for allocation on the specified screen.
-Most routine allocations of color should be made out of this colormap.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultDepth(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDefaultDepth</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultDepth</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultDepth</primary></indexterm>
-Both return the depth (number of planes) of the default root window for the
-specified screen.
-Other depths may also be supported on this screen (see
-<function>XMatchVisualInfo</function>).
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<indexterm significance="preferred"><primary>XListDepths</primary></indexterm>
-To determine the number of depths that are available on a given screen, use
-<function>XListDepths</function>.
-<!-- .sM -->
-</para>
-<para>
-DefaultGC(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>GC <function>XDefaultGC</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
- <paramdef>int<parameter> *count_return</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
-<!-- .ds Cn depths -->
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>count_return</emphasis>
- </term>
- <listitem>
- <para>
-Returns the number of (Cn.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XListDepths</function>
-function returns the array of depths
-that are available on the specified screen.
-If the specified screen_number is valid and sufficient memory for the array
-can be allocated,
-<function>XListDepths</function>
-sets count_return to the number of available depths.
-Otherwise, it does not set count_return and returns NULL.
-To release the memory allocated for the array of depths, use
-<function>XFree</function>.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultGC(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>GC <function>XDefaultGC</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultGC</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultGC</primary></indexterm>
-Both return the default graphics context for the root window of the
-specified screen.
-This GC is created for the convenience of simple applications
-and contains the default GC components with the foreground and
-background pixel values initialized to the black and white
-pixels for the screen, respectively.
-You can modify its contents freely because it is not used in any Xlib
-function.
-This GC should never be freed.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultRootWindow(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Window <function>XDefaultRootWindow</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultRootWindow</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultRootWindow</primary></indexterm>
-Both return the root window for the default screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultScreenOfDisplay(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Screen *<function>XDefaultScreenOfDisplay</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultScreenOfDisplay</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultScreenOfDisplay</primary></indexterm>
-Both return a pointer to the default screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ScreenOfDisplay(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Screen *<function>XScreenOfDisplay</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ScreenOfDisplay</primary></indexterm>
-<indexterm significance="preferred"><primary>XScreenOfDisplay</primary></indexterm>
-Both return a pointer to the indicated screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultScreen(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDefaultScreen</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultScreen</primary></indexterm>
-Both return the default screen number referenced by the
-<function>XOpenDisplay</function>
-function.
-This macro or function should be used to retrieve the screen number
-in applications that will use only a single screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultVisual(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Visual *<function>XDefaultVisual</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultVisual</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultVisual</primary></indexterm>
-Both return the default visual type for the specified screen.
-For further information about visual types,
-see section 3.1.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayCells(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDisplayCells</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayCells</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayCells</primary></indexterm>
-Both return the number of entries in the default colormap.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayPlanes(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDisplayPlanes</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayPlanes</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayPlanes</primary></indexterm>
-Both return the depth of the root window of the specified screen.
-For an explanation of depth,
-see the glossary.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayString(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>char *<function>XDisplayString</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayString</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayString</primary></indexterm>
-Both return the string that was passed to
-<function>XOpenDisplay</function>
-when the current display was opened.
-On <acronym>POSIX</acronym>-conformant systems,
-if the passed string was NULL, these return the value of
-the DISPLAY environment variable when the current display was opened.
-<indexterm><primary><acronym>POSIX</acronym> System Call</primary><secondary>fork</secondary></indexterm>
-These are useful to applications that invoke the
-<function>fork</function>
-system call and want to open a new connection to the same display from the
-child process as well as for printing error messages.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-LastKnownRequestProcessed(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XLastKnownRequestProcessed</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>XExtendedMaxRequestSize</primary></indexterm>
-The
-<function>XExtendedMaxRequestSize</function>
-function returns zero if the specified display does not support an
-extended-length protocol encoding; otherwise,
-it returns the maximum request size (in 4-byte units) supported
-by the server using the extended-length encoding.
-The Xlib functions
-<function>XDrawLines</function>,
-<function>XDrawArcs</function>,
-<function>XFillPolygon</function>,
-<function>XChangeProperty</function>,
-<function>XSetClipRectangles</function>,
-and
-<function>XSetRegion</function>
-will use the extended-length encoding as necessary, if supported
-by the server. Use of the extended-length encoding in other Xlib
-functions (for example,
-<function>XDrawPoints</function>,
-<function>XDrawRectangles</function>,
-<function>XDrawSegments</function>,
-<function>XFillArcs</function>,
-<function>XFillRectangles</function>,
-<function>XPutImage</function>)
-is permitted but not required; an Xlib implementation may choose to
-split the data across multiple smaller requests instead.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-LastKnownRequestProcessed(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XLastKnownRequestProcessed</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>XMaxRequestSize</primary></indexterm>
-The
-<function>XMaxRequestSize</function>
-function returns the maximum request size (in 4-byte units) supported
-by the server without using an extended-length protocol encoding.
-Single protocol requests to the server can be no larger than this size
-unless an extended-length protocol encoding is supported by the server.
-The protocol guarantees the size to be no smaller than 4096 units
-(16384 bytes).
-Xlib automatically breaks data up into multiple protocol requests
-as necessary for the following functions:
-<function>XDrawPoints</function>,
-<function>XDrawRectangles</function>,
-<function>XDrawSegments</function>,
-<function>XFillArcs</function>,
-<function>XFillRectangles</function>,
-and
-<function>XPutImage</function>.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-LastKnownRequestProcessed(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XLastKnownRequestProcessed</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>LastKnownRequestProcessed</primary></indexterm>
-<indexterm significance="preferred"><primary>XLastKnownRequestProcessed</primary></indexterm>
-Both extract the full serial number of the last request known by Xlib
-to have been processed by the X server.
-Xlib automatically sets this number when replies, events, and errors
-are received.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-NextRequest(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XNextRequest</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>NextRequest</primary></indexterm>
-<indexterm significance="preferred"><primary>XNextRequest</primary></indexterm>
-Both extract the full serial number that is to be used for the next
-request.
-Serial numbers are maintained separately for each display connection.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ProtocolVersion(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XProtocolVersion</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ProtocolVersion</primary></indexterm>
-<indexterm significance="preferred"><primary>XProtocolVersion</primary></indexterm>
-Both return the major version number (11) of the X protocol associated with
-the connected display.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ProtocolRevision(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XProtocolRevision</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ProtocolRevision</primary></indexterm>
-<indexterm significance="preferred"><primary>XProtocolRevision</primary></indexterm>
-Both return the minor protocol revision number of the X server.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-QLength(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XQLength</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>QLength</primary></indexterm>
-<indexterm significance="preferred"><primary>XQLength</primary></indexterm>
-Both return the length of the event queue for the connected display.
-Note that there may be more events that have not been read into
-the queue yet (see
-<function>XEventsQueued</function>).
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-RootWindow(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Window <function>XRootWindow</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm><primary>Window</primary><secondary>RootWindow</secondary></indexterm>
-<indexterm significance="preferred"><primary>RootWindow</primary></indexterm>
-<indexterm><primary>Window</primary><secondary>XRootWindow</secondary></indexterm>
-<indexterm significance="preferred"><primary>XRootWindow</primary></indexterm>
-Both return the root window.
-These are useful with functions that need a drawable of a particular screen
-and for creating top-level windows.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ScreenCount(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XScreenCount</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ScreenCount</primary></indexterm>
-<indexterm significance="preferred"><primary>XScreenCount</primary></indexterm>
-Both return the number of available screens.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ServerVendor(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>char *<function>XServerVendor</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ServerVendor</primary></indexterm>
-<indexterm significance="preferred"><primary>XServerVendor</primary></indexterm>
-Both return a pointer to a null-terminated string that provides
-some identification of the owner of the X server implementation.
-If the data returned by the server is in the Latin Portable Character Encoding,
-then the string is in the Host Portable Character Encoding.
-Otherwise, the contents of the string are implementation-dependent.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-VendorRelease(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XVendorRelease</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>VendorRelease</primary></indexterm>
-<indexterm significance="preferred"><primary>XVendorRelease</primary></indexterm>
-Both return a number related to a vendor's release of the X server.
-</para>
-</sect2>
-<sect2 id="Image_Format_Functions_and_Macros">
-<title>Image Format Functions and Macros</title>
-<!-- .XS -->
-<!-- (SN Image Format Functions and Macros -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-Applications are required to present data to the X server
-in a format that the server demands.
-To help simplify applications,
-most of the work required to convert the data is provided by Xlib
-(see sections 8.7 and 16.8).
-</para>
-<para>
-<!-- .LP -->
-The
-<structname>XPixmapFormatValues</structname>
-structure provides an interface to the pixmap format information
-that is returned at the time of a connection setup.
-It contains:
-</para>
-<para>
-<!-- .LP -->
-<!-- .sM -->
-<literallayout class="monospaced">
-<!-- .TA .5i 3i -->
-<!-- .ta .5i 3i -->
-typedef struct {
- int depth;
- int bits_per_pixel;
- int scanline_pad;
-} XPixmapFormatValues;
-</literallayout>
-</para>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<!-- .sp -->
-To obtain the pixmap format information for a given display, use
-<function>XListPixmapFormats</function>.
-<indexterm significance="preferred"><primary>XListPixmapFormats</primary></indexterm>
-<!-- .sM -->
-</para>
-<para>
-ImageByteOrder(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XImageByteOrder</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> *count_return</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
-<!-- .ds Cn pixmap formats that are supported by the display -->
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>count_return</emphasis>
- </term>
- <listitem>
- <para>
-Returns the number of (Cn.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XListPixmapFormats</function>
-function returns an array of
-<structname>XPixmapFormatValues</structname>
-structures that describe the types of Z format images supported
-by the specified display.
-If insufficient memory is available,
-<function>XListPixmapFormats</function>
-returns NULL.
-To free the allocated storage for the
-<structname>XPixmapFormatValues</structname>
-structures, use
-<function>XFree</function>.
-</para>
-<para>
-<!-- .LP -->
-The following lists the C language macros,
-their corresponding function equivalents that are for other language bindings,
-and what data they both return for the specified server and screen.
-These are often used by toolkits as well as by simple applications.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-ImageByteOrder(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XImageByteOrder</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>ImageByteOrder</primary></indexterm>
-<indexterm significance="preferred"><primary>XImageByteOrder</primary></indexterm>
-Both specify the required byte order for images for each scanline unit in
-XY format (bitmap) or for each pixel value in
-Z format.
-The macro or function can return either
-<symbol>LSBFirst</symbol>
-or
-<symbol>MSBFirst</symbol>.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-BitmapUnit(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XBitmapUnit</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>BitmapUnit</primary></indexterm>
-<indexterm significance="preferred"><primary>XBitmapUnit</primary></indexterm>
-Both return the size of a bitmap's scanline unit in bits.
-The scanline is calculated in multiples of this value.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-BitmapBitOrder(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XBitmapBitOrder</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>BitmapBitOrder</primary></indexterm>
-<indexterm significance="preferred"><primary>XBitmapBitOrder</primary></indexterm>
-Within each bitmap unit, the left-most bit in the bitmap as displayed
-on the screen is either the least significant or most significant bit in the
-unit.
-This macro or function can return
-<symbol>LSBFirst</symbol>
-or
-<symbol>MSBFirst</symbol>.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-BitmapPad(<emphasis remap='I'>display</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XBitmapPad</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>BitmapPad</primary></indexterm>
-<indexterm significance="preferred"><primary>XBitmapPad</primary></indexterm>
-Each scanline must be padded to a multiple of bits returned
-by this macro or function.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayHeight(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDisplayHeight</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayHeight</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayHeight</primary></indexterm>
-Both return an integer that describes the height of the screen
-in pixels.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayHeightMM(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDisplayHeightMM</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayHeightMM</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayHeightMM</primary></indexterm>
-Both return the height of the specified screen in millimeters.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayWidth(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDisplayWidth</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayWidth</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayWidth</primary></indexterm>
-Both return the width of the screen in pixels.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayWidthMM(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDisplayWidthMM</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> screen_number</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen_number</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate screen number on the host server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayWidthMM</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayWidthMM</primary></indexterm>
-Both return the width of the specified screen in millimeters.
-</para>
-</sect2>
-<sect2 id="Screen_Information_Macros">
-<title>Screen Information Macros</title>
-<!-- .XS -->
-<!-- (SN Screen Information Macros -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-The following lists the C language macros,
-their corresponding function equivalents that are for other language bindings,
-and what data they both can return.
-These macros or functions all take a pointer to the appropriate screen
-structure.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-BlackPixelOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XBlackPixelOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>BlackPixelOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XBlackPixelOfScreen</primary></indexterm>
-Both return the black pixel value of the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-WhitePixelOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>unsigned long <function>XWhitePixelOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>WhitePixelOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XWhitePixelOfScreen</primary></indexterm>
-Both return the white pixel value of the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-CellsOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XCellsOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>CellsOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XCellsOfScreen</primary></indexterm>
-Both return the number of colormap cells in the default colormap
-of the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultColormapOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Colormap <function>XDefaultColormapOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultColormapOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultColormapOfScreen</primary></indexterm>
-Both return the default colormap of the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultDepthOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDefaultDepthOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultDepthOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultDepthOfScreen</primary></indexterm>
-Both return the depth of the root window.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultGCOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>GC <function>XDefaultGCOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultGCOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultGCOfScreen</primary></indexterm>
-Both return a default graphics context (GC) of the specified screen,
-which has the same depth as the root window of the screen.
-The GC must never be freed.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DefaultVisualOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Visual *<function>XDefaultVisualOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DefaultVisualOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XDefaultVisualOfScreen</primary></indexterm>
-Both return the default visual of the specified screen.
-For information on visual types,
-see section 3.1.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DoesBackingStore(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XDoesBackingStore</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DoesBackingStore</primary></indexterm>
-<indexterm significance="preferred"><primary>XDoesBackingStore</primary></indexterm>
-Both return a value indicating whether the screen supports backing
-stores.
-The value returned can be one of
-<symbol>WhenMapped</symbol>,
-<symbol>NotUseful</symbol>,
-or
-<symbol>Always</symbol>
-(see section 3.2.4).
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DoesSaveUnders(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Bool <function>XDoesSaveUnders</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DoesSaveUnders</primary></indexterm>
-<indexterm significance="preferred"><primary>XDoesSaveUnders</primary></indexterm>
-Both return a Boolean value indicating whether the
-screen supports save unders.
-If
-<symbol>True</symbol>,
-the screen supports save unders.
-If
-<symbol>False</symbol>,
-the screen does not support save unders (see section 3.2.5).
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-DisplayOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Display *<function>XDisplayOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>DisplayOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XDisplayOfScreen</primary></indexterm>
-Both return the display of the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-<indexterm significance="preferred"><primary>XScreenNumberOfScreen</primary></indexterm>
-</para>
-<para>
-EventMaskOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>long <function>XEventMaskOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XScreenNumberOfScreen</function>
-function returns the screen index number of the specified screen.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-EventMaskOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>long <function>XEventMaskOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>EventMaskOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XEventMaskOfScreen</primary></indexterm>
-Both return the event mask of the root window for the specified screen
-at connection setup time.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-WidthOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XWidthOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>WidthOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XWidthOfScreen</primary></indexterm>
-Both return the width of the specified screen in pixels.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-HeightOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XHeightOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>HeightOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XHeightOfScreen</primary></indexterm>
-Both return the height of the specified screen in pixels.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-WidthMMOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XWidthMMOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>WidthMMOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XWidthMMOfScreen</primary></indexterm>
-Both return the width of the specified screen in millimeters.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-HeightMMOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XHeightMMOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>HeightMMOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XHeightMMOfScreen</primary></indexterm>
-Both return the height of the specified screen in millimeters.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-MaxCmapsOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XMaxCmapsOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>MaxCmapsOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XMaxCmapsOfScreen</primary></indexterm>
-Both return the maximum number of installed colormaps supported
-by the specified screen (see section 9.3).
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-MinCmapsOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XMinCmapsOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>MinCmapsOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XMinCmapsOfScreen</primary></indexterm>
-Both return the minimum number of installed colormaps supported
-by the specified screen (see section 9.3).
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-PlanesOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>int <function>XPlanesOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>PlanesOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XPlanesOfScreen</primary></indexterm>
-Both return the depth of the root window.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-<!-- .sM -->
-</para>
-<para>
-RootWindowOfScreen(<emphasis remap='I'>screen</emphasis>)
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Window <function>XRootWindowOfScreen</function></funcdef>
- <paramdef>Screen<parameter> *screen</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>screen</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the appropriate
-<type>Screen</type>
-structure.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-<indexterm significance="preferred"><primary>RootWindowOfScreen</primary></indexterm>
-<indexterm significance="preferred"><primary>XRootWindowOfScreen</primary></indexterm>
-Both return the root window of the specified screen.
-</para>
-</sect2>
-</sect1>
-<sect1 id="Generating_a_NoOperation_Protocol_Request">
-<title>Generating a NoOperation Protocol Request</title>
-<!-- .XS -->
-<!-- (SN Generating a NoOperation Protocol Request -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-To execute a
-<systemitem>NoOperation</systemitem>
-protocol request, use
-<function>XNoOp</function>.
-<indexterm significance="preferred"><primary>XNoOp</primary></indexterm>
-<!-- .sM -->
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef><function>XNoOp</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-
-<variablelist>
- <varlistentry>
- <term><emphasis remap='I'>display</emphasis></term>
- <listitem>
- <para>Specifies the connection to the X server.</para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XNoOp</function>
-function sends a
-<systemitem>NoOperation</systemitem>
-protocol request to the X server,
-thereby exercising the connection.
-</para>
-</sect1>
-<sect1 id="Freeing_Client_Created_Data">
-<title>Freeing Client-Created Data</title>
-<!-- .XS -->
-<!-- (SN Freeing Client-Created Data -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-To free in-memory data that was created by an Xlib function, use
-<function>XFree</function>.
-<indexterm significance="preferred"><primary>XFree</primary></indexterm>
-<!-- .sM -->
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>XFree</funcdef>
- <paramdef>void<parameter> *data</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>data</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the data that is to be freed.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XFree</function>
-function is a general-purpose Xlib routine that frees the specified data.
-You must use it to free any objects that were allocated by Xlib,
-unless an alternate function is explicitly specified for the object.
-A NULL pointer cannot be passed to this function.
-</para>
-</sect1>
-<sect1 id="Closing_the_Display">
-<title>Closing the Display</title>
-<!-- .XS -->
-<!-- (SN Closing the Display -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-To close a display or disconnect from the X server, use
-<function>XCloseDisplay</function>.
-<indexterm significance="preferred"><primary>XCloseDisplay</primary></indexterm>
-</para>
-<para>
-<!-- .LP -->
-<!-- .sM -->
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>XCloseDisplay</funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XCloseDisplay</function>
-function closes the connection to the X server for the display specified in the
-<type>Display</type>
-structure and destroys all windows, resource IDs
-(<type>Window</type>,
-<type>Font</type>,
-<type>Pixmap</type>,
-<type>Colormap</type>,
-<type>Cursor</type>,
-and
-<type>GContext</type>),
-or other resources that the client has created
-on this display, unless the close-down mode of the resource has been changed
-(see
-<function>XSetCloseDownMode</function>).
-Therefore, these windows, resource IDs, and other resources should never be
-referenced again or an error will be generated.
-Before exiting, you should call
-<function>XCloseDisplay</function>
-explicitly so that any pending errors are reported as
-<function>XCloseDisplay</function>
-performs a final
-<function>XSync</function>
-operation.
-<indexterm><primary>Resource IDs</primary></indexterm>
-<indexterm><primary>XCloseDisplay</primary></indexterm>
-</para>
-<para>
-<!-- .LP -->
-<function>XCloseDisplay</function>
-can generate a
-<errorname>BadGC</errorname>
-error.
-<!-- .sp -->
-</para>
-<para>
-<!-- .LP -->
-Xlib provides a function to permit the resources owned by a client
-to survive after the client's connection is closed.
-To change a client's close-down mode, use
-<function>XSetCloseDownMode</function>.
-<indexterm significance="preferred"><primary>XSetCloseDownMode</primary></indexterm>
-<!-- .sM -->
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>XSetCloseDownMode</funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> close_mode</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>close_mode</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the client close-down mode.
-You can pass
-<symbol>DestroyAll</symbol>,
-<symbol>RetainPermanent</symbol>,
-or
-<symbol>RetainTemporary</symbol>.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XSetCloseDownMode</function>
-defines what will happen to the client's resources at connection close.
-A connection starts in
-<symbol>DestroyAll</symbol>
-mode.
-For information on what happens to the client's resources when the
-close_mode argument is
-<symbol>RetainPermanent</symbol>
-or
-<symbol>RetainTemporary</symbol>,
-see section 2.6.
-</para>
-<para>
-<!-- .LP -->
-<function>XSetCloseDownMode</function>
-can generate a
-<errorname>BadValue</errorname>
-error.
-</para>
-</sect1>
-<sect1 id="Using_X_Server_Connection_Close_Operations_">
-<title>Using X Server Connection Close Operations </title>
-<!-- .XS -->
-<!-- (SN Using X Server Connection Close Operations -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-When the X server's connection to a client is closed
-either by an explicit call to
-<function>XCloseDisplay</function>
-or by a process that exits, the X server performs the following
-automatic operations:
-</para>
-<itemizedlist>
- <listitem>
- <para>
-It disowns all selections owned by the client
-(see
-<function>XSetSelectionOwner</function>).
- </para>
- </listitem>
- <listitem>
- <para>
-It performs an
-<function>XUngrabPointer</function>
-and
-<function>XUngrabKeyboard</function>
-if the client has actively grabbed the pointer
-or the keyboard.
- </para>
- </listitem>
- <listitem>
- <para>
-It performs an
-<function>XUngrabServer</function>
-if the client has grabbed the server.
- </para>
- </listitem>
- <listitem>
- <para>
-It releases all passive grabs made by the client.
- </para>
- </listitem>
- <listitem>
- <para>
-It marks all resources (including colormap entries) allocated
-by the client either as permanent or temporary,
-depending on whether the close-down mode is
-<symbol>RetainPermanent</symbol>
-or
-<symbol>RetainTemporary</symbol>.
-However, this does not prevent other client applications from explicitly
-destroying the resources (see
-<function>XSetCloseDownMode</function>).
- </para>
- </listitem>
-</itemizedlist>
-<para>
-<!-- .LP -->
-When the close-down mode is
-<symbol>DestroyAll</symbol>,
-the X server destroys all of a client's resources as follows:
-</para>
-<itemizedlist>
- <listitem>
- <para>
-It examines each window in the client's save-set to determine if it is an inferior
-(subwindow) of a window created by the client.
-(The save-set is a list of other clients' windows
-that are referred to as save-set windows.)
-If so, the X server reparents the save-set window to the closest ancestor so
-that the save-set window is not an inferior of a window created by the client.
-The reparenting leaves unchanged the absolute coordinates (with respect to
-the root window) of the upper-left outer corner of the save-set
-window.
- </para>
- </listitem>
- <listitem>
- <para>
-It performs a
-<systemitem>MapWindow</systemitem>
-request on the save-set window if the save-set window is unmapped.
-The X server does this even if the save-set window was not an inferior of
-a window created by the client.
- </para>
- </listitem>
- <listitem>
- <para>
-It destroys all windows created by the client.
- </para>
- </listitem>
- <listitem>
- <para>
-It performs the appropriate free request on each nonwindow resource created by
-the client in the server (for example,
-<type>Font</type>,
-<type>Pixmap</type>,
-<type>Cursor</type>,
-<type>Colormap</type>,
-and
-<type>GContext</type>).
- </para>
- </listitem>
- <listitem>
- <para>
-It frees all colors and colormap entries allocated by a client application.
- </para>
- </listitem>
-</itemizedlist>
-<para>
-<!-- .LP -->
-Additional processing occurs when the last connection to the X server closes.
-An X server goes through a cycle of having no connections and having some
-connections.
-When the last connection to the X server closes as a result of a connection
-closing with the close_mode of
-<symbol>DestroyAll</symbol>,
-the X server does the following:
-</para>
-<itemizedlist>
- <listitem>
- <para>
-It resets its state as if it had just been
-started.
-The X server begins by destroying all lingering resources from
-clients that have terminated in
-<symbol>RetainPermanent</symbol>
-or
-<symbol>RetainTemporary</symbol>
-mode.
- </para>
- </listitem>
- <listitem>
- <para>
-It deletes all but the predefined atom identifiers.
- </para>
- </listitem>
- <listitem>
- <para>
-It deletes all properties on all root windows (see section 4.3).
- </para>
- </listitem>
- <listitem>
- <para>
-It resets all device maps and attributes
-(for example, key click, bell volume, and acceleration)
-as well as the access control list.
- </para>
- </listitem>
- <listitem>
- <para>
-It restores the standard root tiles and cursors.
- </para>
- </listitem>
- <listitem>
- <para>
-It restores the default font path.
- </para>
- </listitem>
- <listitem>
- <para>
-It restores the input focus to state
-<symbol>PointerRoot</symbol>.
- </para>
- </listitem>
-</itemizedlist>
-<para>
-<!-- .LP -->
-However, the X server does not reset if you close a connection with a close-down
-mode set to
-<symbol>RetainPermanent</symbol>
-or
-<symbol>RetainTemporary</symbol>.
-</para>
-</sect1>
-<sect1 id="Using_Xlib_with_Threads">
-<title>Using Xlib with Threads</title>
-<!-- .XS -->
-<!-- (SN Using Xlib with Threads -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-On systems that have threads, support may be provided to permit
-multiple threads to use Xlib concurrently.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-To initialize support for concurrent threads, use
-<function>XInitThreads</function>.
-<indexterm significance="preferred"><primary>XInitThreads</primary></indexterm>
-<!-- .sM -->
-</para>
-<para>Status XInitThreads();</para>
-<!-- .FN -->
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XInitThreads</function>
-function initializes Xlib support for concurrent threads.
-This function must be the first Xlib function a
-multi-threaded program calls, and it must complete
-before any other Xlib call is made.
-This function returns a nonzero status if initialization was
-successful; otherwise, it returns zero.
-On systems that do not support threads, this function always returns zero.
-</para>
-<para>
-<!-- .LP -->
-It is only necessary to call this function if multiple threads
-might use Xlib concurrently. If all calls to Xlib functions
-are protected by some other access mechanism (for example,
-a mutual exclusion lock in a toolkit or through explicit client
-programming), Xlib thread initialization is not required.
-It is recommended that single-threaded programs not call this function.
-
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-To lock a display across several Xlib calls, use
-<function>XLockDisplay</function>.
-<indexterm significance="preferred"><primary>XLockDisplay</primary></indexterm>
-<!-- .sM -->
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>XLockDisplay</funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XLockDisplay</function>
-function locks out all other threads from using the specified display.
-Other threads attempting to use the display will block until
-the display is unlocked by this thread.
-Nested calls to
-<function>XLockDisplay</function>
-work correctly; the display will not actually be unlocked until
-<function>XUnlockDisplay</function>
-has been called the same number of times as
-<function>XLockDisplay</function>.
-This function has no effect unless Xlib was successfully initialized
-for threads using
-<function>XInitThreads</function>.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-To unlock a display, use
-<function>XUnlockDisplay</function>.
-<indexterm significance="preferred"><primary>XUnlockDisplay</primary></indexterm>
-<!-- .sM -->
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>XUnlockDisplay</funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XUnlockDisplay</function>
-function allows other threads to use the specified display again.
-Any threads that have blocked on the display are allowed to continue.
-Nested locking works correctly; if
-<function>XLockDisplay</function>
-has been called multiple times by a thread, then
-<function>XUnlockDisplay</function>
-must be called an equal number of times before the display is
-actually unlocked.
-This function has no effect unless Xlib was successfully initialized
-for threads using
-<function>XInitThreads</function>.
-</para>
-</sect1>
-<sect1 id="Using_Internal_Connections">
-<title>Using Internal Connections</title>
-<!-- .XS -->
-<!-- (SN Using Internal Connections -->
-<!-- .XE -->
-<para>
-<!-- .LP -->
-In addition to the connection to the X server, an Xlib implementation
-may require connections to other kinds of servers (for example, to
-input method servers as described in chapter 13). Toolkits and clients
-that use multiple displays, or that use displays in combination with
-other inputs, need to obtain these additional connections to correctly
-block until input is available and need to process that input
-when it is available. Simple clients that use a single display and
-block for input in an Xlib event function do not need to use these
-facilities.
-</para>
-<para>
-<!-- .LP -->
-To track internal connections for a display, use
-<function>XAddConnectionWatch</function>.
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>type void XConnectionWatchProc</funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>XPointer<parameter> client_data</parameter></paramdef>
- <paramdef>int<parameter> fd</parameter></paramdef>
- <paramdef>Bool<parameter> opening</parameter></paramdef>
- <paramdef>XPointer<parameter> *watch_data</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-
-<funcsynopsis>
-<funcprototype>
- <funcdef>Status XAddConnectionWatch</funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>XWatchProc<parameter> procedure</parameter></paramdef>
- <paramdef>XPointer<parameter> client_data</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>procedure</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the procedure to be called.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>client_data</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the additional client data.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XAddConnectionWatch</function>
-function registers a procedure to be called each time Xlib opens or closes an
-internal connection for the specified display. The procedure is passed the
-display, the specified client_data, the file descriptor for the connection,
-a Boolean indicating whether the connection is being opened or closed, and a
-pointer to a location for private watch data. If opening is
-<symbol>True</symbol>,
-the procedure can store a pointer to private data in the location pointed
-to by watch_data;
-when the procedure is later called for this same connection and opening is
-<symbol>False</symbol>,
-the location pointed to by watch_data will hold this same private data pointer.
-</para>
-<para>
-<!-- .LP -->
-This function can be called at any time after a display is opened.
-If internal connections already exist, the registered procedure will
-immediately be called for each of them, before
-<function>XAddConnectionWatch</function>
-returns.
-<function>XAddConnectionWatch</function>
-returns a nonzero status if the procedure is successfully registered;
-otherwise, it returns zero.
-</para>
-<para>
-<!-- .LP -->
-The registered procedure should not call any Xlib functions.
-If the procedure directly or indirectly causes the state of internal
-connections or watch procedures to change, the result is not defined.
-If Xlib has been initialized for threads, the procedure is called with
-the display locked and the result of a call by the procedure to any
-Xlib function that locks the display is not defined unless the executing
-thread has externally locked the display using
-<function>XLockDisplay</function>.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-To stop tracking internal connections for a display, use
-<function>XRemoveConnectionWatch</function>.
-<indexterm significance="preferred"><primary>XRemoveConnectionWatch</primary></indexterm>
-<!-- .sM -->
-</para>
-<para>
-()
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Status <function>XRemoveConnectionWatch</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>XWatchProc<parameter> procedure</parameter></paramdef>
- <paramdef>XPointer<parameter> client_data</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>procedure</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the procedure to be called.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>client_data</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the additional client data.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XRemoveConnectionWatch</function>
-function removes a previously registered connection watch procedure.
-The client_data must match the client_data used when the procedure
-was initially registered.
-
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-To process input on an internal connection, use
-<function>XProcessInternalConnection</function>.
-<indexterm significance="preferred"><primary>XProcessInternalConnection</primary></indexterm>
-<!-- .sM -->
-</para>
-<para>
-()
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>void <function>XProcessInternalConnection</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int<parameter> fd</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>fd</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the file descriptor.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XProcessInternalConnection</function>
-function processes input available on an internal connection.
-This function should be called for an internal connection only
-after an operating system facility (for example,
-<function>select</function>
-or
-<function>poll</function>)
-has indicated that input is available; otherwise,
-the effect is not defined.
-</para>
-<para>
-<!-- .LP -->
-<!-- .sp -->
-To obtain all of the current internal connections for a display, use
-<function>XInternalConnectionNumbers</function>.
-<indexterm significance="preferred"><primary>XInternalConnectionNumbers</primary></indexterm>
-<!-- .sM -->
-</para>
-<para>
-()
-</para>
-<funcsynopsis>
-<funcprototype>
- <funcdef>Status <function>XInternalConnectionNumbers</function></funcdef>
- <paramdef>Display<parameter> *display</parameter></paramdef>
- <paramdef>int **<parameter> fd</parameter></paramdef>
- <paramdef>int *<parameter> count_return</parameter></paramdef>
-</funcprototype>
-</funcsynopsis>
-<!-- .FN -->
-<variablelist>
- <varlistentry>
- <term>
- <emphasis remap='I'>display</emphasis>
- </term>
- <listitem>
- <para>
-Specifies the connection to the X server.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>fd_return</emphasis>
- </term>
- <listitem>
- <para>
-Returns the file descriptors.
-<!-- .ds Cn file descriptors -->
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>
- <emphasis remap='I'>count_return</emphasis>
- </term>
- <listitem>
- <para>
-Returns the number of (Cn.
- </para>
- </listitem>
- </varlistentry>
-</variablelist>
-<para>
-<!-- .LP -->
-<!-- .eM -->
-The
-<function>XInternalConnectionNumbers</function>
-function returns a list of the file descriptors for all internal
-connections currently open for the specified display.
-When the allocated list is no longer needed,
-free it by using
-<function>XFree</function>.
-This functions returns a nonzero status if the list is successfully allocated;
-otherwise, it returns zero.
-</para>
-</sect1>
-</chapter>
+<?xml version="1.0" encoding="UTF-8" ?> +<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN" + "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd"> +<chapter id="display_functions"> +<title>Display Functions</title> +<para> +Before your program can use a display, you must establish a connection +to the X server. +Once you have established a connection, +you then can use the Xlib macros and functions discussed in this chapter +to return information about the display. +This chapter discusses how to: +</para> +<itemizedlist> + <listitem> + <para> +Open (connect to) the display + </para> + </listitem> + <listitem> + <para> +Obtain information about the display, image formats, or screens + </para> + </listitem> + <listitem> + <para> +Generate a +<systemitem>NoOperation</systemitem> +protocol request + </para> + </listitem> + <listitem> + <para> +Free client-created data + </para> + </listitem> + <listitem> + <para> +Close (disconnect from) a display + </para> + </listitem> + <listitem> + <para> +Use X Server connection close operations + </para> + </listitem> + <listitem> + <para> +Use Xlib with threads + </para> + </listitem> + <listitem> + <para> +Use internal connections + </para> + </listitem> +</itemizedlist> +<sect1 id="Opening_the_Display"> +<title>Opening the Display</title> +<!-- .XS --> +<!-- (SN Opening the Display --> +<!-- .XE --> +<para> +<!-- .LP --> +To open a connection to the X server that controls a display, use +<function>XOpenDisplay</function>. +<indexterm significance="preferred"><primary>XOpenDisplay</primary></indexterm> +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Display *<function>XOpenDisplay</function></funcdef> + <paramdef>char *<parameter>display_name</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display_name</emphasis> + </term> + <listitem> + <para> +Specifies the hardware display name, which determines the display +and communications domain to be used. +On a <acronym>POSIX</acronym>-conformant system, if the display_name is NULL, +it defaults to the value of the DISPLAY environment variable. +<indexterm><primary>Environment</primary><secondary>DISPLAY</secondary></indexterm> + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The encoding and interpretation of the display name are +implementation-dependent. +Strings in the Host Portable Character Encoding are supported; +support for other characters is implementation-dependent. +On <acronym>POSIX</acronym>-conformant systems, +the display name or DISPLAY environment variable can be a string in the format: +</para> +<!-- .LP --> +<!-- .sM --> +<literallayout class="monospaced"> +<!-- .TA 1i --> +<!-- .ta 1i --> + <emphasis remap='I'>protocol</emphasis>/<emphasis remap='I'>hostname</emphasis>:<emphasis remap='I'>number</emphasis>.<emphasis remap='I'>screen_number</emphasis> +</literallayout> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>protocol</emphasis> + </term> + <listitem> + <para> +Specifies a protocol family or an alias for a protocol family. Supported +protocol families are implementation dependent. The protocol entry is +optional. If protocol is not specified, the / separating protocol and +hostname must also not be specified. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>hostname</emphasis> + </term> + <listitem> + <para> +Specifies the name of the host machine on which the display is physically +attached. +You follow the hostname with either a single colon (:) or a double colon (::). + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>number</emphasis> + </term> + <listitem> + <para> +Specifies the number of the display server on that host machine. +You may optionally follow this display number with a period (.). +A single <acronym>CPU</acronym> can have more than one display. +Multiple displays are usually numbered starting with zero. +<indexterm><primary>Screen</primary></indexterm> + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the screen to be used on that server. +Multiple screens can be controlled by a single X server. +The screen_number sets an internal variable that can be accessed by +using the +<function>DefaultScreen</function> +macro or the +<function>XDefaultScreen</function> +function if you are using languages other than C (see section 2.2.1). + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +For example, the following would specify screen 1 of display 0 on the +machine named ``dual-headed'': +</para> +<para> +<!-- .LP --> +<literallayout class="monospaced"> +dual-headed:0.1 +</literallayout> +</para> +<para> +<!-- .LP --> +The +<function>XOpenDisplay</function> +function returns a +<type>Display</type> +structure that serves as the +connection to the X server and that contains all the information +about that X server. +<function>XOpenDisplay</function> +connects your application to the X server through <acronym>TCP</acronym> +or DECnet communications protocols, +or through some local inter-process communication protocol. +<indexterm><primary>Protocol</primary><secondary><acronym>TCP</acronym></secondary></indexterm> +<indexterm><primary>Protocol</primary><secondary>DECnet</secondary></indexterm> +If the protocol is specified as "tcp", "inet", or "inet6", or +if no protocol is specified and the hostname is a host machine name and a single colon (:) +separates the hostname and display number, +<function>XOpenDisplay</function> +connects using <acronym>TCP</acronym> streams. (If the protocol is specified as "inet", <acronym>TCP</acronym> over +IPv4 is used. If the protocol is specified as "inet6", <acronym>TCP</acronym> over IPv6 is used. +Otherwise, the implementation determines which <acronym>IP</acronym> version is used.) +If the hostname and protocol are both not specified, +Xlib uses whatever it believes is the fastest transport. +If the hostname is a host machine name and a double colon (::) +separates the hostname and display number, +<function>XOpenDisplay</function> +connects using DECnet. +A single X server can support any or all of these transport mechanisms +simultaneously. +A particular Xlib implementation can support many more of these transport +mechanisms. +</para> +<para> +<!-- .LP --> +<indexterm><primary>Display</primary></indexterm> +If successful, +<function>XOpenDisplay</function> +returns a pointer to a +<type>Display</type> +structure, +which is defined in +<filename class="headerfile"><X11/Xlib.h></filename>. +<indexterm type="file"><primary><filename class="headerfile">X11/Xlib.h</filename></primary></indexterm> +<indexterm><primary>Files</primary><secondary><filename class="headerfile"><X11/Xlib.h></filename></secondary></indexterm> +<indexterm><primary>Headers</primary><secondary><filename class="headerfile"><X11/Xlib.h></filename></secondary></indexterm> +If +<function>XOpenDisplay</function> +does not succeed, it returns NULL. +After a successful call to +<function>XOpenDisplay</function>, +all of the screens in the display can be used by the client. +The screen number specified in the display_name argument is returned +by the +<function>DefaultScreen</function> +macro (or the +<function>XDefaultScreen</function> +function). +You can access elements of the +<type>Display</type> +and +<type>Screen</type> +structures only by using the information macros or functions. +For information about using macros and functions to obtain information from +the +<type>Display</type> +structure, +see section 2.2.1. +</para> +<para> +<!-- .LP --> +X servers may implement various types of access control mechanisms +(see section 9.8). +</para> +</sect1> +<sect1 id="Obtaining_Information_about_the_Display_Image_Formats_or_Screens"> +<title>Obtaining Information about the Display, Image Formats, or Screens</title> +<!-- .XS --> +<!-- (SN Obtaining Information about the Display, Image Formats, or Screens --> +<!-- .XE --> +<para> +<!-- .LP --> +The Xlib library provides a number of useful macros +and corresponding functions that return data from the +<type>Display</type> +structure. +The macros are used for C programming, +and their corresponding function equivalents are for other language bindings. +This section discusses the: +</para> +<itemizedlist> + <listitem> + <para> +Display macros + </para> + </listitem> + <listitem> + <para> +Image format functions and macros + </para> + </listitem> + <listitem> + <para> +Screen information macros + </para> + </listitem> +</itemizedlist> +<para> +<!-- .LP --> +<indexterm ><primary>Display</primary><secondary>data structure</secondary></indexterm> +All other members of the +<type>Display</type> +structure (that is, those for which no macros are defined) are private to Xlib +and must not be used. +Applications must never directly modify or inspect these private members of the +<type>Display</type> +structure. +<!-- .NT Note --> +The +<function>XDisplayWidth</function>, +<function>XDisplayHeight</function>, +<function>XDisplayCells</function>, +<function>XDisplayPlanes</function>, +<function>XDisplayWidthMM</function>, +and +<function>XDisplayHeightMM</function> +functions in the next sections are misnamed. +These functions really should be named Screen<emphasis remap='I'>whatever</emphasis> +and XScreen<emphasis remap='I'>whatever</emphasis>, not Display<emphasis remap='I'>whatever</emphasis> or XDisplay<emphasis remap='I'>whatever</emphasis>. +Our apologies for the resulting confusion. +<!-- .NE --> +</para> +<sect2 id="Display_Macros_"> +<title>Display Macros </title> +<!-- .XS --> +<!-- (SN Display Macros --> +<!-- .XE --> +<para> +<!-- .LP --> +Applications should not directly modify any part of the +<type>Display</type> +and +<type>Screen</type> +structures. +The members should be considered read-only, +although they may change as the result of other operations on the display. +</para> +<para> +<!-- .LP --> +The following lists the C language macros, +their corresponding function equivalents that are for other language bindings, +and what data both can return. +</para> +<para>AllPlanes()</para> +<para>XAllPlanes()</para> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>AllPlanes</primary></indexterm> +<indexterm significance="preferred"><primary>XAllPlanes</primary></indexterm> +Both return a value with all bits set to 1 suitable for use in a plane argument to +a procedure. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +Both +<function>BlackPixel</function> +and +<function>WhitePixel</function> +can be used in implementing a monochrome application. +These pixel values are for permanently allocated entries in the default +colormap. +The actual <acronym>RGB</acronym> (red, green, and blue) values are settable on some screens +and, in any case, may not actually be black or white. +The names are intended to convey the expected relative intensity of the colors. +<!-- .sM --> +</para> +<para> +BlackPixel(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XBlackPixel</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>BlackPixel</primary></indexterm> +<indexterm significance="preferred"><primary>XBlackPixel</primary></indexterm> +Both return the black pixel value for the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +WhitePixel(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XWhitePixel</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>WhitePixel</primary></indexterm> +<indexterm significance="preferred"><primary>XWhitePixel</primary></indexterm> +Both return the white pixel value for the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ConnectionNumber(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XConnectionNumber</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> + +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ConnectionNumber</primary></indexterm> +<indexterm significance="preferred"><primary>XConnectionNumber</primary></indexterm> +Both return a connection number for the specified display. +On a <acronym>POSIX</acronym>-conformant system, +this is the file descriptor of the connection. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultColormap(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Colormap <function>XDefaultColormap</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultColormap</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultColormap</primary></indexterm> +Both return the default colormap ID for allocation on the specified screen. +Most routine allocations of color should be made out of this colormap. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultDepth(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDefaultDepth</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultDepth</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultDepth</primary></indexterm> +Both return the depth (number of planes) of the default root window for the +specified screen. +Other depths may also be supported on this screen (see +<function>XMatchVisualInfo</function>). +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<indexterm significance="preferred"><primary>XListDepths</primary></indexterm> +To determine the number of depths that are available on a given screen, use +<function>XListDepths</function>. +<!-- .sM --> +</para> +<para> +DefaultGC(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>GC <function>XDefaultGC</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> + <paramdef>int<parameter> *count_return</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. +<!-- .ds Cn depths --> + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>count_return</emphasis> + </term> + <listitem> + <para> +Returns the number of (Cn. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XListDepths</function> +function returns the array of depths +that are available on the specified screen. +If the specified screen_number is valid and sufficient memory for the array +can be allocated, +<function>XListDepths</function> +sets count_return to the number of available depths. +Otherwise, it does not set count_return and returns NULL. +To release the memory allocated for the array of depths, use +<function>XFree</function>. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultGC(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>GC <function>XDefaultGC</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultGC</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultGC</primary></indexterm> +Both return the default graphics context for the root window of the +specified screen. +This GC is created for the convenience of simple applications +and contains the default GC components with the foreground and +background pixel values initialized to the black and white +pixels for the screen, respectively. +You can modify its contents freely because it is not used in any Xlib +function. +This GC should never be freed. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultRootWindow(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Window <function>XDefaultRootWindow</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultRootWindow</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultRootWindow</primary></indexterm> +Both return the root window for the default screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultScreenOfDisplay(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Screen *<function>XDefaultScreenOfDisplay</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultScreenOfDisplay</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultScreenOfDisplay</primary></indexterm> +Both return a pointer to the default screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ScreenOfDisplay(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Screen *<function>XScreenOfDisplay</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ScreenOfDisplay</primary></indexterm> +<indexterm significance="preferred"><primary>XScreenOfDisplay</primary></indexterm> +Both return a pointer to the indicated screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultScreen(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDefaultScreen</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultScreen</primary></indexterm> +Both return the default screen number referenced by the +<function>XOpenDisplay</function> +function. +This macro or function should be used to retrieve the screen number +in applications that will use only a single screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultVisual(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Visual *<function>XDefaultVisual</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultVisual</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultVisual</primary></indexterm> +Both return the default visual type for the specified screen. +For further information about visual types, +see section 3.1. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayCells(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDisplayCells</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayCells</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayCells</primary></indexterm> +Both return the number of entries in the default colormap. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayPlanes(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDisplayPlanes</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayPlanes</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayPlanes</primary></indexterm> +Both return the depth of the root window of the specified screen. +For an explanation of depth, +see the glossary. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayString(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>char *<function>XDisplayString</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayString</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayString</primary></indexterm> +Both return the string that was passed to +<function>XOpenDisplay</function> +when the current display was opened. +On <acronym>POSIX</acronym>-conformant systems, +if the passed string was NULL, these return the value of +the DISPLAY environment variable when the current display was opened. +<indexterm><primary><acronym>POSIX</acronym> System Call</primary><secondary>fork</secondary></indexterm> +These are useful to applications that invoke the +<function>fork</function> +system call and want to open a new connection to the same display from the +child process as well as for printing error messages. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +LastKnownRequestProcessed(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XLastKnownRequestProcessed</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>XExtendedMaxRequestSize</primary></indexterm> +The +<function>XExtendedMaxRequestSize</function> +function returns zero if the specified display does not support an +extended-length protocol encoding; otherwise, +it returns the maximum request size (in 4-byte units) supported +by the server using the extended-length encoding. +The Xlib functions +<function>XDrawLines</function>, +<function>XDrawArcs</function>, +<function>XFillPolygon</function>, +<function>XChangeProperty</function>, +<function>XSetClipRectangles</function>, +and +<function>XSetRegion</function> +will use the extended-length encoding as necessary, if supported +by the server. Use of the extended-length encoding in other Xlib +functions (for example, +<function>XDrawPoints</function>, +<function>XDrawRectangles</function>, +<function>XDrawSegments</function>, +<function>XFillArcs</function>, +<function>XFillRectangles</function>, +<function>XPutImage</function>) +is permitted but not required; an Xlib implementation may choose to +split the data across multiple smaller requests instead. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +LastKnownRequestProcessed(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XLastKnownRequestProcessed</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>XMaxRequestSize</primary></indexterm> +The +<function>XMaxRequestSize</function> +function returns the maximum request size (in 4-byte units) supported +by the server without using an extended-length protocol encoding. +Single protocol requests to the server can be no larger than this size +unless an extended-length protocol encoding is supported by the server. +The protocol guarantees the size to be no smaller than 4096 units +(16384 bytes). +Xlib automatically breaks data up into multiple protocol requests +as necessary for the following functions: +<function>XDrawPoints</function>, +<function>XDrawRectangles</function>, +<function>XDrawSegments</function>, +<function>XFillArcs</function>, +<function>XFillRectangles</function>, +and +<function>XPutImage</function>. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +LastKnownRequestProcessed(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XLastKnownRequestProcessed</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>LastKnownRequestProcessed</primary></indexterm> +<indexterm significance="preferred"><primary>XLastKnownRequestProcessed</primary></indexterm> +Both extract the full serial number of the last request known by Xlib +to have been processed by the X server. +Xlib automatically sets this number when replies, events, and errors +are received. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +NextRequest(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XNextRequest</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>NextRequest</primary></indexterm> +<indexterm significance="preferred"><primary>XNextRequest</primary></indexterm> +Both extract the full serial number that is to be used for the next +request. +Serial numbers are maintained separately for each display connection. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ProtocolVersion(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XProtocolVersion</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ProtocolVersion</primary></indexterm> +<indexterm significance="preferred"><primary>XProtocolVersion</primary></indexterm> +Both return the major version number (11) of the X protocol associated with +the connected display. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ProtocolRevision(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XProtocolRevision</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ProtocolRevision</primary></indexterm> +<indexterm significance="preferred"><primary>XProtocolRevision</primary></indexterm> +Both return the minor protocol revision number of the X server. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +QLength(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XQLength</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>QLength</primary></indexterm> +<indexterm significance="preferred"><primary>XQLength</primary></indexterm> +Both return the length of the event queue for the connected display. +Note that there may be more events that have not been read into +the queue yet (see +<function>XEventsQueued</function>). +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +RootWindow(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Window <function>XRootWindow</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm><primary>Window</primary><secondary>RootWindow</secondary></indexterm> +<indexterm significance="preferred"><primary>RootWindow</primary></indexterm> +<indexterm><primary>Window</primary><secondary>XRootWindow</secondary></indexterm> +<indexterm significance="preferred"><primary>XRootWindow</primary></indexterm> +Both return the root window. +These are useful with functions that need a drawable of a particular screen +and for creating top-level windows. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ScreenCount(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XScreenCount</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ScreenCount</primary></indexterm> +<indexterm significance="preferred"><primary>XScreenCount</primary></indexterm> +Both return the number of available screens. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ServerVendor(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>char *<function>XServerVendor</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ServerVendor</primary></indexterm> +<indexterm significance="preferred"><primary>XServerVendor</primary></indexterm> +Both return a pointer to a null-terminated string that provides +some identification of the owner of the X server implementation. +If the data returned by the server is in the Latin Portable Character Encoding, +then the string is in the Host Portable Character Encoding. +Otherwise, the contents of the string are implementation-dependent. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +VendorRelease(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XVendorRelease</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>VendorRelease</primary></indexterm> +<indexterm significance="preferred"><primary>XVendorRelease</primary></indexterm> +Both return a number related to a vendor's release of the X server. +</para> +</sect2> +<sect2 id="Image_Format_Functions_and_Macros"> +<title>Image Format Functions and Macros</title> +<!-- .XS --> +<!-- (SN Image Format Functions and Macros --> +<!-- .XE --> +<para> +<!-- .LP --> +Applications are required to present data to the X server +in a format that the server demands. +To help simplify applications, +most of the work required to convert the data is provided by Xlib +(see sections 8.7 and 16.8). +</para> +<para> +<!-- .LP --> +The +<structname>XPixmapFormatValues</structname> +structure provides an interface to the pixmap format information +that is returned at the time of a connection setup. +It contains: +</para> +<para> +<!-- .LP --> +<!-- .sM --> +<literallayout class="monospaced"> +<!-- .TA .5i 3i --> +<!-- .ta .5i 3i --> +typedef struct { + int depth; + int bits_per_pixel; + int scanline_pad; +} XPixmapFormatValues; +</literallayout> +</para> +<para> +<!-- .LP --> +<!-- .eM --> +<!-- .sp --> +To obtain the pixmap format information for a given display, use +<function>XListPixmapFormats</function>. +<indexterm significance="preferred"><primary>XListPixmapFormats</primary></indexterm> +<!-- .sM --> +</para> +<para> +ImageByteOrder(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XImageByteOrder</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> *count_return</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. +<!-- .ds Cn pixmap formats that are supported by the display --> + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>count_return</emphasis> + </term> + <listitem> + <para> +Returns the number of (Cn. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XListPixmapFormats</function> +function returns an array of +<structname>XPixmapFormatValues</structname> +structures that describe the types of Z format images supported +by the specified display. +If insufficient memory is available, +<function>XListPixmapFormats</function> +returns NULL. +To free the allocated storage for the +<structname>XPixmapFormatValues</structname> +structures, use +<function>XFree</function>. +</para> +<para> +<!-- .LP --> +The following lists the C language macros, +their corresponding function equivalents that are for other language bindings, +and what data they both return for the specified server and screen. +These are often used by toolkits as well as by simple applications. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +ImageByteOrder(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XImageByteOrder</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>ImageByteOrder</primary></indexterm> +<indexterm significance="preferred"><primary>XImageByteOrder</primary></indexterm> +Both specify the required byte order for images for each scanline unit in +XY format (bitmap) or for each pixel value in +Z format. +The macro or function can return either +<symbol>LSBFirst</symbol> +or +<symbol>MSBFirst</symbol>. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +BitmapUnit(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XBitmapUnit</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>BitmapUnit</primary></indexterm> +<indexterm significance="preferred"><primary>XBitmapUnit</primary></indexterm> +Both return the size of a bitmap's scanline unit in bits. +The scanline is calculated in multiples of this value. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +BitmapBitOrder(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XBitmapBitOrder</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>BitmapBitOrder</primary></indexterm> +<indexterm significance="preferred"><primary>XBitmapBitOrder</primary></indexterm> +Within each bitmap unit, the left-most bit in the bitmap as displayed +on the screen is either the least significant or most significant bit in the +unit. +This macro or function can return +<symbol>LSBFirst</symbol> +or +<symbol>MSBFirst</symbol>. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +BitmapPad(<emphasis remap='I'>display</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XBitmapPad</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>BitmapPad</primary></indexterm> +<indexterm significance="preferred"><primary>XBitmapPad</primary></indexterm> +Each scanline must be padded to a multiple of bits returned +by this macro or function. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayHeight(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDisplayHeight</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayHeight</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayHeight</primary></indexterm> +Both return an integer that describes the height of the screen +in pixels. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayHeightMM(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDisplayHeightMM</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayHeightMM</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayHeightMM</primary></indexterm> +Both return the height of the specified screen in millimeters. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayWidth(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDisplayWidth</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayWidth</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayWidth</primary></indexterm> +Both return the width of the screen in pixels. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayWidthMM(<emphasis remap='I'>display</emphasis>, <emphasis remap='I'>screen_number</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDisplayWidthMM</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> screen_number</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>screen_number</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate screen number on the host server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayWidthMM</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayWidthMM</primary></indexterm> +Both return the width of the specified screen in millimeters. +</para> +</sect2> +<sect2 id="Screen_Information_Macros"> +<title>Screen Information Macros</title> +<!-- .XS --> +<!-- (SN Screen Information Macros --> +<!-- .XE --> +<para> +<!-- .LP --> +The following lists the C language macros, +their corresponding function equivalents that are for other language bindings, +and what data they both can return. +These macros or functions all take a pointer to the appropriate screen +structure. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +BlackPixelOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XBlackPixelOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>BlackPixelOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XBlackPixelOfScreen</primary></indexterm> +Both return the black pixel value of the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +WhitePixelOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>unsigned long <function>XWhitePixelOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>WhitePixelOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XWhitePixelOfScreen</primary></indexterm> +Both return the white pixel value of the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +CellsOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XCellsOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>CellsOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XCellsOfScreen</primary></indexterm> +Both return the number of colormap cells in the default colormap +of the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultColormapOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Colormap <function>XDefaultColormapOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultColormapOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultColormapOfScreen</primary></indexterm> +Both return the default colormap of the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultDepthOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDefaultDepthOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultDepthOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultDepthOfScreen</primary></indexterm> +Both return the depth of the root window. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultGCOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>GC <function>XDefaultGCOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultGCOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultGCOfScreen</primary></indexterm> +Both return a default graphics context (GC) of the specified screen, +which has the same depth as the root window of the screen. +The GC must never be freed. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DefaultVisualOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Visual *<function>XDefaultVisualOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DefaultVisualOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XDefaultVisualOfScreen</primary></indexterm> +Both return the default visual of the specified screen. +For information on visual types, +see section 3.1. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DoesBackingStore(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XDoesBackingStore</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DoesBackingStore</primary></indexterm> +<indexterm significance="preferred"><primary>XDoesBackingStore</primary></indexterm> +Both return a value indicating whether the screen supports backing +stores. +The value returned can be one of +<symbol>WhenMapped</symbol>, +<symbol>NotUseful</symbol>, +or +<symbol>Always</symbol> +(see section 3.2.4). +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DoesSaveUnders(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Bool <function>XDoesSaveUnders</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DoesSaveUnders</primary></indexterm> +<indexterm significance="preferred"><primary>XDoesSaveUnders</primary></indexterm> +Both return a Boolean value indicating whether the +screen supports save unders. +If +<symbol>True</symbol>, +the screen supports save unders. +If +<symbol>False</symbol>, +the screen does not support save unders (see section 3.2.5). +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +DisplayOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Display *<function>XDisplayOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>DisplayOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XDisplayOfScreen</primary></indexterm> +Both return the display of the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +<indexterm significance="preferred"><primary>XScreenNumberOfScreen</primary></indexterm> +</para> +<para> +EventMaskOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>long <function>XEventMaskOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XScreenNumberOfScreen</function> +function returns the screen index number of the specified screen. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +EventMaskOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>long <function>XEventMaskOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>EventMaskOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XEventMaskOfScreen</primary></indexterm> +Both return the event mask of the root window for the specified screen +at connection setup time. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +WidthOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XWidthOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>WidthOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XWidthOfScreen</primary></indexterm> +Both return the width of the specified screen in pixels. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +HeightOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XHeightOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>HeightOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XHeightOfScreen</primary></indexterm> +Both return the height of the specified screen in pixels. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +WidthMMOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XWidthMMOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>WidthMMOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XWidthMMOfScreen</primary></indexterm> +Both return the width of the specified screen in millimeters. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +HeightMMOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XHeightMMOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>HeightMMOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XHeightMMOfScreen</primary></indexterm> +Both return the height of the specified screen in millimeters. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +MaxCmapsOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XMaxCmapsOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>MaxCmapsOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XMaxCmapsOfScreen</primary></indexterm> +Both return the maximum number of installed colormaps supported +by the specified screen (see section 9.3). +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +MinCmapsOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XMinCmapsOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>MinCmapsOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XMinCmapsOfScreen</primary></indexterm> +Both return the minimum number of installed colormaps supported +by the specified screen (see section 9.3). +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +PlanesOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>int <function>XPlanesOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>PlanesOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XPlanesOfScreen</primary></indexterm> +Both return the depth of the root window. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +<!-- .sM --> +</para> +<para> +RootWindowOfScreen(<emphasis remap='I'>screen</emphasis>) +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Window <function>XRootWindowOfScreen</function></funcdef> + <paramdef>Screen<parameter> *screen</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>screen</emphasis> + </term> + <listitem> + <para> +Specifies the appropriate +<type>Screen</type> +structure. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +<indexterm significance="preferred"><primary>RootWindowOfScreen</primary></indexterm> +<indexterm significance="preferred"><primary>XRootWindowOfScreen</primary></indexterm> +Both return the root window of the specified screen. +</para> +</sect2> +</sect1> +<sect1 id="Generating_a_NoOperation_Protocol_Request"> +<title>Generating a NoOperation Protocol Request</title> +<!-- .XS --> +<!-- (SN Generating a NoOperation Protocol Request --> +<!-- .XE --> +<para> +<!-- .LP --> +To execute a +<systemitem>NoOperation</systemitem> +protocol request, use +<function>XNoOp</function>. +<indexterm significance="preferred"><primary>XNoOp</primary></indexterm> +<!-- .sM --> +</para> +<funcsynopsis> +<funcprototype> + <funcdef><function>XNoOp</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> + +<variablelist> + <varlistentry> + <term><emphasis remap='I'>display</emphasis></term> + <listitem> + <para>Specifies the connection to the X server.</para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XNoOp</function> +function sends a +<systemitem>NoOperation</systemitem> +protocol request to the X server, +thereby exercising the connection. +</para> +</sect1> +<sect1 id="Freeing_Client_Created_Data"> +<title>Freeing Client-Created Data</title> +<!-- .XS --> +<!-- (SN Freeing Client-Created Data --> +<!-- .XE --> +<para> +<!-- .LP --> +To free in-memory data that was created by an Xlib function, use +<function>XFree</function>. +<indexterm significance="preferred"><primary>XFree</primary></indexterm> +<!-- .sM --> +</para> +<funcsynopsis> +<funcprototype> + <funcdef>XFree</funcdef> + <paramdef>void<parameter> *data</parameter></paramdef> +</funcprototype> +</funcsynopsis> + +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>data</emphasis> + </term> + <listitem> + <para> +Specifies the data that is to be freed. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XFree</function> +function is a general-purpose Xlib routine that frees the specified data. +You must use it to free any objects that were allocated by Xlib, +unless an alternate function is explicitly specified for the object. +A NULL pointer cannot be passed to this function. +</para> +</sect1> +<sect1 id="Closing_the_Display"> +<title>Closing the Display</title> +<!-- .XS --> +<!-- (SN Closing the Display --> +<!-- .XE --> +<para> +<!-- .LP --> +To close a display or disconnect from the X server, use +<function>XCloseDisplay</function>. +<indexterm significance="preferred"><primary>XCloseDisplay</primary></indexterm> +</para> +<para> +<!-- .LP --> +<!-- .sM --> +</para> +<funcsynopsis> +<funcprototype> + <funcdef>XCloseDisplay</funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> + +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XCloseDisplay</function> +function closes the connection to the X server for the display specified in the +<type>Display</type> +structure and destroys all windows, resource IDs +(<type>Window</type>, +<type>Font</type>, +<type>Pixmap</type>, +<type>Colormap</type>, +<type>Cursor</type>, +and +<type>GContext</type>), +or other resources that the client has created +on this display, unless the close-down mode of the resource has been changed +(see +<function>XSetCloseDownMode</function>). +Therefore, these windows, resource IDs, and other resources should never be +referenced again or an error will be generated. +Before exiting, you should call +<function>XCloseDisplay</function> +explicitly so that any pending errors are reported as +<function>XCloseDisplay</function> +performs a final +<function>XSync</function> +operation. +<indexterm><primary>Resource IDs</primary></indexterm> +<indexterm><primary>XCloseDisplay</primary></indexterm> +</para> +<para> +<!-- .LP --> +<function>XCloseDisplay</function> +can generate a +<errorname>BadGC</errorname> +error. +<!-- .sp --> +</para> +<para> +<!-- .LP --> +Xlib provides a function to permit the resources owned by a client +to survive after the client's connection is closed. +To change a client's close-down mode, use +<function>XSetCloseDownMode</function>. +<indexterm significance="preferred"><primary>XSetCloseDownMode</primary></indexterm> +<!-- .sM --> +</para> +<funcsynopsis> +<funcprototype> + <funcdef>XSetCloseDownMode</funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> close_mode</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>close_mode</emphasis> + </term> + <listitem> + <para> +Specifies the client close-down mode. +You can pass +<symbol>DestroyAll</symbol>, +<symbol>RetainPermanent</symbol>, +or +<symbol>RetainTemporary</symbol>. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XSetCloseDownMode</function> +defines what will happen to the client's resources at connection close. +A connection starts in +<symbol>DestroyAll</symbol> +mode. +For information on what happens to the client's resources when the +close_mode argument is +<symbol>RetainPermanent</symbol> +or +<symbol>RetainTemporary</symbol>, +see section 2.6. +</para> +<para> +<!-- .LP --> +<function>XSetCloseDownMode</function> +can generate a +<errorname>BadValue</errorname> +error. +</para> +</sect1> +<sect1 id="Using_X_Server_Connection_Close_Operations_"> +<title>Using X Server Connection Close Operations </title> +<!-- .XS --> +<!-- (SN Using X Server Connection Close Operations --> +<!-- .XE --> +<para> +<!-- .LP --> +When the X server's connection to a client is closed +either by an explicit call to +<function>XCloseDisplay</function> +or by a process that exits, the X server performs the following +automatic operations: +</para> +<itemizedlist> + <listitem> + <para> +It disowns all selections owned by the client +(see +<function>XSetSelectionOwner</function>). + </para> + </listitem> + <listitem> + <para> +It performs an +<function>XUngrabPointer</function> +and +<function>XUngrabKeyboard</function> +if the client has actively grabbed the pointer +or the keyboard. + </para> + </listitem> + <listitem> + <para> +It performs an +<function>XUngrabServer</function> +if the client has grabbed the server. + </para> + </listitem> + <listitem> + <para> +It releases all passive grabs made by the client. + </para> + </listitem> + <listitem> + <para> +It marks all resources (including colormap entries) allocated +by the client either as permanent or temporary, +depending on whether the close-down mode is +<symbol>RetainPermanent</symbol> +or +<symbol>RetainTemporary</symbol>. +However, this does not prevent other client applications from explicitly +destroying the resources (see +<function>XSetCloseDownMode</function>). + </para> + </listitem> +</itemizedlist> +<para> +<!-- .LP --> +When the close-down mode is +<symbol>DestroyAll</symbol>, +the X server destroys all of a client's resources as follows: +</para> +<itemizedlist> + <listitem> + <para> +It examines each window in the client's save-set to determine if it is an inferior +(subwindow) of a window created by the client. +(The save-set is a list of other clients' windows +that are referred to as save-set windows.) +If so, the X server reparents the save-set window to the closest ancestor so +that the save-set window is not an inferior of a window created by the client. +The reparenting leaves unchanged the absolute coordinates (with respect to +the root window) of the upper-left outer corner of the save-set +window. + </para> + </listitem> + <listitem> + <para> +It performs a +<systemitem>MapWindow</systemitem> +request on the save-set window if the save-set window is unmapped. +The X server does this even if the save-set window was not an inferior of +a window created by the client. + </para> + </listitem> + <listitem> + <para> +It destroys all windows created by the client. + </para> + </listitem> + <listitem> + <para> +It performs the appropriate free request on each nonwindow resource created by +the client in the server (for example, +<type>Font</type>, +<type>Pixmap</type>, +<type>Cursor</type>, +<type>Colormap</type>, +and +<type>GContext</type>). + </para> + </listitem> + <listitem> + <para> +It frees all colors and colormap entries allocated by a client application. + </para> + </listitem> +</itemizedlist> +<para> +<!-- .LP --> +Additional processing occurs when the last connection to the X server closes. +An X server goes through a cycle of having no connections and having some +connections. +When the last connection to the X server closes as a result of a connection +closing with the close_mode of +<symbol>DestroyAll</symbol>, +the X server does the following: +</para> +<itemizedlist> + <listitem> + <para> +It resets its state as if it had just been +started. +The X server begins by destroying all lingering resources from +clients that have terminated in +<symbol>RetainPermanent</symbol> +or +<symbol>RetainTemporary</symbol> +mode. + </para> + </listitem> + <listitem> + <para> +It deletes all but the predefined atom identifiers. + </para> + </listitem> + <listitem> + <para> +It deletes all properties on all root windows (see section 4.3). + </para> + </listitem> + <listitem> + <para> +It resets all device maps and attributes +(for example, key click, bell volume, and acceleration) +as well as the access control list. + </para> + </listitem> + <listitem> + <para> +It restores the standard root tiles and cursors. + </para> + </listitem> + <listitem> + <para> +It restores the default font path. + </para> + </listitem> + <listitem> + <para> +It restores the input focus to state +<symbol>PointerRoot</symbol>. + </para> + </listitem> +</itemizedlist> +<para> +<!-- .LP --> +However, the X server does not reset if you close a connection with a close-down +mode set to +<symbol>RetainPermanent</symbol> +or +<symbol>RetainTemporary</symbol>. +</para> +</sect1> +<sect1 id="Using_Xlib_with_Threads"> +<title>Using Xlib with Threads</title> +<!-- .XS --> +<!-- (SN Using Xlib with Threads --> +<!-- .XE --> +<para> +<!-- .LP --> +On systems that have threads, support may be provided to permit +multiple threads to use Xlib concurrently. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +To initialize support for concurrent threads, use +<function>XInitThreads</function>. +<indexterm significance="preferred"><primary>XInitThreads</primary></indexterm> +<!-- .sM --> +</para> +<para>Status XInitThreads();</para> +<!-- .FN --> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XInitThreads</function> +function initializes Xlib support for concurrent threads. +This function must be the first Xlib function a +multi-threaded program calls, and it must complete +before any other Xlib call is made. +This function returns a nonzero status if initialization was +successful; otherwise, it returns zero. +On systems that do not support threads, this function always returns zero. +</para> +<para> +<!-- .LP --> +It is only necessary to call this function if multiple threads +might use Xlib concurrently. If all calls to Xlib functions +are protected by some other access mechanism (for example, +a mutual exclusion lock in a toolkit or through explicit client +programming), Xlib thread initialization is not required. +It is recommended that single-threaded programs not call this function. + +</para> +<para> +<!-- .LP --> +<!-- .sp --> +To lock a display across several Xlib calls, use +<function>XLockDisplay</function>. +<indexterm significance="preferred"><primary>XLockDisplay</primary></indexterm> +<!-- .sM --> +</para> +<funcsynopsis> +<funcprototype> + <funcdef>XLockDisplay</funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> + +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XLockDisplay</function> +function locks out all other threads from using the specified display. +Other threads attempting to use the display will block until +the display is unlocked by this thread. +Nested calls to +<function>XLockDisplay</function> +work correctly; the display will not actually be unlocked until +<function>XUnlockDisplay</function> +has been called the same number of times as +<function>XLockDisplay</function>. +This function has no effect unless Xlib was successfully initialized +for threads using +<function>XInitThreads</function>. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +To unlock a display, use +<function>XUnlockDisplay</function>. +<indexterm significance="preferred"><primary>XUnlockDisplay</primary></indexterm> +<!-- .sM --> +</para> +<funcsynopsis> +<funcprototype> + <funcdef>XUnlockDisplay</funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XUnlockDisplay</function> +function allows other threads to use the specified display again. +Any threads that have blocked on the display are allowed to continue. +Nested locking works correctly; if +<function>XLockDisplay</function> +has been called multiple times by a thread, then +<function>XUnlockDisplay</function> +must be called an equal number of times before the display is +actually unlocked. +This function has no effect unless Xlib was successfully initialized +for threads using +<function>XInitThreads</function>. +</para> +</sect1> +<sect1 id="Using_Internal_Connections"> +<title>Using Internal Connections</title> +<!-- .XS --> +<!-- (SN Using Internal Connections --> +<!-- .XE --> +<para> +<!-- .LP --> +In addition to the connection to the X server, an Xlib implementation +may require connections to other kinds of servers (for example, to +input method servers as described in chapter 13). Toolkits and clients +that use multiple displays, or that use displays in combination with +other inputs, need to obtain these additional connections to correctly +block until input is available and need to process that input +when it is available. Simple clients that use a single display and +block for input in an Xlib event function do not need to use these +facilities. +</para> +<para> +<!-- .LP --> +To track internal connections for a display, use +<function>XAddConnectionWatch</function>. +</para> +<funcsynopsis> +<funcprototype> + <funcdef>type void XConnectionWatchProc</funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>XPointer<parameter> client_data</parameter></paramdef> + <paramdef>int<parameter> fd</parameter></paramdef> + <paramdef>Bool<parameter> opening</parameter></paramdef> + <paramdef>XPointer<parameter> *watch_data</parameter></paramdef> +</funcprototype> +</funcsynopsis> + +<funcsynopsis> +<funcprototype> + <funcdef>Status XAddConnectionWatch</funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>XWatchProc<parameter> procedure</parameter></paramdef> + <paramdef>XPointer<parameter> client_data</parameter></paramdef> +</funcprototype> +</funcsynopsis> + +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>procedure</emphasis> + </term> + <listitem> + <para> +Specifies the procedure to be called. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>client_data</emphasis> + </term> + <listitem> + <para> +Specifies the additional client data. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XAddConnectionWatch</function> +function registers a procedure to be called each time Xlib opens or closes an +internal connection for the specified display. The procedure is passed the +display, the specified client_data, the file descriptor for the connection, +a Boolean indicating whether the connection is being opened or closed, and a +pointer to a location for private watch data. If opening is +<symbol>True</symbol>, +the procedure can store a pointer to private data in the location pointed +to by watch_data; +when the procedure is later called for this same connection and opening is +<symbol>False</symbol>, +the location pointed to by watch_data will hold this same private data pointer. +</para> +<para> +<!-- .LP --> +This function can be called at any time after a display is opened. +If internal connections already exist, the registered procedure will +immediately be called for each of them, before +<function>XAddConnectionWatch</function> +returns. +<function>XAddConnectionWatch</function> +returns a nonzero status if the procedure is successfully registered; +otherwise, it returns zero. +</para> +<para> +<!-- .LP --> +The registered procedure should not call any Xlib functions. +If the procedure directly or indirectly causes the state of internal +connections or watch procedures to change, the result is not defined. +If Xlib has been initialized for threads, the procedure is called with +the display locked and the result of a call by the procedure to any +Xlib function that locks the display is not defined unless the executing +thread has externally locked the display using +<function>XLockDisplay</function>. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +To stop tracking internal connections for a display, use +<function>XRemoveConnectionWatch</function>. +<indexterm significance="preferred"><primary>XRemoveConnectionWatch</primary></indexterm> +<!-- .sM --> +</para> +<para> +() +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Status <function>XRemoveConnectionWatch</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>XWatchProc<parameter> procedure</parameter></paramdef> + <paramdef>XPointer<parameter> client_data</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>procedure</emphasis> + </term> + <listitem> + <para> +Specifies the procedure to be called. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>client_data</emphasis> + </term> + <listitem> + <para> +Specifies the additional client data. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XRemoveConnectionWatch</function> +function removes a previously registered connection watch procedure. +The client_data must match the client_data used when the procedure +was initially registered. + +</para> +<para> +<!-- .LP --> +<!-- .sp --> +To process input on an internal connection, use +<function>XProcessInternalConnection</function>. +<indexterm significance="preferred"><primary>XProcessInternalConnection</primary></indexterm> +<!-- .sM --> +</para> +<para> +() +</para> +<funcsynopsis> +<funcprototype> + <funcdef>void <function>XProcessInternalConnection</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int<parameter> fd</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>fd</emphasis> + </term> + <listitem> + <para> +Specifies the file descriptor. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XProcessInternalConnection</function> +function processes input available on an internal connection. +This function should be called for an internal connection only +after an operating system facility (for example, +<function>select</function> +or +<function>poll</function>) +has indicated that input is available; otherwise, +the effect is not defined. +</para> +<para> +<!-- .LP --> +<!-- .sp --> +To obtain all of the current internal connections for a display, use +<function>XInternalConnectionNumbers</function>. +<indexterm significance="preferred"><primary>XInternalConnectionNumbers</primary></indexterm> +<!-- .sM --> +</para> +<para> +() +</para> +<funcsynopsis> +<funcprototype> + <funcdef>Status <function>XInternalConnectionNumbers</function></funcdef> + <paramdef>Display<parameter> *display</parameter></paramdef> + <paramdef>int **<parameter> fd</parameter></paramdef> + <paramdef>int *<parameter> count_return</parameter></paramdef> +</funcprototype> +</funcsynopsis> +<!-- .FN --> +<variablelist> + <varlistentry> + <term> + <emphasis remap='I'>display</emphasis> + </term> + <listitem> + <para> +Specifies the connection to the X server. + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>fd_return</emphasis> + </term> + <listitem> + <para> +Returns the file descriptors. +<!-- .ds Cn file descriptors --> + </para> + </listitem> + </varlistentry> + <varlistentry> + <term> + <emphasis remap='I'>count_return</emphasis> + </term> + <listitem> + <para> +Returns the number of (Cn. + </para> + </listitem> + </varlistentry> +</variablelist> +<para> +<!-- .LP --> +<!-- .eM --> +The +<function>XInternalConnectionNumbers</function> +function returns a list of the file descriptors for all internal +connections currently open for the specified display. +When the allocated list is no longer needed, +free it by using +<function>XFree</function>. +This functions returns a nonzero status if the list is successfully allocated; +otherwise, it returns zero. +</para> +</sect1> +</chapter> |