path: root/libXaw/spec/Toggle

.\" $Xorg: Toggle,v 1.3 2000/08/17 19:42:29 cpqbld Exp $
.NH 2
Toggle Widget
.XS
	Toggle Widget
.XE
.IN "Toggle widget" "" "@DEF@"
.Ds 0
.TA 2.0i
.ta 2.0i
.sp
Application Header file	<Xaw/Toggle.h>
.IN "Toggle.h" ""
Class Header file	<Xaw/ToggleP.h>
.IN "ToggleP.h" ""
Class		toggleWidgetClass
.IN "toggleWidgetClass" ""
Class Name	Toggle
.IN "Toggle widget" "class name"
Superclass 	Command
.sp
.De
.LP
The Toggle widget is an area, often rectangular,
that displays a graphic.  The graphic may be a text
string containing multiple lines of characters in an 8
bit or 16 bit character set (to be displayed with a
\fIfont\fP), or in a multi-byte encoding (for use with
a \fIfontset\fP).  The graphic may also be a bitmap or
pixmap.
.LP
This widget maintains a Boolean state (e.g.
True/False or On/Off) and changes state whenever it is selected.  When
the pointer is on the Toggle widget, the Toggle widget may become highlighted by
drawing a rectangle around its perimeter.  This highlighting indicates
that the Toggle widget is ready for selection.  When pointer button 1 is
pressed and released, the Toggle widget indicates that it has changed
state by reversing its foreground and background colors, and its
\fBnotify\fP action is invoked, calling all functions on its callback
list.  If the pointer is moved off of the widget before the pointer button is
released, the Toggle widget reverts to its previous foreground and background
colors, and releasing the pointer button has no effect.  This behavior allows
the user to cancel the operation.
.LP
Toggle widgets may also be part of a ``radio group.''  A radio group is a
.IN "Radio groups" ""
.IN "Radio button" ""
.IN "Toggle widget" "used in radio groups"
list of at least two Toggle widgets in which no more than one Toggle may
be set at
any time.  A radio group is identified by the widget ID of any one of
its members.  The convenience routine \fBXawToggleGetCurrent\fP will
return information about the Toggle widget in the radio group.
.LP
Toggle widget state is preserved across changes in sensitivity.
.NH 3
Resources
.LP
When creating a Toggle widget instance, the following resources are
retrieved from the argument list or from the resource database:
.LP
.IN "Toggle widget" "resources"
.TS H
expand;
lw(1i) lw(1i) lw(1i) lw(.5i) lw(2i).
_
.sp 3p
.TB
Name	Class	Type	Notes	Default Value
.sp 3p
_
.TH
.R
.sp 3p
accelerators	Accelerators	AcceleratorTable		NULL
ancestorSensitive	AncestorSensitive	Boolean	D	True
background	Background	Pixel		XtDefaultBackground
backgroundPixmap	Pixmap	Pixmap		XtUnspecifiedPixmap
bitmap	Bitmap	Pixmap		None
borderColor	BorderColor	Pixel		XtDefaultForeground
borderPixmap	Pixmap	Pixmap		XtUnspecifiedPixmap
borderWidth	BorderWidth	Dimension		1
callback	Callback	XtCallbackList		NULL
colormap	Colormap	Colormap		Parent's Colormap
cornerRoundPercent	CornerRoundPercent	Dimension		25
cursor	Cursor	Cursor		None
cursorName	Cursor	String		NULL
depth	Depth	int	C	Parent's Depth
destroyCallback	Callback	XtCallbackList		NULL
encoding	Encoding	UnsignedChar		XawTextEncoding8bit
font	Font	XFontStruct		XtDefaultFont
fontSet	FontSet	XFontSet		XtDefaultFontSet
foreground	Foreground	Pixel		XtDefaultForeground
height	Height	Dimension	A	graphic height + 2 * \fBinternalHeight\fP
highlightThickness	Thickness	Dimension	A	2 (0 if Shaped)
insensitiveBorder	Insensitive	Pixmap		GreyPixmap
internalHeight	Height	Dimension		2
internalWidth	Width	Dimension		4
international	International	Boolean	C	False
justify	Justify	Justify		XtJustifyCenter (center)
label	Label	String		name of widget
leftBitmap	LeftBitmap	Bitmap		None
mappedWhenManaged	MappedWhenManaged	Boolean		True
pointerColor	Foreground	Pixel		XtDefaultForeground
pointerColorBackground	Background	Pixel		XtDefaultBackground
radioData	RadioData	Pointer		Name of widget
radioGroup	Widget	Widget		No radio group
resize	Resize	Boolean		True
screen	Screen	Screen	R	Parent's Screen
sensitive	Sensitive	Boolean		True
shapeStype	ShapeStyle	ShapeStyle		Rectangle
state	State	Boolean		Off
translations	Translations	TranslationTable		See below
width	Width	Dimension	A	graphic width + 2 * \fBinternalWidth\fP
x	Position	Position		0
y	Position	Position		0
.sp 3p
_
.TE
.Ac
.As
.Bg
.Gp
.Bm
.Bc
.Bp
.Bw
.Cb
.Cm
.Cr
.Cu
.Cn
.Dp
.Dc
.Le
.Lf
.Ls
.Lg
.Hw
.Ht
.Ib
.Ih
.In
.Ju
.La
.Ll
.Mm
.Pf
.Pb
.IP \fBradioData\fP 1.5i
Specifies the data that will be returned by \fBXawToggleGetCurrent\fP
when this is the currently \fIset\fP widget in the radio group.  This
value is also used to identify the Toggle that will be set by a call to
\fBXawToggleSetCurrent\fP.  The value NULL will be returned by
\fBXawToggleGetCurrent\fP if no widget in a radio group is currently
set.  Programmers must not specify NULL (or Zero) as \fBradioData\fP.
.IP \fBradioGroup\fP 1.5i
Specifies another Toggle widget that is in the radio group to which this
Toggle widget should be added.  A radio group is a group of at least two Toggle
widgets, only one of which may be \fIset\fP at a time.  If this value is
NULL (the default) then the Toggle will not be part of any radio group
and can change state without affecting any other Toggle widgets.  If the
widget specified in this resource is not already in a radio group then a
new radio group will be created containing these two Toggle widgets.  No
Toggle widget can be in multiple radio groups.  The behavior of a radio
group of one toggle is undefined.  A converter is registered which will
convert widget names to widgets without caching.
.Re
.Sc
.Se
.Ss
.IP \fBstate\fP
Specifies whether the Toggle widget is set (\fBTrue\fP) or unset
(\fBFalse\fP).
.Tr
.Xy
.NH 3
Toggle Actions
.IN "Toggle widget" "actions"
.LP
The Toggle widget supports the following actions:
.IP \(bu 5
Switching the Toggle widget between the foreground and background
colors with \fBset\fP and \fBunset\fP and \fBtoggle\fP
.IP \(bu 5
Processing application callbacks with \fBnotify\fP
.IP \(bu 5
Switching the internal border between highlighted
and unhighlighted states with \fBhighlight\fP and \fBunhighlight\fP
.LP
The following are the default translation bindings used by the
Toggle widget:
.IN "Toggle widget" "default translation table"
.LP
.sp
.Ds 0
.TA .5i 2.25i
.ta .5i 2.25i
	<EnterWindow>:	highlight(Always)
	<LeaveWindow>:	unhighlight(\|)
	<Btn1Down>,<Btn1Up>:	toggle(\|) notify(\|)
.De
.NH 3
Toggle Actions
.LP
The full list of actions supported by Toggle is:
.IP \fBhighlight\fP(\fIcondition\fP) 1.5i
Displays the internal highlight border in the color (\fBforeground\fP
or \fBbackground\fP ) that contrasts with the interior color of the
Toggle widget.  The conditions \fBWhenUnset\fP and \fBAlways\fP are
understood by this action procedure.  If no argument is passed then
\fBWhenUnset\fP is assumed.
.IP \fBunhighlight\fP(\|) 1.5i
Displays the internal highlight border in the color (\fBforeground\fP
or \fBbackground\fP ) that matches the interior color of the
Toggle widget.
.IP \fBset\fP(\|) 1.5i
Enters the \fIset\fP state, in which \fBnotify\fP is possible.  This
action causes the Toggle widget to display its interior in the
\fBforeground\fP color.  The label or bitmap is displayed in the
\fBbackground\fP color.
.IP \fBunset\fP(\|) 1.5i
Cancels the \fIset\fP state and displays the interior of the Toggle widget in the
\fBbackground\fP color.  The label or bitmap is displayed in the
\fBforeground\fP color.
.IP \fBtoggle\fP(\|) 1.5i
Changes the current state of the Toggle widget, causing to be set
if it was previously unset, and unset if it was previously set.
If the widget is to be set, and is in a radio group then this procedure may
unset another Toggle widget causing all routines on its callback list
to be invoked.  The callback routines for the Toggle that
is to be unset will be called before the one that is to be set.
.IP \fBreset\fP(\|) 1.5i
Cancels any \fBset\fP or \fBhighlight\fP and displays the interior of the
Toggle widget in the \fBbackground\fP color, with the label displayed in the
\fBforeground\fP color.
.IP \fBnotify\fP(\|) 1.5i
When the Toggle widget is in the \fBset\fP state this action calls all functions in
the callback list named by the \fBcallback\fP resource.  The value of
the call_data argument in these callback functions is undefined.
.LP
.NT
When a bitmap of depth greater that one (1) is specified the
\fIset\fP(), \fIunset\fP(), and \fIreset\fP() actions have no effect,
since there are no foreground and background colors used in a
multi-plane pixmap.
.NE
.NH 3
Radio Groups
.IN "Radio groups"
.LP
There are typically two types of radio groups desired by applications.
The default translations for the Toggle widget implement a "zero or one
.IN "Radio groups" "zero or one of many"
of many" radio group.  This means that there may be no more than one
Toggle widget active, but there need not be any Toggle widgets active.
.LP
The other type of radio group is "one of many" and has the more strict
.IN "Radio groups" "one of many"
policy that there will always be exactly one radio button active.
Toggle widgets can be used to provide this interface with a slight
modification to the translation table of each Toggle in the group.
.Ds 0
.TA .5i 2.25i
.ta .5i 2.25i
.sp
	<EnterWindow>:	highlight(Always)
	<LeaveWindow>:	unhighlight(\|)
	<Btn1Down>,<Btn1Up>:	set(\|) notify(\|)
.sp
.De
This translation table will not allow any Toggle to be \fIunset\fP
except as a result of another Toggle becoming \fIset\fP.  It is
the application programmer's responsibility to choose an initial
state for the radio group by setting the \fBstate\fP resource of one of
its member widgets to \fBTrue\fP.
.NH 3
Convenience Routines
.LP
The following functions allow easy access to the Toggle widget's radio
group functionality.
.NH 4
Changing the Toggle's Radio Group.
.LP
To enable an application to change the Toggle's radio group, add
the Toggle to a radio group, or remove the Toggle from a radio group, use
\fBXawToggleChangeRadioGroup\fP.
.IN "XawToggleChangeRadioGroup" "" "@DEF@"
.FD
void XawToggleChangeRadioGroup(\fIw\fP, \fIradio_group\fP)
.br
     Widget \fIw\fP, \fIradio_group\fP;
.FN
.IP \fIw\fP 1i
Specifies the Toggle widget.
.IP \fIradio_group\fP 1i
Specifies any Toggle in the new radio group.  If NULL then the Toggle
will be removed from any radio group of which it is a member.
.LP
If a Toggle is already \fIset\fP in the new radio group,
and the Toggle to be added is also \fIset\fP then the previously
\fIset\fP Toggle in the radio group is \fIunset\fP and its callback
procedures are invoked.
.SH
Finding the Currently selected Toggle in a radio group of Toggles
.LP
To find the currently selected Toggle in a radio group of Toggle widgets
use
\fBXawToggleGetCurrent\fP.
.IN "XawToggleGetCurrent" "" "@DEF@"
.FD
XtPointer XawToggleGetCurrent(\fIradio_group\fP);
.br
     Widget \fIradio_group\fP;
.FN
.IP \fIradio_group\fP 1i
Specifies any Toggle widget in the radio group.
.LP
The value returned by this function is the
.PN radioData
of the Toggle in this radio group that is currently set.  The default
value for
.PN radioData
is the name of that Toggle widget.  If no Toggle is set in the radio
group specified then NULL is returned.
.SH
Changing the Toggle that is set in a radio group.
.LP
To change the Toggle that is currently set in a radio group use
\fBXawToggleSetCurrent\fP.
.IN "XawToggleSetCurrent" "" "@DEF@"
.FD
void XawToggleSetCurrent(\fIradio_group\fP, \fIradio_data\fP);
.br
     Widget \fIradio_group\fP;
     XtPointer \fIradio_data\fP;
.FN
.IP \fIradio_group\fP 1i
Specifies any Toggle widget in the radio group.
.IP \fIradio_data\fP 1i
Specifies the
.PN radioData
identifying the Toggle that should be set in the radio group specified
by the \fIradio_group\fP argument.
.LP
\fBXawToggleSetCurrent\fP locates the Toggle widget to be set by
matching \fIradio_data\fP against the \fBradioData\fP for each Toggle in
the radio group.  If none match, \fBXawToggleSetCurrent\fP returns
without making any changes.  If more than one Toggle matches,
\fBXawToggleSetCurrent\fP will choose a Toggle to set arbitrarily.  If
this causes any Toggle widgets to change state, all routines in their
callback lists will be invoked.  The callback routines for a Toggle that
is to be unset will be called before the one that is to be set.
.SH
Unsetting all Toggles in a radio group.
.LP
To unset all Toggle widgets in a radio group use
\fBXawToggleUnsetCurrent\fP.
.IN "XawToggleUnsetCurrent" "" "@DEF@"
.FD
void XawToggleUnsetCurrent(\fIradio_group\fP);
.br
     Widget \fIradio_group\fP;
.FN
.IP \fIradio_group\fP 1i
Specifies any Toggle widget in the radio group.
.LP
If this causes a Toggle widget to change state, all routines on its
callback list will be invoked.