StripChart Widget
Application Header file <Xaw/StripChart.h>
Class Header file <Xaw/StripCharP.h>
Class stripChartWidgetClass
Class Name StripChart
Superclass Simple
The StripChart widget is used to provide a roughly real
time graphical chart of a single value. For example,
it is used by the common client program xload
to provide a graph of processor load. The StripChart
reads data from an application, and updates the chart
at the update interval specified.
Resources
When creating a StripChart widget instance, the following resources are
retrieved from the argument list or from the resource database:
Name
Class
Type
Notes
Default Value
accelerators
Accelerators
AcceleratorTable
NULL
ancestorSensitive
AncestorSensitive
Boolean
D
True
background
Background
Pixel
XtDefaultBackground
backgroundPixmap
Pixmap
Pixmap
XtUnspecifiedPixmap
borderColor
BorderColor
Pixel
XtDefaultForeground
borderPixmap
Pixmap
Pixmap
XtUnspecifiedPixmap
borderWidth
BorderWidth
Dimension
1
colormap
Colormap
Colormap
Parent's Colormap
cursor
Cursor
Cursor
None
cursorName
Cursor
String
NULL
depth
Depth
int
C
Parent's Depth
destroyCallback
Callback
XtCallbackList
NULL
foreground
Foreground
Pixel
XtDefaultForeground
getValue
Callback
XtCallbackList
NULL
height
Height
Dimension
120
highlight
Foreground
Pixel
XtDefaultForeground
insensitiveBorder
Insensitive
Pixmap
GreyPixmap
international
International
Boolean
C
False
jumpScroll
JumpScroll
int
A
half the width of the widget
mappedWhenManaged
MappedWhenManaged
Boolean
True
minScale
Scale
int
1
pointerColor
Foreground
Pixel
XtDefaultForeground
pointerColorBackground
Background
Pixel
XtDefaultBackground
screen
Screen
Pointer
R
Parent's Screen
sensitive
Sensitive
Boolean
True
translations
Translations
TranslationTable
NULL
update
Interval
int
10
width
Width
Dimension
120
x
Position
Position
0
y
Position
Position
0
foreground
A pixel value which indexes the widget's colormap to derive the color
that will be used to draw the graph.
getValue
A list of callback functions to call every update seconds.
This list should contain one function, which returns the
value to be graphed by the StripChart widget. The following
section describes the procedural interface. Behavior when this list has
more than one function is undefined.
highlight
A pixel value which indexes the widget's colormap to derive the color
that will be used to draw the scale lines on the graph.
jumpScroll
When the graph reaches the right edge of the window it must be
scrolled to the left. This resource specifies the number of pixels
it will jump. Smooth scrolling can be achieved by setting this resource
to 1.
minScale
The minimum scale for the graph. The number of divisions on the graph
will always be greater than or equal to this value.
update
The number of seconds between graph updates. Each update is
represented on the graph as a 1 pixel wide line. Every update seconds
the getValue procedure will be used to get a new graph point,
and this point will be added to the right end of the StripChart.
Getting the StripChart Value
The StripChart widget will call the application routine passed to it
as the getValue callback function every update seconds to
obtain another point for the StripChart graph.
The calling interface for the getValue callback is:
void(*getValueProc)
Widget w
XtPointer client_data
XtPointer value
w
Specifies the StripChart widget.
client_data
Specifies the client data.
value
Returns a pointer to a double. The application should set the address
pointed to by this argument to a double containing the value to be
graphed on the StripChart.
This function is used by the StripChart to call an application routine.
The routine will pass the value to be graphed back to the the StripChart
in the value field of this routine.