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.