Specifications

Athena Widget Set libXaw 1.0.7
3.4.8. Restrictions
Manyprogrammers create a ‘‘scrolled list’’byputting a List widget with manyentries as a child
of a Viewport widget. The List continues to create a windowasbig as its contents, but that big
windowisonly visible where it intersects the parent Viewport’swindow. (I.e., it is ‘‘clipped.’’)
While this is a useful technique, there is a serious drawback. X does not support windows above
32,767 pixels in width or height, but this height limit will be exceeded by a List’swindowwhen
the List has manyentries (i.e., with a 12 point font, about 3000 entries would be too many.)
3.5. Panner Widget
Application header file <X11/Xaw/Panner.h>
Class header file <X11/Xaw/PannerP.h>
Class pannerWidgetClass
Class Name Panner
Superclass Simple
APanner widget is a rectangle, called the ‘‘canvas,’’ onwhich another rectangle, the ‘‘slider,’’
movesintwo dimensions. It is often used with a Porthole widget to move,or‘‘scroll,’’ a third
widget in twodimensions, in which case the slider’ssize and position givesfeedback as to what
portion of the third widget is visible.
The slider may be scrolled around the canvasbypressing, dragging, and releasing Button1; the
default translation also enables scrolling via arrowkeysand some other keys. While scrolling is
in progress, the application receivesnotification through callback procedures. Notification may
be done either continuously wheneverthe slider movesordiscretely wheneverthe slider has been
givenanew location.
3.5.1. Resources
When creating a Panner widget instance, the following resources are retrievedfrom the argument
list or from the resource database:
Name Class Type Notes Default Value
accelerators Accelerators AcceleratorTable NULL
allowOffAllowOffBoolean False
ancestorSensitive AncestorSensitive Boolean D True
background Background Pixel XtDefaultBackground
backgroundPixmap Pixmap Pixmap XtUnspecifiedPixmap
backgroundStipple BackgroundStipple String NULL
borderColor BorderColor Pixel XtDefaultForeground
borderPixmap Pixmap Pixmap XtUnspecifiedPixmap
borderWidth BorderWidth Dimension 1
canvasHeight CanvasHeight Dimension 0
canvasWidth CanvasWidth Dimension 0
colormap Colormap Colormap Parent’sColormap
cursor Cursor Cursor None
cursorName Cursor String NULL
defaultScale DefaultScale Dimension 8
depth Depth int C Parent’sDepth
destroyCallback Callback XtCallbackList NULL
foreground Foreground Pixel XtDefaultForeground
height Height Dimension A depends on orientation
internalSpace InternalSpace Dimension 4
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