NAME

XwswindowWidgetClass − the X Widget’s scrolled window widget

SYNOPSIS

#include <X11/StringDefs.h>
#include <X11/Intrinsic.h>
#include <Xw/Xw.h>
#include <Xw/Valuator.h>
#include <Xw/Arrow.h>
#include <Xw/ScrollBar.h>
#include <Xw/SWindow.h>

CLASSES

The ScrolledWindow is built from the Core, Composite, and XwManager classes. 

The widget class to use when creating a scrolled window is XwswindowWidgetClass. The class name is ScrolledWindow. 

DESCRIPTION

The ScrolledWindow widget combines the ScrollBar and BulletinBoard widgets to implement a visible window onto some other (usually larger) data display. The visible part of the window can be scrolled through the larger display by the use of scroll bars. 

To use the scrolled window, an application first creates a ScrolledWindow widget, and then creates a widget capable of displaying the desired data as a child of the ScrolledWindow. ScrolledWindow will position the child widget within its BulletinBoard manager instance, and create scroll bars for the horizontal and vertical dimensions. When the user performs some action on the scroll bars, the child widget will be repositioned accordingly within the bulletin board. 

NEW RESOURCES

The ScrolledWindow widget defines a unique set of resource types which can be used by the programmer to control the appearence and behavior of the scrolled window.  The programmer can also set the values for the Core, Composite and Manager widget classes to set attributes for this widget.  To reference a resource in a .Xdefaults file, strip off the XtN from the resource string.  The following table contains the set of resources defined by ScrolledWindow.   

XtNvScrollBarWidth
This is the width in pixels of the vertical scroll bar.

XtNhScrollBarHeight
This is the height in pixels of the horizontal scroll bar.

XtNforceHorizontalSB
When the child widget is created and positioned within the scrolled window, its width and height are examined. If the entire child widget will fit within the width of the scrolled window, the horizontal scrollbar will not be created, since there is no need to scroll in that direction. Setting this resource to TRUE disables this checking and will force a horizontal scrollbar to be attached to the window regardless of the dimension of the child widget.

XtNforceVerticalSB
This resource controls the existence of the vertical scrollbar. As described above, if this is set to TRUE a vertical scrollbar will always be created.

XtNvScrollEvent and XtNvScrollEvent
An application program may track the position of the child within the scrolled window by linking into these callbacks. Whenever the user moves the valuator in either scroll bar, ScrolledWindow moves the child accordingly and then calls the appropriate callback. The call_data parameter is set to the new valuator origin for the scrollbar.

XtNinitialX and XtNinitialY
The child widget is initially positioned at (0,0) within the bulletin board. This positioning can be changed by specifying a new X and Y location. If a non-zero value is given, that becomes the initial location, and the valuators inside the scrollbars are adjusted to give a visual indication of the new offset. This value should be negative to assure proper operation of the scrolled window. These resources are only used at initialization time; they cannot be set through a call to XtSetValues. 

INCORPORATED RESOURCES

The ScrolledWindow  widget is built from two ScrollBar widgets and a BulletinBoard widget.  As such, it uses a large number of the resources defined by these widgets.  Many of the attributes for these widgets can be set through the .Xdefaults file or by use of XtSetValues() when communicating with the ScrolledWindow widget. 

Only the resources within the following tables will have any effect on the scroll bars.  The other resource types defined by the ScrollBar widget are either overridden or unused by ScrolledWindow. 

The following tables list the resources incorporated by ScrolledWindow.  For a complete description of these resources, refer to the manual page listed in the table heading.   

INHERITED RESOURCES

The following resources are inherited from the named superclasses:  

KEYBOARD TRAVERSAL

If the XtNtraversalType resource is set to highlight_traversal (XwHIGHLIGHT_TRAVERSAL in an argument list) at either create time or during a call to XtSetValues, the XwPrimitive superclass will automatically augment the primitive widget’s translations to support keyboard traversal.  Refer to the XwPrimitive man page for a complete description of these translations.  Refer to the TRANSLATIONS section in this man page for a description of the translations local to the scrolled window widget. 

TRANSLATIONS

Input to the ScrolledWindow widget is driven by the mouse buttons.  However the translations driving the actions are defined by the ScrollBar widgets.  The additional translations used for ScrolledWindow are as follows:

<EnterWindow>: enter(),
<LeaveWindow>: leave(),

ACTIONS

enter:  Enter window events occurring on the scrolled window are handled by this action.  leave:  Leave window events occurring on the scrolled window are handled by this action. 

ORIGIN

Hewlett-Packard Company. 

SEE ALSO

CORE(3X), XWMANAGER(3X) XWPRIMITIVE(3X), XWSCROLLBAR(3X),XWBULLETINBOARD(3X),XWVALUATOR(3X), XWARROW(3X)

September 29, 2021