OSF

NAME

XmScrolledWindow — the ScrolledWindow widget class.

SYNOPSIS

#include <Xm/ScrolledW.h>

DESCRIPTION

The ScrolledWindow widget combines one or two ScrollBar widgets and a viewing area 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 ScrollBars. 

To use ScrolledWindow, an application first creates a ScrolledWindow widget, any needed ScrollBar widgets, and a widget capable of displaying any desired data as the work area of ScrolledWindow.  ScrolledWindow positions the work area widget and display the ScrollBars if so requested.  When the user performs some action on the ScrollBar, the application is notified through the normal ScrollBar callback interface. 

ScrolledWindow can be configured to operate automatically so that it performs all scrolling and display actions with no need for application program involvement.  It can also be configured to provide a minimal support framework in which the application is responsible for processing all user input and making all visual changes to the displayed data in response to that input. 

When ScrolledWindow is performing automatic scrolling it creates a clipping window.  Conceptually, this window becomes the viewport through which the user examines the larger underlying data area.  The application simply creates the desired data, then makes that data the work area of the ScrolledWindow.  When the user moves the slider to change the displayed data, the workspace is moved under the viewing area so that a new portion of the data becomes visible. 

Sometimes it is impractical for an application to create a large data space and simply display it through a small clipping window.  For example, in a text editor, creating a single data area that consisted of a large file would involve an undesirable amount of overhead.  The application needs to use a ScrolledWindow (a small viewport onto some larger data), but needs to be notified when the user scrolled the viewport so it could bring in more data from storage and update the display area.  For these cases the ScrolledWindow can be configured so that it provides only visual layout support.  No clipping window is created, and the application must maintain the data displayed in the work area, as well as respond to user input on the ScrollBars. 

Classes

ScrolledWindow inherits behavior and resources from Core, Composite, Constraint, and XmManager Classes. 

The class pointer is xmScrolledWindowWidgetClass. 

The class name is XmScrolledWindow. 

New Resources

The following table defines a set of widget resources used by the programmer to specify data.  The programmer can also set the resource values for the inherited classes to set attributes for this widget.  To reference a resource by name or by class in a .Xdefaults file, remove the XmN or XmC prefix and use the remaining letters.  To specify one of the defined values for a resource in a .Xdefaults file, remove the Xm prefix and use the remaining letters (in either lowercase or uppercase, but include any underscores between words).  The codes in the access column indicate if the given resource can be set at creation time (C), set by using XtSetValues (S), retrieved by using XtGetValues (G), or is not applicable (N/A). 

XmNclipWindow
Specifies the widget ID of the clipping area.  This is automatically created by ScrolledWindow when the XmNvisualPolicy resource is set to XmCONSTANT and can be read only by the application.  Any attempt to set this resource to a new value causes a warning message to be printed by the scrolled window.  If the XmNvisualPolicy resource is set to XmVARIABLE, this resource is set to NULL, and no clipping window is created. 

XmNhorizontalScrollBar
Specifies the widget ID of the horizontal ScrollBar.

XmNscrollBarDisplayPolicy
Controls the automatic placement of the ScrollBars.  If it is set to XmAS_NEEDED and if XmNscrollingPolicy is set to XmAUTOMATIC, ScrollBars are displayed only if the workspace exceeds the clip area in one or both dimensions.  A resource value of XmSTATIC causes the ScrolledWindow to display the ScrollBars whenever they are managed, regardless of the relationship between the clip window and the work area.  This resource must be XmSTATIC when XmNscrollingPolicy is XmAPPLICATION_DEFINED.  The default is XmAS_NEEDED when XmNscrollingPolicy is AUTOMATIC, and XmSTATIC otherwise. 

XmNscrollBarPlacement
Specifies the positioning of the ScrollBars in relation to the work window.  The following are the values:

•XmTOP_LEFT — The horizontal ScrollBar is placed above the work window; the vertical ScrollBar to the left. 

•XmBOTTOM_LEFT — The horizontal ScrollBar is placed below the work window; the vertical ScrollBar to the left. 

•XmTOP_RIGHT — The horizontal ScrollBar is placed above the work window; the vertical ScrollBar to the right. 

•XmBOTTOM_RIGHT — The horizontal ScrollBar is placed below the work window; the vertical ScrollBar to the right. 

The default value may depend on the value of the XmNstringDirection resource. 

XmNscrolledWindowMarginHeight
Specifies the margin height on the top and bottom of the ScrolledWindow.

XmNscrolledWindowMarginWidth
Specifies the margin width on the right and left sides of the ScrolledWindow.

XmNscrollingPolicy
Performs automatic scrolling of the work area with no application interaction.  If the value of this resource is XmAUTOMATIC, ScrolledWindow automatically creates the ScrollBars; attaches callbacks to the ScrollBars; sets the visual policy to XmCONSTANT; and automatically moves the work area through the clip window in response to any user interaction with the ScrollBars.  An application can also add its own callbacks to the ScrollBars.  This allows the application to be notified of a scroll event without having to perform any layout procedures. 

NOTE:  Since the ScrolledWindow adds callbacks to the ScrollBars, an application should not perform an XtRemoveAllCallbacks on any of the ScrollBar widgets. 

When XmNscrollingPolicy is set to XmAPPLICATION_DEFINED, the application is responsible for all aspects of scrolling.  The ScrollBars must be created by the application, and it is responsible for performing any visual changes in the work area in response to user input. 

This resource must be set to the desired policy at the time the ScrolledWindow is created.  It cannot be changed through SetValues. 

XmNspacing
Specifies the distance that separates the ScrollBars from the work window.

XmNverticalScrollBar
Specifies the widget ID of the vertical ScrollBar.

XmNvisualPolicy
Grows the ScrolledWindow to match the size of the work area, or it can be used as a static viewport onto a larger data space.  If the visual policy is XmVARIABLE, the ScrolledWindow forces the ScrollBar display policy to XmSTATIC and allow the work area to grow or shrink at any time and adjusts its layout to accommodate the new size.  When the policy is XmCONSTANT, the work area grows or shrinks as requested, but a clipping window forces the size of the visible portion to remain constant.  The only time the viewing area can grow is in response to a resize from the ScrolledWindow’s parent.  The default is XmCONSTANT when XmNscrollingPolicy is XmAUTOMATIC, and XmVARIABLE otherwise. 

NOTE:  This resource must be set to the desired policy at the time the ScrolledWindow is created.  It cannot be changed through SetValues. 

XmNworkWindow
Specifies the widget ID of the viewing area.

Inherited Resources

ScrolledWindow inherits behavior and resources from the following superclasses.  For a complete description of each resource, refer to the man page for that superclass. 

Callback Information

ScrolledWindow defines no new callback structures.  The application must use the ScrollBar callbacks to be notified of user input. 

Translations

XmScrolledWindow includes the translations from XmManager. 

Additional Behavior

This widget has the additional behavior described below:

KPageUp:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window up the height of the viewport.  The distance scrolled my be reduced to provide some overlap.  The actual distance scrolled depends on the XmNpageIncrement resource of the vertical ScrollBar. 

KPageDown:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window down the height of the viewport.  The distance scrolled my be reduced to provide some overlap.  The actual distance scrolled depends on the XmNpageIncrement resource of the vertical ScrollBar. 

KPageLeft:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window left the width of the viewport.  The distance scrolled my be reduced to provide some overlap.  The actual distance scrolled depends on the XmNpageIncrement resource of the horizontal ScrollBar. 

KPageRight:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window right the width of the viewport.  The distance scrolled my be reduced to provide some overlap.  The actual distance scrolled depends on the XmNpageIncrement resource of the horizontal ScrollBar. 

KBeginLine:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window horizontally to the edge corresponding to the horizontal ScrollBar’s minimum value. 

KEndLine:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window horizontally to the edge corresponding to the horizontal ScrollBar’s maximum value. 

KBeginData:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window vertically to the edge corresponding to the vertical ScrollBar’s minimum value. 

KEndData:
If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window vertically to the edge corresponding to the vertical ScrollBar’s maximum value. 

Virtual Bindings

The bindings for virtual keys are vendor specific.  For information about bindings for virtual buttons and keys, see VirtualBindings(3X). 

RELATED INFORMATION

Composite(3X), Constraint(3X), Core(3X), XmCreateScrolledWindow(3X), XmManager(3X), and XmScrolledWindowSetAreas(3X).