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 displays 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 and automatically creates the scroll bars. 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 scrolls the viewport so it can 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.
The user can specify resources in a resource file for the
automatically created widgets that contain the horizontal and vertical
scrollbars and the clipping area of the ScrolledWindow widget. The names of
these widgets are HorScrollBar, VertScrollBar, and
ClipWindow respectively, and remain consistent whether created by
XmCreateScrolledList, XmCreateScrolledText or
XmCreateScrolledWindow.
ScrolledWindow uses the XmQTnavigator trait, and holds the
XmQTscrollFrame trait.
ScrolledWindow automatically creates the descendants shown in the
following table. An application can use XtNameToWidget to gain access
to the named descendant. In addition, a user or an application can use the
named descendant when specifying resource values.
Named Descendant |
Class |
Identity |
|
|
|
|
|
|
VertScrollBar |
XmScrollBar |
vertical scroll bar |
|
|
|
HorScrollBar |
XmScrollBar |
horizontal scroll bar |
|
|
|
ClipWindow |
XmClipWindow |
clip window |
|
|
|
ScrolledWindow inherits behavior, resources, and traits from
Core, Composite, Constraint, and XmManager.
The class pointer is xmScrolledWindowWidgetClass.
The class name is XmScrolledWindow.
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).
XmScrolledWindow Resource
Set |
Name |
Class |
Type |
Default |
Access |
|
|
|
|
|
XmNautoDragModel |
XmCAutoDragModel |
XtEnum |
XmAUTO_DRAG_ENABLED |
CSG |
|
|
|
|
|
XmNclipWindow |
XmCClipWindow |
Widget |
dynamic |
G |
|
|
|
|
|
XmNhorizontalScrollBar |
XmCHorizontalScrollBar |
Widget |
dynamic |
CSG |
|
|
|
|
|
XmNscrollBarDisplayPolicy |
XmCScrollBarDisplayPolicy |
unsigned char |
dynamic |
CSG |
|
|
|
|
|
XmNscrollBarPlacement |
XmCScrollBarPlacement |
unsigned char |
XmBOTTOM_RIGHT |
CSG |
|
|
|
|
|
XmNscrolledWindowMarginHeight |
XmCScrolledWindowMarginHeight |
Dimension |
0 |
CSG |
|
|
|
|
|
XmNscrolledWindowMarginWidth |
XmCScrolledWindowMarginWidth |
Dimension |
0 |
CSG |
|
|
|
|
|
XmNscrollingPolicy |
XmCScrollingPolicy |
unsigned char |
XmAPPLICATION_DEFINED |
CG |
|
|
|
|
|
XmNspacing |
XmCSpacing |
Dimension |
4 |
CSG |
|
|
|
|
|
XmNtraverseObscuredCallback |
XmCCallback |
XtCallbackList |
NULL |
CSG |
|
|
|
|
|
XmNverticalScrollBar |
XmCVerticalScrollBar |
Widget |
dynamic |
CSG |
|
|
|
|
|
XmNvisualPolicy |
XmCVisualPolicy |
unsigned char |
dynamic |
G |
|
|
|
|
|
XmNworkWindow |
XmCWorkWindow |
Widget |
NULL |
CSG |
|
|
|
|
|
- XmNautoDragModel
- Indicates whether automatic drag is enabled (XmAUTO_DRAG_ENABLED or
disabled (XmAUTO_DRAG_DISABLED). By default it is enabled.
- 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 only be read 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. This is automatically
created by ScrolledWindow when the XmNscrollingPolicy is
initialized to XmAUTOMATIC; otherwise, the default is NULL.
- 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 XmAUTOMATIC,
and XmSTATIC otherwise.
- XmNscrollBarPlacement
- Specifies the positioning of the ScrollBars in relation to the work
window. The values are
- XmTOP_LEFT
- The horizontal ScrollBar is placed above the work window; the vertical
ScrollBar to is placed the left.
- XmBOTTOM_LEFT
- The horizontal ScrollBar is placed below the work window; the vertical
ScrollBar to is placed the left.
- XmTOP_RIGHT
- The horizontal ScrollBar is placed above the work window; the vertical
ScrollBar to is placed the right.
- XmBOTTOM_RIGHT
- The horizontal ScrollBar is placed below the work window; the vertical
ScrollBar to is placed the right.
-
- The default value depends on the value of the XmNlayoutDirection
resource of the widget.
- XmNscrolledWindowMarginHeight
- Specifies the margin height on the top and bottom of the ScrolledWindow.
In order to use the autoscroll drag feature of the Motif drag and drop
facility, a user must be able to hold a drag icon over the margin of a
scrolled window. Though drag and drop will work with the default margin
size of zero, a user may find it difficult to position the icon precisely
enough to use the feature easily. The application programmer should ensure
that the window margins are set to an adequate size, if the use of the
autoscroll drag feature is desired.
- XmNscrolledWindowMarginWidth
- Specifies the margin width on the right and left sides of the
ScrolledWindow. Please refer to the warning concerning the default margin
size for the XmNscrolledWindowMarginHeight resource, above.
- 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.
- XmNtraverseObscuredCallback
- Specifies a list of callbacks that is called when traversing to a widget
or gadget that is obscured due to its position in the work area relative
to the location of the ScrolledWindow viewport. This resource is valid
only when XmNscrollingPolicy is XmAUTOMATIC. If this
resource is NULL, an obscured widget cannot be traversed to. The callback
reason is XmCR_OBSCURED_TRAVERSAL.
- XmNverticalScrollBar
- Specifies the widget ID of the vertical ScrollBar. This is automatically
created by ScrolledWindow when the XmNscrollingPolicy is
initialized to XmAUTOMATIC; otherwise, the default is NULL.
- XmNvisualPolicy
- Enlarges the ScrolledWindow to match the size of the work area. It can
also 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 allows 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.
XmScrolledWindow
Constraint Resource Set |
Name |
Class |
Type |
Default |
Access |
|
|
|
|
|
XmNscrolledWindowChildType |
XmCScrolledWindowChildType |
unsigned char |
RESOURCE_DEFAULT |
CSG |
|
|
|
|
|
- XmNscrolledWindowChildType
- Specifies what the child is. ScrolledWindow supports a number of child
types. The possible values are:
- XmWORK_AREA
- Indicates a work area child. This specifies that both ScrollBars are
limited to moving the child inside the clipping window. If the scrolling
policy is XmAUTOMATIC, the work area child can move in both
directions.
- XmHOR_SCROLLBAR
- Indicates a horizontal child widget; the child must have the
XmQTnavigator trait installed. For example, the XmScrollBar
widget has the XmQTnavigator trait installed.
- XmVERT_SCROLLBAR
- Indicates a vertical child widget; the child must have the
XmQTnavigator trait installed.
- XmSCROLL_HOR
- Indicates that only the horizontal ScrollBar moves the child. This value
is only meaningful if the scrolling policy is XmAUTOMATIC.
- XmSCROLL_VERT
- Indicates that only the vertical ScrollBar moves the child. This value is
only meaningful if the scrolling policy is XmAUTOMATIC.
- XmNO_SCROLL
- Indicates that the child does not move with the ScrollBars. This value is
only meaningful if the scrolling policy is XmAUTOMATIC.
ScrolledWindow inherits behavior and resources from the
superclasses described in the following tables. For a complete description
of each resource, refer to the reference page for that superclass.
XmManager Resource
Set |
Name |
Class |
Type |
Default |
Access |
|
|
|
|
|
XmNbottomShadowColor |
XmCBottomShadowColor |
Pixel |
dynamic |
CSG |
|
|
|
|
|
XmNbottomShadowPixmap |
XmCBottomShadowPixmap |
Pixmap |
XmUNSPECIFIED_PIXMAP |
CSG |
|
|
|
|
|
XmNforeground |
XmCForeground |
Pixel |
dynamic |
CSG |
|
|
|
|
|
XmNhelpCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
|
|
|
|
|
XmNhighlightColor |
XmCHighlightColor |
Pixel |
dynamic |
CSG |
|
|
|
|
|
XmNhighlightPixmap |
XmCHighlightPixmap |
Pixmap |
dynamic |
CSG |
|
|
|
|
|
XmNinitialFocus |
XmCInitialFocus |
Widget |
NULL |
CSG |
|
|
|
|
|
XmNlayoutDirection |
XmCLayoutDirection |
XmDirection |
dynamic |
CG |
|
|
|
|
|
XmNnavigationType |
XmCNavigationType |
XmNavigationType |
XmTAB_GROUP |
CSG |
|
|
|
|
|
XmNpopupHandlerCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
|
|
|
|
|
XmNshadowThickness |
XmCShadowThickness |
Dimension |
dynamic |
CSG |
|
|
|
|
|
XmNstringDirection |
XmCStringDirection |
XmStringDirection |
dynamic |
CG |
|
|
|
|
|
XmNtopShadowColor |
XmCTopShadowColor |
Pixel |
dynamic |
CSG |
|
|
|
|
|
XmNtopShadowPixmap |
XmCTopShadowPixmap |
Pixmap |
dynamic |
CSG |
|
|
|
|
|
XmNtraversalOn |
XmCTraversalOn |
Boolean |
True |
CSG |
|
|
|
|
|
XmNunitType |
XmCUnitType |
unsigned char |
dynamic |
CSG |
|
|
|
|
|
XmNuserData |
XmCUserData |
XtPointer |
NULL |
CSG |
|
|
|
|
|
Composite Resource
Set |
Name |
Class |
Type |
Default |
Access |
|
|
|
|
|
XmNchildren |
XmCReadOnly |
WidgetList |
NULL |
G |
|
|
|
|
|
XmNinsertPosition |
XmCInsertPosition |
XtOrderProc |
NULL |
CSG |
|
|
|
|
|
XmNnumChildren |
XmCReadOnly |
Cardinal |
0 |
G |
|
|
|
|
|
Core Resource Set |
Name |
Class |
Type |
Default |
Access |
|
|
|
|
|
XmNaccelerators |
XmCAccelerators |
XtAccelerators |
dynamic |
CSG |
|
|
|
|
|
XmNancestorSensitive |
XmCSensitive |
Boolean |
dynamic |
G |
|
|
|
|
|
XmNbackground |
XmCBackground |
Pixel |
dynamic |
CSG |
|
|
|
|
|
XmNbackgroundPixmap |
XmCPixmap |
Pixmap |
XmUNSPECIFIED_PIXMAP |
CSG |
|
|
|
|
|
XmNborderColor |
XmCBorderColor |
Pixel |
XtDefaultForeground |
CSG |
|
|
|
|
|
XmNborderPixmap |
XmCPixmap |
Pixmap |
XmUNSPECIFIED_PIXMAP |
CSG |
|
|
|
|
|
XmNborderWidth |
XmCBorderWidth |
Dimension |
0 |
CSG |
|
|
|
|
|
XmNcolormap |
XmCColormap |
Colormap |
dynamic |
CG |
|
|
|
|
|
XmNdepth |
XmCDepth |
int |
dynamic |
CG |
|
|
|
|
|
XmNdestroyCallback |
XmCCallback |
XtCallbackList |
NULL |
C |
|
|
|
|
|
XmNheight |
XmCHeight |
Dimension |
dynamic |
CSG |
|
|
|
|
|
XmNinitialResourcesPersistent |
XmCInitialResourcesPersistent |
Boolean |
True |
C |
|
|
|
|
|
XmNmappedWhenManaged |
XmCMappedWhenManaged |
Boolean |
True |
CSG |
|
|
|
|
|
XmNscreen |
XmCScreen |
Screen * |
dynamic |
CG |
|
|
|
|
|
XmNsensitive |
XmCSensitive |
Boolean |
True |
CSG |
|
|
|
|
|
XmNtranslations |
XmCTranslations |
XtTranslations |
dynamic |
CSG |
|
|
|
|
|
XmNwidth |
XmCWidth |
Dimension |
dynamic |
CSG |
|
|
|
|
|
XmNx |
XmCPosition |
Position |
0 |
CSG |
|
|
|
|
|
XmNy |
XmCPosition |
Position |
0 |
CSG |
|
|
|
|
|
The application must use the ScrollBar callbacks to be notified of
user input.
ScrolledWindow defines a callback structure for use with
XmNtraverseObscuredCallback callbacks. The
XmNtraverseObscuredCallback resource provides a mechanism for
traversal to obscured widgets (or gadgets) due to their position in the work
area of a ScrolledWindow. The XmNtraverseObscuredCallback routine has
responsibility for adjusting the position of the work area such that the
specified traversal destination widget is positioned within the viewport of
the ScrolledWindow. A NULL XmNtraverseObscuredCallback resource
causes obscured widgets within the ScrolledWindow to be nontraversable.
Traversal to an obscured widget or gadget requires these
conditions to be met: the widget or gadget can be obscured only due to its
position in the work area of a ScrolledWindow relative to the viewport; the
viewport of the associated ScrolledWindow is fully visible, or can be made
so by virtue of ancestral XmNtraverseObscuredCallback routines; and
the XmNtraverseObscuredCallback resource must be non-NULL.
When ScrolledWindow widgets are nested, the
XmNtraverseObscuredCallback routine for each ScrolledWindow that
obscures the traversal destination is called in ascending order within the
given hierarchy.
A pointer to the following structure is passed to callbacks for
XmNtraverseObscuredCallback.
typedef struct
{
int reason;
XEvent *event:
Widget traversal_destination;
XmTraversalDirection direction;
} XmTraverseObscuredCallbackStruct;
- reason
- Indicates why the callback was invoked.
- event
- Points to the XEvent that triggered the callback.
- traversal_destination
- Specifies the widget or gadget to traverse to, which will be a descendant
of the work window.
- direction
- Specifies the direction of traversal. See the description of the
direction parameter in the XmProcessTraversal reference page
for an explanation of the valid values.
XmScrolledWindow includes the translations from
XmManager.
This widget has the following additional behavior:
- <Key><osfPageUp>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window up
the height of the viewport. The distance scrolled may be reduced to
provide some overlap. The actual distance scrolled depends on the
XmNpageIncrement resource of the vertical ScrollBar.
- <Key><osfPageDown>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
down the height of the viewport. The distance scrolled may be reduced to
provide some overlap. The actual distance scrolled depends on the
XmNpageIncrement resource of the vertical ScrollBar.
- <Key><osfPageLeft>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
left the width of the viewport. The distance scrolled may be reduced to
provide some overlap. The actual distance scrolled depends on the
XmNpageIncrement resource of the horizontal ScrollBar.
- <Key><osfPageRight>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
right the width of the viewport. The distance scrolled may be reduced to
provide some overlap. The actual distance scrolled depends on the
XmNpageIncrement resource of the horizontal ScrollBar.
- <Key><osfBeginLine>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
horizontally to the edge corresponding to the horizontal ScrollBar's
minimum value.
- <Key><osfEndLine>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
horizontally to the edge corresponding to the horizontal ScrollBar's
maximum value.
- <Key><osfBeginData>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
vertically to the edge corresponding to the vertical ScrollBar's minimum
value.
- <Key><osfEndData>:
- If XmNscrollingPolicy is XmAUTOMATIC, scrolls the window
vertically to the edge corresponding to the vertical ScrollBar's maximum
value.
Certain applications will want to replace the page bindings with
ones that are specific to the content of the scrolled area.
The bindings for virtual keys are vendor specific. For information
about bindings for virtual buttons and keys, see
VirtualBindings(3).