Name

XmScrollBar(3X) — XmScrollBar--The ScrollBar widget class XmScrollBarwidget class

Synopsis

#include <Xm/ScrollBar.h>

DESCRIPTION

The ScrollBar widget allows the user to view data that is too large to be displayed all at once. ScrollBars are usually located inside a ScrolledWindow and adjacent to the widget that contains the data to be viewed. When the user interacts with the ScrollBar, the data within the other widget scrolls.

A ScrollBar consists of two arrows placed at each end of a rectangle. The rectangle is called the scroll region. A smaller rectangle, called the slider, is placed within the scroll region. The data is scrolled by clicking either arrow, selecting on the scroll region, or dragging the slider. When an arrow is selected, the slider within the scroll region is moved in the direction of the arrow by an amount supplied by the application. If the mouse button is held down, the slider continues to move at a constant rate.

The ratio of the slider size to the scroll region size typically corresponds to the relationship between the size of the visible data and the total size of the data. For example, if 10 percent of the data is visible, the slider typically occupies 10 percent of the scroll region. This provides the user with a visual clue to the size of the invisible data.

Classes

ScrollBar inherits behavior and resources from the Core and XmPrimitive classes.

The class pointer is xmScrollBarWidgetClass.

The class name is XmScrollBar.

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).

Name

Class

Type

Default

Access

XmNdecrementCallback

XmCCallback

XtCallbackList

NULL

C

XmNdragCallback

XmCCallback

XtCallbackList

NULL

C

XmNincrement

XmCIncrement

int

1

CSG

XmNincrementCallback

XmCCallback

XtCallbackList

NULL

C

XmNinitialDelay

XmCInitialDelay

int

250 ms

CSG

XmNmaximum

XmCMaximum

int

dynamic

CSG

XmNminimum

XmCMinimum

int

0

CSG

XmNorientation

XmCOrientation

unsigned char

XmVERTICAL

CSG

XmNpageDecrementCallback

XmCCallback

XtCallbackList

NULL

C

XmNpageIncrement

XmCPageIncrement

int

10

CSG

XmNpageIncrementCallback

XmCCallback

XtCallbackList

NULL

C

XmNprocessingDirection

XmCProcessingDirection

unsigned char

dynamic

CSG

XmNrepeatDelay

XmCRepeatDelay

int

50 ms

CSG

XmNshowArrows

XmCShowArrows

Boolean

True

CSG

XmNsliderSize

XmCSliderSize

int

dynamic

CSG

XmNtoBottomCallback

XmCCallback

XtCallbackList

NULL

C

XmNtoTopCallback

XmCCallback

XtCallbackList

NULL

C

XmNtroughColor

XmCTroughColor

Pixel

dynamic

CSG

XmNvalue

XmCValue

int

dynamic

CSG

XmNvalueChangedCallback

XmCCallback

XtCallbackList

NULL

C


XmNdecrementCallback 

Specifies the list of callbacks that is called when the user takes an action that moves the ScrollBar by one increment and the value decreases. The reason passed to the callback is XmCR_DECREMENT.

XmNdragCallback 

Specifies the list of callbacks that is called on each incremental change of position when the slider is being dragged. The reason sent by the callback is XmCR_DRAG.

XmNincrement 

Specifies the amount by which the value increases or decreases when the user takes an action that moves the slider by one increment. The actual change in value is the lesser of XmNincrement and (previous XmNvalue - XmNminimum) when the slider moves to the end of the ScrollBar with the minimum value, and the lesser ofXmNincrement and (XmNmaximum- XmNsliderSize - previous XmNvalue) when the slider moves to the end of the ScrollBar with the maximum value. The value of this resource must be greater than 0.

XmNincrementCallback 

Specifies the list of callbacks that is called when the user takes an action that moves the ScrollBar by one increment and the value increases. The reason passed to the callback is XmCR_INCREMENT.

XmNinitialDelay 

Specifies the amount of time in milliseconds to wait before starting continuous slider movement while a button is pressed in an arrow or the scroll region. The value of this resource must be greater than 0.

XmNmaximum 

Specifies the slider's maximum value. ScrollBars contained within ScrolledWindows have a maximum equal to the size of ScrollBar (that is, the height if it is vertical, or the width if it is horizontal). XmNmaximum must be greater than XmNminimum.

XmNminimum 

Specifies the slider's minimum value. XmNmaximum must be greater than XmNminimum.

XmNorientation 

Specifies whether the ScrollBar is displayed vertically or horizontally. This resource can have values of XmVERTICAL and XmHORIZONTAL.

XmNpageDecrementCallback 

Specifies the list of callbacks that is called when the user takes an action that moves the ScrollBar by one page increment and the value decreases. The reason passed to the callback is XmCR_PAGE_DECREMENT.

XmNpageIncrement 

Specifies the amount by which the value increases or decreases when the user takes an action that moves the slider by one page increment. The actual change in value is the lesser of XmNpageIncrement and (previous XmNvalue - XmNminimum) when the slider moves to the end of the ScrollBar with the minimum value, and the lesser of XmNpageIncrement and (XmNmaximum- XmNsliderSize - previous XmNvalue) when the slider moves to the end of the ScrollBar with the maximum value. The value of this resource must be greater than 0.

XmNpageIncrementCallback 

Specifies the list of callbacks that is called when the user takes an action that moves the ScrollBar by one page increment and the value increases. The reason passed to the callback is XmCR_PAGE_INCREMENT.

XmNprocessingDirection 

Specifies whether the value for XmNmaximum should be on the right or left side of XmNminimum for horizontal ScrollBars or above or below XmNminimum for vertical ScrollBars. This resource can have values of XmMAX_ON_TOP, XmMAX_ON_BOTTOM,XmMAX_ON_LEFT, and XmMAX_ON_RIGHT. If the XmScrollBar is oriented vertically, the default value is XmMAX_ON_BOTTOM. If the XmScrollBar is oriented horizontally, the default value may depend on the value of the XmNstringDirection resource.

XmNrepeatDelay 

Specifies the amount of time in milliseconds to wait between subsequent slider movements after the XmNinitialDelay has been processed. The value of this resource must be greater than 0.

XmNshowArrows 

Specifies whether the arrows are displayed.

XmNsliderSize 

Specifies the length of the slider between the values of 1 and (XmNmaximum - XmNminimum). The value is constrained to be within these inclusive bounds. The default value is (XmNmaximum - XmNminimum) divided by 10, with a minimum of 1.

XmNtoBottomCallback 

Specifies the list of callbacks that is called when the user takes an action that moves the slider to the end of the ScrollBar with the maximum value. The reason passed to the callback is XmCR_TO_BOTTOM.

XmNtoTopCallback 

Specifies the list of callbacks that is called when the user takes an action that moves the slider to the end of the ScrollBar with the minimum value. The reason passed to the callback is XmCR_TO_TOP.

XmNtroughColor 

Specifies the color of the slider trough.

XmNvalue 

Specifies the slider's position, between XmNminimum and (XmNmaximum - XmNsliderSize). The value is constrained to be within these inclusive bounds. The initial value of this resource is the larger of 0 and XmNminimum.

XmNvalueChangedCallback 

Specifies the list of callbacks that is called when the slider is released after being dragged. These callbacks are also called in place of XmNincrementCallback, XmNdecrementCallback, XmNpageIncrementCallback, XmNpageDecrementCallback, XmNtoTopCallback, or XmNtoBottomCallback when one of these callback lists would normally be called but the value of the corresponding resource is NULL. The reason passed to the callback is XmCR_VALUE_CHANGED.

Inherited Resources

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

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

XmNhighlightOnEnter

XmCHighlightOnEnter

Boolean

False

CSG

XmNhighlightPixmap

XmCHighlightPixmap

Pixmap

dynamic

CSG

XmNhighlightThickness

XmCHighlightThickness

Dimension

dynamic

CSG

XmNnavigationType

XmCNavigationType

XmNavigationType

XmSTICKY_TAB_GROUP

CSG

XmNshadowThickness

XmCShadowThickness

Dimension

2

CSG

XmNtopShadowColor

XmCTopShadowColor

Pixel

dynamic

CSG

XmNtopShadowPixmap

XmCTopShadowPixmap

Pixmap

dynamic

CSG

XmNtraversalOn

XmCTraversalOn

Boolean

dynamic

CSG

XmNunitType

XmCUnitType

unsigned char

dynamic

CSG

XmNuserData

XmCUserData

XtPointer

NULL

CSG


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


Callback Information

A pointer to the following structure is passed to each callback:

typedef struct 

{ 

   int   reason; 

   XEvent   * event; 

   int   value; 

   int   pixel; 

} XmScrollBarCallbackStruct; 

reason 

Indicates why the callback was invoked.

event 

Points to the XEvent that triggered the callback.

value 

Contains the new slider location value.

pixel 

Is used only for XmNtoTopCallback and XmNtoBottomCallback. For horizontal ScrollBars, it contains the x coordinate of where the mouse button selection occurred. For vertical ScrollBars, it contains the y coordinate.

Translations

XmScrollBar includes translations from Primitive. The XmScrollBar translations are listed below. These translations may not directly correspond to a translation table.

BSelect Press:

Select()

BSelect Release:

Release()

BSelect Press Moved:

Moved()

BDrag Press:

Select()

BDrag Release:

Release()

BDrag Press Moved:

Moved()

MCtrl BSelect Press:

TopOrBottom()

MCtrl BSelect Release:

Release()

KUp:

IncrementUpOrLeft(0)

MCtrl KUp:

PageUpOrLeft(0)

KDown:

IncrementDownOrRight(0)

MCtrl KDown:

PageDownOrRight(0)

KLeft:

IncrementUpOrLeft(1)

MCtrl KLeft:

PageUpOrLeft(1)

KRight:

IncrementDownOrRight(1)

MCtrl KRight:

PageDownOrRight(1)

KPageUp:

PageUpOrLeft(0)

KPageDown:

PageDownOrRight(0)

KPageLeft:

PageUpOrLeft(1)

KPageRight:

PageDownOrRight(1)

KBeginLine:

TopOrBottom()

KEndLine:

TopOrBottom()

KBeginData:

TopOrBottom()

KEndData:

TopOrBottom()

KNextField:

PrimitiveNextTabGroup()

KPrevField:

PrimitivePrevTabGroup()

KActivate:

PrimitiveParentActivate()

KCancel:

CancelDrag()

KHelp:

PrimitiveHelp()


Action Routines

The ScrollBar action routines are described below:

CancelDrag(): 

If the key press occurs during scrolling, cancels the scroll and returns the slider to its previous location in the scrollbar, otherwise, and if the parent is a manager, it passes the event to the parent.

IncrementDownOrRight(0|1): 

With an argument of 0, moves the slider down by one increment. With an argument of 1, moves the slider right by one increment. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement toward the right or bottom calls the callbacks for XmNincrementCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement toward the right or bottom calls the callbacks for XmNdecrementCallback. The XmNvalueChangedCallback is called if the XmNincrementCallback or XmNdecrementCallback is NULL.

IncrementUpOrLeft(0|1): 

With an argument of 0, moves the slider up by one increment. With an argument of 1, moves the slider left by one increment. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement to the left or top calls the callbacks for XmNdecrementCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement to the left or top calls the callbacks for XmNincrementCallback. The XmNvalueChangedCallback is called if the XmNincrementCallback or XmNdecrementCallback is NULL.

Moved(): 

If the button press occurs within the slider, the subsequent motion events move the slider to the position of the pointer and call the callbacks for XmNdragCallback.

PageDownOrRight(0|1): 

With an argument of 0, moves the slider down by one page increment. With an argument of 1, moves the slider right by one page increment. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement toward the right or bottom calls the callbacks for XmNpageIncrementCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement toward the right or bottom calls the callbacks for XmNpageDecrementCallback. The XmNvalueChangedCallback is called if the XmNpageIncrementCallback or XmNpageDecrementCallback is NULL.

PageUpOrLeft(0|1): 

With an argument of 0, moves the slider up by one page increment. With an argument of 1, moves the slider left by one page increment. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement to the left or top calls the callbacks for XmNpageDecrementCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement to the left or top calls the callbacks for XmNpageIncrementCallback. The XmNvalueChangedCallback is called if the XmNpageIncrementCallback or XmNpageDecrementCallback is NULL.

PrimitiveHelp(): 

Calls the callbacks for XmNhelpCallback if any exist. If there are no help callbacks for this widget, this action calls the help callbacks for the nearest ancestor that has them.

PrimitiveNextTabGroup(): 

Traverses to the first item in the next tab group. If the current tab group is the last entry in the tab group list, it wraps to the beginning of the tab group list.

PrimitiveParentActivate(): 

If the parent is a manager, passes the event to the parent.

PrimitivePrevTabGroup(): 

Traverses to the first item in the previous tab group. If the beginning of the tab group list is reached, it wraps to the end of the tab group list.

Release(): 

If the button press occurs within the slider and the slider position is changed, the callbacks for XmNvalueChangedCallback are called.

Select(): 

(in arrow): Moves the slider by one increment in the direction of the arrow. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement toward the right or bottom calls the callbacks for XmNincrementCallback, and movement to the left or top calls the callbacks for XmNdecrementCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement toward the right or bottom calls the callbacks for XmNdecrementCallback, and movement to the left or top calls the callbacks for XmNincrementCallback. The XmNvalueChangedCallback is called if the XmNincrementCallback or XmNdecrementCallback is NULL.

(in scroll region between an arrow and the slider): Moves the slider by one page increment in the direction of the arrow. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement toward the right or bottom calls the callbacks for XmNpageIncrementCallback, and movement to the left or top calls the callbacks for XmNpageDecrementCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement toward the right or bottom calls the callbacks for XmNpageDecrementCallback, and movement to the left or top calls the callbacks for XmNpageIncrementCallback. The XmNvalueChangedCallback is called if the XmNpageIncrementCallback or XmNpageDecrementCallback is NULL.

(in slider): Activates the interactive dragging of the slider.

If the button is held down in either the arrows or the scroll region longer than the XmNinitialDelay resource, the slider is moved again by the same increment and the same callbacks are called.

After the initial delay has been used, the time delay changes to the time defined by the resource XmNrepeatDelay.

TopOrBottom(): 

MCtrl BSelect Press in an arrow or in the scroll region between an arrow and the slider moves the slider as far as possible in the direction of the arrow. If XmNprocessingDirection is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement toward the right or bottom calls the callbacks for XmNtoBottomCallback, and movement to the left or top calls the callbacks for XmNtoTopCallback. If XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP, movement toward the right or bottom calls the callbacks for XmNtoTopCallback, and movement to the left or top calls the callbacks for XmNtoBottomCallback. The XmNvalueChangedCallback is called if the XmNtoTopCallback or XmNtoBottomCallback is NULL. Pressing KBeginLine or KBeginData moves the slider to the minimum value and invokes the XmNtoTopCallback. Pressing KEndLine or KEndData moves the slider to the maximum value and invokes the XmNtoBottomCallback.

Virtual Bindings

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

RELATED INFORMATION

Core(3X), XmCreateScrollBar(3X), XmPrimitive(3X), XmScrollBarGetValues(3X), and XmScrollBarSetValues(3X).