Tribblix: manual page: XmScrollBar.3

XmScrollBar(library call) XmScrollBar(library call)

NAME

XmScrollBar -- The ScrollBar widget 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.

If the ScrollBar parent is an automatic ScrolledWindow, the
XmNtraversalOn default is True. Otherwise, the default is False.

ScrollBar holds the XmQTnavigator traits.

Classes

ScrollBar inherits behavior, resources, and traits 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).

+------------------------------------------------------------------------------------------+
| XmScrollBar Resource Set |
|Name | Class | Type | Default | Access |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNdecrementCallback | XmCCallback | XtCallbackList | NULL | C |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNdragCallback | XmCCallback | XtCallbackList | NULL | C |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNeditable | XmCEditable | Boolean | True | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNincrement | XmCIncrement | int | 1 | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNincrementCallback | XmCCallback | XtCallbackList | NULL | C |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNinitialDelay | XmCInitialDelay | int | 250 ms | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNmaximum | XmCMaximum | int | 100 | 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 | XtEnum | XmEACH_SIDE | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNsliderSize | XmCSliderSize | int | dynamic | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNsliderMark | XmCSliderMark | XtEnum | dynamic | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNsliderVisual | XmCSliderVisual | XtEnum | XmSHADOWED | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNslidingMode | XmCSlidingMode | XtEnum | XmSLIDER | CSG |
+-------------------------+------------------------+----------------+-------------+--------+
|XmNsnapBackMultiple | XmCSnapBackMultiple | unsigned short | MaxValue | 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.

XmNeditable
Specifies how ScrollBar will react to user input. This
resource can be True or False values, as follows:

True Allows the scrollbar to be sensitive to user
input. This is the default value.

False Makes the Scale scrollbar insensitive to user
input. The visual is not greyed out. This value
would mostly be used in XmTHERMOMETER mode.

When XmNeditable is used on a widget it sets the dropsite
to XmDROP_SITE_ACTIVE.

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 of XmNincrement 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
(zero).

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 (zero).

XmNmaximum
Specifies the slider's maximum value. 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 (zero).

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 ScrollBar is
oriented vertically, the default value is XmMAX_ON_BOTTOM.
If the ScrollBar is oriented horizontally, the default
value depends on the XmNlayoutDirection resource of the
widget.

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 (zero).

XmNshowArrows
Specifies whether the arrows are displayed and how they are
to be displayed. This resource can take the following
values:

XmEACH_SIDE
Indicates that one arrow is displayed on each end
of the ScrollBar slider. This corresponds to a
value of True in previous releases.

XmMAX_SIDE
Indicates that both arrows are displayed on the
XmNmaximum side of the ScrollBar slider.

XmMIN_SIDE
Indicates that both arrows are displayed on the
XmNminimum side of the ScrollBar slider.

XmNONE Indicates that no arrows are displayed. This
corresponds to a value of False in previous
releases.

XmEACH_SIDE is the default value.

XmNsliderMark
Specifies the shape the slider is to be displayed in. This
resource can take the following values:

XmETCHED_LINE
Specifies the slider as an etched line.

XmNONE Specifies the slider as a foregrounded rectangle.
This is the default for a regular slider.

XmROUND_MARK
Specifies the slider as a shadowed circle. This
is the default when the slider is a thermometer.

XmTHUMB_MARK
Specifies the slider as a series of three etched
lines centered in the middle of the slider.

XmNslidingMode
Specifies the mode the slider works in. There are two
possible modes:

XmSLIDER Allows the slider to move freely between the
minimum and maximum ends of the scale. This is
the default value.

XmTHERMOMETER
Forces the slider to be anchored to one side of
the trough area.

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.

XmNsliderVisual
Specifies the color of the slider visual. This resource can
take the following values:

XmBACKGROUND_COLOR
Specifies that the slider visual is in the
background color.

XmFOREGROUND_COLOR
Specifies that the slider visual is in the
foreground color.

XmSHADOWED_BACKGROUND
Specifies that the slider visual is in the
background color, with a shadow. This is the
default for a regular slider.

XmTROUGH_COLOR
Specifies that the slider visual is in the trough
color. This is the default when the slider is a
thermometer.

XmNsnapBackMultiple
Specifies the distance over which the scrollbar slider
snaps back to its original position when the user drags the
mouse outside the ScrollBar edge. This distance is defined
in terms of multiples of the width of the slider. For
example, a multiple of 0 (zero) causes the slider to snap
back as soon as the pointer moves out of the ScrollBar
frame, a multiple of 1 causes the slider to snap back as
soon as the pointer moves beyond 1 ScrollBar width of the
ScrollBar edge. Whenever the slider snaps back, the
ScrollBar dragCallback is called if there is one.

The default value is large enough to prevent unwanted
snapBack activity if the mouse is moved within the
boundaries of any reasonable screen. To reset the default,
set this resource to a large value, such as 10000.

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. This color
defaults to the color used for selections.

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 (zero) 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

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 described in the following list.

The following key names are listed in the X standard key event
translation table syntax. This format is the one used by Motif to
specify the widget actions corresponding to a given key. A brief
overview of the format is provided under VirtualBindings(3). For a
complete description of the format, please refer to the X Toolkit
Instrinsics Documentation.

~s ~c ~m ~a <Btn1Down>:
Select()

~s ~c ~m ~a <Btn1Up>:
Release()

~s ~c ~m ~a Button1<PtrMoved>:
Moved()

~s ~c ~m ~a <Btn2Down>:
Select()

~s ~c ~m ~a <Btn2Up>:
Release()

~s ~c ~m ~a Button2<PtrMoved>:
Moved()

~s c ~m ~a <Btn1Down>:
TopOrBottom()

~s c ~m ~a <Btn1Up>:
Release()

:<Key><osfActivate>:
PrimitiveParentActivate()

:<Key><osfCancel>:
CancelDrag()

:<Key><osfBeginLine>:
TopOrBottom()

:<Key><osfEndLine>:
TopOrBottom()

:<Key><osfPageLeft>:
PageUpOrLeft(Left)

:c <Key><osfPageUp>:
PageUpOrLeft(Left)

:<Key><osfPageUp>:
PageUpOrLeft(Up)

:<Key><osfPageRight>:
PageDownOrRight(Right)

:c <Key><osfPageDown>:
PageDownOrRight(Right)

:<Key><osfPageDown>:
PageDownOrRight(Down)

:<Key><osfHelp>:
PrimitiveHelp()

:c <Key><osfUp>:
PageUpOrLeft(Up)

:<Key><osfUp>:
IncrementUpOrLeft(Up)

:c <Key><osfDown>:
PageDownOrRight(Down)

:<Key><osfDown>:
IncrementDownOrRight(Down)

:c <Key><osfLeft>:
PageUpOrLeft(Left)

:<Key><osfLeft>:
IncrementUpOrLeft(Left)

:c <Key><osfRight>:
PageDownOrRight(Right)

:<Key><osfRight>:
IncrementDownOrRight(Right)

~s ~m ~a <Key>Return:
PrimitiveParentActivate()

s ~m ~a <Key>Tab:
PrimitivePrevTabGroup()

~m ~a <Key>Tab:
PrimitiveNextTabGroup()

Action Routines

The ScrollBar action routines are

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(Down|Right):
With an argument of Down, or 0 (zero) for compatibility,
moves the slider down by one increment. With an argument
of Right, or 1 for compatibility, it 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(Up|Left):
With an argument of Up, or 0 (zero) for compatibility,
moves the slider up by one increment. With an argument of
Left, or 1 for compatibility, it 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(Down|Right):
With an argument of Down, or 0 (zero) for compatibility,
moves the slider down by one page increment. With an
argument of Right, or 1 for compatibility, 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 XmNpageDecrementCallback callbacks. The
XmNvalueChangedCallback is called if the
XmNpageIncrementCallback or XmNpageDecrementCallback is
NULL.

PageUpOrLeft(Up|Left):
With an argument of Up, or 0 (zero) for compatibility,
moves the slider up by one page increment. With an
argument of Left, or 1 for compatibility, it 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
XmNpageIncrementCallback callbacks. 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():
<Ctrl><Btn1Down> 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
<Key><osfBeginLine> or <Key><osfBeginData> moves the slider
to the minimum value and invokes the XmNtoTopCallback.
Pressing <Key><osfEndLine> or <Key><osfEndData> 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(3).

Core(3), XmCreateScrollBar(3), XmPrimitive(3),
XmScrollBarGetValues(3), XmScrollBarSetValues(3),
XmVaCreateScrollBar(3), and XmVaCreateManagedScrollBar(3).

XmScrollBar(library call)