NAME
XmScale — The Scale widget class
SYNOPSIS
#include <Xm/Scale.h>
DESCRIPTION
Scale is used by an application to indicate a value from within a range
of values, and it allows the user to input or modify a value from the
same range.
A Scale has an elongated rectangular region similar to a ScrollBar. A
slider inside this region indicates the current value along the Scale.
The user can also modify the Scale’s value by moving the slider within
the rectangular region of the Scale. A Scale can also include a label
set located outside the Scale region. These can indicate the relative
value at various positions along the scale. The placement of this
label depends on the XmNlayoutDirection resource of the widget.
A Scale can be either input/output or output only. An input/output
Scale’s value can be set by the application and also modified by the
user with the slider. An output-only Scale is used strictly as an
indicator of the current value of something and cannot be modified
interactively by the user. The XmScale resource XmNeditable specifies
whether the user can interactively modify the Scale’s value.
The user can specify resources in a resource file for the automatically
created gadget that contains the title of the Scale widget. The name of
the gadget is Title. The placement of the title depends on the
XmNlayoutDirection resource of the widget. The direction of the title
is based on the widget’s layout direction.
Scale uses the XmQTspecifyRenderTable trait, and holds the XmQTtransfer
trait.
Data Transfer Behavior
Scale supports dragging of the representation of the Scale value from
the Scale when the value is displayed and when the value of the
XmNenableUnselectableDrag resource of XmDisplay is set to True.
As a source of data, Scale supports the following targets and
associated conversions of data to these targets:
COMPOUND_TEXT
The widget transfers a string representation of XmNvalue as
type COMPOUND_TEXT.
STRING The widget transfers a string representation of XmNvalue as
type STRING.
_MOTIF_CLIPBOARD_TARGETS
The widget transfers, as type ATOM, a list of the targets it
supports for the CLIPBOARD selection. These include STRING
and COMPOUND_TEXT.
_MOTIF_EXPORT_TARGETS
The widget transfers, as type ATOM, a list of the targets to
be used as the value of the DragContext’s XmNexportTargets in
a drag-and-drop transfer. These include STRING and
COMPOUND_TEXT.
As a source of data, Scale also supports the following standard Motif
targets:
BACKGROUND
The widget transfers XmNbackground as type PIXEL.
CLASS The widget finds the first shell in the widget hierarchy that
has a WM_CLASS property and transfers the contents as text in
the current locale.
CLIENT_WINDOW
The widget finds the first shell in the widget hierarchy and
transfers its window as type WINDOW.
COLORMAP The widget transfers XmNcolormap as type COLORMAP.
FOREGROUND
The widget transfers XmNforeground as type PIXEL.
NAME The widget finds the first shell in the widget hierarchy that
has a WM_NAME property and transfers the contents as text in
the current locale.
TARGETS The widget transfers, as type ATOM, a list of the targets it
supports. These include the standard targets in this list.
These also include STRING and COMPOUND_TEXT.
TIMESTAMP The widget transfers the timestamp used to acquire the
selection as type INTEGER.
_MOTIF_RENDER_TABLE
The widget transfers XmNrenderTable if it exists, or else the
default text render table, as type STRING.
_MOTIF_ENCODING_REGISTRY
The widget transfers its encoding registry as type STRING.
The value is a list of NULL separated items in the form of
tag encoding pairs. This target symbolizes the transfer
target for the Motif Segment Encoding Registry. Widgets and
applications can use this Registry to register text encoding
formats for specified render table tags. Applications access
this Registry by calling XmRegisterSegmentEncoding and
XmMapSegmentEncoding.
Descendants
Scale 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 |
+-----------------+---------------+----------------+
+-----------------+---------------+----------------+
+-----------------+---------------+----------------+
|Scrollbar | XmScrollBar | scroll bar |
+-----------------+---------------+----------------+
|Title | XmLabelGadget | title of scale |
+-----------------+---------------+----------------+
+-----------------+---------------+----------------+
Classes
Scale inherits behavior, resources, and traits from Core, Composite,
Constraint, and XmManager classes.
The class pointer is xmScaleWidgetClass.
The class name is XmScale.
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).
+----------------------------------------------------------------------------------------+
| | XmScale Resource|Set | | |
|Name | Class | Type | Default | Access |
+------------------------+------------------------+----------------+------------+--------+
|XmNconvertCallback | XmCCallback | XtCallbackList | NULL | C |
+------------------------+------------------------+----------------+------------+--------+
|XmNdecimalPoints | XmCDecimalPoints | short | 0 | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNdragCallback | XmCCallback | XtCallbackList | NULL | C |
+------------------------+------------------------+----------------+------------+--------+
|XmNeditable | XmCEditable | Boolean | True | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNfontList | XmCFontList | XmFontList | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNhighlightOnEnter | XmCHighlightOnEnter | Boolean | False | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNhighlightThickness | XmCHighlightThickness | Dimension | 2 | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNmaximum | XmCMaximum | int | 100 | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNminimum | XmCMinimum | int | 0 | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNorientation | XmCOrientation | unsigned char | XmVERTICAL | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNprocessingDirection | XmCProcessingDirection | unsigned char | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNscaleHeight | XmCScaleHeight | Dimension | 0 | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNscaleMultiple | XmCScaleMultiple | int | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNscaleWidth | XmCScaleWidth | Dimension | 0 | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNrenderTable | XmCRenderTable | XmRenderTable | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNshowArrows | XmCShowArrows | XtEnum | XmNONE | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNshowValue | XmCShowValue | XtEnum | XmNONE | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNsliderMark | XmCSliderMark | XtEnum | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNsliderVisual | XmCSliderVisual | XtEnum | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNslidingMode | XmCSlidingMode | XtEnum | XmSLIDER | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNtitleString | XmCTitleString | XmString | NULL | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNvalue | XmCValue | int | dynamic | CSG |
+------------------------+------------------------+----------------+------------+--------+
|XmNvalueChangedCallback | XmCCallback | XtCallbackList | NULL | C |
+------------------------+------------------------+----------------+------------+--------+
+------------------------+------------------------+----------------+------------+--------+
XmNconvertCallback
Specifies a list of callbacks called when the Scale is asked
to convert a selection. The type of the structure whose
address is passed to these callbacks is
XmConvertCallbackStruct. The reason is XmCR_OK.
XmNdecimalPoints
Specifies the number of decimal points to shift the slider
value when displaying it. For example, a slider value of
2,350 and an XmdecimalPoints value of 2 results in a display
value of 23.50. The value must not be negative.
XmNdragCallback
Specifies the list of callbacks that is called when the
slider position changes as the slider is being dragged. The
reason sent by the callback is XmCR_DRAG.
XmNeditable
Specifies how the Scale 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.
XmNfontList
Specifies the font list to use for the title text string
specified by XmNtitleString, and the label displayed when
XmNshowValue is True. The font list is an obsolete structure,
and is retained only for compatibility with earlier releases
of Motif. See the XmNrenderTable resource.
XmNhighlightOnEnter
Specifies whether the highlighting rectangle is drawn when
the cursor moves into the widget. If the shell’s focus
policy is XmEXPLICIT, this resource is ignored, and the
widget is highlighted when it has the focus. If the shell’s
focus policy is XmPOINTER and if this resource is True, the
highlighting rectangle is drawn when the the cursor moves
into the widget. If the shell’s focus policy is XmPOINTER
and if this resource is False, the highlighting rectangle is
not drawn when the the cursor moves into the widget. The
default is False.
XmNhighlightThickness
Specifies the size of the slider’s border drawing rectangle
used for enter window and traversal highlight drawing.
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
Displays Scale vertically or horizontally. This resource can
have values of XmVERTICAL and XmHORIZONTAL.
XmNprocessingDirection
Specifies whether the value for XmNmaximum is on the right or
left side of XmNminimum for horizontal Scales or above or
below XmNminimum for vertical Scales. This resource can have
values of XmMAX_ON_TOP, XmMAX_ON_BOTTOM, XmMAX_ON_LEFT, and
XmMAX_ON_RIGHT. If the Scale is oriented vertically, the
default value is XmMAX_ON_TOP. If the XmScale is oriented
horizontally, the default value depends on the
XmNlayoutDirection resource of the widget.
XmNrenderTable
Specifies the render table to use for the title text string
specified by XmNtitleString, and the label displayed when
XmNshowValue is True. If this value is NULL at
initialization, the parent hierarchy is searched for an
ancestor that holds the XmQTspecifyRenderTable trait. If such
an ancestor is found, the render table is initialized to the
XmLABEL_RENDER_TABLE value of the ancestor widget. If no such
ancestor is found, the default is implementation dependent.
If a font list (XmNfontList) and a render table are both
specified, the render table will take precedence. Refer to
XmRenderTable(3) for more information on the creation and
structure of a render table.
XmNscaleHeight
Specifies the height of the slider area. The value should be
in the specified unit type (the default is pixels). If no
value is specified a default height is computed.
XmNscaleMultiple
Specifies the amount to move the slider when the user takes
an action that moves the slider by a multiple increment. The
default is (XmNmaximum - XmNminimum) divided by 10, with a
minimum of 1.
XmNscaleWidth
Specifies the width of the slider area. The value should be
in the specified unit type (the default is pixels). If no
value is specified a default width is computed.
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.
XmMAX_SIDE
Indicates that one arrow is displayed on the
XmNmaximum side of the ScrollBar slider.
XmMIN_SIDE
Indicates that one arrow is displayed on the
XmNminimum side of the ScrollBar slider.
XmNONE Indicates that no arrows are displayed.
XmNONE is the default value.
XmNshowValue
Specifies whether a label for the current slider value should
be displayed next to the slider. If the value is
XmNEAR_SLIDER, the current slider value is displayed. If the
value is XmNONE, no slider value is displayed. If the value
is XmNEAR_BORDER, the current slider value is displayed near
the border.
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. This is the
default when XmNslidingMode is XmSLIDER.
XmNONE Specifies the slider as a foregrounded rectangle.
This is the default when XmNslidingMode is
XmTHERMOMETER and the Scale scrollbar is
insensitive to user input (XmNeditable is False.
XmROUND_MARK
Specifies the slider as a shadowed circle. This is
the default when XmNslidingMode is XmTHERMOMETER
and the Scale scrollbar is sensitive to user input
(XmNeditable is True.
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.
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 when the XmNslidingModel resource is
XmSLIDER.
XmTROUGH_COLOR
Specifies that the slider visual is in the trough
color. This is the default when the XmNslidingModel
resource is XmTHERMOMETER.
XmNtitleString
Specifies the title text string to appear in the Scale widget
window.
XmNvalue Specifies the slider’s current position along the scale,
between XmNminimum and XmNmaximum. 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 value
of the slider has changed. The reason sent by the callback is
XmCR_VALUE_CHANGED.
Inherited Resources
Scale 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 | 2 | 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 |
+------------------------------+-------------------------------+----------------+----------------------+--------+
+------------------------------+-------------------------------+----------------+----------------------+--------+
Callback Information
A pointer to the following structure is passed to the XmNdragCallback
and XmNvalueChangedCallback procedures:
typedef struct
{
int reason;
XEvent * event;
int value;
} XmScaleCallbackStruct;
reason Indicates why the callback was invoked
event Points to the XEvent that triggered the callback
value Is the new slider value
A pointer to the following structure is passed to the
XmNconvertCallback procedures:
typedef struct
{
int reason;
XEvent *event;
Atom selection;
Atom target;
XtPointer source_data;
XtPointer location_data;
int flags;
XtPointer parm;
int parm_format;
unsigned long parm_length;
int status;
XtPointer value;
Atom type;
int format;
unsigned long length;
} XmConvertCallbackStruct;
reason Indicates why the callback was invoked.
event Points to the XEvent that triggered the callback. It can be
NULL.
selection Indicates the selection for which conversion is being
requested. Possible values are CLIPBOARD, PRIMARY,
SECONDARY, and _MOTIF_DROP.
target Indicates the conversion target.
source_data
Contains information about the selection source. When the
selection is _MOTIF_DROP, source_data is the DragContext.
Otherwise, it is NULL.
location_data
Contains information about the location of data to be
converted. If the value is NULL, the data to be transferred
consists of the widget’s current selection.
flags Indicates the status of the conversion. Following are the
possible values:
XmCONVERTING_NONE
This flag is currently unused.
XmCONVERTING_PARTIAL
The target widget was able to be converted, but
some data was lost.
XmCONVERTING_SAME
The conversion target is the source of the data to
be transferred.
XmCONVERTING_TRANSACT
This flag is currently unused.
parm Contains parameter data for this target. If no parameter
data exists, the value is NULL.
When selection is CLIPBOARD and target is
_MOTIF_CLIPBOARD_TARGETS or
_MOTIF_DEFERRED_CLIPBOARD_TARGETS, the value is the requested
operation (XmCOPY, XmMOVE, or XmLINK).
parm_format
Specifies whether the data in parm should be viewed as a list
of char, short, or long quantities. Possible values are 0
(when parm is NULL), 8 (when the data in parm should be
viewed as a list of chars), 16 (when the data in parm should
be viewed as a list of shorts), or 32 (when the data in parm
should be viewed as a list of longs). Note that parm_format
symbolizes a data type, not the number of bits in each list
element. For example, on some machines, a parm_format of 32
means that the data in parm should be viewed as a list of
64-bit quantities, not 32-bit quantities.
parm_length
Specifies the number of elements of data in parm, where each
element has the size specified by parm_format. When parm is
NULL, the value is 0.
status An IN/OUT member that specifies the status of the conversion.
The initial value is XmCONVERT_DEFAULT. The callback
procedure can set this member to one of the following values:
XmCONVERT_DEFAULT
This value means that the widget class conversion
procedure, if any, is called after the callback
procedures return. If the widget class conversion
procedure produces any data, it overwrites the data
provided by the callback procedures in the value
member.
XmCONVERT_MERGE
This value means that the widget class conversion
procedure, if any, is called after the callback
procedures return. If the widget class conversion
procedure produces any data, it appends its data to
the data provided by the callback procedures in the
value member. This value is intended for use with
targets that result in lists of data, such as
TARGETS.
XmCONVERT_DONE
This value means that the callback procedure has
successfully finished the conversion. The widget
class conversion procedure, if any, is not called
after the callback procedures return.
XmCONVERT_REFUSE
This value means that the callback procedure has
terminated the conversion process without
completing the requested conversion. The widget
class conversion procedure, if any, is not called
after the callback procedures return.
value An IN/OUT parameter that contains any data that the callback
procedure produces as a result of the conversion. The
initial value is NULL. If the callback procedure sets this
member, it must ensure that the type, format, and length
members correspond to the data in value. The callback
procedure is responsible for allocating, but not for freeing,
memory when it sets this member.
type An IN/OUT parameter that indicates the type of the data in
the value member. The initial value is INTEGER.
format An IN/OUT parameter that specifies whether the data in value
should be viewed as a list of char, short, or long
quantities. The initial value is 8. The callback procedure
can set this member to 8 (for a list of char), 16 (for a list
of short), or 32 (for a list of long).
length An IN/OUT member that specifies the number of elements of
data in value, where each element has the size symbolized by
format. The initial value is 0.
Behavior
XmScale has the following behavior:
<Btn1Down> or <Btn2Down>:
In the region between an end of the Scale and the slider:
Moves the slider by one multiple increment in the direction
of the end of the Scale and calls the XmNvalueChangedCallback
callbacks. If XmNprocessingDirection is XmMAX_ON_RIGHT or
XmMAX_ON_BOTTOM, movement toward the right or bottom
increments the Scale value, and movement toward the left or
top decrements the Scale value. If XmNprocessingDirection is
XmMAX_ON_LEFT or XmMAX_ON_TOP, movement toward the right or
bottom decrements the Scale value, and movement toward the
left or top increments the Scale value. If the button is
held down longer than a delay period, the slider is moved
again by the same increment and the same callbacks are
called.
In slider: Activates the interactive dragging of the slider.
<Btn2Down> in value label:
Drags the contents of the label showing the current slider
value. This action sets the XmNconvertProc of the
DragContext to a function that calls the XmNconvertCallback
procedures, possibly multiple times, for the _MOTIF_DROP
selection.
<Btn1Motion> or <Btn2Motion>:
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.
<Btn1Up> or <Btn2Up>:
If the button press occurs within the slider and the slider
position is changed, the callbacks for
XmNvalueChangedCallback are called.
<Ctrl><Btn1Down>:
In the region between an end of the Scale and the slider:
Moves the slider to that end of the Scale and calls the
XmNvalueChangedCallback callbacks. If XmNprocessingDirection
is XmMAX_ON_RIGHT or XmMAX_ON_BOTTOM, movement toward the
right or bottom increments the Scale value, and movement
toward the left or top decrements the Scale value. If
XmNprocessingDirection is XmMAX_ON_LEFT or XmMAX_ON_TOP,
movement toward the right or bottom decrements the Scale
value, and movement toward the left or top increments the
Scale value.
<Key><osfUp>:
For vertical Scales, moves the slider up one increment and
calls the XmNvalueChangedCallback callbacks. If
XmNprocessingDirection is XmMAX_ON_TOP, movement toward the
top increments the Scale value. If XmNprocessingDirection is
XmMAX_ON_BOTTOM, movement toward the top decrements the Scale
value.
<Key><osfDown>:
For vertical Scales, moves the slider down one increment and
calls the XmNvalueChangedCallback callbacks. If
XmNprocessingDirection is XmMAX_ON_BOTTOM, movement toward
the bottom increments the Scale value. If
XmNprocessingDirection is XmMAX_ON_TOP, movement toward the
bottom decrements the Scale value.
<Key><osfLeft>:
For horizontal Scales, moves the slider one increment to the
left and calls the XmNvalueChangedCallback callbacks. If
XmNprocessingDirection is XmMAX_ON_LEFT, movement toward the
left increments the Scale value. If XmNprocessingDirection
is XmMAX_ON_RIGHT, movement toward the left decrements the
Scale value.
<Key><osfRight>:
For horizontal Scales, moves the slider one increment to the
right and calls the XmNvalueChangedCallback callbacks. If
XmNprocessingDirection is XmMAX_ON_RIGHT, movement toward the
right increments the Scale value. If XmNprocessingDirection
is XmMAX_ON_LEFT, movement toward the right decrements the
Scale value.
<Ctrl><Key><osfUp> or <Key><osfPageUp>:
For vertical Scales, moves the slider up one multiple
increment and calls the XmNvalueChangedCallback callbacks.
If XmNprocessingDirection is XmMAX_ON_TOP, movement toward
the top increments the Scale value. If
XmNprocessingDirection is XmMAX_ON_BOTTOM, movement toward
the top decrements the Scale value.
<Ctrl><Key><osfDown> or <Key><osfPageDown>:
For vertical Scales, moves the slider down one multiple
increment and calls the XmNvalueChangedCallback callbacks.
If XmNprocessingDirection is XmMAX_ON_BOTTOM, movement toward
the bottom increments the Scale value. If
XmNprocessingDirection is XmMAX_ON_TOP, movement toward the
bottom decrements the Scale value.
<Ctrl><Key><osfLeft> or <Key><osfPageLeft>:
For horizontal Scales, moves the slider one multiple
increment to the left and calls the XmNvalueChangedCallback
callbacks. If XmNprocessingDirection is XmMAX_ON_LEFT,
movement toward the left increments the Scale value. If
XmNprocessingDirection is XmMAX_ON_RIGHT, movement toward the
left decrements the Scale value.
<Ctrl><Key><osfRight> or <Key><osfPageRight>:
For horizontal Scales, moves the slider one multiple
increment to the right and calls the XmNvalueChangedCallback
callbacks. If XmNprocessingDirection is XmMAX_ON_RIGHT,
movement toward the right increments the Scale value. If
XmNprocessingDirection is XmMAX_ON_LEFT, movement toward the
right decrements the Scale value.
<Key><osfBeginLine> or <Key><osfBeginData>:
Moves the slider to the minimum value and calls the
XmNvalueChangedCallback callbacks.
<Key><osfEndLine> or <Key><osfEndData>:
Moves the slider to the maximum value and calls the
XmNvalueChangedCallback callbacks.
<Key><osfNextField>:
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.
<Key><osfPrevField>:
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.
<Key><osfHelp>:
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.
Virtual Bindings
The bindings for virtual keys are vendor specific. For information
about bindings for virtual buttons and keys, see VirtualBindings(3).
RELATED
Composite(3), Constraint(3), Core(3), XmCreateScale(3), XmManager(3),
XmScaleGetValue(3), and XmScaleSetValue(3).
XmScale(library call)