XmLabelGadget(3)

NAME
XmLabelGadget — The LabelGadget widget class

SYNOPSIS

#include <Xm/LabelG.h>

DESCRIPTION

LabelGadget is an instantiable widget and is also used as a superclass for other button gadgets, such as PushButtonGadget and ToggleButtonGadget.

LabelGadget can contain either text or a pixmap. LabelGadget text is a compound string. Refer to the Motif Programmer's Guide for more information on compound strings. The text can be multilingual, multiline, and/or multifont. When a LabelGadget is insensitive, its text is stippled, or the user-supplied insensitive pixmap is displayed.

LabelGadget supports both accelerators and mnemonics primarily for use in LabelGadget subclass widgets that are contained in menus. Mnemonics are available in a menu system when the button is visible. Accelerators in a menu system are accessible even when the button is not visible. The LabelGadget displays the mnemonic by underlining the first matching character in the text string. The accelerator is displayed as a text string adjacent to the label text or pixmap, depending on the layout direction.

LabelGadget consists of many margin fields surrounding the text or pixmap. These margin fields are resources that may be set by the user, but LabelGadget subclasses and Manager parents also modify some of these fields. They tend to modify the XmNmarginLeft, XmNmarginRight, XmNmarginTop, and XmNmarginBottom resources and leave the XmNmarginWidth and XmNmarginHeight resources as set by the application.

LabelGadget takes into account XmNshadowThickness in determining its layout but does not draw the shadow. That is, if XmNshadowThickness is greater than 0 (zero), LabelGadget leaves space for the shadow, but the shadow does not appear.

In a LabelGadget, XmNtraversalOn and XmNhighlightOnEnter are forced to False inside Popup menu panes, Pulldown menu panes, and OptionMenus. Otherwise these resources default to False.

LabelGadget uses the XmQTmenuSystem and XmQTspecifyRenderTable traits, and holds the XmQTaccessTextual, XmQTcareParentVisual, XmQTmenuSavvy, and XmQTtransfer traits.

  Data Transfer Behavior

LabelGadget and it subclasses, except when used in a menu system, support dragging of the label contents from the LabelGadget. However, the label contents are draggable only if the XmNenableUnselectableDrag resource of XmDisplay is set to True.

As a source of data, LabelGadget and its subclasses support the following targets and associated conversions of data to these targets:

locale
    If the locale target matches the widget's locale, the widget transfers XmNlabelString in the encoding of the locale. This target is supported only when XmNlabelType is XmSTRING.

COMPOUND_TEXT
    The widget transfers XmNlabelString as type COMPOUND_TEXT. This target is supported only when XmNlabelType is XmSTRING.

PIXMAP
    The widget transfers XmNlabelPixmap as type DRAWABLE. This target is supported only when XmNlabelType is XmPIXMAP.

STRING
    The widget transfers XmNlabelString as type STRING. This target is supported only when XmNlabelType is XmSTRING.

TEXT
    If XmNlabelString is fully convertible to the encoding of the locale, the widget transfers XmNlabelString in the encoding of the locale. Otherwise, the widget transfers XmNlabelString as type COMPOUND_TEXT. This target is supported only when XmNlabelType is XmSTRING.

_MOTIF_CLIPBOARD_TARGETS
    The widget transfers, as type ATOM, a list of the targets it supports for the CLIPBOARD selection. When XmNlabelType is XmSTRING, these include the following targets:

    •   _MOTIF_COMPOUND_STRING

    •   COMPOUND_TEXT

    •   The encoding of the locale, if XmNlabelString is fully convertible to the encoding of the locale

    •   STRING, if XmNlabelString is fully convertible to STRING

    When XmNlabelType is XmPIXMAP, the targets include PIXMAP.

_MOTIF_COMPOUND_STRING
    The widget transfers XmNlabelString as a compound string in Byte Stream format. This target is supported only when XmNlabelType is XmSTRING.

_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. When XmNlabelType is XmSTRING, these include _MOTIF_COMPOUND_STRING, COMPOUND_TEXT, the encoding of the locale, STRING, TEXT, BACKGROUND, and FOREGROUND. When XmNlabelType is XmPIXMAP, these include PIXMAP, BACKGROUND, and FOREGROUND.

As a source of data, LabelGadget also supports the following standard Motif targets:

BACKGROUND
    The widget transfers the parent's 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 the parent's XmNcolormap as type COLORMAP.

FOREGROUND
    The widget transfers the parent's 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. When XmNlabelType is XmSTRING, these also include _MOTIF_COMPOUND_STRING, COMPOUND_TEXT, the encoding of the locale, STRING, and TEXT. When XmNlabelType is XmPIXMAP, these also include PIXMAP.

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.

  Classes

LabelGadget inherits behavior, resources, and traits from Object, RectObj and XmGadget.

The class pointer is xmLabelGadgetClass.

The class name is XmLabelGadget.

  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).

XmNaccelerator
    Sets the accelerator on a button widget in a menu, which activates a visible or invisible, but managed, button from the keyboard. This resource is a string that describes a set of modifiers and the key that may be used to select the button. The format of this string is identical to that used by the translations manager, with the exception that only a single event may be specified and only KeyPress events are allowed.

    Accelerators for buttons are supported only for PushButtonGadgets and ToggleButtonGadgets in Pulldown and Popup menus.

XmNacceleratorText
    Specifies the text displayed for the accelerator. The text is displayed adjacent to the label string or pixmap. The direction of its layout depends on the XmNlayoutDirection resource of the widget. Accelerator text for buttons is displayed only for PushButtonGadgets and ToggleButtonGadgets in Pulldown and Popup Menus.

XmNalignment
    Specifies the label alignment for text or pixmap.

    XmALIGNMENT_BEGINNING (left alignment)
        Causes the left sides of the lines of text to be vertically aligned with the left edge of the gadget. For a pixmap, its left side is vertically aligned with the left edge of the gadget.

    XmALIGNMENT_CENTER (center alignment)
        Causes the centers of the lines of text to be vertically aligned in the center of the gadget. For a pixmap, its center is vertically aligned with the center of the gadget.

    XmALIGNMENT_END (right alignment)
        Causes the right sides of the lines of text to be vertically aligned with the right edge of the gadget. For a pixmap, its right side is vertically aligned with the right edge of the gadget.

    The preceding descriptions for text are correct when XmNlayoutDirection is XmLEFT_TO_RIGHT. When that resource is XmRIGHT_TO_LEFT, the descriptions for XmALIGNMENT_BEGINNING and XmALIGNMENT_END are switched.

    If the parent is a RowColumn whose XmNisAligned resource is True, XmNalignment is forced to the same value as the RowColumn's XmNentryAlignment if the RowColumn's XmNrowColumnType is XmWORK_AREA or if the gadget is a subclass of XmLabelGadget. Otherwise, the default is XmALIGNMENT_CENTER.

XmNfontList
    Specifies the font of the text used in the gadget. XmNfontList is obsolete and exists for compatibility with previous releases. You should now use XmNrenderTable instead of XmNfontList. If both are specified, the render table will take precedence. If XmNfontList is NULL at initialization, the parent hierarchy of the widget is searched for an ancestor that is a subclass of the XmBulletinBoard, VendorShell, or XmMenuShell widget class. If such an ancestor is found, the font list is initialized to the XmNbuttonFontList (for button gadget subclasses) or XmNlabelFontList of the ancestor widget. If no such ancestor is found, the default is implementation dependent. Refer to XmFontList(3) for more information on the creation and structure of a font list.

XmNlabelInsensitivePixmap
    Specifies a pixmap used as the button face if XmNlabelType is XmPIXMAP and the button is insensitive. The default value, XmUNSPECIFIED_PIXMAP, displays an empty label.

XmNlabelPixmap
    Specifies the pixmap when XmNlabelType is XmPIXMAP. The default value, XmUNSPECIFIED_PIXMAP, displays an empty label.

XmNlabelString
    Specifies the compound string when XmNlabelType is XmSTRING. If the value of this resource is NULL, it is initialized to name of the gadget converted to a compound string. Refer to XmString(3) for more information on the creation and the structure of compound strings.

XmNlabelType
    Specifies the label type.

    XmSTRING
        Text displays XmNlabelString

    XmPIXMAP
        Icon data in pixmap displays XmNlabelPixmap or XmNlabelInsensitivePixmap

XmNmarginBottom
    Specifies the amount of spacing between the bottom of the label text and the top of the bottom margin specified by XmNmarginHeight. This may be modified by LabelGadget's subclasses. For example, CascadeButtonGadget may increase this field to make room for the cascade pixmap.

XmNmarginHeight
    Specifies an equal amount of spacing above the margin defined by XmNmarginTop and below the margin defined by XmNmarginBottom. XmNmarginHeight specifies the amount of spacing between the top edge of the margin set by XmNmarginTop and the bottom edge of the top shadow, and the amount of spacing between the bottom edge of the margin specified by XmNmarginBottom and the top edge of the bottom shadow.

XmNmarginLeft
    Specifies the amount of spacing between the left edge of the label text and the right side of the left margin (specified by XmNmarginWidth). This may be modified by LabelGadget's subclasses. For example, ToggleButtonGadget may increase this field to make room for the toggle indicator and for spacing between the indicator and label. Whether this actually applies to the left or right side of the label depends on the value of XmNlayoutDirection.

XmNmarginRight
    Specifies the amount of spacing between the right edge of the label text and the left side of the right margin (specified by XmNmarginWidth). This may be modified by LabelGadget's subclasses. For example, CascadeButtonGadget may increase this field to make room for the cascade pixmap. Whether this actually applies to the left or right side of the label depends on the value of XmNlayoutDirection.

XmNmarginTop
    Specifies the amount of spacing between the top of the label text and the bottom of the top margin specified by XmNmarginHeight. This may be modified by LabelGadget's subclasses. For example, CascadeButtonGadget may increase this field to make room for the cascade pixmap.

XmNmarginWidth
    Specifies an equal amount of spacing to the left of the margin defined by XmNmarginLeft and to the right of the margin defined by XmNmarginRight. XmNmarginWidth specifies the amount of spacing between the left edge of the margin set by XmNmarginLeft and the right edge of the left shadow, and the amount of spacing between the right edge of the margin specified by XmNmarginRight and the left edge of the right shadow.

XmNmnemonic
    Provides the user with an alternate means of activating a button. A button in a MenuBar, a Popup menu pane, or a Pulldown menu pane can have a mnemonic.

    This resource contains a keysym as listed in the X11 keysym table. The first character in the label string that exactly matches the mnemonic in the character set specified in XmNmnemonicCharSet is underlined when the button is displayed.

    When a mnemonic has been specified, the user activates the button by pressing the mnemonic key while the button is visible. If the button is a CascadeButtonGadget in a MenuBar and the MenuBar does not have the focus, the user must use the MAlt modifier while pressing the mnemonic. The user can activate the button by pressing either the shifted or the unshifted mnemonic key.

XmNmnemonicCharSet
    Specifies the character set of the mnemonic for the label. The default is XmFONTLIST_DEFAULT_TAG.

XmNrecomputeSize
    Specifies a Boolean value that indicates whether the gadget shrinks or expands to accommodate its contents (label string or pixmap) as a result of an XtSetValues resource value that would change the size of the gadget. If True, the gadget shrinks or expands to exactly fit the label string or pixmap. If False, the gadget never attempts to change size on its own.

XmNrenderTable
    Specifies the render table associated with the labelString. If this value is NULL at initialization, Label searches its parent hierarchy for an ancestor that holds the XmQTspecifyRenderTable trait. If such an ancestor is found, Label initializes XmNrenderTable to the XmLABEL_RENDER_TABLE value of the ancestor widget. Similarly, button subclasses of Label initialize XmNrenderTable to the XmBUTTON_RENDER_TABLE value of the ancestor widget. (Note that all current subclasses of Label are button subclasses.) If no such ancestor is found, the default is implementation dependent. If a font list 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.

XmNstringDirection
    Is a synthetic resource for setting XmNlayoutDirection. The values for this resource are XmSTRING_DIRECTION_L_TO_R and XmSTRING_DIRECTION_R_TO_L. Refer to the XmNlayoutDirection resource description. The XmNstringDirection resource is obsoleted by XmNlayoutDirection, but is kept here for backward compatibility.

  Inherited Resources

LabelGadget 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.

  Behavior

XmLabelGadget includes behavior from XmGadget. Additional XmLabelGadget behavior is described in the following list:

<Btn2Down>:
    Drags the contents of a LabelGadget, identified when BTransfer is pressed. This action is undefined for LabelGadgets used in a menu system.

<Key><osfHelp>:
    In a Popup or Pulldown MenuPane, unposts all menus in the menu hierarchy and, when the shell's keyboard focus policy is XmEXPLICIT, restores keyboard focus to the widget that had the focus before the menu system was entered. 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.

<key><osfCancel>:
    In a MenuBar, disarms the CascadeButton and the menu and, when the shell's keyboard focus policy is XmEXPLICIT, restores keyboard focus to the widget that had the focus before the menu was entered.

    In a toplevel Pulldown MenuPane from a MenuBar, unposts the menu, disarms the MenuBar CascadeButton and the MenuBar, and, when the shell's keyboard focus policy is XmEXPLICIT, restores keyboard focus to the widget that had the focus before the MenuBar was entered. In other Pulldown MenuPanes, unposts the menu.

    In a Popup MenuPane, unposts the menu and, when the shell's keyboard focus policy is XmEXPLICIT, restores keyboard focus to the widget from which the menu was posted.

<Key><osfDown>:
    If the current menu item has a submenu and is in a MenuBar, then this action posts the submenu, disarms the current menu item, and arms the submenu's first traversable menu item.

    If the current menu item is in a MenuPane, then this action disarms the current menu item and arms the item below it. This action wraps within the MenuPane. The direction of the wrapping depends on the XmNlayoutDirection resource.

<Key><osfLeft>:
    When the current menu item is in a MenuBar, then this action disarms the current item and arms the MenuBar item to the left. This action wraps within the MenuBar.

    In MenuPanes, if the current menu item is not at the left edge of a MenuPane, this action disarms the current item and arms the item to its left. If the current menu item is at the left edge of a submenu attached to a MenuBar item, then this action unposts the submenu and traverses to the MenuBar item to the left, wrapping if necessary. If that MenuBar item has a submenu, it posts the submenu and arms the first traversable item in the submenu. If the current menu item is at the left edge of a submenu not directly attached to a MenuBar item, then this action unposts the current submenu only.

    In Popup or Torn-off MenuPanes, when the current menu item is at the left edge, this action wraps within the MenuPane. If the current menu item is at the left edge of the MenuPane and not in the top row, this action wraps to the rightmost menu item in the row above. If the current menu item is in the upper, leftmost corner, this action wraps to the tear-off control, if present, or else it wraps to the bottom, rightmost menu item in the MenuPane. The preceding description applies when the XmNlayoutDirection horizontal direction is XmLEFT_TO_RIGHT. If the XmNlayoutDirection horizontal direction is XmRIGHT_TO_LEFT, then the following applies.

    If the current menu item is in a MenuBar, then this action disarms the current item and arms the MenuBar item to the left. This action wraps within the MenuBar.

    In MenuPanes, if the current menu item is a CascadeButton, then this action posts its associated submenu. If the current menu item is not a CascadeButton and is not at the left edge of a MenuPane, this action disarms the current item and arms the item to its left, wrapping if necessary. If the current menu item is not a CascadeButton and is at the left edge of a submenu that is a descendent of a MenuBar, then this action unposts all submenus and traverses to the MenuBar item to the left. If that MenuBar item has a submenu, it posts the submenu and arms the submenu's first traversable item.

    In Popup or Torn-off menus, if the current menu item is not a CascadeButton and is at the left edge of a row (except the bottom row), this action wraps to the rightmost menu item in the row below. If the current menu item is not a CascadeButton and is in the bottom, leftmost corner of a Popup or Pulldown MenuPane, this action wraps to the tear-off control, if present, or else it wraps to the top, rightmost menu item of the MenuPane.

<Key><osfRight>:
    If the current menu item is in a MenuBar, then this action disarms the current item and arms the MenuBar item to the right. This action wraps within the MenuBar.

    In MenuPanes, if the current menu item is a CascadeButton, then this action posts its associated submenu. If the current menu item is not a CascadeButton and is not at the right edge of a MenuPane, this action disarms the current item and arms the item to its right, wrapping if necessary. If the current menu item is not a CascadeButton and is at the right edge of a submenu that is a descendent of a MenuBar, then this action unposts all submenus and traverses to the MenuBar item to the right. If that MenuBar item has a submenu, it posts the submenu and arms the submenu's first traversable item.

    In Popup or Torn-off menus, if the current menu item is not a CascadeButton and is at the right edge of a row (except the bottom row), this action wraps to the leftmost menu item in the row below. If the current menu item is not a CascadeButton and is in the bottom, rightmost corner of a Popup or Pulldown MenuPane, this action wraps to the tear-off control, if present, or else it wraps to the top, leftmost menu item of the MenuPane. The preceding description applies when the XmNlayoutDirection horizontal direction is XmLEFT_TO_RIGHT. If the XmNlayoutDirection horizontal direction is XmRIGHT_TO_LEFT, then the following applies.

    When the current menu item is in a MenuBar, then this action disarms the current item and arms the MenuBar item to the right. This action wraps within the MenuBar.

    In MenuPanes, if the current menu item is not at the right edge of a MenuPane, this action disarms the current item and arms the item to its right. If the current menu item is at the right edge of a submenu attached to a MenuBar item, then this action unposts the submenu and traverses to the MenuBar item to the right, wrapping if necessary. If that MenuBar item has a submenu, it posts the submenu and arms the first traversable item in the submenu. If the current menu item is at the right edge of a submenu not directly attached to a MenuBar item, then this action unposts the current submenu only.

    In Popup or Torn-off MenuPanes, when the current menu item is at the right edge, this action wraps within the MenuPane. If the current menu item is at the right edge of the MenuPane and not in the top row, this action wraps to the leftmost menu item in the row above. If the current menu item is in the upper, rightmost corner, this action wraps to the tear-off control, if present, or else it wraps to the bottom, leftmost menu item in the MenuPane.

<Key><osfUp>:
    When the current menu item is in a MenuPane, then this action disarms the current menu item and arms the item above it. This action wraps within the MenuPane. The direction of the wrapping depends on the XmNlayoutDirection resource.

  Virtual Bindings

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

RELATED

Object(3), RectObj(3), XmCreateLabelGadget(3), XmFontListCreate(3), XmStringCreate(3), XmStringCreateLtoR(3), and XmGadget(3).