OSF/Motif

NAME

XmScreen − The Screen widget class

SYNOPSIS

#include <Xm/Screen.h>

DESCRIPTION

The XmScreen object is used by Motif widgets to store information that is specific to a screen.  It also allows the toolkit to store certain information on widget hierarchies that would otherwise be unavailable. Each client has one XmScreen object for each screen that it accesses. 

An XmScreen object is automatically created when the application creates the first shell on a screen (usually accomplished by a call to XtAppInitialize or XtAppCreateShell). It is not necessary to create an XmScreen object by any other means. An application can use the function XmGetXmScreen to obtain the widget ID of the XmScreen object for a given screen. 

An application cannot supply initial values for XmScreen resources as arguments to a call to any function that creates widgets. The application or user can supply initial values in a resource file. After creating the first shell on the screen, the application can use XmGetXmScreen to obtain the widget ID of the XmScreen object and then call XtSetValues to set the XmScreen resources. 

Classes

Screen inherits behavior and resources from Core. 

The class pointer is xmScreenClass. 

The class name is XmScreen. 

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 an .Xdefaults file, remove the XmN or XmC prefix and use the remaining letters.  To specify one of the defined values for a resource in an .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). 

XmScreen Resource Set

XmNdarkThreshold

Class: XmCDarkThreshold
Default: dynamic
Type:  int
Access: C

XmNdefaultCopyCursorIcon

Class: XmCDefaultCopyCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNdefaultInvalidCursorIcon

Class: XmCDefaultInvalidCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNdefaultLinkCursorIcon

Class: XmCDefaultLinkCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNdefaultMoveCursorIcon

Class: XmCDefaultMoveCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNdefaultNoneCursorIcon

Class: XmCDefaultNoneCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNdefaultSourceCursorIcon

Class: XmCDefaultSourceCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNdefaultValidCursorIcon

Class: XmCDefaultValidCursorIcon
Default: NULL
Type:  Widget
Access: CSG

XmNfont

Class: XmCFont
Default: NULL
Type:  XFontStruct ∗
Access: CSG

XmNforegroundThreshold

Class: XmCForegroundThreshold
Default: dynamic
Type:  int
Access: C

XmNhorizontalFontUnit

Class: XmCHorizontalFontUnit
Default: dynamic
Type:  int
Access: CSG

XmNlightThreshold

Class: XmCLightThreshold
Default: dynamic
Type:  int
Access: C

XmNmenuCursor

Class: XmCCursor
Default: arrow
Type:  String
Access: C

XmNmoveOpaque

Class: XmCMoveOpaque
Default: False
Type:  Boolean
Access: CSG

XmNunpostBehavior

Class: XmCUnpostBehavior
Default: XmUNPOST_AND_REPLAY
Type:  unsigned char
Access: CSG

XmNverticalFontUnit

Class: XmCVerticalFontUnit
Default: dynamic
Type:  int
Access: CSG

XmNdarkThreshold
An integer between 0 and 100, inclusive, that specifies a level of perceived brightness for a color.  If the perceived brightness of the background color is below this level, Motif treats the background as “dark” when computing default shadow and select colors. If this resource is specified for a particular screen, it applies to widgets created on that screen; otherwise it applies to widgets created on all screens.  The default value is implementation specific.

XmNdefaultCopyCursorIcon
Specifies the DragIcon used during a drag operation when the operation is a copy and no other pixmap is specified by the application. If NULL, a system default icon is used.

XmNdefaultInvalidCursorIcon
Specifies the DragIcon used to indicate that the cursor is over an invalid drop site during a drag operation when no other pixmap symbol is specified by the application.  If NULL, a system default icon is used.

XmNdefaultLinkCursorIcon
Specifies the DragIcon used during a drag operation when the operation  is a link and no other pixmap is specified by the application. If NULL, a system default icon is used.

XmNdefaultMoveCursorIcon
Specifies the DragIcon used during a drag operation when the operation  is a move and no other pixmap is specified by the application. If NULL, a system default icon is used.

XmNdefaultNoneCursorIcon
Specifies the DragIcon used to indicate that the cursor is not over a drop site during a drag operation when no other pixmap is specified by the application.  If NULL, a system default icon is used.

XmNdefaultSourceCursorIcon
Specifies the depth-1 pixmap used as a cursor when an XmNsourceCursorIcon is not provided by the DragContext, or it is not usable.  If NULL, a system default icon is used. 

XmNdefaultValidCursorIcon
Specifies the DragIcon used to indicate that the cursor is over a valid drop site during a drag operation when no other pixmap is specified by the application.  If NULL, a system default icon is used.

XmNfont
Specifies a font for use in computing values for XmNhorizontalFontUnit and XmNverticalFontUnit. When an application is initialized, this resource can be supplied in a resource file or through the standard command line options −fn, −font, and −xrm. 

XmNforegroundThreshold
An integer between 0 and 100, inclusive, that specifies a level of perceived brightness for a color.  If the perceived brightness of the background color is equal to or below this level, Motif treats the background as “dark” when computing the default foreground and highlight colors.  If the perceived brightness of the background color is above this level, Motif treats the background as “light” when computing the default foreground and highlight colors.  When the background is “dark”, the default foreground and highlight is white; when the background is “light”, the default foreground and highlight is black.  If this resource is specified for a particular screen, it applies to widgets created on that screen; otherwise, it applies to widgets created on all screens.  The default value is implementation specific.

XmNhorizontalFontUnit
Specifies the horizontal component of the font units used by XmConvertUnits, and is used to interpret the values of geometry resources when the XmNshellUnitType resource of VendorShell or the XmNunitType resource of Gadget, Manager, or Primitive has the value Xm100TH_FONT_UNITS. If no initial value is supplied for this resource, the default is computed from the font specified in XmNfont. If no initial value is supplied for this resource or for XmNfont, the default is 10. 

If a call to XtSetValues specifies a value for XmNhorizontalFontUnit, this resource is set to that value. If a call to XtSetValues specifies a value for XmNfont but not for XmNhorizontalFontUnit, this resource is set to a value computed from the new XmNfont. 

A horizontal font unit is derived from a font as follows:

       •If the font has an AVERAGE_WIDTH property, the horizontal font unit is the AVERAGE_WIDTH property divided by 10. 

       •If the font has no AVERAGE_WIDTH property but has a QUAD_WIDTH property, the horizontal font unit is the QUAD_WIDTH property. 

       •If the font has no AVERAGE_WIDTH or QUAD_WIDTH property, the horizontal font unit is the sum of the font structure’s min_bounds.width and max_bounds.width divided by 2.3. 

XmNlightThreshold
An integer between 0 and 100, inclusive, that specifies a level of perceived brightness for a color.  If the perceived brightness of the background color is above this level, Motif treats the background as “light” when computing default shadow and select colors.  If this resource is specified for a particular screen, it applies to widgets created on that screen; otherwise, it applies to widgets created on all screens.  The default value is implementation specific.

XmNmenuCursor
Sets a variable that controls the cursor used whenever this application posts a menu.  This resource can be specified only once at application startup time, either by placing it within a defaults file or by using the −xrm command line argument.  For example:

myProg −xrm "∗menuCursor: arrow"

The menu cursor can also be selected in the program through the function XmSetMenuCursor. The following is a list of acceptable cursor names.  If the application does not specify a cursor or if an invalid name is supplied, the default cursor (an arrow pointing up and to the right) is used. 

XmNmoveOpaque
Specifies whether an interactive operation that moves a window, such as tearing off and dragging a tear-off menu or moving a window in MWM, displays an outline of the window or a representation of the window itself during the move. If the value is True, the operation displays a representation of the window during the move. If the value is False, the operation displays an outline of the window.

XmNunpostBehavior
Specifies the behavior of an active menu posted in traversal mode when a subsequent menu button selection is made outside the posted menu. When the value is XmUNPOST_AND_REPLAY, the resource unposts the menu hierarchy and causes the server to replay the event to the window in which the pointer is located.  When the value is XmUNPOST, the resource unposts the hierarchy without replaying the event. 

XmNverticalFontUnit
Specifies the vertical component of the font units used by XmConvertUnits and used to interpret the values of geometry resources when the XmNshellUnitType resource of VendorShell or the XmNunitType resource of Gadget, Manager, or Primitive has the value Xm100TH_FONT_UNITS. If no initial value is supplied for this resource, the default is computed from the font specified in XmNfont. If no initial value is supplied for this resource or for XmNfont, the default is 10. 

If a call to XtSetValues specifies a value for XmNverticalFontUnit, this resource is set to that value. If a call to XtSetValues specifies a value for XmNfont but not for XmNverticalFontUnit, this resource is set to a value computed from the new XmNfont. 

A vertical font unit is derived from a font as follows:

       •If the font has a PIXEL_SIZE property, the vertical font unit is the PIXEL_SIZE property divided by 1.8. 

       •If the font has no PIXEL_SIZE property but has POINT_SIZE and RESOLUTION_Y properties, the vertical font unit is the product of the POINT_SIZE and RESOLUTION_Y properties divided by 1400. 

       •If the font has no PIXEL_SIZE, POINT_SIZE, or RESOLUTION_Y properties, the vertical font unit is the sum of the font structure’s max_bounds.ascent and max_bounds.descent divided by 2.2. 

Inherited Resources

All of the superclass resources inherited by XmScreen are designated N/A (not applicable). 

SEE ALSO

Core(3X), XmDisplay(3X), XmGetXmScreen(3X)