XtAddGrab

XtAddGrab(3Xt)			 XT FUNCTIONS		       XtAddGrab(3Xt)



NAME
       XtAddGrab, XtRemoveGrab - redirect user input to a modal widget

SYNTAX
       void XtAddGrab(Widget w, Boolean exclusive, Boolean spring_loaded);

       void XtRemoveGrab(Widget w);

ARGUMENTS
       exclusive Specifies whether user events should be dispatched exclu-
		 sively to this widget or also to previous widgets in the
		 cascade.

       spring_loaded
		 Specifies whether this widget was popped up because the user
		 pressed a pointer button.

       w	 Specifies the widget to add to or remove from the modal cas-
		 cade.

DESCRIPTION
       The XtAddGrab function appends the widget (and associated parameters)
       to the modal cascade and checks that exclusive is True if
       spring_loaded is True.  If these are not True, XtAddGrab generates an
       error.

       The modal cascade is used by XtDispatchEvent when it tries to dispatch
       a user event.  When at least one modal widget is in the widget cas-
       cade, XtDispatchEvent first determines if the event should be deliv-
       ered.  It starts at the most recent cascade entry and follows the cas-
       cade up to and including the most recent cascade entry added with the
       exclusive parameter True.

       This subset of the modal cascade along with all descendants of these
       widgets comprise the active subset.  User events that occur outside
       the widgets in this subset are ignored or remapped.  Modal menus with
       submenus generally add a submenu widget to the cascade with exclusive
       False.  Modal dialog boxes that need to restrict user input to the
       most deeply nested dialog box add a subdialog widget to the cascade
       with exclusive True.  User events that occur within the active subset
       are delivered to the appropriate widget, which is usually a child or
       further descendant of the modal widget.

       Regardless of where on the screen they occur, remap events are always
       delivered to the most recent widget in the active subset of the cas-
       cade that has spring_loaded True, if any such widget exists.

       The XtRemoveGrab function removes widgets from the modal cascade
       starting at the most recent widget up to and including the specified
       widget.	It issues an error if the specified widget is not on the
       modal cascade.

SEE ALSO
       X Toolkit Intrinsics - C Language Interface
       Xlib - C Language X Interface



							       XtAddGrab(3Xt)