XGrabButton(3X11)           X Version 11(Release 5)           XGrabButton(3X11)


NAME
      XGrabButton, XUngrabButton - grab pointer buttons

SYNTAX
      XGrabButton(display, button, modifiers, grab_window, owner_events,
      event_mask,
                      pointer_mode, keyboard_mode, confine_to, cursor)
            Display *display;
            unsigned int button;
            unsigned int modifiers;
            Window grab_window;
            Bool owner_events;
            unsigned int event_mask;
            int pointer_mode, keyboard_mode;
            Window confine_to;
            Cursor cursor;

      XUngrabButton(display, button, modifiers, grab_window)
            Display *display;
            unsigned int button;
            unsigned int modifiers;
            Window grab_window;

ARGUMENTS
      button    Specifies the pointer button that is to be grabbed or released
                or AnyButton.

      confine_to
                Specifies the window to confine the pointer in or None.

      cursor    Specifies the cursor that is to be displayed or None.

      display   Specifies the connection to the X server.

      event_mask
                Specifies which pointer events are reported to the client.  The
                mask is the bitwise inclusive OR of the valid pointer event
                mask bits.

      grab_window
                Specifies the grab window.

      keyboard_mode
                Specifies further processing of keyboard events.  You can pass
                GrabModeSync or GrabModeAsync.

      modifiers Specifies the set of keymasks or AnyModifier.  The mask is the
                bitwise inclusive OR of the valid keymask bits.

      owner_events
                Specifies a Boolean value that indicates whether the pointer
                events are to be reported as usual or reported with respect to


10/89                                                                    Page 1

XGrabButton(3X11)           X Version 11(Release 5)           XGrabButton(3X11)


                the grab window if selected by the event mask.

      pointer_mode
                Specifies further processing of pointer events.  You can pass
                GrabModeSync or GrabModeAsync.

DESCRIPTION
      The XGrabButton function establishes a passive grab.  In the future, the
      pointer is actively grabbed (as for XGrabPointer), the last-pointer-grab
      time is set to the time at which the button was pressed (as transmitted
      in the ButtonPress event), and the ButtonPress event is reported if all
      of the following conditions are true:

      ⊕    The pointer is not grabbed, and the specified button is logically
           pressed when the specified modifier keys are logically down, and no
           other buttons or modifier keys are logically down.

      ⊕    The grab_window contains the pointer.

      ⊕    The confine_to window (if any) is viewable.

      ⊕    A passive grab on the same button/key combination does not exist on
           any ancestor of grab_window.

      The interpretation of the remaining arguments is as for XGrabPointer.
      The active grab is terminated automatically when the logical state of the
      pointer has all buttons released (independent of the state of the logical
      modifier keys).

      Note that the logical state of a device (as seen by client applications)
      may lag the physical state if device event processing is frozen.

      This request overrides all previous grabs by the same client on the same
      button/key combinations on the same window.  A modifiers of AnyModifier
      is equivalent to issuing the grab request for all possible modifier
      combinations (including the combination of no modifiers). It is not
      required that all modifiers specified have currently assigned KeyCodes.
      A button of AnyButton is equivalent to issuing the request for all
      possible buttons.  Otherwise, it is not required that the specified
      button currently be assigned to a physical button.

      If some other client has already issued a XGrabButton with the same
      button/key combination on the same window, a BadAccess error results.
      When using AnyModifier or AnyButton, the request fails completely, and a
      BadAccess error results (no grabs are established) if there is a
      conflicting grab for any combination.  XGrabButton has no effect on an
      active grab.

      XGrabButton can generate BadCursor, BadValue, and BadWindow errors.





Page 2                                                                    10/89

XGrabButton(3X11)           X Version 11(Release 5)           XGrabButton(3X11)


      The XUngrabButton function releases the passive button/key combination on
      the specified window if it was grabbed by this client.  A modifiers of
      AnyModifier is equivalent to issuing the ungrab request for all possible
      modifier combinations, including the combination of no modifiers.  A
      button of AnyButton is equivalent to issuing the request for all possible
      buttons.  XUngrabButton has no effect on an active grab.

      XUngrabButton can generate BadValue and BadWindow errors.

DIAGNOSTICS
      BadCursor A value for a Cursor argument does not name a defined Cursor.

      BadValue  Some numeric value falls outside the range of values accepted
                by the request.  Unless a specific range is specified for an
                argument, the full range defined by the argument's type is
                accepted.  Any argument defined as a set of alternatives can
                generate this error.

      BadWindow A value for a Window argument does not name a defined Window.

SEE ALSO
      XAllowEvents(3X11), XGrabPointer(3X11), XGrabKey(3X11),
      XGrabKeyboard(3X11),
      Xlib - C Language X Interface






























10/89                                                                    Page 3