NAME

       XGrabButton, XUngrabButton - grab pointer buttons

SYNTAX

       int  XGrabButton(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);

       int  XUngrabButton(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 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), at which  point  a  ButtonRelease
       event is reported to the grabbing window.

       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.

       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(3), XGrabPointer(3), XGrabKey(3), XGrabKeyboard(3),
       Xlib - C Language X Interface