NAME

       XGrabPointer, XUngrabPointer, XChangeActivePointerGrab - grab the pointer

SYNTAX

       int  XGrabPointer(Display  *display,  Window grab_window, Bool owner_events, unsigned int event_mask, int
              pointer_mode, int keyboard_mode, Window confine_to, Cursor cursor, Time time);

       int XUngrabPointer(Display *display, Time time);

       int XChangeActivePointerGrab(Display *display, unsigned int event_mask, Cursor cursor, Time time);

ARGUMENTS

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

       cursor    Specifies the cursor that is to be displayed during the grab 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.

       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.

       time      Specifies the time.  You can pass either a timestamp or CurrentTime.

DESCRIPTION

       The  XGrabPointer  function actively grabs control of the pointer and returns GrabSuccess if the grab was
       successful.  Further pointer events are reported only to the grabbing client.  XGrabPointer overrides any
       active pointer grab by this client.  If owner_events is False, all generated pointer events are  reported
       with respect to grab_window and are reported only if selected by event_mask.  If owner_events is True and
       if  a  generated  pointer  event  would  normally  be  reported  to this client, it is reported as usual.
       Otherwise, the event is reported with respect to the grab_window and is  reported  only  if  selected  by
       event_mask.  For either value of owner_events, unreported events are discarded.

       If  the  pointer_mode  is  GrabModeAsync, pointer event processing continues as usual.  If the pointer is
       currently frozen by this  client,  the  processing  of  events  for  the  pointer  is  resumed.   If  the
       pointer_mode  is  GrabModeSync,  the  state  of  the  pointer, as seen by client applications, appears to
       freeze, and the X server generates no further pointer events until the grabbing client calls XAllowEvents
       or until the pointer grab is released.  Actual pointer changes are not lost while the pointer is  frozen;
       they are simply queued in the server for later processing.

       If the keyboard_mode is GrabModeAsync, keyboard event processing is unaffected by activation of the grab.
       If  the keyboard_mode is GrabModeSync, the state of the keyboard, as seen by client applications, appears
       to freeze, and the X server generates  no  further  keyboard  events  until  the  grabbing  client  calls
       XAllowEvents  or  until  the  pointer  grab  is released.  Actual keyboard changes are not lost while the
       pointer is frozen; they are simply queued in the server for later processing.

       If a cursor is specified, it is displayed regardless of what window  the  pointer  is  in.   If  None  is
       specified,  the  normal  cursor for that window is displayed when the pointer is in grab_window or one of
       its subwindows; otherwise, the cursor for grab_window is displayed.

       If a confine_to window is specified, the pointer is restricted to stay contained  in  that  window.   The
       confine_to  window  need have no relationship to the grab_window.  If the pointer is not initially in the
       confine_to window, it is warped automatically to the closest edge just  before  the  grab  activates  and
       enter/leave  events  are  generated as usual.  If the confine_to window is subsequently reconfigured, the
       pointer is warped automatically, as necessary, to keep it contained in the window.

       The time argument allows you to avoid certain circumstances that come up if applications take a long time
       to respond or if there are long network delays.  Consider a situation where you  have  two  applications,
       both of which normally grab the pointer when clicked on.  If both applications specify the timestamp from
       the  event,  the second application may wake up faster and successfully grab the pointer before the first
       application.  The first application then will get an indication that the other  application  grabbed  the
       pointer before its request was processed.

       XGrabPointer generates EnterNotify and LeaveNotify events.

       Either  if  grab_window  or confine_to window is not viewable or if the confine_to window lies completely
       outside the boundaries of the root window,  XGrabPointer  fails  and  returns  GrabNotViewable.   If  the
       pointer is actively grabbed by some other client, it fails and returns AlreadyGrabbed.  If the pointer is
       frozen  by  an  active grab of another client, it fails and returns GrabFrozen.  If the specified time is
       earlier than the last-pointer-grab time or later than the current X server time,  it  fails  and  returns
       GrabInvalidTime.   Otherwise,  the  last-pointer-grab  time  is set to the specified time (CurrentTime is
       replaced by the current X server time).

       XGrabPointer can generate BadCursor, BadValue, and BadWindow errors.

       The XUngrabPointer function releases the pointer and any  queued  events  if  this  client  has  actively
       grabbed  the  pointer from XGrabPointer, XGrabButton, or from a normal button press.  XUngrabPointer does
       not release the pointer if the specified time is earlier than the last-pointer-grab time or is later than
       the current X server time.  It also generates EnterNotify and LeaveNotify events.  The X server  performs
       an  UngrabPointer  request  automatically  if the event window or confine_to window for an active pointer
       grab becomes not viewable or if window reconfiguration causes the confine_to  window  to  lie  completely
       outside the boundaries of the root window.

       The XChangeActivePointerGrab function changes the specified dynamic parameters if the pointer is actively
       grabbed  by  the  client  and  if the specified time is no earlier than the last-pointer-grab time and no
       later than the current X server time.  This function has  no  effect  on  the  passive  parameters  of  a
       XGrabButton.  The interpretation of event_mask and cursor is the same as described in XGrabPointer.

       XChangeActivePointerGrab can generate a BadCursor and BadValue error.

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

X Version 11                                      libX11 1.8.7                                   XGrabPointer(3)