XGrabPointer(3)

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 Cur-
                 rentTime.

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 gen-
       erated 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 contin-
       ues 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 applica-
       tions, 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 GrabMod-
       eSync, 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 subwin-
       dows; 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 relation-
       ship to the grab_window.  If the pointer is not initially in the con-
       fine_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 applica-
       tion 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 Already-
       Grabbed.  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 cur-
       rent 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.

XGrabPointer(3)

NAME

SYNTAX

ARGUMENTS

DESCRIPTION

DIAGNOSTICS

SEE ALSO