1XGrabPointer(3)                 XLIB FUNCTIONS                 XGrabPointer(3)
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NAME

6       XGrabPointer, XUngrabPointer, XChangeActivePointerGrab - grab the
7       pointer
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SYNTAX

10       int XGrabPointer(Display *display, Window grab_window, Bool
11              owner_events, unsigned int event_mask, int pointer_mode, int
12              keyboard_mode, Window confine_to, Cursor cursor, Time time);
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14       int XUngrabPointer(Display *display, Time time);
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16       int XChangeActivePointerGrab(Display *display, unsigned int event_mask,
17              Cursor cursor, Time time);
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ARGUMENTS

20       confine_to
21                 Specifies the window to confine the pointer in or None.
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23       cursor    Specifies the cursor that is to be displayed during the grab
24                 or None.
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26       display   Specifies the connection to the X server.
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28       event_mask
29                 Specifies which pointer events are reported to the client.
30                 The mask is the bitwise inclusive OR of the valid pointer
31                 event mask bits.
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33       grab_window
34                 Specifies the grab window.
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36       keyboard_mode
37                 Specifies further processing of keyboard events.  You can
38                 pass GrabModeSync or GrabModeAsync.
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40       owner_events
41                 Specifies a Boolean value that indicates whether the pointer
42                 events are to be reported as usual or reported with respect
43                 to the grab window if selected by the event mask.
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45       pointer_mode
46                 Specifies further processing of pointer events.  You can pass
47                 GrabModeSync or GrabModeAsync.
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49       time      Specifies the time.  You can pass either a timestamp or Cur‐
50                 rentTime.
51

DESCRIPTION

53       The XGrabPointer function actively grabs control of the pointer and
54       returns GrabSuccess if the grab was successful.  Further pointer events
55       are reported only to the grabbing client.  XGrabPointer overrides any
56       active pointer grab by this client.  If owner_events is False, all gen‐
57       erated pointer events are reported with respect to grab_window and are
58       reported only if selected by event_mask.  If owner_events is True and
59       if a generated pointer event would normally be reported to this client,
60       it is reported as usual.  Otherwise, the event is reported with respect
61       to the grab_window and is reported only if selected by event_mask.  For
62       either value of owner_events, unreported events are discarded.
63
64       If the pointer_mode is GrabModeAsync, pointer event processing contin‐
65       ues as usual.  If the pointer is currently frozen by this client, the
66       processing of events for the pointer is resumed.  If the pointer_mode
67       is GrabModeSync, the state of the pointer, as seen by client applica‐
68       tions, appears to freeze, and the X server generates no further pointer
69       events until the grabbing client calls XAllowEvents or until the
70       pointer grab is released.  Actual pointer changes are not lost while
71       the pointer is frozen; they are simply queued in the server for later
72       processing.
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74       If the keyboard_mode is GrabModeAsync, keyboard event processing is
75       unaffected by activation of the grab.  If the keyboard_mode is GrabMod‐
76       eSync, the state of the keyboard, as seen by client applications,
77       appears to freeze, and the X server generates no further keyboard
78       events until the grabbing client calls XAllowEvents or until the
79       pointer grab is released.  Actual keyboard changes are not lost while
80       the pointer is frozen; they are simply queued in the server for later
81       processing.
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83       If a cursor is specified, it is displayed regardless of what window the
84       pointer is in.  If None is specified, the normal cursor for that window
85       is displayed when the pointer is in grab_window or one of its subwin‐
86       dows; otherwise, the cursor for grab_window is displayed.
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88       If a confine_to window is specified, the pointer is restricted to stay
89       contained in that window.  The confine_to window need have no relation‐
90       ship to the grab_window.  If the pointer is not initially in the con‐
91       fine_to window, it is warped automatically to the closest edge just
92       before the grab activates and enter/leave events are generated as
93       usual.  If the confine_to window is subsequently reconfigured, the
94       pointer is warped automatically, as necessary, to keep it contained in
95       the window.
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97       The time argument allows you to avoid certain circumstances that come
98       up if applications take a long time to respond or if there are long
99       network delays.  Consider a situation where you have two applications,
100       both of which normally grab the pointer when clicked on.  If both
101       applications specify the timestamp from the event, the second applica‐
102       tion may wake up faster and successfully grab the pointer before the
103       first application.  The first application then will get an indication
104       that the other application grabbed the pointer before its request was
105       processed.
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107       XGrabPointer generates EnterNotify and LeaveNotify events.
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109       Either if grab_window or confine_to window is not viewable or if the
110       confine_to window lies completely outside the boundaries of the root
111       window, XGrabPointer fails and returns GrabNotViewable.  If the pointer
112       is actively grabbed by some other client, it fails and returns Already‐
113       Grabbed.  If the pointer is frozen by an active grab of another client,
114       it fails and returns GrabFrozen.  If the specified time is earlier than
115       the last-pointer-grab time or later than the current X server time, it
116       fails and returns GrabInvalidTime.  Otherwise, the last-pointer-grab
117       time is set to the specified time (CurrentTime is replaced by the cur‐
118       rent X server time).
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120       XGrabPointer can generate BadCursor, BadValue, and BadWindow errors.
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122       The XUngrabPointer function releases the pointer and any queued events
123       if this client has actively grabbed the pointer from XGrabPointer,
124       XGrabButton, or from a normal button press.  XUngrabPointer does not
125       release the pointer if the specified time is earlier than the last-
126       pointer-grab time or is later than the current X server time.  It also
127       generates EnterNotify and LeaveNotify events.  The X server performs an
128       UngrabPointer request automatically if the event window or confine_to
129       window for an active pointer grab becomes not viewable or if window
130       reconfiguration causes the confine_to window to lie completely outside
131       the boundaries of the root window.
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133       The XChangeActivePointerGrab function changes the specified dynamic
134       parameters if the pointer is actively grabbed by the client and if the
135       specified time is no earlier than the last-pointer-grab time and no
136       later than the current X server time.  This function has no effect on
137       the passive parameters of a XGrabButton.  The interpretation of
138       event_mask and cursor is the same as described in XGrabPointer.
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140       XChangeActivePointerGrab can generate a BadCursor and BadValue error.
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DIAGNOSTICS

143       BadCursor A value for a Cursor argument does not name a defined Cursor.
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145       BadValue  Some numeric value falls outside the range of values accepted
146                 by the request.  Unless a specific range is specified for an
147                 argument, the full range defined by the argument's type is
148                 accepted.  Any argument defined as a set of alternatives can
149                 generate this error.
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151       BadWindow A value for a Window argument does not name a defined Window.
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SEE ALSO

154       XAllowEvents(3), XGrabButton(3), XGrabKey(3), XGrabKeyboard(3)
155       Xlib - C Language X Interface
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159X Version 11                     libX11 1.6.7                  XGrabPointer(3)
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