1XGrabPointer(3) XLIB FUNCTIONS XGrabPointer(3)
2
6 XGrabPointer, XUngrabPointer, XChangeActivePointerGrab - grab the
7 pointer
8
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);
13 int XUngrabPointer(Display *display, Time time);
15 int XChangeActivePointerGrab(Display *display, unsigned int event_mask,
17 Cursor cursor, Time time);
18
20 confine_to
21 Specifies the window to confine the pointer in or None.
22 cursor Specifies the cursor that is to be displayed during the grab
24 or None.
25 display Specifies the connection to the X server.
27 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.
32 grab_window
34 Specifies the grab window.
35 keyboard_mode
37 Specifies further processing of keyboard events. You can
38 pass GrabModeSync or GrabModeAsync.
39 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.
44 pointer_mode
46 Specifies further processing of pointer events. You can pass
47 GrabModeSync or GrabModeAsync.
48 time Specifies the time. You can pass either a timestamp or Cur‐
50 rentTime.
51
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 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.
73 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.
82 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.
87 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.
96 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.
106 XGrabPointer generates EnterNotify and LeaveNotify events.
108 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).
119 XGrabPointer can generate BadCursor, BadValue, and BadWindow errors.
121 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.
132 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.
139 XChangeActivePointerGrab can generate a BadCursor and BadValue error.
141
143 BadCursor A value for a Cursor argument does not name a defined Cursor.
144 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.
150 BadWindow A value for a Window argument does not name a defined Window.
152
154 XAllowEvents(3), XGrabButton(3), XGrabKey(3), XGrabKeyboard(3)
155 Xlib - C Language X Interface
156X Version 11 libX11 1.6.4 XGrabPointer(3)