XLIB FUNCTIONS XGrabPointer(3x11)
NAME
XGrabPointer, XUngrabPointer, XChangeActivePointerGrab -
grab the pointer SYNTAXcc [ flag... ] file... -lX11 [ library... ]
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);
ARGUMENTSconfine_to
Specifies the window to confine the pointer in or None.cursor Specifies the cursor that is to be displayed dur-
ing 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 times-
tamp or CurrentTime. X Version 11 Last change: libX11 1.3.5 1 XLIB FUNCTIONS XGrabPointer(3x11)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 bythis 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 thegrab_window and is reported only if selected by event_mask.
For either value of owner_events, unreported events are dis-
carded.If the pointer_mode is GrabModeAsync, pointer event process-
ing continues as usual. If the pointer is currently frozen by this client, the processing of events for the pointer isresumed. 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 pro-
cessing is unaffected by activation of the grab. If thekeyboard_mode is GrabModeSync, the state of the keyboard, as
seen by client applications, appears to freeze, and the Xserver generates no further keyboard events until the grab-
bing 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 ingrab_window or one of its subwindows; otherwise, the cursor
for grab_window is displayed.
If a confine_to window is specified, the pointer is res-
tricted 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 asusual. If the confine_to window is subsequently reconfig-
ured, the pointer is warped automatically, as necessary, to keep it contained in the window. X Version 11 Last change: libX11 1.3.5 2 XLIB FUNCTIONS XGrabPointer(3x11) 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 specifiedtime is earlier than the last-pointer-grab time or later
than the current X server time, it fails and returns GrabIn-
validTime. 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 pointerif 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 eventwindow or confine_to window for an active pointer grab
becomes not viewable or if window reconfiguration causes theconfine_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 thelast-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 ofevent_mask and cursor is the same as described in XGrab-
Pointer. X Version 11 Last change: libX11 1.3.5 3 XLIB FUNCTIONS XGrabPointer(3x11)XChangeActivePointerGrab can generate a BadCursor and Bad-
Value 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. Anyargument defined as a set of alternatives can gen-
erate this error. BadWindow A value for a Window argument does not name a defined Window.SEE ALSO
XAllowEvents(3x11), XGrabButton(3x11), XGrabKey(3x11), XGrabKeyboard(3x11)Xlib - C Language X Interface
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | x11/library/libx11 ||_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| MT-Level | See XInitThreads(3X11) |
|_____________________________|_____________________________|
X Version 11 Last change: libX11 1.3.5 4