xcb_grab_pointer(3) XCB Requests xcb_grab_pointer(3)
NAME
xcb_grab_pointer - Grab the pointer
SYNOPSIS
#include <xcb/xproto.h> Request function
xcb_grab_pointer_cookie_t
xcb_grab_pointer(xcb_connection_t *
conn,
uint8_t
owner_events, xcb_window_t
grab_window,
uint16_t
event_mask, uint8_t
pointer_mode,
uint8_t
keyboard_mode, xcb_window_t
confine_to,
xcb_cursor_t
cursor, xcb_timestamp_t
time);
Reply datastructure
typedef struct xcb_grab_pointer_reply_t {
uint8_t
response_type;
uint8_t
status;
uint16_t
sequence;
uint32_t
length;
}
xcb_grab_pointer_reply_t;
Reply function
xcb_grab_pointer_reply_t
*
xcb_grab_pointer_reply(xcb_connection_t *
conn,
xcb_grab_pointer_cookie_t
cookie, xcb_generic_error_t **
e);
REQUEST ARGUMENTS
conn The XCB connection to X11.
owner_events If 1, the
grab_window will still get the pointer events. If
0, events are not reported to the
grab_window.
grab_window Specifies the window on which the pointer should be
grabbed.
event_mask Specifies which pointer events are reported to the client.
TODO: which values?
pointer_mode One of the following values:
XCB_GRAB_MODE_SYNC The state of the keyboard appears to freeze: No
further keyboard events are generated by the
server until the grabbing client issues a
releasing
AllowEvents request or until the
keyboard grab is released.
XCB_GRAB_MODE_ASYNC Keyboard event processing continues normally.
keyboard_mode One of the following values:
XCB_GRAB_MODE_SYNC The state of the keyboard appears to freeze: No
further keyboard events are generated by the
server until the grabbing client issues a
releasing
AllowEvents request or until the
keyboard grab is released.
XCB_GRAB_MODE_ASYNC Keyboard event processing continues normally.
confine_to Specifies the window to confine the pointer in (the user
will not be able to move the pointer out of that window).
The special value
XCB_NONE means don't confine the pointer.
cursor Specifies the cursor that should be displayed or
XCB_NONE to not change the cursor.
time 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.
The special value
XCB_CURRENT_TIME will be replaced with
the current server time.
REPLY FIELDS
response_type The type of this reply, in this case
XCB_GRAB_POINTER. This
field is also present in the
xcb_generic_reply_t and can be
used to tell replies apart from each other.
sequence The sequence number of the last request processed by the
X11 server.
length The length of the reply, in words (a word is 4 bytes).
status One of the following values:
XCB_GRAB_STATUS_SUCCESS TODO: NOT YET DOCUMENTED.
XCB_GRAB_STATUS_ALREADY_GRABBED TODO: NOT YET DOCUMENTED.
XCB_GRAB_STATUS_INVALID_TIME TODO: NOT YET DOCUMENTED.
XCB_GRAB_STATUS_NOT_VIEWABLE TODO: NOT YET DOCUMENTED.
XCB_GRAB_STATUS_FROZEN TODO: NOT YET DOCUMENTED.
TODO: NOT YET DOCUMENTED.
DESCRIPTION
Actively grabs control of the pointer. Further pointer events are
reported only to the grabbing client. Overrides any active pointer
grab by this client.
RETURN VALUE
Returns an
xcb_grab_pointer_cookie_t. Errors have to be handled when
calling the reply function
xcb_grab_pointer_reply.
If you want to handle errors in the event loop instead, use
xcb_grab_pointer_unchecked. See
xcb-requests(3) for details.
ERRORS
xcb_value_error_t TODO: reasons?
xcb_window_error_t The specified
window does not exist.
EXAMPLE
/*
* Grabs the pointer actively
*
*/
void my_example(xcb_connection_t *conn, xcb_screen_t *screen, xcb_cursor_t cursor) {
xcb_grab_pointer_cookie_t cookie;
xcb_grab_pointer_reply_t *reply;
cookie = xcb_grab_pointer(
conn,
false, /* get all pointer events specified by the following mask */
screen->root, /* grab the root window */
XCB_NONE, /* which events to let through */
XCB_GRAB_MODE_ASYNC, /* pointer events should continue as normal */
XCB_GRAB_MODE_ASYNC, /* keyboard mode */
XCB_NONE, /* confine_to = in which window should the cursor stay */
cursor, /* we change the cursor to whatever the user wanted */
XCB_CURRENT_TIME
);
if ((reply = xcb_grab_pointer_reply(conn, cookie, NULL))) {
if (reply->status == XCB_GRAB_STATUS_SUCCESS)
printf("successfully grabbed the pointer\n");
free(reply);
}
}
SEE ALSO
xcb-requests(3),
xcb-examples(3),
xcb_grab_keyboard(3)AUTHOR
Generated from xproto.xml. Contact xcb@lists.freedesktop.org for
corrections and improvements.
X Version 11 libxcb 1.16.1 xcb_grab_pointer(3)
