xcb_grab_pointer(3) XCB Requests xcb_grab_pointer(3)NAMExcb_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 Allow‐
Events request or until the keyboard grab is re‐
leased.
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 Allow‐
Events request or until the keyboard grab is re‐
leased.
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 ap‐
plication. The first application then will get an indication
that the other application grabbed the pointer before its re‐
quest 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 re‐
ported 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_window_error_t
The specified window does not exist.
xcb_value_error_t
TODO: reasons?
EXAMPLE
/*
* Grabs the pointer actively
*
*/
void my_example(xcb_connection *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(preply);
}
}
SEE ALSOxcb-requests(3), xcb-examples(3), xcb_grab_keyboard(3)AUTHOR
Generated from xproto.xml. Contact xcb@lists.freedesktop.org for cor‐
rections and improvements.
XCB 2013-07-27 xcb_grab_pointer(3)
