xcb_grab_button(3) - phpMan

xcb_grab_button(3) XCB Requests xcb_grab_button(3)

NAME
xcb_grab_button - Grab pointer button(s)

SYNOPSIS
#include <xcb/xproto.h>

Request function
xcb_void_cookie_t xcb_grab_button(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,
uint8_t button, uint16_t modifiers);

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_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 cur-
sor.

button One of the following values:

XCB_BUTTON_INDEX_ANY
Any of the following (or none):

XCB_BUTTON_INDEX_1
The left mouse button.

XCB_BUTTON_INDEX_2
The right mouse button.

XCB_BUTTON_INDEX_3
The middle mouse button.

XCB_BUTTON_INDEX_4
Scroll wheel. TODO: direction?

XCB_BUTTON_INDEX_5
Scroll wheel. TODO: direction?

modifiers The modifiers to grab.

Using the special value XCB_MOD_MASK_ANY means grab the pointer with all possi-
ble modifier combinations.

DESCRIPTION
This request establishes a passive grab. The pointer is actively grabbed as described in
GrabPointer, the last-pointer-grab time is set to the time at which the button was pressed
(as transmitted in the ButtonPress event), and the ButtonPress event is reported if all of
the following conditions are true:

The pointer is not grabbed and the specified button is logically pressed when the speci-
fied modifier keys are logically down, and no other buttons or modifier keys are logically
down.

The grab-window contains the pointer.

The confine-to window (if any) is viewable.

A passive grab on the same button/key combination does not exist on any ancestor of grab-
window.

The interpretation of the remaining arguments is the same as for GrabPointer. The active
grab is terminated automatically when the logical state of the pointer has all buttons re-
leased, independent of the logical state of modifier keys. Note that the logical state of
a device (as seen by means of the protocol) may lag the physical state if device event
processing is frozen. This request overrides all previous passive grabs by the same client
on the same button/key combinations on the same window. A modifier of AnyModifier is
equivalent to issuing the request for all possible modifier combinations (including the
combination of no modifiers). It is not required that all specified modifiers have cur-
rently assigned keycodes. A button of AnyButton is equivalent to issuing the request for
all possible buttons. Otherwise, it is not required that the button specified currently be
assigned to a physical button.

An Access error is generated if some other client has already issued a GrabButton request
with the same button/key combination on the same window. When using AnyModifier or Any-
Button, the request fails completely (no grabs are established), and an Access error is
generated if there is a conflicting grab for any combination. The request has no effect on
an active grab.

RETURN VALUE
Returns an xcb_void_cookie_t. Errors (if any) have to be handled in the event loop.

If you want to handle errors directly with xcb_request_check instead, use xcb_grab_but-
ton_checked. See xcb-requests(3) for details.

ERRORS
xcb_access_error_t
Another client has already issued a GrabButton with the same button/key combina-
tion on the same window.

xcb_cursor_error_t
The specified cursor does not exist.

xcb_value_error_t
TODO: reasons?

xcb_window_error_t
The specified window does not exist.