XGrabButton
Syntax
XGrabButton(display, button, modifiers, grab_window, owner_events, event_mask,
pointer_mode, keyboard_mode, confine_to, cursor)
Display *display;
unsigned int button;
unsigned int modifiers;
Window grab_window;
Bool owner_events;
unsigned int event_mask;
int pointer_mode, keyboard_mode;
Window confine_to;
Cursor cursor;
Arguments
| display
| Specifies the connection to the X server.
|
| button
| Specifies the pointer button that is to be grabbed or
AnyButton.
|
| modifiers
| Specifies the set of keymasks or
AnyModifier.
The mask is the bitwise inclusive OR of the valid keymask bits.
|
| grab_window
| Specifies the grab window.
|
| 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.
|
| 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.
|
| pointer_mode
| Specifies further processing of pointer events.
You can pass
GrabModeSync
or
GrabModeAsync.
|
| keyboard_mode
| Specifies further processing of keyboard events.
You can pass
GrabModeSync
or
GrabModeAsync.
|
| confine_to
| Specifies the window to confine the pointer in or
None.
|
| cursor
| Specifies the cursor that is to be displayed or
None.
|
Description
The
XGrabButton()
function establishes a passive grab.
In the future,
the pointer is actively grabbed (as for
XGrabPointer()),
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 specified 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 as for
XGrabPointer().
The active grab is terminated automatically when the logical state of the
pointer has all buttons released
(independent of the state of the logical modifier keys).
Note that the logical state of a device (as seen by client applications)
may lag the physical state if device event processing is frozen.
This request overrides all previous grabs by the same client on the same
button/key combinations on the same window.
A modifiers of
AnyModifier
is equivalent to issuing the grab request for all
possible modifier combinations (including the combination of no modifiers).
It is not required that all modifiers specified have currently assigned
KeyCodes.
A button of
AnyButton
is equivalent to
issuing the request for all possible buttons.
Otherwise, it is not required that the specified button currently be assigned
to a physical button.
If some other client has already issued a
XGrabButton()
with the same button/key combination on the same window, a
BadAccess
error results.
When using
AnyModifier
or
AnyButton,
the request fails completely,
and a
BadAccess
error results (no grabs are
established) if there is a conflicting grab for any combination.
XGrabButton()
has no effect on an active grab.
XGrabButton()
can generate
BadCursor,
BadValue,
and
BadWindow
errors.
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. Any argument defined as a set of
alternatives can generate this error.
|
| BadWindow
| A value for a Window argument does not name a defined Window.
|
See also
XAllowEvents(),
XChangeActivePointerGrab(),
XGrabKey(),
XGrabKeyboard(),
XGrabPointer(),
XUngrabPointer(),
"
Pointer Grabbing".
Christophe Tronche, [email protected]
