NAME
XGrabButton, XUngrabButton - grab pointer buttons
SYNTAX
int
XGrabButton(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);
int
XUngrabButton(Display * display, unsigned int button, unsigned
int modifiers, Window grab_window);
ARGUMENTS
- button
- Specifies the pointer button that is to be grabbed or
released or AnyButton.
- confine_to
- Specifies the window to confine the pointer in or
None.
- cursor
- Specifies the cursor that is to be displayed 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.
- modifiers
- Specifies the set of keymasks or AnyModifier. The
mask is the bitwise inclusive OR of the valid keymask bits.
- 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.
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), at which point a
ButtonRelease event is reported to the grabbing
window.
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.
The
XUngrabButton function releases the passive button/key combination on
the specified window if it was grabbed by this client. A modifiers of
AnyModifier is equivalent to issuing the ungrab request for all
possible modifier combinations, including the combination of no modifiers. A
button of
AnyButton is equivalent to issuing the request for all
possible buttons.
XUngrabButton has no effect on an active grab.
XUngrabButton can generate
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(3), XGrabPointer(3), XGrabKey(3), XGrabKeyboard(3),
Xlib - C Language X Interface