XGrabButton(3) XLIB FUNCTIONS XGrabButton(3)

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:

+o 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.

+o The grab_window contains the pointer.

+o The confine_to window (if any) is viewable.

+o 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

X Version 11 libX11 1.8.10 XGrabButton(3)