xref: /xsrc/external/mit/libXi/dist/man/XGrabDeviceButton.txt

XGRABDEVICEBUTTON(libmansuffix)
===============================

NAME
----

   XGrabDeviceButton, XUngrabDeviceButton - grab/ungrab extension
   input device buttons

SYNOPSIS
--------

   #include <X11/extensions/XInput.h>

   int XGrabDeviceButton( Display *display,
                          XDevice *device,
                          unsigned int button,
                          unsigned int modifiers,
                          XDevice* modifier_device,
                          Window grab_window,
                          Bool owner_events,
                          unsigned int event_count,
                          XEventClass *event_list,
                          int this_device_mode,
                          int other_devices_mode);

   int XUngrabDeviceButton( Display *display,
                            XDevice *device,
                            unsigned int button,
                            unsigned int modifiers,
                            XDevice* modifier_device,
                            Window grab_window);

   display
          Specifies the connection to the X server.

   device
          Specifies the device that is to be grabbed or released

   button
          Specifies the device button that is to be grabbed or
          released or AnyButton.

   modifiers
          Specifies the set of keymasks or AnyModifier. The mask is
          the bitwise inclusive OR of the valid keymask bits.
          Valid bits are: ShiftMask, LockMask, ControlMask,
          Mod1Mask, Mod2Mask, Mod3Mask, Mod4Mask, Mod5Mask.

   modifier_device
          specifies the device whose modifiers are to be used. If
          the modifier_device specified is NULL, the X keyboard
          will be used as the modifier_device.

   grab_window
          Specifies the grab window.

   owner_events
          Specifies a Boolean value that indicates whether the
          device events are to be reported as usual or reported
          with respect to the grab window if selected by the event
          list.

   event_count
          Specifies the number of event classes in the event list.

   event_list
          Specifies which events are reported to the client.

   this_device_mode
          Specifies further processing of events from this
          device. You can pass GrabModeSync or GrabModeAsync.

   other_devices_mode
          Specifies further processing of events from all other
          devices. You can pass GrabModeSync or GrabModeAsync.

DESCRIPTION
-----------

   The XGrabDeviceButton request establishes a passive grab. In
   the future, the device is actively grabbed (as for XGrabDevice,
   the last-grab time is set to the time at which the button was
   pressed (as transmitted in the DeviceButtonPress event), and
   the DeviceButtonPress event is reported if all of the following
   conditions are true:
     * The device is not grabbed, and the specified button is
       logically pressed when the specified modifier keys are
       logically down on the specified modifier device and no
       other buttons or modifier keys are logically down.
     * Either the grab window is an ancestor of (or is) the focus
       window, OR the grab window is a descendent of the focus
       window and contains the device.
     * A passive grab on the same button/modifier combination does
       not exist on any ancestor of grab_window.

   The interpretation of the remaining arguments is as for
   XGrabDevice. The active grab is terminated automatically when
   the logical state of the device has all buttons released
   (independent of the logical state of the 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/modifier 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.

   A modifier_device of NULL indicates that the X keyboard is to
   be used as the modifier_device.

   If some other client has already issued a XGrabDeviceButton
   with the same button/modifier 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. XGrabDeviceButton has no effect on an active grab.

   XGrabDeviceButton can generate BadClass, BadDevice, BadMatch,
   BadValue, and BadWindow errors.

   The XUngrabDeviceButton request releases the passive grab for a
   button/modifier combination on the specified window if it was
   grabbed by this client. A modifier 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.
   XUngrabDeviceButton has no effect on an active grab.

   A modifier_device of NULL indicates that the X keyboard should
   be used as the modifier_device.

   XUngrabDeviceButton can generate BadDevice, BadMatch, BadValue
   and BadWindow errors.

DIAGNOSTICS
-----------

   BadDevice
          An invalid device was specified. The specified device
          does not exist or has not been opened by this client via
          XOpenInputDevice. This error may also occur if the
          specified device is the X keyboard or X pointer device.

   BadMatch
          This error may occur if an XGrabDeviceButton request was
          made specifying a device that has no buttons, or
          specifying a modifier device that has no keys.

   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
--------

   XAllowDeviceEvents(libmansuffix), XGrabDevice(libmansuffix), XGrabDeviceKey(libmansuffix)