Gdk-3.0 Python API Documentation

The #GdkCursor structure represents a cursor. Its contents are private.

The #GdkDevice object represents a single input device, such as a keyboard, a mouse, a touchpad, etc. See the #GdkDeviceManager documentation for more information about the various kinds of master and slave devices, and their relationships.

In addition to a single pointer and keyboard for user interface input, GDK contains support for a variety of input devices, including graphics tablets, touchscreens and multiple pointers/keyboards interacting simultaneously with the user interface. Under X, the support for multiple input devices is done through the <firstterm>XInput 2</firstterm> extension, which also supports additional features such as sub-pixel positioning information and additional device-dependent information. By default, and if the platform supports it, GDK is aware of multiple keyboard/pointer pairs and multitouch devices, this behavior can be changed by calling gdk_disable_multidevice() before gdk_display_open(), although there would rarely be a reason to do that. For a widget or window to be dealt as multipointer aware, gdk_window_set_support_multidevice() or gtk_widget_set_support_multidevice() must have been called on it. Conceptually, in multidevice mode there are 2 device types. Virtual devices (or master devices) are represented by the pointer cursors and keyboard foci that are seen on the screen. Physical devices (or slave devices) represent the hardware that is controlling the virtual devices, and thus have no visible cursor on the screen. Virtual devices are always paired, so there is a keyboard device for every pointer device. Associations between devices may be inspected through gdk_device_get_associated_device(). There may be several virtual devices, and several physical devices could be controlling each of these virtual devices. Physical devices may also be "floating", which means they are not attached to any virtual device. By default, GDK will automatically listen for events coming from all master devices, setting the #GdkDevice for all events coming from input devices, <footnote> Events containing device information are #GDK_MOTION_NOTIFY, #GDK_BUTTON_PRESS, #GDK_2BUTTON_PRESS, #GDK_3BUTTON_PRESS, #GDK_BUTTON_RELEASE, #GDK_SCROLL, #GDK_KEY_PRESS, #GDK_KEY_RELEASE, #GDK_ENTER_NOTIFY, #GDK_LEAVE_NOTIFY, #GDK_FOCUS_CHANGE, #GDK_PROXIMITY_IN, #GDK_PROXIMITY_OUT, #GDK_DRAG_ENTER, #GDK_DRAG_LEAVE, #GDK_DRAG_MOTION, #GDK_DRAG_STATUS, #GDK_DROP_START, #GDK_DROP_FINISHED and #GDK_GRAB_BROKEN. </footnote> Although gdk_window_set_support_multidevice() must be called on #GdkWindows in order to support additional features of multiple pointer interaction, such as multiple per-device enter/leave events, the default setting will emit just one enter/leave event pair for all devices on the window. See gdk_window_set_support_multidevice() documentation for more information. In order to listen for events coming from other than a virtual device, gdk_window_set_device_events() must be called. Generally, this function can be used to modify the event mask for any given device. Input devices may also provide additional information besides X/Y. For example, graphics tablets may also provide pressure and X/Y tilt information. This information is device-dependent, and may be queried through gdk_device_get_axis(). In multidevice mode, virtual devices will change axes in order to always represent the physical device that is routing events through it. Whenever the physical device changes, the #GdkDevice:n-axes property will be notified, and gdk_device_list_axes() will return the new device axes. Devices may also have associated <firstterm>keys</firstterm> or macro buttons. Such keys can be globally set to map into normal X keyboard events. The mapping is set using gdk_device_set_key(). In order to query the device hierarchy and be aware of changes in the device hierarchy (such as virtual devices being created or removed, or physical devices being plugged or unplugged), GDK provides #GdkDeviceManager. On X11, multidevice support is implemented through XInput 2. Unless gdk_disable_multidevice() is called, the XInput 2.x #GdkDeviceManager implementation will be used as the input source. Otherwise either the core or XInput 1.x implementations will be used.