gtk.gdk.Device
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## gtk.gdk.Device

gtk.gdk.Device — an object for supporting input devices

## Synopsis

    class gtk.gdk.Device(gobject.GObject):
        def set_source(source)
        def set_mode(mode)
        def set_key(index, keyval, modifiers)
        def set_axis_use(index, use)
        def get_state(window)
        def get_history(window, start, stop)
        def get_axis(axes, use)

    Functions

        def gtk.gdk.devices_list()
        def gtk.gdk.device_get_core_pointer()

## Ancestry

    +-- gobject.GObject
      +-- gtk.gdk.Device

## Attributes

"axes" | Read | a tuple containing axes information. Each axes is described by a tuple containing: use information (one of: `gtk.gdk.AXIS_IGNORE`, `gtk.gdk.AXIS_X`, `gtk.gdk.AXIS_Y`, `gtk.gdk.AXIS_PRESSURE`, `gtk.gdk.AXIS_XTILT`, `gtk.gdk.AXIS_YTILT`, `gtk.gdk.AXIS_WHEEL`, `gtk.gdk.AXIS_LAST`), the minimum and maximum axes values.
"has_cursor" | Read | if `True` the pointer follows device motion.
"keys" | Read | a tuple describing the mapped macro buttons. Each macro button is described by a tuple containing: a key value output when the macro button is pressed and a set of modifiers output with the key value.
"mode" | Read | the mode of this device - one of: `gtk.gdk.MODE_DISABLED`, `gtk.gdk.MODE_SCREEN`, `gtk.gdk.MODE_WINDOW`
"name" | Read | the name of this device.
"num_axes" | Read | the length of the `axes` tuple.
"num_keys" | Read | the length of the `keys` tuple
"source" | Read | the type of this device - one of: `gtk.gdk.SOURCE_MOUSE`, `gtk.gdk.SOURCE_PEN`, `gtk.gdk.SOURCE_ERASER`, `gtk.gdk.SOURCE_CURSOR`

## Description

In addition to the normal keyboard and mouse input devices, `PyGTK` also contains support for extended input devices. In particular, this support is targeted at graphics tablets. Graphics tablets typically return sub-pixel positioning information and possibly information about the pressure and tilt of the stylus. Under X, the support for extended devices is done through the XInput extension. Because handling extended input devices may involve considerable overhead, they need to be turned on for each `gtk.gdk.Window` individually using `gtk.gdk.Window.input_set_extension_events`(). (Or, more typically, for `gtk.Widget` objects, using the `gtk.Widget.set_extension_events`() method). As an additional complication, depending on the support from the windowing system, its possible that a normal mouse cursor will not be displayed for a particular extension device. If an application does not want to deal with displaying a cursor itself, it can ask only to get extension events from devices that will display a cursor, by passing the `gtk.gdk.EXTENSION_EVENTS_CURSOR` value to the `gtk.gdk.Window.input_set_extension_events`() method. Otherwise, the application must retrieve the device information using the `gtk.gdk.devices_list`() function, check the has_cursor field, and, if it is `False`, draw a cursor itself when it receives motion events.

Each pointing device is assigned a unique integer ID; events from a particular device can be identified by the `deviceid` attribute in the event structure. The events generated by pointer devices have also been extended to contain `pressure`, `xtilt` and `ytilt` attributes which contain the extended information reported as additional valuators from the device. The `pressure` attribute ranges from 0.0 to 1.0, while the tilt attributes range from -1.0 to 1.0. (With -1.0 representing the maximum tilt to the left or up, and 1.0 representing the maximum tilt to the right or down.) One additional attribute in each event is the `source` attribute, which contains an enumeration value describing the type of device; this currently can be one of `gtk.gdk.SOURCE_MOUSE`, `gtk.gdk.SOURCE_PEN`, `gtk.gdk.SOURCE_ERASER`, or `gtk.gdk.SOURCE_CURSOR`. This attribute is present to allow simple applications to (for instance) delete when they detect eraser devices without having to keep track of complicated per-device settings.

Various aspects of each device may be configured. The easiest way of creating a GUI to allow the user to configure such a device is to use the `gtk.InputDialog` widget in `PyGTK`. However, even when using this widget, application writers will need to directly query and set the configuration parameters in order to save the state between invocations of the application. The configuration of devices is queried using the `gtk.gdk.devices_list`() function. Each device must be activated using the `set_mode`() method, which also controls whether the device's range is mapped to the entire screen or to a single window. The mapping of the valuators of the device onto the predefined valuator types is set using the `set_axis_use`() method. And the source type for each device can be set with the `set_source`() method.

Devices may also have associated keys or macro buttons. Such keys can be globally set to map into normal X keyboard events. The mapping is set using the `set_key`() method. The interfaces in this section will most likely be considerably modified in the future to accommodate devices that may have different sets of additional valuators than the pressure xtilt and ytilt.

## Methods

### gtk.gdk.Device.set_source

        def set_source(source)

`source` : | the source type of the device

The `set_source`() method sets the source type for the input device to the value specified by `source`. The value of `source` must be one of:

`gtk.gdk.SOURCE_MOUSE` | the device is a mouse. (This will be reported for the core pointer, even if it is something else, such as a trackball.)
`gtk.gdk.SOURCE_PEN` | the device is a stylus of a graphics tablet or similar device.
`gtk.gdk.SOURCE_ERASER` | the device is an eraser. Typically, this would be the other end of a stylus on a graphics tablet.
`gtk.gdk.SOURCE_CURSOR` | the device is a graphics tablet "puck" or similar device.

### gtk.gdk.Device.set_mode

        def set_mode(mode)

`mode` : | the input mode
Returns : | `True` if the mode was successfully changed.

The `set_mode`() method sets the input device mode to the value specified by `mode`. The value of `mode` must be one of:

`gtk.gdk.MODE_DISABLED` | the device is disabled and will not report any events.
`gtk.gdk.MODE_SCREEN` | the device is enabled. The device's coordinate space maps to the entire screen.
`gtk.gdk.MODE_WINDOW` | the device is enabled. The device's coordinate space is mapped to a single window. The manner in which this window is chosen is undefined, but it will typically be the same way in which the focus window for key events is determined.

### gtk.gdk.Device.set_key

        def set_key(index, keyval, modifiers)

`index` : | the index of the macro button to set.
`keyval` : | the key value to generate.
`modifiers` : | the modifiers to set.

The `set_key`() method sets the key event to generate when a macro button of a device is pressed. The macro button is specified by `index`. The key value and modifiers generated are specified by `keyval` and `modifiers` respectively.

### gtk.gdk.Device.set_axis_use

        def set_axis_use(index, use)

`index` : | the index of the axis.
`use` : | how the axis is used.

The `set_axis_use`() method sets the axis (specified by `index`) of the input device to be used in the fashion specified by `use`. The value of `use` must be one of:

`gtk.gdk.AXIS_IGNORE` | the axis is ignored.
`gtk.gdk.AXIS_X` | the axis is used as the x axis.
`gtk.gdk.AXIS_Y` | the axis is used as the y axis.
`gtk.gdk.AXIS_PRESSURE` | the axis is used for pressure information.
`gtk.gdk.AXIS_XTILT` | the axis is used for x tilt information.
`gtk.gdk.AXIS_YTILT` | the axis is used for y tilt information.
`gtk.gdk.AXIS_WHEEL` | the axis is used for wheel information.
`gtk.gdk.AXIS_LAST` | a constant equal to the numerically highest axis value.

### gtk.gdk.Device.get_state

        def get_state(window)

`window` : | a `gtk.gdk.Window`
Returns : | a tuple containing: a tuple containing the axes data; and, the modifiers in effect.

The `get_state`() method returns a tuple containing:

- a tuple containing the axes data
- the bitmask containing the set of key modifiers in effect

The state information is relative to the `gtk.gdk.Window` specified by `window`.

### gtk.gdk.Device.get_history

        def get_history(window, start, stop)

`window` : | a `gtk.gdk.Window`
`start` : | the earliest event time limit
`stop` : | the latest event time limit
Returns : | a tuple containing event tuples each with axes data and a timestamp

The `get_history`() method returns a tuple containing the motion history for the device with respect to the `gtk.gdk.Window` specified by window between the time limits specified by `start` and `stop`. The motion history is a tuple containing event motion tuples that each contain a timestamp for the event and a tuple with the axes data for the event.

### gtk.gdk.Device.get_axis

        def get_axis(axes, use)

`axes` : | a sequence of axes values
`use` : | the axis use to match
Returns : | the axis value from `axes` that matches the use type or `None` if there is no match.

The `get_axis`() method returns the value in `axes` whose axis matches the specified `use`.

## Functions

### gtk.gdk.devices_list

        def gtk.gdk.devices_list()

Returns : | a list containing the `gtk.gdk.Device` objects for the default display

The `gtk.gdk.devices_list`() function returns a list containing the `gtk.gdk.Device` objects fro the default display.

### gtk.gdk.device_get_core_pointer

        def gtk.gdk.device_get_core_pointer()

Returns : | the

The `gtk.gdk.device_get_core_pointer`() function returns the device that is used as the core pointer.

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