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Functions
GList * | gdk_devices_list () |
const gchar * | gdk_device_get_name () |
void | gdk_device_set_source () |
GdkInputSource | gdk_device_get_source () |
gboolean | gdk_device_set_mode () |
GdkInputMode | gdk_device_get_mode () |
void | gdk_device_set_key () |
void | gdk_device_get_key () |
void | gdk_device_set_axis_use () |
GdkAxisUse | gdk_device_get_axis_use () |
GdkDevice * | gdk_device_get_core_pointer () |
void | gdk_device_get_state () |
gboolean | gdk_device_get_history () |
void | gdk_device_free_history () |
gboolean | gdk_device_get_axis () |
gint | gdk_device_get_n_axes () |
void | gdk_input_set_extension_events () |
Types and Values
struct | GdkDevice |
enum | GdkInputSource |
enum | GdkInputMode |
struct | GdkDeviceKey |
struct | GdkDeviceAxis |
enum | GdkAxisUse |
struct | GdkTimeCoord |
enum | GdkExtensionMode |
Description
In addition to the normal keyboard and mouse input devices, GTK+ 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 GdkWindow
individually using gdk_input_set_extension_events()
.
(Or, more typically, for GtkWidgets, using gtk_widget_set_extension_events()
).
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
GDK_EXTENSION_EVENTS_CURSOR
value to
gdk_input_set_extension_events()
. Otherwise, the application
must retrieve the device information using gdk_devices_list()
,
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
field in the event structure. The
events generated by pointer devices have also been extended to contain
pressure
, xtilt
and ytilt
fields which contain the extended
information reported as additional valuators
from the device. The pressure
field is a
a double value ranging from 0.0 to 1.0, while the tilt fields are
double values ranging 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 field in each event is the
source
field, which contains an
enumeration value describing the type of device; this currently
can be one of GDK_SOURCE_MOUSE
, GDK_SOURCE_PEN
, GDK_SOURCE_ERASER
,
or GDK_SOURCE_CURSOR
. This field 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 configuration of devices is queried using gdk_devices_list()
.
Each device must be activated using gdk_device_set_mode()
, 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
gdk_device_set_axis_use()
. And the source type for each device
can be set with gdk_device_set_source()
.
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
gdk_device_set_key()
.
The interfaces in this section will most likely be considerably
modified in the future to accomodate devices that may have different
sets of additional valuators than the pressure xtilt
and ytilt
.
Functions
gdk_devices_list ()
GList *
gdk_devices_list (void
);
Returns the list of available input devices for the default display. The list is statically allocated and should not be freed.
gdk_device_get_name ()
const gchar *
gdk_device_get_name (GdkDevice *device
);
Determines the name of the device.
Since: 2.22
gdk_device_set_source ()
void gdk_device_set_source (GdkDevice *device
,GdkInputSource source
);
Sets the source type for an input device.
gdk_device_get_source ()
GdkInputSource
gdk_device_get_source (GdkDevice *device
);
Determines the type of the device.
Since: 2.22
gdk_device_set_mode ()
gboolean gdk_device_set_mode (GdkDevice *device
,GdkInputMode mode
);
Sets a the mode of an input device. The mode controls if the device is active and whether the device's range is mapped to the entire screen or to a single window.
gdk_device_get_mode ()
GdkInputMode
gdk_device_get_mode (GdkDevice *device
);
Determines the mode of the device.
Since: 2.22
gdk_device_set_key ()
void gdk_device_set_key (GdkDevice *device
,guint index_
,guint keyval
,GdkModifierType modifiers
);
Specifies the X key event to generate when a macro button of a device is pressed.
Parameters
device |
a GdkDevice. |
|
index_ |
the index of the macro button to set. |
|
keyval |
the keyval to generate. |
|
modifiers |
the modifiers to set. |
gdk_device_get_key ()
void gdk_device_get_key (GdkDevice *device
,guint index
,guint *keyval
,GdkModifierType *modifiers
);
If index
has a valid keyval, this function will
fill in keyval
and modifiers
with the keyval settings.
Parameters
device |
a GdkDevice. |
|
index |
the index of the macro button to get. |
|
keyval |
return value for the keyval. |
|
modifiers |
return value for modifiers. |
Since: 2.22
gdk_device_set_axis_use ()
void gdk_device_set_axis_use (GdkDevice *device
,guint index_
,GdkAxisUse use
);
Specifies how an axis of a device is used.
gdk_device_get_axis_use ()
GdkAxisUse gdk_device_get_axis_use (GdkDevice *device
,guint index
);
Returns the axis use for index
.
Since: 2.22
gdk_device_get_core_pointer ()
GdkDevice *
gdk_device_get_core_pointer (void
);
Returns the core pointer device for the default display.
gdk_device_get_state ()
void gdk_device_get_state (GdkDevice *device
,GdkWindow *window
,gdouble *axes
,GdkModifierType *mask
);
Gets the current state of a device.
gdk_device_get_history ()
gboolean gdk_device_get_history (GdkDevice *device
,GdkWindow *window
,guint32 start
,guint32 stop
,GdkTimeCoord ***events
,gint *n_events
);
Obtains the motion history for a device; given a starting and
ending timestamp, return all events in the motion history for
the device in the given range of time. Some windowing systems
do not support motion history, in which case, FALSE
will
be returned. (This is not distinguishable from the case where
motion history is supported and no events were found.)
Parameters
device |
||
window |
the window with respect to which which the event coordinates will be reported |
|
start |
starting timestamp for range of events to return |
|
stop |
ending timestamp for the range of events to return |
|
events |
location to store a newly-allocated array of GdkTimeCoord, or |
[array length=n_events][out][transfer none] |
n_events |
location to store the length of |
gdk_device_free_history ()
void gdk_device_free_history (GdkTimeCoord **events
,gint n_events
);
Frees an array of GdkTimeCoord that was returned by gdk_device_get_history()
.
Frees an array of GdkTimeCoord that was returned by gdk_device_get_history()
.
Parameters
events |
an array of GdkTimeCoord. |
[inout][transfer none] |
n_events |
the length of the array. |
gdk_device_get_axis ()
gboolean gdk_device_get_axis (GdkDevice *device
,gdouble *axes
,GdkAxisUse use
,gdouble *value
);
Interprets an array of double as axis values for a given device, and locates the value in the array for a given axis use.
gdk_device_get_n_axes ()
gint
gdk_device_get_n_axes (GdkDevice *device
);
Gets the number of axes of a device.
Since: 2.22
gdk_input_set_extension_events ()
void gdk_input_set_extension_events (GdkWindow *window
,gint mask
,GdkExtensionMode mode
);
Turns extension events on or off for a particular window, and specifies the event mask for extension events.
Parameters
window |
a GdkWindow. |
|
mask |
the event mask |
|
mode |
the type of extension events that are desired. |
Types and Values
struct GdkDevice
struct GdkDevice { GObject parent_instance; /* All fields are read-only */ gchar *GSEAL (name); GdkInputSource GSEAL (source); GdkInputMode GSEAL (mode); gboolean GSEAL (has_cursor); /* TRUE if the X pointer follows device motion */ gint GSEAL (num_axes); GdkDeviceAxis *GSEAL (axes); gint GSEAL (num_keys); GdkDeviceKey *GSEAL (keys); };
A GdkDevice structure contains
a detailed description of an extended input device. All
fields are read-only; but you can use gdk_device_set_source()
,
gdk_device_set_mode()
, gdk_device_set_key()
and gdk_device_set_axis_use()
to configure various aspects of the device.
enum GdkInputSource
An enumeration describing the type of an input device in general terms.
Members
the device is a mouse. (This will be reported for the core pointer, even if it is something else, such as a trackball.) |
||
the device is a stylus of a graphics tablet or similar device. |
||
the device is an eraser. Typically, this would be the other end of a stylus on a graphics tablet. |
||
the device is a graphics tablet "puck" or similar device. |
enum GdkInputMode
An enumeration that describes the mode of an input device.
Members
the device is disabled and will not report any events. |
||
the device is enabled. The device's coordinate space maps to the entire screen. |
||
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. |
struct GdkDeviceKey
struct GdkDeviceKey { guint keyval; GdkModifierType modifiers; };
The GdkDeviceKey structure contains information about the mapping of one device macro button onto a normal X key event. It has the following fields:
Members
guint |
the keyval to generate when the macro button is pressed. If this is 0, no keypress will be generated. |
|
GdkModifierType |
the modifiers set for the generated key event. |
struct GdkDeviceAxis
struct GdkDeviceAxis { GdkAxisUse use; gdouble min; gdouble max; };
The GdkDeviceAxis structure contains information about the range and mapping of a device axis.
Members
GdkAxisUse |
specifies how the axis is used. |
|
gdouble |
the minimal value that will be reported by this axis. |
|
gdouble |
the maximal value that will be reported by this axis. |
enum GdkAxisUse
An enumeration describing the way in which a device axis (valuator) maps onto the predefined valuator types that GTK+ understands.
Members
the axis is ignored. |
||
the axis is used as the x axis. |
||
the axis is used as the y axis. |
||
the axis is used for pressure information. |
||
the axis is used for x tilt information. |
||
the axis is used for x tilt information. |
||
the axis is used for wheel information. |
||
a constant equal to the numerically highest axis value. |
struct GdkTimeCoord
struct GdkTimeCoord { guint32 time; gdouble axes[GDK_MAX_TIMECOORD_AXES]; };
The GdkTimeCoord structure stores a single event in a motion history. It contains the following fields: