gtk/gdk/gdkdevicemanager.c
Carlos Garnacho 49448290c3 gdk: Document the behavior of device grabs on slave devices
This may be useful for certain applications, so document it explicitly.
2014-07-21 22:16:05 +02:00

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/* GDK - The GIMP Drawing Kit
* Copyright (C) 2009 Carlos Garnacho <carlosg@gnome.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gdkdevicemanagerprivate.h"
#include "gdkdisplay.h"
#include "gdkintl.h"
/**
* SECTION:gdkdevicemanager
* @Short_description: Functions for handling input devices
* @Title: GdkDeviceManager
* @See_also: #GdkDevice, #GdkEvent
*
* 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. Such input devices often have
* additional features, such as sub-pixel positioning information and
* additional device-dependent information.
*
* 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.
*
* 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().
* There should rarely be a need to do that though, since GDK defaults
* to a compatibility mode in which it will emit just one enter/leave
* event pair for all devices on a window. To enable per-device
* enter/leave events and other multi-pointer interaction features,
* gdk_window_set_support_multidevice() must be called on
* #GdkWindows (or gtk_widget_set_support_multidevice() on widgets).
* window. See the gdk_window_set_support_multidevice() documentation
* for more information.
*
* On X11, multi-device support is implemented through XInput 2.
* Unless gdk_disable_multidevice() is called, the XInput 2
* #GdkDeviceManager implementation will be used as the input source.
* Otherwise either the core or XInput 1 implementations will be used.
*
* For simple applications that dont have any special interest in
* input devices, the so-called “client pointer”
* provides a reasonable approximation to a simple setup with a single
* pointer and keyboard. The device that has been set as the client
* pointer can be accessed via gdk_device_manager_get_client_pointer().
*
* 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.
*
* # Master and slave devices
*
* |[
* carlos@sacarino:~$ xinput list
* ⎡ Virtual core pointer id=2 [master pointer (3)]
* ⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
* ⎜ ↳ Wacom ISDv4 E6 Pen stylus id=10 [slave pointer (2)]
* ⎜ ↳ Wacom ISDv4 E6 Finger touch id=11 [slave pointer (2)]
* ⎜ ↳ SynPS/2 Synaptics TouchPad id=13 [slave pointer (2)]
* ⎜ ↳ TPPS/2 IBM TrackPoint id=14 [slave pointer (2)]
* ⎜ ↳ Wacom ISDv4 E6 Pen eraser id=16 [slave pointer (2)]
* ⎣ Virtual core keyboard id=3 [master keyboard (2)]
* ↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
* ↳ Power Button id=6 [slave keyboard (3)]
* ↳ Video Bus id=7 [slave keyboard (3)]
* ↳ Sleep Button id=8 [slave keyboard (3)]
* ↳ Integrated Camera id=9 [slave keyboard (3)]
* ↳ AT Translated Set 2 keyboard id=12 [slave keyboard (3)]
* ↳ ThinkPad Extra Buttons id=15 [slave keyboard (3)]
* ]|
*
* By default, GDK will automatically listen for events coming from all
* master devices, setting the #GdkDevice for all events coming from input
* devices. 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. When dealing with an event on a master device,
* it is possible to get the source (slave) device that the event originated
* from via gdk_event_get_source_device().
*
* On a standard session, all physical devices are connected by default to
* the "Virtual Core Pointer/Keyboard" master devices, hence routing all events
* through these. This behavior is only modified by device grabs, where the
* slave device is temporarily detached for as long as the grab is held, and
* more permanently by user modifications to the device hierarchy.
*
* On certain application specific setups, it may make sense
* to detach a physical device from its master pointer, and mapping it to
* an specific window. This can be achieved by the combination of
* gdk_device_grab() and gdk_device_set_mode().
*
* In order to listen for events coming from devices
* 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 “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().
*/
static void gdk_device_manager_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void gdk_device_manager_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
G_DEFINE_ABSTRACT_TYPE (GdkDeviceManager, gdk_device_manager, G_TYPE_OBJECT)
enum {
PROP_0,
PROP_DISPLAY
};
enum {
DEVICE_ADDED,
DEVICE_REMOVED,
DEVICE_CHANGED,
LAST_SIGNAL
};
static guint signals [LAST_SIGNAL] = { 0 };
static void
gdk_device_manager_class_init (GdkDeviceManagerClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->set_property = gdk_device_manager_set_property;
object_class->get_property = gdk_device_manager_get_property;
g_object_class_install_property (object_class,
PROP_DISPLAY,
g_param_spec_object ("display",
P_("Display"),
P_("Display for the device manager"),
GDK_TYPE_DISPLAY,
G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
G_PARAM_STATIC_STRINGS));
/**
* GdkDeviceManager::device-added:
* @device_manager: the object on which the signal is emitted
* @device: the newly added #GdkDevice.
*
* The ::device-added signal is emitted either when a new master
* pointer is created, or when a slave (Hardware) input device
* is plugged in.
*/
signals [DEVICE_ADDED] =
g_signal_new (g_intern_static_string ("device-added"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GdkDeviceManagerClass, device_added),
NULL, NULL,
g_cclosure_marshal_VOID__OBJECT,
G_TYPE_NONE, 1,
GDK_TYPE_DEVICE);
/**
* GdkDeviceManager::device-removed:
* @device_manager: the object on which the signal is emitted
* @device: the just removed #GdkDevice.
*
* The ::device-removed signal is emitted either when a master
* pointer is removed, or when a slave (Hardware) input device
* is unplugged.
*/
signals [DEVICE_REMOVED] =
g_signal_new (g_intern_static_string ("device-removed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GdkDeviceManagerClass, device_removed),
NULL, NULL,
g_cclosure_marshal_VOID__OBJECT,
G_TYPE_NONE, 1,
GDK_TYPE_DEVICE);
/**
* GdkDeviceManager::device-changed:
* @device_manager: the object on which the signal is emitted
* @device: the #GdkDevice that changed.
*
* The ::device-changed signal is emitted whenever a device
* has changed in the hierarchy, either slave devices being
* disconnected from their master device or connected to
* another one, or master devices being added or removed
* a slave device.
*
* If a slave device is detached from all master devices
* (gdk_device_get_associated_device() returns %NULL), its
* #GdkDeviceType will change to %GDK_DEVICE_TYPE_FLOATING,
* if it's attached, it will change to %GDK_DEVICE_TYPE_SLAVE.
*/
signals [DEVICE_CHANGED] =
g_signal_new (g_intern_static_string ("device-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GdkDeviceManagerClass, device_changed),
NULL, NULL,
g_cclosure_marshal_VOID__OBJECT,
G_TYPE_NONE, 1,
GDK_TYPE_DEVICE);
}
static void
gdk_device_manager_init (GdkDeviceManager *device_manager)
{
}
static void
gdk_device_manager_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
switch (prop_id)
{
case PROP_DISPLAY:
GDK_DEVICE_MANAGER (object)->display = g_value_get_object (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gdk_device_manager_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
switch (prop_id)
{
case PROP_DISPLAY:
g_value_set_object (value, GDK_DEVICE_MANAGER (object)->display);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* gdk_device_manager_get_display:
* @device_manager: a #GdkDeviceManager
*
* Gets the #GdkDisplay associated to @device_manager.
*
* Returns: (nullable) (transfer none): the #GdkDisplay to which
* @device_manager is associated to, or #NULL. This memory is
* owned by GDK and must not be freed or unreferenced.
*
* Since: 3.0
**/
GdkDisplay *
gdk_device_manager_get_display (GdkDeviceManager *device_manager)
{
g_return_val_if_fail (GDK_IS_DEVICE_MANAGER (device_manager), NULL);
return device_manager->display;
}
/**
* gdk_device_manager_list_devices:
* @device_manager: a #GdkDeviceManager
* @type: device type to get.
*
* Returns the list of devices of type @type currently attached to
* @device_manager.
*
* Returns: (transfer container) (element-type Gdk.Device): a list of
* #GdkDevices. The returned list must be
* freed with g_list_free (). The list elements are owned by
* GTK+ and must not be freed or unreffed.
*
* Since: 3.0
**/
GList *
gdk_device_manager_list_devices (GdkDeviceManager *device_manager,
GdkDeviceType type)
{
g_return_val_if_fail (GDK_IS_DEVICE_MANAGER (device_manager), NULL);
return GDK_DEVICE_MANAGER_GET_CLASS (device_manager)->list_devices (device_manager, type);
}
/**
* gdk_device_manager_get_client_pointer:
* @device_manager: a #GdkDeviceManager
*
* Returns the client pointer, that is, the master pointer that acts as the core pointer
* for this application. In X11, window managers may change this depending on the interaction
* pattern under the presence of several pointers.
*
* You should use this function seldomly, only in code that isnt triggered by a #GdkEvent
* and there arent other means to get a meaningful #GdkDevice to operate on.
*
* Returns: (transfer none): The client pointer. This memory is
* owned by GDK and must not be freed or unreferenced.
*
* Since: 3.0
**/
GdkDevice *
gdk_device_manager_get_client_pointer (GdkDeviceManager *device_manager)
{
g_return_val_if_fail (GDK_IS_DEVICE_MANAGER (device_manager), NULL);
return GDK_DEVICE_MANAGER_GET_CLASS (device_manager)->get_client_pointer (device_manager);
}