2. Multitouch Touchscreen interaction with more than one
appendage Getting more common 3. And not only mobile devices... 4.
Multitouch Recognition of the shapes of pressure points 5. The good
ol' times Single mouse pointer Single keyboard focus Nothing new
since the 80s 6. So what now? Collaborative interfaces Multiple
users Multiple pointer/keyboard pairs Multitouch Single user Single
keyboard Multiple pointers 7. And any combination... 8. Device
hierarchy Master: Devices visible in the screen Slave: Hardware
devices Attached: Control a Master device Floating: Not attached to
any Master device 9. Device hierarchy typedef enum {
GDK_DEVICE_TYPE_MASTER, GDK_DEVICE_TYPE_SLAVE,
GDK_DEVICE_TYPE_FLOATING } GdkDeviceType; GList *
gdk_device_manager_list_devices (GdkDeviceManager *device_manager,
GdkDeviceType type); GdkDevice * gdk_device_get_associated_device
(GdkDevice *device); GdkDeviceType gdk_device_get_device_type
(GdkDevice *device); 10. Device hotplugging Signals in
GdkDeviceManager device-added device-removed device-changed 11.
Event interaction Events generated by input devices Button
press/release Key press/release Grab broken These events will
contain information about the device that generated them 12.
GdkDevice* gdk_event_get_device (const GdkEvent *event); /*
EXPERIMENTAL */ GdkDevice* gdk_event_get_source_device (const
GdkEvent *event); 13. Enabling events A GdkWindow only obeys Master
devices by default Slave devices need explicit events activation
void gdk_window_set_device_events (GdkWindow *window, GdkDevice
*device, GdkEventMask event_mask); /* EXPERIMENTAL */ void
gdk_window_set_source_events (GdkWindow *window, GdkInputSource
source, GdkEventMask event_mask); 14. Enter/Leave events Emitted
whenever a pointer enters or leaves a GdkWindow For backwards
compatibility, only a pair of events is emitted if several pointers
are within the window area First pointer entering GDK_ENTER_NOTIFY
Last pointer leaving GDK_LEAVE_NOTIFY 15. Enter/Leave events Each
pointer emits its own Enter/Leave events Widgets need to take this
into account if these functions are called void
gdk_window_set_support_multidevice (GdkWindow *window, gboolean
support_multidevice); void gtk_widget_set_support_multidevice
(GtkWidget *widget, gboolean support_multidevice); 16. Where are
thou, pointer? The old calls are non deterministic Basically, the
position of a favourite pointer is obtained, the client pointer 17.
void gdk_display_get_device_state (GdkDisplay *display, GdkDevice
*device, GdkScreen **screen, gint *x, gint *y, GdkModifierType
*mask); GdkWindow * gdk_display_get_window_at_device_position
(GdkDisplay *display, GdkDevice *device, gint *win_x, gint *win_y);
GdkWindow * gdk_window_get_device_position (GdkWindow *window,
GdkDevice *device, gint *x, gint *y, GdkModifierType *mask); 18.
Pointer and keyboard grabs Capture events from the device, and
confine them to a window Menus Drag and Drop Blocks interaction
with further applications 19. GdkGrabStatus gdk_device_grab
(GdkDevice *device, GdkWindow *window, GdkGrabOwnership
grab_ownership, gboolean owner_events, GdkEventMask event_mask,
GdkCursor *cursor, guint32 time_); void gdk_device_ungrab
(GdkDevice *device, guint32 time_); 20. Grab Ownership Defines how
the device owns control over the grabbed window None: Any other
devices are free to interact Window: The GdkWindow is effectively
blocked for any other device Application: The full application is
blocked 21. Grab Ownership Several devices may hold a grab at the
same time, on the same or different windows The device with most
restrictive ownership blocks the others 22. GTK+ grabs Similar to
GDK grabs, but don't block interaction with other applications
Modal dialogs 23. void gtk_device_grab_add (GtkWidget *widget,
GdkDevice *device, gboolean block_others); void
gtk_device_grab_remove (GtkWidget *widget, GdkDevice *device); /*
To be used in grab-notify handler */ gboolean
gtk_widget_device_is_shadowed (GtkWidget *widget, GdkDevice
*device); 24. Multitouch Each finger gets a device Devices emit
individual events There is a need to gather and correlate them
Obtain an event packet Calculate the distance and relative angle
between 2 events GtkDeviceGroup and multidevice-event signal 25. /*
EXPERIMENTAL */ GtkDeviceGroup * gtk_widget_create_device_group
(GtkWidget *widget); void gtk_widget_remove_device_group (GtkWidget
*widget, GtkDeviceGroup *group); void gtk_device_group_add_device
(GtkDeviceGroup *group, GdkDevice *device); void
gtk_device_group_remove_device (GtkDeviceGroup *group, GdkDevice
*device); GList * gtk_device_group_get_devices (GtkDeviceGroup
*group); 26. /* EXPERIMENTAL */ typedef enum {
GTK_EVENT_DEVICE_ADDED, GTK_EVENT_DEVICE_REMOVED,
GTK_EVENT_DEVICE_UPDATED } GtkMultiDeviceEventType; struct
_GtkMultiDeviceEvent { GtkMultiDeviceEventType type; guint
n_events; GdkEventMotion **events; GdkEventMotion *updated_event;
GdkDevice *updated_device; }; 27. gboolean gdk_events_get_distance
(GdkEvent *event1, GdkEvent *event2, gdouble *distance); gboolean
gdk_events_get_angle (GdkEvent *event1, GdkEvent *event2, gdouble
*angle); gboolean gdk_events_get_center (GdkEvent *event1, GdkEvent
*event2, gdouble *x, gdouble *y); 28. Gestures Definition: The act
of moving the limbs or body as an expression of though or emphasis
Not really computable Gestures are a set of finger movements over
time, reduced to an expression with a meaning, The logic to get an
expression out of a gesture is highly heuristic 29. Gestures (2)
Gestures are something extending and complementing multi-touch,
rather on top than part of it. 30. What's left? Consolidating
multidevice-event Gesture support Further multidevice support for
stock widgets 31. Where's all this? Now in GTK+ master Methods
marked as experimental: git clone -b xi2-playground
git://git.gnome.org/gtk+ 32. Questions? 33. Thank you!
