clutter: add hooks for kbd a11y configuration

Use a set of bitwise enum flags to set different keyboard accessibility
features and the necessary vfunc hooks in clutter input device so that
keyboard preferences can be passed to different input device
implementations.

The idea is to be able to configure either the clutter own
implementation of keyboard accessibility for evdev, or eventually
configure AccessX from the X11 clutter input device using the same
mechanism.

https://bugzilla.gnome.org/show_bug.cgi?id=788564

clutter/clutter/clutter-device-manager.c

@@ -54,6 +54,9 @@ struct _ClutterDeviceManagerPrivate
 {
   /* back-pointer to the backend */
   ClutterBackend *backend;
+
+  /* Keyboard a11y */
+  ClutterKbdA11ySettings kbd_a11y_settings;
 };
 
 enum
@@ -487,3 +490,43 @@ _clutter_device_manager_compress_motion (ClutterDeviceManager *device_manager,
 
   manager_class->compress_motion (device_manager, event, to_discard);
 }
+
+static gboolean
+are_kbd_a11y_settings_equal (ClutterKbdA11ySettings *a,
+                             ClutterKbdA11ySettings *b)
+{
+  return (a->controls == b->controls &&
+          a->slowkeys_delay == b->slowkeys_delay &&
+          a->debounce_delay == b->debounce_delay &&
+          a->timeout_delay == b->timeout_delay &&
+          a->mousekeys_init_delay == b->mousekeys_init_delay &&
+          a->mousekeys_max_speed == b->mousekeys_max_speed &&
+          a->mousekeys_accel_time == b->mousekeys_accel_time);
+}
+
+void
+clutter_device_manager_set_kbd_a11y_settings (ClutterDeviceManager   *device_manager,
+                                              ClutterKbdA11ySettings *settings)
+{
+  ClutterDeviceManagerClass *manager_class;
+
+  g_return_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager));
+
+  if (are_kbd_a11y_settings_equal (&device_manager->priv->kbd_a11y_settings, settings))
+    return;
+
+  device_manager->priv->kbd_a11y_settings = *settings;
+
+  manager_class = CLUTTER_DEVICE_MANAGER_GET_CLASS (device_manager);
+  if (manager_class->apply_kbd_a11y_settings)
+    manager_class->apply_kbd_a11y_settings (device_manager, settings);
+}
+
+void
+clutter_device_manager_get_kbd_a11y_settings (ClutterDeviceManager   *device_manager,
+                                              ClutterKbdA11ySettings *settings)
+{
+  g_return_if_fail (CLUTTER_IS_DEVICE_MANAGER (device_manager));
+
+  *settings = device_manager->priv->kbd_a11y_settings;
+}

clutter/clutter/clutter-device-manager.h

@@ -44,6 +44,25 @@ typedef struct _ClutterDeviceManager            ClutterDeviceManager;
 typedef struct _ClutterDeviceManagerPrivate     ClutterDeviceManagerPrivate;
 typedef struct _ClutterDeviceManagerClass       ClutterDeviceManagerClass;
 
+
+/**
+ * ClutterKbdA11ySettings:
+ *
+ * The #ClutterKbdA11ySettings structure contains keyboard accessibility
+ * settings
+ *
+ */
+typedef struct _ClutterKbdA11ySettings
+{
+  ClutterKeyboardA11yFlags controls;
+  gint slowkeys_delay;
+  gint debounce_delay;
+  gint timeout_delay;
+  gint mousekeys_init_delay;
+  gint mousekeys_max_speed;
+  gint mousekeys_accel_time;
+} ClutterKbdA11ySettings;
+
 /**
  * ClutterDeviceManager:
  *
@@ -88,7 +107,9 @@ struct _ClutterDeviceManagerClass
   void                (* compress_motion) (ClutterDeviceManager *device_manger,
                                            ClutterEvent         *event,
                                            const ClutterEvent   *to_discard);
-
+  /* Keyboard accessbility */
+  void                (* apply_kbd_a11y_settings) (ClutterDeviceManager   *device_manger,
+                                                   ClutterKbdA11ySettings *settings);
   /* padding */
   gpointer _padding[6];
 };
@@ -114,6 +135,13 @@ CLUTTER_AVAILABLE_IN_ALL
 ClutterVirtualInputDevice *clutter_device_manager_create_virtual_device (ClutterDeviceManager  *device_manager,
                                                                          ClutterInputDeviceType device_type);
 
+CLUTTER_AVAILABLE_IN_ALL
+void clutter_device_manager_set_kbd_a11y_settings (ClutterDeviceManager   *device_manager,
+                                                   ClutterKbdA11ySettings *settings);
+CLUTTER_AVAILABLE_IN_ALL
+void clutter_device_manager_get_kbd_a11y_settings (ClutterDeviceManager   *device_manager,
+                                                   ClutterKbdA11ySettings *settings);
+
 G_END_DECLS
 
 #endif /* __CLUTTER_DEVICE_MANAGER_H__ */

clutter/clutter/clutter-enums.h

@@ -396,6 +396,43 @@ typedef enum {
   CLUTTER_MODIFIER_MASK = 0x5c001fff
 } ClutterModifierType;
 
+/**
+ * ClutterKeyboardA11yFlags:
+ * @CLUTTER_A11Y_KEYBOARD_ENABLED:
+ * @CLUTTER_A11Y_TIMEOUT_ENABLED:
+ * @CLUTTER_A11Y_MOUSE_KEYS_ENABLED:
+ * @CLUTTER_A11Y_SLOW_KEYS_ENABLED:
+ * @CLUTTER_A11Y_SLOW_KEYS_BEEP_PRESS:
+ * @CLUTTER_A11Y_SLOW_KEYS_BEEP_ACCEPT:
+ * @CLUTTER_A11Y_SLOW_KEYS_BEEP_REJECT:
+ * @CLUTTER_A11Y_BOUNCE_KEYS_ENABLED:
+ * @CLUTTER_A11Y_BOUNCE_KEYS_BEEP_REJECT:
+ * @CLUTTER_A11Y_TOGGLE_KEYS_ENABLED:
+ * @CLUTTER_A11Y_STICKY_KEYS_ENABLED:
+ * @CLUTTER_A11Y_STICKY_KEYS_TWO_KEY_OFF:
+ * @CLUTTER_A11Y_STICKY_KEYS_BEEP:
+ * @CLUTTER_A11Y_FEATURE_STATE_CHANGE_BEEP:
+ *
+ * Keyboard accessibility features applied to a ClutterInputDevice keyboard.
+ *
+ */
+typedef enum {
+  CLUTTER_A11Y_KEYBOARD_ENABLED          = 1 << 0,
+  CLUTTER_A11Y_TIMEOUT_ENABLED           = 1 << 1,
+  CLUTTER_A11Y_MOUSE_KEYS_ENABLED        = 1 << 2,
+  CLUTTER_A11Y_SLOW_KEYS_ENABLED         = 1 << 3,
+  CLUTTER_A11Y_SLOW_KEYS_BEEP_PRESS      = 1 << 4,
+  CLUTTER_A11Y_SLOW_KEYS_BEEP_ACCEPT     = 1 << 5,
+  CLUTTER_A11Y_SLOW_KEYS_BEEP_REJECT     = 1 << 6,
+  CLUTTER_A11Y_BOUNCE_KEYS_ENABLED       = 1 << 7,
+  CLUTTER_A11Y_BOUNCE_KEYS_BEEP_REJECT   = 1 << 8,
+  CLUTTER_A11Y_TOGGLE_KEYS_ENABLED       = 1 << 9,
+  CLUTTER_A11Y_STICKY_KEYS_ENABLED       = 1 << 10,
+  CLUTTER_A11Y_STICKY_KEYS_TWO_KEY_OFF   = 1 << 11,
+  CLUTTER_A11Y_STICKY_KEYS_BEEP          = 1 << 12,
+  CLUTTER_A11Y_FEATURE_STATE_CHANGE_BEEP = 1 << 13,
+} ClutterKeyboardA11yFlags;
+
 /**
  * ClutterActorFlags:
  * @CLUTTER_ACTOR_MAPPED: the actor will be painted (is visible, and inside