keyboard: add API to track whether a shortcut is default

The current keyboard item API does not track whether the
keyboard shortcut is the default value or not. In order to
properly implement the Reset operation, the keyboard item
must receive this API and ideally handle it internally.

This patch adds the necessary API to CcKeyboardItem to track
whether the shortcut is the default value or not.

https://bugzilla.gnome.org/show_bug.cgi?id=769063

panels/keyboard/cc-keyboard-item.c

@@ -50,6 +50,7 @@ enum {
   PROP_BINDING,
   PROP_EDITABLE,
   PROP_TYPE,
+  PROP_IS_VALUE_DEFAULT,
   PROP_COMMAND
 };
 
@@ -155,6 +156,8 @@ _set_binding (CcKeyboardItem *item,
     return;
 
   settings_set_binding (item->settings, item->key, item->priv->binding);
+
+  g_object_notify (G_OBJECT (item), "is-value-default");
 }
 
 static void
@@ -232,6 +235,9 @@ cc_keyboard_item_get_property (GObject    *object,
   case PROP_COMMAND:
     g_value_set_string (value, self->command);
     break;
+  case PROP_IS_VALUE_DEFAULT:
+    g_value_set_boolean (value, cc_keyboard_item_is_value_default (self));
+    break;
   default:
     G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
     break;
@@ -304,6 +310,14 @@ cc_keyboard_item_class_init (CcKeyboardItemClass *klass)
                                                         NULL,
                                                         G_PARAM_READWRITE));
 
+  g_object_class_install_property (object_class,
+                                   PROP_IS_VALUE_DEFAULT,
+                                   g_param_spec_boolean ("is-value-default",
+                                                         "is value default",
+                                                         "is value default",
+                                                         TRUE,
+                                                         G_PARAM_READABLE));
+
   g_type_class_add_private (klass, sizeof (CcKeyboardItemPrivate));
 }
 
@@ -508,6 +522,74 @@ cc_keyboard_item_is_hidden (CcKeyboardItem *item)
 {
   return item->priv->hidden;
 }
+
+/**
+ * cc_keyboard_item_is_value_default:
+ * @self: a #CcKeyboardItem
+ *
+ * Retrieves whether the shortcut is the default value or not.
+ *
+ * Returns: %TRUE if the shortcut is the default value, %FALSE otherwise.
+ */
+gboolean
+cc_keyboard_item_is_value_default (CcKeyboardItem *self)
+{
+  GVariant *user_value;
+  gboolean is_value_default;
+
+  g_return_val_if_fail (CC_IS_KEYBOARD_ITEM (self), FALSE);
+
+  /*
+   * When the shortcut is custom, we don't treat it as modified
+   * since we don't know what would be its default value.
+   */
+  if (self->type == CC_KEYBOARD_ITEM_TYPE_GSETTINGS_PATH)
+    return TRUE;
+
+  user_value = g_settings_get_user_value (self->settings, self->key);
+
+  is_value_default = TRUE;
+
+  if (user_value)
+    {
+      GVariant *default_value;
+      const gchar *default_binding;
+
+      default_value = g_settings_get_default_value (self->settings, self->key);
+
+      if (g_variant_is_of_type (default_value, G_VARIANT_TYPE_STRING))
+        default_binding = g_variant_get_string (default_value, NULL);
+      else if (g_variant_is_of_type (default_value, G_VARIANT_TYPE_STRING_ARRAY))
+        default_binding = g_variant_get_strv (default_value, NULL)[0];
+      else
+        default_binding = "";
+
+      is_value_default = (g_strcmp0 (default_binding, g_variant_get_string (user_value, NULL)) == 0);
+
+      g_clear_pointer (&default_value, g_variant_unref);
+    }
+
+  g_clear_pointer (&user_value, g_variant_unref);
+
+  return is_value_default;
+}
+
+/**
+ * cc_keyboard_item_reset:
+ * @self: a #CcKeyboardItem
+ *
+ * Reset the keyboard binding to the default value.
+ */
+void
+cc_keyboard_item_reset (CcKeyboardItem *self)
+{
+  g_return_if_fail (CC_IS_KEYBOARD_ITEM (self));
+
+  g_settings_reset (self->settings, self->key);
+
+  g_object_notify (G_OBJECT (self), "is-value-default");
+}
+
 /*
  * vim: sw=2 ts=8 cindent noai bs=2
  */

panels/keyboard/cc-keyboard-item.h

@@ -109,6 +109,10 @@ void             cc_keyboard_item_set_hidden       (CcKeyboardItem *item,
 						    gboolean hidden);
 gboolean         cc_keyboard_item_is_hidden        (CcKeyboardItem *item);
 
+gboolean         cc_keyboard_item_is_value_default (CcKeyboardItem *self);
+
+void             cc_keyboard_item_reset            (CcKeyboardItem *self);
+
 G_END_DECLS
 
 #endif /* __CC_KEYBOARD_ITEM_H */