deck: Add the navigatable child property

This can be used to skip children during navigation.

src/hdy-deck.c

@@ -75,6 +75,7 @@ enum {
 enum {
   CHILD_PROP_0,
   CHILD_PROP_NAME,
+  CHILD_PROP_NAVIGATABLE,
   LAST_CHILD_PROP,
 };
 
@@ -398,8 +399,8 @@ hdy_deck_get_interpolate_size (HdyDeck *self)
  * @self: a #HdyDeck
  * @can_swipe_back: the new value
  *
- * Sets whether or not @self allows switching to the previous child via a swipe
- * gesture.
+ * Sets whether or not @self allows switching to the previous child that has
+ * 'navigatable' child property set to %TRUE via a swipe gesture
  *
  * Since: 1.0
  */
@@ -435,8 +436,8 @@ hdy_deck_get_can_swipe_back (HdyDeck *self)
  * @self: a #HdyDeck
  * @can_swipe_forward: the new value
  *
- * Sets whether or not @self allows switching to the next child via a swipe
- * gesture.
+ * Sets whether or not @self allows switching to the next child that has
+ * 'navigatable' child property set to %TRUE via a swipe gesture.
  *
  * Since: 1.0
  */
@@ -472,8 +473,9 @@ hdy_deck_get_can_swipe_forward (HdyDeck *self)
  * @self: a #HdyDeck
  * @direction: the direction
  *
- * Gets the previous or next child, or %NULL if it doesn't exist. This will be
- * the same widget hdy_deck_navigate() will navigate to.
+ * Gets the previous or next child that doesn't have 'navigatable' child
+ * property set to %FALSE, or %NULL if it doesn't exist. This will be the same
+ * widget hdy_deck_navigate() will navigate to.
  *
  * Returns: (nullable) (transfer none): the previous or next child, or
  *   %NULL if it doesn't exist.
@@ -494,8 +496,9 @@ hdy_deck_get_adjacent_child (HdyDeck                *self,
  * @self: a #HdyDeck
  * @direction: the direction
  *
- * Switches to the previous or next child, similar to performing a swipe
- * gesture to go in @direction.
+ * Switches to the previous or next child that doesn't have 'navigatable' child
+ * property set to %FALSE, similar to performing a swipe gesture to go in
+ * @direction.
  *
  * Returns: %TRUE if visible child was changed, %FALSE otherwise.
  *
@@ -745,6 +748,10 @@ hdy_deck_get_child_property (GtkContainer *container,
     g_value_set_string (value, hdy_stackable_box_get_child_name (HDY_GET_HELPER (container), widget));
     break;
 
+  case CHILD_PROP_NAVIGATABLE:
+    g_value_set_boolean (value, hdy_stackable_box_get_child_navigatable (HDY_GET_HELPER (container), widget));
+    break;
+
   default:
     GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
     break;
@@ -764,6 +771,11 @@ hdy_deck_set_child_property (GtkContainer *container,
     gtk_container_child_notify_by_pspec (container, widget, pspec);
     break;
 
+  case CHILD_PROP_NAVIGATABLE:
+    hdy_stackable_box_set_child_navigatable (HDY_GET_HELPER (container), widget, g_value_get_boolean (value));
+    gtk_container_child_notify_by_pspec (container, widget, pspec);
+    break;
+
   default:
     GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
     break;
@@ -997,8 +1009,8 @@ hdy_deck_class_init (HdyDeckClass *klass)
   /**
    * HdyDeck:can-swipe-back:
    *
-   * Whether or not the deck allows switching to the previous child via a swipe
-   * gesture.
+   * Whether or not the deck allows switching to the previous child that has
+   * 'navigatable' child property set to %TRUE via a swipe gesture.
    *
    * Since: 1.0
    */
@@ -1012,8 +1024,8 @@ hdy_deck_class_init (HdyDeckClass *klass)
   /**
    * HdyDeck:can-swipe-forward:
    *
-   * Whether or not the deck allows switching to the next child via a swipe
-   * gesture.
+   * Whether or not the deck allows switching to the next child that has
+   * 'navigatable' child property set to %TRUE via a swipe gesture.
    *
    * Since: 1.0
    */
@@ -1033,6 +1045,22 @@ hdy_deck_class_init (HdyDeckClass *klass)
                          NULL,
                          G_PARAM_READWRITE);
 
+  /**
+   * HdyDeck:navigatable:
+   *
+   * Whether the child can be navigated to.
+   * If %FALSE, the child will be ignored by hdy_deck_get_adjacent_child(),
+   * hdy_deck_navigate(), and swipe gestures.
+   *
+   * Since: 1.0
+   */
+  child_props[CHILD_PROP_NAVIGATABLE] =
+    g_param_spec_boolean ("navigatable",
+                          _("Allow navigation"),
+                          _("Whether the child can be navigated to"),
+                          TRUE,
+                          G_PARAM_READWRITE);
+
   gtk_container_class_install_child_properties (container_class, LAST_CHILD_PROP, child_props);
 
   gtk_widget_class_set_accessible_role (widget_class, ATK_ROLE_PANEL);