keyboard: add support to reset shortcuts to their default values

Following the proposed mockups, the shortcut list must
have the ability to reset modified to non-default shortcuts
right from the listbox.

After adding the necessary API in CcKeyboardItem, adding
the user-visible elements to enable that is easy.

To make that happen, add a button that resets the
keyboard shortcut.

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

panels/keyboard/cc-keyboard-manager.c

@@ -84,6 +84,17 @@ free_key_array (GPtrArray *keys)
     }
 }
 
+static const gchar*
+get_binding_from_variant (GVariant *variant)
+{
+  if (g_variant_is_of_type (variant, G_VARIANT_TYPE_STRING))
+    return g_variant_get_string (variant, NULL);
+  else if (g_variant_is_of_type (variant, G_VARIANT_TYPE_STRING_ARRAY))
+    return g_variant_get_strv (variant, NULL)[0];
+
+  return NULL;
+}
+
 static gboolean
 compare_keys_for_uniqueness (CcKeyboardItem   *current_item,
                              CcUniquenessData *data)
@@ -937,3 +948,53 @@ cc_keyboard_manager_disable_shortcut (CcKeyboardManager *self,
 
   g_object_set (item, "binding", NULL, NULL);
 }
+
+/**
+ * cc_keyboard_manager_reset_shortcut:
+ * @self: a #CcKeyboardManager
+ * @item: a #CcKeyboardItem
+ *
+ * Resets the keyboard shortcut managed by @item, and eventually
+ * disables any shortcut that conflicts with the new shortcut's
+ * value.
+ */
+void
+cc_keyboard_manager_reset_shortcut (CcKeyboardManager *self,
+                                    CcKeyboardItem    *item)
+{
+  GVariant *default_value;
+  const gchar *default_binding;
+
+  g_return_if_fail (CC_IS_KEYBOARD_MANAGER (self));
+  g_return_if_fail (CC_IS_KEYBOARD_ITEM (item));
+
+  default_value = g_settings_get_default_value (item->settings, item->key);
+  default_binding = get_binding_from_variant (default_value);
+
+  /* Disables any any shortcut that conflicts with the new shortcut's value */
+  if (default_binding && *default_binding != '\0')
+    {
+      GdkModifierType mask;
+      CcKeyboardItem *collision;
+      guint *keycodes;
+      guint keyval;
+
+      gtk_accelerator_parse_with_keycode (default_binding, &keyval, &keycodes, &mask);
+
+      collision = cc_keyboard_manager_get_collision (self,
+                                                     NULL,
+                                                     keyval,
+                                                     mask,
+                                                     keycodes ? keycodes[0] : 0);
+
+      if (collision)
+        cc_keyboard_manager_disable_shortcut (self, collision);
+
+      g_free (keycodes);
+    }
+
+  /* Resets the current item */
+  cc_keyboard_item_reset (item);
+
+  g_variant_unref (default_value);
+}

panels/keyboard/cc-keyboard-manager.h

@@ -54,6 +54,9 @@ CcKeyboardItem*      cc_keyboard_manager_get_collision           (CcKeyboardMana
 void                 cc_keyboard_manager_disable_shortcut        (CcKeyboardManager  *self,
                                                                   CcKeyboardItem     *item);
 
+void                 cc_keyboard_manager_reset_shortcut          (CcKeyboardManager  *self,
+                                                                  CcKeyboardItem     *item);
+
 G_END_DECLS
 
 #endif /* CC_KEYBOARD_MANAGER_H */

panels/keyboard/cc-keyboard-panel.c

@@ -61,6 +61,11 @@ enum {
   PROP_PARAMETERS
 };
 
+static const gchar* custom_css =
+"button.reset-shortcut-button {"
+"    padding: 0;"
+"}";
+
 /* RowData functions */
 static RowData *
 row_data_new (CcKeyboardItem *item,
@@ -97,24 +102,67 @@ transform_binding_to_accel (GBinding     *binding,
 
   item = CC_KEYBOARD_ITEM (g_binding_get_source (binding));
 
-  accelerator = convert_keysym_state_to_string (item->keyval, item->mask, item->keycode);
+  /* Embolden the label when the shortcut is modified */
+  if (!cc_keyboard_item_is_value_default (item))
+    {
+      gchar *tmp;
+
+      tmp = convert_keysym_state_to_string (item->keyval,
+                                            item->mask,
+                                            item->keycode);
+
+      accelerator = g_strdup_printf ("<b>%s</b>", tmp);
+
+      g_free (tmp);
+    }
+  else
+    {
+      accelerator = convert_keysym_state_to_string (item->keyval,
+                                                    item->mask,
+                                                    item->keycode);
+    }
 
   g_value_take_string (to_value, accelerator);
 
   return TRUE;
 }
 
+static void
+shortcut_modified_changed_cb (CcKeyboardItem *item,
+                              GParamSpec     *pspec,
+                              GtkWidget      *button)
+{
+  gtk_widget_set_child_visible (button, !cc_keyboard_item_is_value_default (item));
+}
+
+static void
+reset_shortcut_cb (GtkWidget      *reset_button,
+                   CcKeyboardItem *item)
+{
+  CcKeyboardPanel *self;
+
+  self = CC_KEYBOARD_PANEL (gtk_widget_get_ancestor (reset_button, CC_TYPE_KEYBOARD_PANEL));
+
+  cc_keyboard_manager_reset_shortcut (self->manager, item);
+}
+
 static void
 add_item (CcKeyboardPanel *self,
           CcKeyboardItem  *item,
           const gchar     *section_id,
           const gchar     *section_title)
 {
-  GtkWidget *row, *box, *label;
+  GtkWidget *row, *box, *label, *reset_button;
 
   /* Horizontal box */
-  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 12);
+  box = g_object_new (GTK_TYPE_BOX,
-  gtk_container_set_border_width (GTK_CONTAINER (box), 6);
+                      "orientation", GTK_ORIENTATION_HORIZONTAL,
+                      "spacing", 18,
+                      "margin-start", 6,
+                      "margin-end", 6,
+                      "margin-bottom", 4,
+                      "margin-top", 4,
+                      NULL);
 
   /* Shortcut title */
   label = gtk_label_new (item->description);
@@ -134,6 +182,7 @@ add_item (CcKeyboardPanel *self,
   /* Shortcut accelerator */
   label = gtk_label_new ("");
   gtk_label_set_xalign (GTK_LABEL (label), 0.0);
+  gtk_label_set_use_markup (GTK_LABEL (label), TRUE);
 
   gtk_size_group_add_widget (self->accelerator_sizegroup, label);
 
@@ -149,6 +198,31 @@ add_item (CcKeyboardPanel *self,
 
   gtk_style_context_add_class (gtk_widget_get_style_context (label), "dim-label");
 
+  /* Reset shortcut button */
+  reset_button = gtk_button_new_from_icon_name ("window-close-symbolic", GTK_ICON_SIZE_BUTTON);
+  gtk_widget_set_valign (reset_button, GTK_ALIGN_CENTER);
+
+  gtk_button_set_relief (GTK_BUTTON (reset_button), GTK_RELIEF_NONE);
+  gtk_widget_set_child_visible (reset_button, !cc_keyboard_item_is_value_default (item));
+
+  gtk_widget_set_tooltip_text (reset_button, _("Reset the shortcut to its default value"));
+
+  gtk_container_add (GTK_CONTAINER (box), reset_button);
+
+  gtk_style_context_add_class (gtk_widget_get_style_context (reset_button), "flat");
+  gtk_style_context_add_class (gtk_widget_get_style_context (reset_button), "circular");
+  gtk_style_context_add_class (gtk_widget_get_style_context (reset_button), "reset-shortcut-button");
+
+  g_signal_connect (item,
+                    "notify::is-value-default",
+                    G_CALLBACK (shortcut_modified_changed_cb),
+                    reset_button);
+
+  g_signal_connect (reset_button,
+                    "clicked",
+                    G_CALLBACK (reset_shortcut_cb),
+                    item);
+
   /* The row */
   row = gtk_list_box_row_new ();
   gtk_container_add (GTK_CONTAINER (row), box);
@@ -390,10 +464,23 @@ cc_keyboard_panel_class_init (CcKeyboardPanelClass *klass)
 static void
 cc_keyboard_panel_init (CcKeyboardPanel *self)
 {
+  GtkCssProvider *provider;
+
   g_resources_register (cc_keyboard_get_resource ());
 
   gtk_widget_init_template (GTK_WIDGET (self));
 
+  /* Custom CSS */
+  provider = gtk_css_provider_new ();
+  gtk_css_provider_load_from_data (provider, custom_css, -1, NULL);
+
+  gtk_style_context_add_provider_for_screen (gdk_screen_get_default (),
+                                             GTK_STYLE_PROVIDER (provider),
+                                             GTK_STYLE_PROVIDER_PRIORITY_APPLICATION + 1);
+
+  g_object_unref (provider);
+
+  /* Shortcut manager */
   self->manager = cc_keyboard_manager_new ();
 
   /* Use a sizegroup to make the accelerator labels the same width */

panels/keyboard/cc-keyboard-shortcut-editor.c

@@ -43,6 +43,7 @@ struct _CcKeyboardShortcutEditor
   GtkWidget          *new_shortcut_conflict_label;
   GtkWidget          *remove_button;
   GtkWidget          *replace_button;
+  GtkWidget          *reset_button;
   GtkWidget          *shortcut_accel_label;
   GtkWidget          *shortcut_conflict_label;
   GtkWidget          *stack;
@@ -54,6 +55,7 @@ struct _CcKeyboardShortcutEditor
 
   CcKeyboardManager  *manager;
   CcKeyboardItem     *item;
+  GBinding           *reset_item_binding;
 
   CcKeyboardItem     *collision_item;
 
@@ -402,6 +404,20 @@ replace_button_clicked_cb (CcKeyboardShortcutEditor *self)
   gtk_widget_hide (GTK_WIDGET (self));
 }
 
+static void
+reset_item_clicked_cb (CcKeyboardShortcutEditor *self)
+{
+  gchar *accel;
+
+  /* Reset first, then update the shortcut */
+  cc_keyboard_manager_reset_shortcut (self->manager, self->item);
+
+  accel = gtk_accelerator_name (self->item->keyval, self->item->mask);
+  gtk_shortcut_label_set_accelerator (GTK_SHORTCUT_LABEL (self->shortcut_accel_label), accel);
+
+  g_free (accel);
+}
+
 static void
 setup_keyboard_item (CcKeyboardShortcutEditor *self,
                      CcKeyboardItem           *item)
@@ -433,6 +449,13 @@ setup_keyboard_item (CcKeyboardShortcutEditor *self,
   gtk_shortcut_label_set_accelerator (GTK_SHORTCUT_LABEL (self->shortcut_accel_label), accel);
   gtk_shortcut_label_set_accelerator (GTK_SHORTCUT_LABEL (self->custom_shortcut_accel_label), accel);
 
+  g_clear_pointer (&self->reset_item_binding, g_binding_unbind);
+  self->reset_item_binding = g_object_bind_property (item,
+                                                     "is-value-default",
+                                                     self->reset_button,
+                                                     "visible",
+                                                     G_BINDING_DEFAULT | G_BINDING_INVERT_BOOLEAN | G_BINDING_SYNC_CREATE);
+
   /* Setup the custom entries */
   if (is_custom)
     {
@@ -468,6 +491,8 @@ cc_keyboard_shortcut_editor_finalize (GObject *object)
   g_clear_object (&self->item);
   g_clear_object (&self->manager);
 
+  g_clear_pointer (&self->reset_item_binding, g_binding_unbind);
+
   G_OBJECT_CLASS (cc_keyboard_shortcut_editor_parent_class)->finalize (object);
 }
 
@@ -660,6 +685,7 @@ cc_keyboard_shortcut_editor_class_init (CcKeyboardShortcutEditorClass *klass)
   gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, new_shortcut_conflict_label);
   gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, remove_button);
   gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, replace_button);
+  gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, reset_button);
   gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, shortcut_accel_label);
   gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, shortcut_conflict_label);
   gtk_widget_class_bind_template_child (widget_class, CcKeyboardShortcutEditor, stack);
@@ -672,6 +698,7 @@ cc_keyboard_shortcut_editor_class_init (CcKeyboardShortcutEditorClass *klass)
   gtk_widget_class_bind_template_callback (widget_class, name_entry_changed_cb);
   gtk_widget_class_bind_template_callback (widget_class, remove_button_clicked_cb);
   gtk_widget_class_bind_template_callback (widget_class, replace_button_clicked_cb);
+  gtk_widget_class_bind_template_callback (widget_class, reset_item_clicked_cb);
 }
 
 static void

panels/keyboard/shortcut-editor.ui

@@ -64,6 +64,7 @@
                     <property name="can_focus">True</property>
                     <property name="receives_default">True</property>
                     <property name="halign">end</property>
+                    <signal name="clicked" handler="reset_item_clicked_cb" object="CcKeyboardShortcutEditor" swapped="yes" />
                   </object>
                 </child>
               </object>