[gnome-control-center] power: Improve keyboard navigation

[Bastien Nocera <hadess src gnome org>]

commit cf7530b2347891a60c7980e7ec96f0650bc9e316
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Jan 22 21:42:18 2013 -0500

    power: Improve keyboard navigation
    
    This commit 'links' the arrow navigation between the list boxes
    in the power page, so that it becomes possible to arrow down all
    the way from the battery section to automatic suspend. We also
    set up the focus adjustment so that the focus row gets scrolled
    into view.
    
    This requires the egg-list-box module to have
    commit 98b0a39efe7b1892570ece53748ab153a91b9cbc.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=692171

 panels/power/cc-power-panel.c |   81 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 81 insertions(+), 0 deletions(-)
---
diff --git a/panels/power/cc-power-panel.c b/panels/power/cc-power-panel.c
index 31c0386..4fc24ea 100644
--- a/panels/power/cc-power-panel.c
+++ b/panels/power/cc-power-panel.c
@@ -73,6 +73,9 @@ struct _CcPowerPanelPrivate
   GDBusProxy    *screen_proxy;
   gboolean       has_batteries;
 
+  GList         *boxes;
+  GList         *boxes_reverse;
+
   GtkSizeGroup  *row_sizegroup;
   GtkSizeGroup  *battery_sizegroup;
   GtkSizeGroup  *charge_sizegroup;
@@ -109,6 +112,8 @@ struct _CcPowerPanelPrivate
   GtkWidget     *mobile_switch;
   GtkWidget     *mobile_row;
 #endif
+
+  GtkAdjustment *focus_adjustment;
 };
 
 enum
@@ -139,6 +144,8 @@ cc_power_panel_dispose (GObject *object)
 #ifdef HAVE_NETWORK_MANAGER
   g_clear_object (&priv->nm_client);
 #endif
+  g_clear_pointer (&priv->boxes, g_list_free);
+  g_clear_pointer (&priv->boxes_reverse, g_list_free);
 
   G_OBJECT_CLASS (cc_power_panel_parent_class)->dispose (object);
 }
@@ -1284,6 +1291,66 @@ nm_device_changed (NMClient     *client,
 
 #endif
 
+static gboolean
+keynav_failed (GtkWidget *list, GtkDirectionType direction, CcPowerPanel *self)
+{
+  CcPowerPanelPrivate *priv = self->priv;
+  GtkWidget *next_list = NULL;
+  GList *item, *boxes_list;
+  gdouble value, lower, upper, page;
+
+  /* Find the list in the list of EggListBoxes */
+  if (direction == GTK_DIR_DOWN)
+    boxes_list = priv->boxes;
+  else
+    boxes_list = priv->boxes_reverse;
+
+  item = g_list_find (boxes_list, list);
+  g_assert (item);
+  item = item->next;
+  while (1)
+    {
+      if (item == NULL)
+        item = boxes_list;
+
+      /* Avoid looping */
+      if (item->data == list)
+        break;
+
+      if (gtk_widget_is_visible (item->data))
+        {
+          next_list = item->data;
+          break;
+        }
+
+    item = item->next;
+  }
+
+  if (next_list)
+    {
+      gtk_widget_child_focus (next_list, direction);
+      return TRUE;
+    }
+
+  value = gtk_adjustment_get_value (priv->focus_adjustment);
+  lower = gtk_adjustment_get_lower (priv->focus_adjustment);
+  upper = gtk_adjustment_get_upper (priv->focus_adjustment);
+  page  = gtk_adjustment_get_page_size (priv->focus_adjustment);
+
+  if (direction == GTK_DIR_UP && value > lower)
+    {
+      gtk_adjustment_set_value (priv->focus_adjustment, lower);
+      return TRUE;
+    }
+  else if (direction == GTK_DIR_DOWN && value < upper - page)
+    {
+      gtk_adjustment_set_value (priv->focus_adjustment, upper - page);
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
 static void
 combo_idle_delay_changed_cb (GtkWidget *widget, CcPowerPanel *self)
 {
@@ -1333,6 +1400,8 @@ add_power_saving_section (CcPowerPanel *self)
   gtk_widget_show (widget);
 
   widget = GTK_WIDGET (egg_list_box_new ());
+  priv->boxes_reverse = g_list_prepend (priv->boxes_reverse, widget);
+  g_signal_connect (widget, "keynav-failed", G_CALLBACK (keynav_failed), self);
   egg_list_box_set_selection_mode (EGG_LIST_BOX (widget), GTK_SELECTION_NONE);
   egg_list_box_set_separator_funcs (EGG_LIST_BOX (widget),
                                     update_separator_func,
@@ -1682,6 +1751,8 @@ add_automatic_suspend_section (CcPowerPanel *self)
   gtk_widget_show (widget);
 
   widget = GTK_WIDGET (egg_list_box_new ());
+  priv->boxes_reverse = g_list_prepend (priv->boxes_reverse, widget);
+  g_signal_connect (widget, "keynav-failed", G_CALLBACK (keynav_failed), self);
   egg_list_box_set_selection_mode (EGG_LIST_BOX (widget), GTK_SELECTION_NONE);
   egg_list_box_set_separator_funcs (EGG_LIST_BOX (widget),
                                     update_separator_func,
@@ -1853,6 +1924,8 @@ add_battery_section (CcPowerPanel *self)
   gtk_box_pack_start (GTK_BOX (box), widget, FALSE, TRUE, 0);
 
   priv->battery_list = widget = GTK_WIDGET (egg_list_box_new ());
+  priv->boxes_reverse = g_list_prepend (priv->boxes_reverse, priv->battery_list);
+  g_signal_connect (widget, "keynav-failed", G_CALLBACK (keynav_failed), self);
   egg_list_box_set_selection_mode (EGG_LIST_BOX (widget), GTK_SELECTION_NONE);
   egg_list_box_set_separator_funcs (EGG_LIST_BOX (widget),
                                     update_separator_func,
@@ -1902,6 +1975,8 @@ add_device_section (CcPowerPanel *self)
   gtk_box_pack_start (GTK_BOX (box), widget, FALSE, TRUE, 0);
 
   priv->device_list = widget = GTK_WIDGET (egg_list_box_new ());
+  priv->boxes_reverse = g_list_prepend (priv->boxes_reverse, priv->device_list);
+  g_signal_connect (widget, "keynav-failed", G_CALLBACK (keynav_failed), self);
   egg_list_box_set_selection_mode (EGG_LIST_BOX (widget), GTK_SELECTION_NONE);
   egg_list_box_set_separator_funcs (EGG_LIST_BOX (widget),
                                     update_separator_func,
@@ -1988,6 +2063,9 @@ cc_power_panel_init (CcPowerPanel *self)
   add_power_saving_section (self);
   add_automatic_suspend_section (self);
 
+  priv->boxes = g_list_copy (priv->boxes_reverse);
+  priv->boxes = g_list_reverse (priv->boxes);
+
   set_ac_battery_ui_mode (self);
   update_automatic_suspend_label (self);
 
@@ -2009,4 +2087,7 @@ cc_power_panel_init (CcPowerPanel *self)
   gtk_widget_unparent (widget);
   gtk_scrolled_window_add_with_viewport (GTK_SCROLLED_WINDOW (box), widget);
   g_object_unref (widget);
+
+  priv->focus_adjustment = gtk_scrolled_window_get_vadjustment (GTK_SCROLLED_WINDOW (box));
+  gtk_container_set_focus_vadjustment (GTK_CONTAINER (widget), priv->focus_adjustment);
 }