Add GtkSidebar

GtkSidebar behaves internally much like GtkStackSwitcher, providing a vertical
sidebar like widget. It is virtually identical in appearance to the widget
currently used in GNOME Tweak Tool.

This widget is connected to a GtkStack, and builds its own contents as a
GtkListBox subclass, using the "title" child property to provide a consistent
navigatable widget.

Being a subclass of GtkListBox it benefits immediately from strong keyboard
navigation, and minimal changes are required for theming.

https://bugzilla.gnome.org/show_bug.cgi?id=735293

Signed-off-by: Ikey Doherty <michael.i.doherty@intel.com>

demos/gtk-demo/Makefile.am

@@ -48,6 +48,7 @@ demos =						\
 	rotated_text.c				\
 	search_entry.c				\
 	search_entry2.c				\
+	sidebar.c				\
 	sizegroup.c				\
 	spinner.c				\
 	stack.c					\

demos/gtk-demo/demo.gresource.xml

@@ -118,6 +118,7 @@
     <file>search_entry.c</file>
     <file>search_entry2.c</file>
     <file>sizegroup.c</file>
+    <file>sidebar.c</file>
     <file>stack.c</file>
     <file>spinner.c</file>
     <file>textview.c</file>

demos/gtk-demo/sidebar.c

@@ -0,0 +1,77 @@
+/* Sidebar
+ *
+ * GtkSidebar provides an automatic sidebar widget to control navigation
+ * of a GtkStack object. This widget automatically updates it content
+ * based on what is presently available in the GtkStack object, and
+ * using the "title" child property to set the display labels.
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+static GtkWidget *window = NULL;
+
+GtkWidget *
+do_sidebar (GtkWidget *do_widget)
+{
+  GtkWidget *sidebar;
+  GtkWidget *stack;
+  GtkWidget *box;
+  GtkWidget *widget;
+  GtkWidget *header;
+  const gchar* pages[] = { "Welcome to GTK+", "GtkSidebar Widget", "Automatic navigation", "Consistent appearance", NULL };
+  const gchar *c = NULL;
+  guint i;
+
+  if (!window)
+    {
+      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+      gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
+      gtk_widget_set_size_request (window, 500, 350);
+
+      header = gtk_header_bar_new ();
+      gtk_header_bar_set_show_close_button (GTK_HEADER_BAR(header), TRUE);
+      gtk_window_set_titlebar (GTK_WINDOW(window), header);
+      gtk_window_set_title (GTK_WINDOW(window), "Sidebar demo");
+
+      g_signal_connect (window, "destroy",
+                        G_CALLBACK (gtk_widget_destroyed), &window);
+
+      box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+      sidebar = gtk_sidebar_new ();
+      gtk_box_pack_start (GTK_BOX (box), sidebar, FALSE, FALSE, 0);
+
+      stack = gtk_stack_new ();
+      gtk_stack_set_transition_type (GTK_STACK (stack), GTK_STACK_TRANSITION_TYPE_SLIDE_UP_DOWN);
+      gtk_sidebar_set_stack (GTK_SIDEBAR (sidebar), GTK_STACK (stack));
+
+      /* Separator between sidebar and stack */
+      widget = gtk_separator_new (GTK_ORIENTATION_VERTICAL);
+      gtk_box_pack_start (GTK_BOX(box), widget, FALSE, FALSE, 0);
+
+      gtk_box_pack_start (GTK_BOX (box), stack, TRUE, TRUE, 0);
+
+      for (i=0; (c = *(pages+i)) != NULL; i++ )
+        {
+          if (i == 0)
+            {
+              widget = gtk_image_new_from_icon_name ("help-about", GTK_ICON_SIZE_INVALID);
+              gtk_image_set_pixel_size (GTK_IMAGE (widget), 256);
+            } else
+            {
+              widget = gtk_label_new (c);
+            }
+          gtk_stack_add_named (GTK_STACK (stack), widget, c);
+          gtk_container_child_set (GTK_CONTAINER (stack), widget, "title", c, NULL);
+        }
+
+       gtk_container_add (GTK_CONTAINER (window), box);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show_all (window);
+  else
+    gtk_widget_destroy (window);
+
+  return window;
+}