Add link support to GtkLabel

This patch is based on SexyUrlLabel, but with significantly enhanced
functionality: keynav, tooltips, context menu, theming.

demos/gtk-demo/Makefile.am

@@ -3,7 +3,7 @@ include $(top_srcdir)/Makefile.decl
 
 democodedir=$(datadir)/gtk-2.0/demo
 
-## These should be in the order you want them to appear in the 
+## These should be in the order you want them to appear in the
 ## demo app, which means alphabetized by demo title, not filename
 demos =						\
 	appwindow.c				\
@@ -23,6 +23,7 @@ demos =						\
 	iconview.c				\
 	iconview_edit.c				\
 	images.c				\
+        links.c					\
 	list_store.c				\
 	menus.c					\
 	panes.c					\

demos/gtk-demo/links.c

@@ -0,0 +1,88 @@
+/* Links
+ *
+ * GtkLabel can show hyperlinks. The default action is to call
+ * gtk_show_uri() on their URI, but it is possible to override
+ * this with a custom handler.
+ */
+
+#include <gtk/gtk.h>
+
+static void
+response_cb (GtkWidget *dialog,
+             gint       response_id,
+             gpointer   data)
+{
+  gtk_widget_destroy (dialog);
+}
+
+static gboolean
+activate_link (GtkWidget *label,
+               gpointer   data)
+{
+  const gchar *uri;
+
+  uri = gtk_label_get_current_uri (GTK_LABEL (label));
+
+  if (g_strcmp0 (uri, "keynav") == 0)
+    {
+      GtkWidget *dialog;
+      GtkWidget *parent;
+
+      parent = gtk_widget_get_toplevel (label);
+      dialog = gtk_message_dialog_new_with_markup (GTK_WINDOW (parent),
+                 GTK_DIALOG_DESTROY_WITH_PARENT,
+                 GTK_MESSAGE_INFO,
+                 GTK_BUTTONS_OK,
+                 "The term <i>keynav</i> is a shorthand for "
+                 "keyboard navigation and refers to the process of using "
+                 "a program (exclusively) via keyboard input.");
+
+      gtk_window_present (GTK_WINDOW (dialog));
+      g_signal_connect (dialog, "response", G_CALLBACK (response_cb), NULL);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+GtkWidget *
+do_links (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+  GtkWidget *box;
+  GtkWidget *label;
+
+  if (!window)
+    {
+      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+      gtk_window_set_screen (GTK_WINDOW (window),
+			     gtk_widget_get_screen (do_widget));
+      gtk_container_set_border_width (GTK_CONTAINER (window), 12);
+      g_signal_connect (window, "destroy",
+			G_CALLBACK(gtk_widget_destroyed), &window);
+      g_signal_connect (window, "delete-event",
+			G_CALLBACK (gtk_true), NULL);
+
+      label = gtk_label_new ("Some <a href=\"http://en.wikipedia.org/wiki/Text\""
+                             "title=\"plain text\">text</a> may be marked up\n"
+                             "as hyperlinks, which can be clicked\n"
+                             "or activated via <a href=\"keynav\">keynav</a>");
+      gtk_label_set_use_markup (GTK_LABEL (label), TRUE);
+      g_signal_connect (label, "activate-link", G_CALLBACK (activate_link), NULL);
+      gtk_container_add (GTK_CONTAINER (window), label);
+      gtk_widget_show (label);
+    }
+
+  if (!GTK_WIDGET_VISIBLE (window))
+    {
+      gtk_widget_show (window);
+    }
+  else
+    {
+      gtk_widget_destroy (window);
+      window = NULL;
+    }
+
+  return window;
+}