[longomatch] Add a workaround to set a URL Handler for GtkLabel

[Andoni Morales Alastruey <amorales src gnome org>]

commit 2c51e83b3fce5800621959d88e8c35d0c5f371b2
Author: Julien Moutte <julien fluendo com>
Date:   Sat Nov 29 12:30:02 2014 +0100

    Add a workaround to set a URL Handler for GtkLabel

 LongoMatch.GUI/Gui/GtkGlue.cs |   38 ++++++++++++++++++++++++++++++++++++++
 1 files changed, 38 insertions(+), 0 deletions(-)
---
diff --git a/LongoMatch.GUI/Gui/GtkGlue.cs b/LongoMatch.GUI/Gui/GtkGlue.cs
index 99e659b..56fed75 100644
--- a/LongoMatch.GUI/Gui/GtkGlue.cs
+++ b/LongoMatch.GUI/Gui/GtkGlue.cs
@@ -30,6 +30,44 @@ namespace LongoMatch
                public static void MenuItemSetLabel (MenuItem menu, string label) {
                        gtk_menu_item_set_label (menu.Handle, GLib.Marshaller.StringToFilenamePtr (label));
                }
+
+               /// <summary>
+               /// Sets the link handler for a given GtkLabel.
+               /// </summary>
+               /// <param name="label">GtkLabel to set the handler for.</param>
+               /// <param name="urlHandler">URL handler.</param>
+               public static void SetLinkHandler (Gtk.Label label, Action<string> urlHandler)
+               {
+                       new UrlHandlerClosure (urlHandler).ConnectTo (label);
+               }
+
+               class UrlHandlerClosure
+               {
+                       Action<string> urlHandler;
+
+                       public UrlHandlerClosure (Action<string> urlHandler)
+                       {
+                               this.urlHandler = urlHandler;
+                       }
+
+                       [GLib.ConnectBefore]
+                       void HandleLink (object sender, ActivateLinkEventArgs args)
+                       {
+                               urlHandler (args.Url);
+                               args.RetVal = true;
+                       }
+
+                       public void ConnectTo (Gtk.Label label)
+                       {
+                               var signal = GLib.Signal.Lookup (label, "activate-link", 
typeof(ActivateLinkEventArgs));
+                               signal.AddDelegate (new EventHandler<ActivateLinkEventArgs> (HandleLink));
+                       }
+
+                       class ActivateLinkEventArgs : GLib.SignalArgs
+                       {
+                               public string Url { get { return (string)base.Args [0]; } }
+                       }
+               }
        }
 }