[longomatch] Add event to notify about camera selection changes.

[Andoni Morales Alastruey <amorales src gnome org>]

commit 5ba6244c7bd28f534eee30e77c70fa14667c7643
Author: Julien Moutte <julien fluendo com>
Date:   Sat Mar 14 13:50:18 2015 +0100

    Add event to notify about camera selection changes.
    
    This will be useful to optimise the behaviour of the ProjectPeriods widget.

 LongoMatch.Drawing/Widgets/CamerasTimeline.cs |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)
---
diff --git a/LongoMatch.Drawing/Widgets/CamerasTimeline.cs b/LongoMatch.Drawing/Widgets/CamerasTimeline.cs
index c389c10..6e3d227 100644
--- a/LongoMatch.Drawing/Widgets/CamerasTimeline.cs
+++ b/LongoMatch.Drawing/Widgets/CamerasTimeline.cs
@@ -15,6 +15,7 @@
 //  along with this program; if not, write to the Free Software
 //  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 //
+using System;
 using System.Linq;
 using LongoMatch.Core.Store;
 using LongoMatch.Drawing.CanvasObjects;
@@ -30,6 +31,7 @@ namespace LongoMatch.Drawing.Widgets
        {
                // For cameras
                public event CameraDraggedHandler CameraDragged;
+               public event EventHandler SelectedCameraChanged;
                // And periods
                public event TimeNodeChangedHandler TimeNodeChanged;
                public event ShowTimerMenuHandler ShowTimerMenuEvent;
@@ -86,6 +88,17 @@ namespace LongoMatch.Drawing.Widgets
                        }
                }
 
+               public CameraObject SelectedCamera {
+                       get {
+                               Selection sel = Selections.FirstOrDefault ();
+
+                               if (sel != null && sel.Drawable is CameraObject)
+                                       return sel.Drawable as CameraObject;
+                               else
+                                       return null;
+                       }
+               }
+
                void Update ()
                {
                        double width;
@@ -168,6 +181,14 @@ namespace LongoMatch.Drawing.Widgets
                        }
                }
 
+               protected override void SelectionChanged (List<Selection> sel)
+               {
+                       // Fire an event
+                       if (SelectedCameraChanged != null) {
+                               SelectedCameraChanged (this, new EventArgs ());
+                       }
+               }
+
                protected override void ShowMenu (Point coords)
                {
                        if (ShowTimerMenuEvent != null) {