[longomatch] Add support for roi in copying surfaces

[Andoni Morales Alastruey <amorales src gnome org>]

commit eff196a0fa175e916ceeb7ef617443b46ee519a8
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Thu Apr 23 13:36:19 2015 +0200

    Add support for roi in copying surfaces

 .../Interfaces/Drawing/IDrawingToolkit.cs          |    2 +-
 LongoMatch.Drawing.Cairo/CairoBackend.cs           |   28 ++++++++-----------
 2 files changed, 13 insertions(+), 17 deletions(-)
---
diff --git a/LongoMatch.Core/Interfaces/Drawing/IDrawingToolkit.cs 
b/LongoMatch.Core/Interfaces/Drawing/IDrawingToolkit.cs
index cb76f3a..81c218f 100644
--- a/LongoMatch.Core/Interfaces/Drawing/IDrawingToolkit.cs
+++ b/LongoMatch.Core/Interfaces/Drawing/IDrawingToolkit.cs
@@ -107,7 +107,7 @@ namespace LongoMatch.Core.Interfaces.Drawing
 
                void Save (ICanvas canvas, Area area, string filename);
 
-               Image Copy (ICanvas canvas, double width, double height);
+               Image Copy (ICanvas canvas, Area area);
 
                Area UserToDevice (Area area);
 
diff --git a/LongoMatch.Drawing.Cairo/CairoBackend.cs b/LongoMatch.Drawing.Cairo/CairoBackend.cs
index 1696b3f..a5d0965 100644
--- a/LongoMatch.Drawing.Cairo/CairoBackend.cs
+++ b/LongoMatch.Drawing.Cairo/CairoBackend.cs
@@ -475,34 +475,30 @@ namespace LongoMatch.Drawing.Cairo
                        }
                }
 
-               public Image Copy (ICanvas canvas, double width, double height)
+               public Image Copy (ICanvas canvas, Area area)
                {
                        Image img;
                        Pixmap pm;
+                       global::Cairo.Context ctx;
                        
-                       pm = new Pixmap (null, (int)width, (int)height, 24);
+                       pm = new Pixmap (null, (int)area.Width, (int)area.Height, 24);
+                       ctx = Gdk.CairoHelper.Create (pm);
                        disableScalling = true;
-                       using (CairoContext c = new CairoContext (Gdk.CairoHelper.Create (pm))) {
-                               canvas.Draw (c, new Area (new Point (0, 0), width, height));
+                       using (CairoContext c = new CairoContext (ctx)) {
+                               ctx.Translate (-area.Start.X, -area.Start.Y);
+                               canvas.Draw (c, null);
                        }
-                       img = new Image (Gdk.Pixbuf.FromDrawable (pm, Colormap.System, 0, 0, 0, 0,
-                               (int)width, (int)height));
                        disableScalling = false;
-                       Context = null;
+                       img = new Image (Pixbuf.FromDrawable (pm, Colormap.System, 0, 0, 0, 0,
+                               (int)area.Width, (int)area.Height));
                        return img;
                }
 
                public void Save (ICanvas canvas, Area area, string filename)
                {
-                       ImageSurface pngSurface = new ImageSurface (Format.ARGB32, (int)area.Width, 
(int)area.Height);
-                       disableScalling = true;
-                       using (CairoContext c = new CairoContext (new global::Cairo.Context (pngSurface))) {
-                               (c.Value as global::Cairo.Context).Translate (-area.Start.X, -area.Start.Y);
-                               canvas.Draw (c, null);
-                       }
-                       pngSurface.WriteToPng (filename);
-                       disableScalling = false;
-                       pngSurface.Dispose ();
+                       Image img = Copy (canvas, area);
+                       img.Save (filename);
+                       img.Dispose ();
                }
 
                global::Cairo.Context CContext {