[longomatch] Add support for scaled canvas

[Andoni Morales Alastruey <amorales src gnome org>]

commit cd31ca09bafc681e602485629793cecd0cca3393
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Tue Jun 17 18:48:56 2014 +0200

    Add support for scaled canvas

 LongoMatch.Drawing/Canvas.cs |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/LongoMatch.Drawing/Canvas.cs b/LongoMatch.Drawing/Canvas.cs
index 35bb27a..8806822 100644
--- a/LongoMatch.Drawing/Canvas.cs
+++ b/LongoMatch.Drawing/Canvas.cs
@@ -30,6 +30,8 @@ namespace LongoMatch.Drawing
        {
                protected IDrawingToolkit tk;
                protected IWidget widget;
+               protected double scaleX, scaleY;
+               protected Point translation;
                
                public Canvas (IWidget widget)
                {
@@ -37,6 +39,9 @@ namespace LongoMatch.Drawing
                        tk = Config.DrawingToolkit;
                        Objects = new List<ICanvasObject>();
                        widget.DrawEvent += HandleDraw;
+                       scaleX = 1;
+                       scaleY = 1;
+                       translation = new Point (0, 0);
                }
                
                public List<ICanvasObject> Objects {
@@ -44,14 +49,23 @@ namespace LongoMatch.Drawing
                        set;
                }
                
+               protected Point ToUserCoords (Point p) {
+                       return new Point ((p.X - translation.X) / scaleX,
+                                         (p.Y - translation.Y) / scaleY);
+               
+               }
+               
                protected virtual void HandleDraw (object context, Area area) {
                        tk.Context = context;
+                       tk.TranslateAndScale (translation, new Point (scaleX, scaleY));
+                       tk.Begin ();
                        for (int i=Objects.Count - 1; i >= 0; i--) {
                                ICanvasObject o = Objects[i];
                                if (o.Visible) {
                                        o.Draw (tk, area);
                                }
                        }
+                       tk.End ();
                        tk.Context = null;
                }
        }