[longomatch] Only redraw the timeline area that's in the clip region

[Andoni Morales Alastruey <amorales src gnome org>]

commit eff46505d20b6a07df8f308f84f16cc4ecd8b010
Author: Andoni Morales Alastruey <ylatuya gmail com>
Date:   Tue Sep 2 15:39:11 2014 +0200

    Only redraw the timeline area that's in the clip region

 LongoMatch.Drawing/CanvasObjects/TimelineObject.cs |    3 +-
 LongoMatch.Drawing/Widgets/Timerule.cs             |   24 +++++++++++++------
 2 files changed, 17 insertions(+), 10 deletions(-)
---
diff --git a/LongoMatch.Drawing/CanvasObjects/TimelineObject.cs 
b/LongoMatch.Drawing/CanvasObjects/TimelineObject.cs
index a96e2fe..debb449 100644
--- a/LongoMatch.Drawing/CanvasObjects/TimelineObject.cs
+++ b/LongoMatch.Drawing/CanvasObjects/TimelineObject.cs
@@ -107,8 +107,7 @@ namespace LongoMatch.Drawing.CanvasObjects
                        tk.StrokeColor = background;
                        tk.LineWidth = 0;
                        
-                       tk.DrawRectangle (new Point (0, OffsetY), Width,
-                                         Height);
+                       tk.DrawRectangle (new Point (area.Start.X, OffsetY), area.Width, Height);
                }
 
                public override void Draw (IDrawingToolkit tk, Area area)
diff --git a/LongoMatch.Drawing/Widgets/Timerule.cs b/LongoMatch.Drawing/Widgets/Timerule.cs
index e8ca0b4..c2b93d1 100644
--- a/LongoMatch.Drawing/Widgets/Timerule.cs
+++ b/LongoMatch.Drawing/Widgets/Timerule.cs
@@ -69,9 +69,8 @@ namespace LongoMatch.Drawing.Widgets
 
                public override void Draw (IContext context, Area area)
                {
-                       double height = widget.Height;
-                       double width = widget.Width;
-                       double tpos;
+                       int startX, start, stop;
+                       double tpos, height, width;
                        
                        if (Duration == null) {
                                return;
@@ -83,6 +82,9 @@ namespace LongoMatch.Drawing.Widgets
                                needle = tk.CreateSurface (img.Width, img.Height, img);
                        }
 
+                       height = widget.Height;
+                       width = widget.Width;
+
                        tk.Context = context;
                        tk.Begin ();
                        tk.Clear (Config.Style.PaletteBackgroundDark);
@@ -92,19 +94,25 @@ namespace LongoMatch.Drawing.Widgets
                        tk.LineWidth = Constants.TIMELINE_LINE_WIDTH;
                        tk.FontSlant = FontSlant.Normal;
                        tk.FontSize = 12;
-                       tk.DrawLine (new Point (0, height), new Point (width, height));
-               
+                       tk.DrawLine (new Point (area.Start.X, height),
+                                    new Point (area.Start.X + area.Width, height));
+
+                       startX = (int) (area.Start.X + Scroll);
+                       start = (startX - (startX % TIME_SPACING)) + TIME_SPACING;
+                       stop = (int) (startX + area.Width);
+
                        /* Draw big lines each 10 * secondsPerPixel */
-                       for (int i=0; i <= Duration.Seconds / SecondsPerPixel; i += TIME_SPACING) {
+                       for (int i=start; i <= stop; i += TIME_SPACING) {
                                double pos = i - Scroll;
                                tk.DrawLine (new Point (pos, height),
                                             new Point (pos, height - BIG_LINE_HEIGHT));
                                tk.DrawText (new Point (pos - TEXT_WIDTH / 2, 0), TEXT_WIDTH, height - 
BIG_LINE_HEIGHT - 4,
                                             new Time { Seconds = (int) (i * SecondsPerPixel) 
}.ToSecondsString ());
                        }
-                       
+
+                       start = (startX - (startX % (TIME_SPACING / 10))) + (TIME_SPACING/10);
                        /* Draw small lines each 1 * secondsPerPixel */
-                       for (int i=0; i<= Duration.Seconds / SecondsPerPixel; i+= TIME_SPACING / 10) {
+                       for (int i=start; i<= stop; i+= TIME_SPACING / 10) {
                                double pos;
                                
                                if (i % TIME_SPACING == 0)