Add internal drawing context

Xwt.WPF/Xwt.WPF.csproj

@@ -54,6 +54,7 @@
     <Compile Include="Xwt.WPFBackend\ComboBoxEntryBackend.cs" />
     <Compile Include="Xwt.WPFBackend.Utilities\DataSourceNotifyWrapper.cs" />
     <Compile Include="Xwt.WPFBackend\ComboBoxTextEntryBackend.cs" />
+    <Compile Include="Xwt.WPFBackend\DrawingContext.cs" />
     <Compile Include="Xwt.WPFBackend\FrameBackend.cs" />
     <Compile Include="Xwt.WPFBackend\GradientBackendHandler.cs" />
     <Compile Include="Xwt.WPFBackend\ImageHandler.cs" />

Xwt.WPF/Xwt.WPFBackend/DrawingContext.cs

@@ -0,0 +1,101 @@
+// 
+// DrawingContext.cs
+//  
+// Author:
+//       Eric Maupin <ermau@xamarin.com>
+// 
+// Copyright (c) 2012 Xamarin, Inc.
+// 
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+// 
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+
+namespace Xwt.WPFBackend
+{
+	internal class DrawingContext
+	{
+		internal DrawingContext (Graphics graphics)
+		{
+			if (graphics == null)
+				throw new ArgumentNullException ("graphics");
+
+			Graphics = graphics;
+		}
+
+		internal DrawingContext (DrawingContext context)
+		{
+			Graphics = context.Graphics;
+			
+			var f = context.Font;
+			Font = new Font (f.FontFamily, f.Size, f.Style, f.Unit, f.GdiCharSet, f.GdiVerticalFont);
+			Pen = new Pen (context.Pen.Brush, context.Pen.Width);
+			Brush = (Brush)context.Brush.Clone ();
+			Path = new GraphicsPath (context.Path.PathPoints, context.Path.PathTypes, context.Path.FillMode);
+			
+			CurrentX = context.CurrentX;
+			CurrentY = context.CurrentY;
+		}
+
+		internal readonly Graphics Graphics;
+
+		internal Font Font = new Font (FontFamily.GenericSansSerif, 12);
+		internal Pen Pen = new Pen (Color.Black, 1);
+		internal Brush Brush = new SolidBrush (Color.Black);
+
+		internal float CurrentX;
+		internal float CurrentY;
+
+		internal GraphicsPath Path = new GraphicsPath();
+
+		internal void SetColor (Color color)
+		{
+			Pen.Color = color;
+			Brush = new SolidBrush (color);
+		}
+
+		internal void Save()
+		{
+			if (this.contexts == null)
+				this.contexts = new Stack<DrawingContext> ();
+
+			this.contexts.Push (new DrawingContext (this));
+		}
+
+		internal void Restore()
+		{
+			if (this.contexts == null || this.contexts.Count == 0)
+				throw new InvalidOperationException();
+
+			var dc = this.contexts.Pop ();
+
+			Font = dc.Font;
+			Pen = dc.Pen;
+			Brush = dc.Brush;
+			Path = dc.Path;
+
+			CurrentX = dc.CurrentX;
+			CurrentY = dc.CurrentY;
+		}
+
+		private Stack<DrawingContext> contexts;
+	}
+}