WpfWorkbench: Fixed window bound restore code

- When closing a minimized SharpDevelop instance, save the previous state (before minimizing)
 - Use RestoreBounds so that window size is saved even when maximized
 - Validate the bounds being restored (avoid placing SharpDevelop on deactivated monitor)

src/Main/Base/Project/Src/Gui/FormLocationHelper.cs

@@ -60,7 +60,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 			};
 		}
 		
-		static Rect Validate(Rect bounds)
+		public static Rect Validate(Rect bounds)
 		{
 			// Check if form is outside the screen and get it back if necessary.
 			// This is important when the user uses multiple screens, a window stores its location

src/Main/Base/Project/Src/Gui/Workbench/WpfWorkbench.cs

@@ -529,25 +529,36 @@ namespace ICSharpCode.SharpDevelop.Gui
 		}
 		#endregion
 		
+		System.Windows.WindowState lastNonMinimizedWindowState = System.Windows.WindowState.Normal;
+		Rect restoreBoundsBeforeClosing;
+		
+		protected override void OnStateChanged(EventArgs e)
+		{
+			base.OnStateChanged(e);
+			if (this.WindowState != System.Windows.WindowState.Minimized)
+				lastNonMinimizedWindowState = this.WindowState;
+		}
+		
 		public Properties CreateMemento()
 		{
 			Properties prop = new Properties();
-			prop.Set("WindowState", this.WindowState);
+			prop.Set("WindowState", lastNonMinimizedWindowState);
-			if (this.WindowState == System.Windows.WindowState.Normal) {
+			var bounds = this.RestoreBounds;
-				prop.Set("Left", this.Left);
+			if (bounds.IsEmpty) bounds = restoreBoundsBeforeClosing;
-				prop.Set("Top", this.Top);
+			if (!bounds.IsEmpty) {
-				prop.Set("Width", this.Width);
+				prop.Set("Bounds", bounds);
-				prop.Set("Height", this.Height);
 			}
 			return prop;
 		}
 		
 		public void SetMemento(Properties memento)
 		{
-			this.Left = memento.Get("Left", 10.0);
+			Rect bounds = memento.Get("Bounds", new Rect(10, 10, 750, 550));
-			this.Top = memento.Get("Top", 10.0);
+			bounds = FormLocationHelper.Validate(bounds);
-			this.Width = memento.Get("Width", 600.0);
+			this.Left = bounds.Left;
-			this.Height = memento.Get("Height", 400.0);
+			this.Top = bounds.Top;
+			this.Width = bounds.Width;
+			this.Height = bounds.Height;
 			this.WindowState = memento.Get("WindowState", System.Windows.WindowState.Maximized);
 		}
 		
@@ -574,6 +585,8 @@ namespace ICSharpCode.SharpDevelop.Gui
 				Project.ProjectService.CloseSolution();
 				ParserService.StopParserThread();
 				
+				restoreBoundsBeforeClosing = this.RestoreBounds;
+				
 				this.WorkbenchLayout = null;
 				
 				foreach (PadDescriptor padDescriptor in this.PadContentCollection) {