allow resizing and deleting Grid rows and columns

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@2442 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Controls/ControlStyles.xaml

@@ -161,6 +161,8 @@
 							<ColumnDefinition Width="10"/> <!-- 10=RailSize -->
 							<ColumnDefinition Width="*"/>
 						</Grid.ColumnDefinitions>
+						<!-- put a transparent rectangle in the rail so the user does not have to hit the small railHandle -->
+						<Rectangle Fill="Transparent"/>
 						<Path Name="railHandle" Fill="#FFE6E6FF" Stretch="Fill" Stroke="#FF584FFF" Data="M0,0 L0,1 1,0.5 z"/>
 						<Path Name="line" Stretch="Fill" Stroke="#FF584FFF" Grid.Column="2" Margin="-1 0 0 0" Data="M0,0.5 L1,0.5"/>
 					</Grid>
@@ -187,6 +189,8 @@
 							<RowDefinition Height="10"/> <!-- 10=RailSize -->
 							<RowDefinition Height="*"/>
 						</Grid.RowDefinitions>
+						<!-- put a transparent rectangle in the rail so the user does not have to hit the small railHandle -->
+						<Rectangle Fill="Transparent"/>
 						<Path Name="railHandle" Fill="#FFE6E6FF" Stretch="Fill" Stroke="#FF584FFF" Data="M0,0 L1,0 0.5,1 z"/>
 						<Path Name="line" Stretch="Fill" Stroke="#FF584FFF" Grid.Row="2" Margin="0 -1 0 0" Data="M0.5,0 L0.5,1"/>
 					</Grid>

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Controls/GridAdorner.cs

@@ -6,15 +6,13 @@
 // </file>
 
 using System;
-using System.Collections.Generic;
 using System.Diagnostics;
-using ICSharpCode.WpfDesign.Adorners;
-using ICSharpCode.WpfDesign.Extensions;
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Shapes;
-using System.Windows.Media;
 using System.Windows.Input;
+using System.Windows.Media;
+
+using ICSharpCode.WpfDesign.Adorners;
 
 namespace ICSharpCode.WpfDesign.Designer.Controls
 {
@@ -35,6 +33,7 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 		readonly Orientation orientation;
 		
 		public const double RailSize = 10;
+		public const double RailDistance = 6;
 		public const double SplitterWidth = 10;
 		
 		public GridRailAdorner(DesignItem gridItem, AdornerPanel adornerPanel, Orientation orientation)
@@ -49,10 +48,10 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 			
 			if (orientation == Orientation.Horizontal) {
 				this.Height = RailSize;
-				previewAdorner = new GridColumnSplitterAdorner();
+				previewAdorner = new GridColumnSplitterAdorner(gridItem, null, null);
 			} else { // vertical
 				this.Width = RailSize;
-				previewAdorner = new GridRowSplitterAdorner();
+				previewAdorner = new GridRowSplitterAdorner(gridItem, null, null);
 			}
 			previewAdorner.IsPreview = true;
 			previewAdorner.IsHitTestVisible = false;
@@ -70,14 +69,14 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 			base.OnMouseMove(e);
 			RelativePlacement rp = new RelativePlacement();
 			if (orientation == Orientation.Vertical) {
-				rp.XOffset = -RailSize;
-				rp.WidthOffset = RailSize;
+				rp.XOffset = -(RailSize + RailDistance);
+				rp.WidthOffset = RailSize + RailDistance;
 				rp.WidthRelativeToContentWidth = 1;
 				rp.HeightOffset = SplitterWidth;
 				rp.YOffset = e.GetPosition(this).Y - SplitterWidth / 2;
 			} else {
-				rp.YOffset = -RailSize;
-				rp.HeightOffset = RailSize;
+				rp.YOffset = -(RailSize + RailDistance);
+				rp.HeightOffset = RailSize + RailDistance;
 				rp.HeightRelativeToContentHeight = 1;
 				rp.WidthOffset = SplitterWidth;
 				rp.XOffset = e.GetPosition(this).X - SplitterWidth / 2;
@@ -95,6 +94,7 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 		{
 			base.OnMouseLeftButtonDown(e);
 			e.Handled = true;
+			Focus();
 			adornerPanel.Children.Remove(previewAdorner);
 			if (orientation == Orientation.Vertical) {
 				using (ChangeGroup changeGroup = gridItem.OpenGroup("Split grid row")) {
@@ -119,6 +119,7 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 						rowCollection.CollectionElements[i].Properties[RowDefinition.HeightProperty].SetValue(newLength1);
 						newRowDefinition.Properties[RowDefinition.HeightProperty].SetValue(newLength2);
 						changeGroup.Commit();
+						gridItem.Services.Selection.SetSelectedComponents(new DesignItem[] { newRowDefinition }, SelectionTypes.Auto);
 						break;
 					}
 				}
@@ -145,6 +146,7 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 						newColumnDefinition.Properties[ColumnDefinition.WidthProperty].SetValue(newLength2);
 						columnCollection.CollectionElements.Insert(i + 1, newColumnDefinition);
 						changeGroup.Commit();
+						gridItem.Services.Selection.SetSelectedComponents(new DesignItem[] { newColumnDefinition }, SelectionTypes.Auto);
 						break;
 					}
 				}
@@ -164,15 +166,126 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 		#endregion
 	}
 	
-	public class GridSplitterAdorner : Control
+	public abstract class GridSplitterAdorner : Control
 	{
 		public static readonly DependencyProperty IsPreviewProperty
 			= DependencyProperty.Register("IsPreview", typeof(bool), typeof(GridSplitterAdorner), new PropertyMetadata(SharedInstances.BoxedFalse));
 		
+		protected readonly Grid grid;
+		protected readonly DesignItem gridItem;
+		protected readonly DesignItem firstRow, secondRow; // can also be columns
+		
+		internal GridSplitterAdorner(DesignItem gridItem, DesignItem firstRow, DesignItem secondRow)
+		{
+			Debug.Assert(gridItem != null);
+			this.grid = (Grid)gridItem.Component;
+			this.gridItem = gridItem;
+			this.firstRow = firstRow;
+			this.secondRow = secondRow;
+		}
+		
 		public bool IsPreview {
 			get { return (bool)GetValue(IsPreviewProperty); }
 			set { SetValue(IsPreviewProperty, SharedInstances.Box(value)); }
 		}
+		
+		ChangeGroup activeChangeGroup;
+		double mouseStartPos;
+		bool mouseIsDown;
+		
+		protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
+		{
+			e.Handled = true;
+			if (CaptureMouse()) {
+				Focus();
+				gridItem.Services.Selection.SetSelectedComponents(new DesignItem[] { secondRow }, SelectionTypes.Auto);
+				mouseStartPos = GetCoordinate(e.GetPosition(grid));
+				mouseIsDown = true;
+			}
+		}
+		
+		protected override void OnMouseMove(MouseEventArgs e)
+		{
+			if (mouseIsDown) {
+				double mousePos = GetCoordinate(e.GetPosition(grid));
+				if (activeChangeGroup == null) {
+					if (Math.Abs(mousePos - mouseStartPos)
+					    >= GetCoordinate(new Point(SystemParameters.MinimumHorizontalDragDistance, SystemParameters.MinimumVerticalDragDistance)))
+					{
+						activeChangeGroup = gridItem.OpenGroup("Change grid row/column size");
+						RememberOriginalSize();
+					}
+				}
+				if (activeChangeGroup != null) {
+					ChangeSize(mousePos - mouseStartPos);
+				}
+			}
+		}
+		
+		protected GridLength original1, original2;
+		protected double originalPixelSize1, originalPixelSize2;
+		
+		protected abstract double GetCoordinate(Point point);
+		protected abstract void RememberOriginalSize();
+		protected abstract DependencyProperty RowColumnSizeProperty { get; }
+		
+		void ChangeSize(double delta)
+		{
+			// delta = difference in pixels
+			
+			if (delta < -originalPixelSize1) delta = -originalPixelSize1;
+			if (delta > originalPixelSize2) delta = originalPixelSize2;
+			
+			// replace Auto lengths with absolute lengths if necessary
+			if (original1.IsAuto) original1 = new GridLength(originalPixelSize1);
+			if (original2.IsAuto) original2 = new GridLength(originalPixelSize2);
+			
+			GridLength new1;
+			if (original1.IsStar && originalPixelSize1 > 0)
+				new1 = new GridLength(original1.Value * (originalPixelSize1 + delta) / originalPixelSize1, GridUnitType.Star);
+			else
+				new1 = new GridLength(original1.Value + delta);
+			GridLength new2;
+			if (original2.IsStar && originalPixelSize2 > 0)
+				new2 = new GridLength(original2.Value * (originalPixelSize2 - delta) / originalPixelSize2, GridUnitType.Star);
+			else
+				new2 = new GridLength(original2.Value - delta);
+			firstRow.Properties[RowColumnSizeProperty].SetValue(new1);
+			secondRow.Properties[RowColumnSizeProperty].SetValue(new2);
+			((UIElement)VisualTreeHelper.GetParent(this)).InvalidateArrange();
+		}
+		
+		protected override void OnMouseUp(MouseButtonEventArgs e)
+		{
+			if (activeChangeGroup != null) {
+				activeChangeGroup.Commit();
+				activeChangeGroup = null;
+			}
+			Stop();
+		}
+		
+		protected override void OnLostMouseCapture(MouseEventArgs e)
+		{
+			Stop();
+		}
+		
+		protected override void OnKeyDown(KeyEventArgs e)
+		{
+			if (e.Key == Key.Escape) {
+				e.Handled = true;
+				Stop();
+			}
+		}
+		
+		protected void Stop()
+		{
+			ReleaseMouseCapture();
+			mouseIsDown = false;
+			if (activeChangeGroup != null) {
+				activeChangeGroup.Abort();
+				activeChangeGroup = null;
+			}
+		}
 	}
 	
 	public class GridRowSplitterAdorner : GridSplitterAdorner
@@ -182,14 +295,61 @@ namespace ICSharpCode.WpfDesign.Designer.Controls
 			DefaultStyleKeyProperty.OverrideMetadata(typeof(GridRowSplitterAdorner), new FrameworkPropertyMetadata(typeof(GridRowSplitterAdorner)));
 			CursorProperty.OverrideMetadata(typeof(GridRowSplitterAdorner), new FrameworkPropertyMetadata(Cursors.SizeNS));
 		}
+		
+		
+		internal GridRowSplitterAdorner(DesignItem gridItem, DesignItem firstRow, DesignItem secondRow) : base(gridItem, firstRow, secondRow)
+		{
+		}
+		
+		protected override double GetCoordinate(Point point)
+		{
+			return point.Y;
+		}
+		
+		protected override void RememberOriginalSize()
+		{
+			RowDefinition r1 = (RowDefinition)firstRow.Component;
+			RowDefinition r2 = (RowDefinition)secondRow.Component;
+			original1 = (GridLength)r1.GetValue(RowDefinition.HeightProperty);
+			original2 = (GridLength)r2.GetValue(RowDefinition.HeightProperty);
+			originalPixelSize1 = r1.ActualHeight;
+			originalPixelSize2 = r2.ActualHeight;
+		}
+		
+		protected override DependencyProperty RowColumnSizeProperty {
+			get { return RowDefinition.HeightProperty; }
+		}
 	}
 	
-	public class GridColumnSplitterAdorner : GridSplitterAdorner
+	public sealed class GridColumnSplitterAdorner : GridSplitterAdorner
 	{
 		static GridColumnSplitterAdorner()
 		{
 			DefaultStyleKeyProperty.OverrideMetadata(typeof(GridColumnSplitterAdorner), new FrameworkPropertyMetadata(typeof(GridColumnSplitterAdorner)));
 			CursorProperty.OverrideMetadata(typeof(GridColumnSplitterAdorner), new FrameworkPropertyMetadata(Cursors.SizeWE));
 		}
+		
+		internal GridColumnSplitterAdorner(DesignItem gridItem, DesignItem firstRow, DesignItem secondRow) : base(gridItem, firstRow, secondRow)
+		{
+		}
+		
+		protected override double GetCoordinate(Point point)
+		{
+			return point.X;
+		}
+		
+		protected override void RememberOriginalSize()
+		{
+			ColumnDefinition r1 = (ColumnDefinition)firstRow.Component;
+			ColumnDefinition r2 = (ColumnDefinition)secondRow.Component;
+			original1 = (GridLength)r1.GetValue(ColumnDefinition.WidthProperty);
+			original2 = (GridLength)r2.GetValue(ColumnDefinition.WidthProperty);
+			originalPixelSize1 = r1.ActualWidth;
+			originalPixelSize2 = r2.ActualWidth;
+		}
+		
+		protected override DependencyProperty RowColumnSizeProperty {
+			get { return ColumnDefinition.WidthProperty; }
+		}
 	}
 }

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/DesignSurface.cs

@@ -6,10 +6,11 @@
 // </file>
 
 using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Windows;
-using System.Windows.Input;
 using System.Windows.Controls;
+using System.Windows.Input;
 using System.Xml;
 
 using ICSharpCode.WpfDesign.Designer.Controls;
@@ -58,7 +59,7 @@ namespace ICSharpCode.WpfDesign.Designer
 			IUndoAction action = Func.First(undoService.UndoActions);
 			Debug.WriteLine("Undo " + action.Title);
 			undoService.Undo();
-			_designContext.Services.Selection.SetSelectedComponents(action.AffectedElements);
+			_designContext.Services.Selection.SetSelectedComponents(GetLiveElements(action.AffectedElements));
 		}
 		
 		void OnUndoCanExecute(object sender, CanExecuteRoutedEventArgs e)
@@ -73,7 +74,7 @@ namespace ICSharpCode.WpfDesign.Designer
 			IUndoAction action = Func.First(undoService.RedoActions);
 			Debug.WriteLine("Redo " + action.Title);
 			undoService.Redo();
-			_designContext.Services.Selection.SetSelectedComponents(action.AffectedElements);
+			_designContext.Services.Selection.SetSelectedComponents(GetLiveElements(action.AffectedElements));
 		}
 		
 		void OnRedoCanExecute(object sender, CanExecuteRoutedEventArgs e)
@@ -81,6 +82,19 @@ namespace ICSharpCode.WpfDesign.Designer
 			UndoService undoService = GetService<UndoService>();
 			e.CanExecute = undoService != null && undoService.CanRedo;
 		}
+		
+		// Filters an element list, dropping all elements that are not part of the xaml document
+		// (e.g. because they were deleted).
+		static List<DesignItem> GetLiveElements(ICollection<DesignItem> items)
+		{
+			List<DesignItem> result = new List<DesignItem>(items.Count);
+			foreach (DesignItem item in items) {
+				if (ModelTools.IsInDocument(item)) {
+					result.Add(item);
+				}
+			}
+			return result;
+		}
 		#endregion
 		
 		#region Command: Delete

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Extensions/CanvasPlacementSupport.cs

@@ -10,9 +10,8 @@ using System.Collections.Generic;
 using System.Windows;
 using System.Windows.Controls;
 
-using ICSharpCode.WpfDesign.Adorners;
-using ICSharpCode.WpfDesign.Extensions;
 using ICSharpCode.WpfDesign.Designer.Controls;
+using ICSharpCode.WpfDesign.Extensions;
 
 namespace ICSharpCode.WpfDesign.Designer.Extensions
 {

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Extensions/GridAdornerProvider.cs

@@ -7,14 +7,13 @@
 
 using System;
 using System.Collections.Generic;
-using ICSharpCode.WpfDesign.Adorners;
-using ICSharpCode.WpfDesign.Extensions;
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Shapes;
-using System.Windows.Media;
 using System.Windows.Threading;
+
+using ICSharpCode.WpfDesign.Adorners;
 using ICSharpCode.WpfDesign.Designer.Controls;
+using ICSharpCode.WpfDesign.Extensions;
 
 namespace ICSharpCode.WpfDesign.Designer.Extensions
 {
@@ -22,7 +21,8 @@ namespace ICSharpCode.WpfDesign.Designer.Extensions
 	/// Allows arranging the rows/column on a grid.
 	/// </summary>
 	[ExtensionFor(typeof(Grid))]
-	public class GridAdornerProvider : PrimarySelectionAdornerProvider
+	[ExtensionServer(typeof(LogicalOrExtensionServer<PrimarySelectionExtensionServer, PrimarySelectionParentExtensionServer>))]
+	public class GridAdornerProvider : AdornerProvider
 	{
 		sealed class RowSplitterPlacement : AdornerPlacement
 		{
@@ -31,9 +31,9 @@ namespace ICSharpCode.WpfDesign.Designer.Extensions
 			
 			public override void Arrange(AdornerPanel panel, UIElement adorner, Size adornedElementSize)
 			{
-				adorner.Arrange(new Rect(-GridRailAdorner.RailSize,
+				adorner.Arrange(new Rect(-(GridRailAdorner.RailSize + GridRailAdorner.RailDistance),
 				                         row.Offset - GridRailAdorner.SplitterWidth / 2,
-				                         GridRailAdorner.RailSize + adornedElementSize.Width,
+				                         GridRailAdorner.RailSize + GridRailAdorner.RailDistance + adornedElementSize.Width,
 				                         GridRailAdorner.SplitterWidth));
 			}
 		}
@@ -46,9 +46,9 @@ namespace ICSharpCode.WpfDesign.Designer.Extensions
 			public override void Arrange(AdornerPanel panel, UIElement adorner, Size adornedElementSize)
 			{
 				adorner.Arrange(new Rect(column.Offset - GridRailAdorner.SplitterWidth / 2,
-				                         -GridRailAdorner.RailSize,
+				                         -(GridRailAdorner.RailSize + GridRailAdorner.RailDistance),
 				                         GridRailAdorner.SplitterWidth,
-				                         GridRailAdorner.RailSize + adornedElementSize.Height));
+				                         GridRailAdorner.RailSize + GridRailAdorner.RailDistance + adornedElementSize.Height));
 			}
 		}
 		
@@ -60,8 +60,12 @@ namespace ICSharpCode.WpfDesign.Designer.Extensions
 			leftBar = new GridRailAdorner(this.ExtendedItem, adornerPanel, Orientation.Vertical);
 			topBar = new GridRailAdorner(this.ExtendedItem, adornerPanel, Orientation.Horizontal);
 			
-			AdornerPanel.SetPlacement(leftBar, new RelativePlacement(HorizontalAlignment.Left, VerticalAlignment.Stretch));
-			AdornerPanel.SetPlacement(topBar, new RelativePlacement(HorizontalAlignment.Stretch, VerticalAlignment.Top));
+			RelativePlacement rp = new RelativePlacement(HorizontalAlignment.Left, VerticalAlignment.Stretch);
+			rp.XOffset -= GridRailAdorner.RailDistance;
+			AdornerPanel.SetPlacement(leftBar, rp);
+			rp = new RelativePlacement(HorizontalAlignment.Stretch, VerticalAlignment.Top);
+			rp.YOffset -= GridRailAdorner.RailDistance;
+			AdornerPanel.SetPlacement(topBar, rp);
 			
 			adornerPanel.Children.Add(leftBar);
 			adornerPanel.Children.Add(topBar);
@@ -110,16 +114,18 @@ namespace ICSharpCode.WpfDesign.Designer.Extensions
 					}
 					splitterList.Clear();
 					Grid grid = (Grid)this.ExtendedItem.Component;
+					IList<DesignItem> col = this.ExtendedItem.Properties["RowDefinitions"].CollectionElements;
 					for (int i = 1; i < grid.RowDefinitions.Count; i++) {
 						RowDefinition row = grid.RowDefinitions[i];
-						GridRowSplitterAdorner splitter = new GridRowSplitterAdorner();
+						GridRowSplitterAdorner splitter = new GridRowSplitterAdorner(this.ExtendedItem, col[i-1], col[i]);
 						AdornerPanel.SetPlacement(splitter, new RowSplitterPlacement(row));
 						adornerPanel.Children.Add(splitter);
 						splitterList.Add(splitter);
 					}
+					col = this.ExtendedItem.Properties["ColumnDefinitions"].CollectionElements;
 					for (int i = 1; i < grid.ColumnDefinitions.Count; i++) {
 						ColumnDefinition column = grid.ColumnDefinitions[i];
-						GridColumnSplitterAdorner splitter = new GridColumnSplitterAdorner();
+						GridColumnSplitterAdorner splitter = new GridColumnSplitterAdorner(this.ExtendedItem, col[i-1], col[i]);
 						AdornerPanel.SetPlacement(splitter, new ColumnSplitterPlacement(column));
 						adornerPanel.Children.Add(splitter);
 						splitterList.Add(splitter);

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/Extensions/GridPlacementSupport.cs

@@ -0,0 +1,83 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Daniel Grunwald" email="daniel@danielgrunwald.de"/>
+//     <version>$Revision$</version>
+// </file>
+
+using System;
+using System.Collections.Generic;
+using System.Windows;
+using System.Windows.Controls;
+
+using ICSharpCode.WpfDesign.Adorners;
+using ICSharpCode.WpfDesign.Extensions;
+using ICSharpCode.WpfDesign.Designer.Controls;
+
+namespace ICSharpCode.WpfDesign.Designer.Extensions
+{
+	/// <summary>
+	/// Provides <see cref="IPlacementBehavior"/> behavior for <see cref="Grid"/>.
+	/// </summary>
+	[ExtensionFor(typeof(Grid))]
+	public sealed class GridPlacementSupport : BehaviorExtension, IPlacementBehavior
+	{
+		protected override void OnInitialized()
+		{
+			base.OnInitialized();
+			this.ExtendedItem.AddBehavior(typeof(IPlacementBehavior), this);
+		}
+		
+		public bool CanPlace(ICollection<DesignItem> childItems, PlacementType type, PlacementAlignment position)
+		{
+			return type == PlacementType.Delete;
+		}
+		
+		public void BeginPlacement(PlacementOperation operation)
+		{
+		}
+		
+		public void EndPlacement(PlacementOperation operation)
+		{
+		}
+		
+		public Rect GetPosition(PlacementOperation operation, DesignItem child)
+		{
+			return new Rect();
+		}
+		
+		public void SetPosition(PlacementInformation info)
+		{
+			throw new NotImplementedException();
+		}
+		
+		public bool CanLeaveContainer(PlacementOperation operation)
+		{
+			return true;
+		}
+		
+		public void LeaveContainer(PlacementOperation operation)
+		{
+			foreach (PlacementInformation info in operation.PlacedItems) {
+				if (info.Item.ComponentType == typeof(ColumnDefinition)) {
+					// TODO: combine the width of the deleted column with the previous column
+					this.ExtendedItem.Properties["ColumnDefinitions"].CollectionElements.Remove(info.Item);
+				} else if (info.Item.ComponentType == typeof(RowDefinition)) {
+					this.ExtendedItem.Properties["RowDefinitions"].CollectionElements.Remove(info.Item);
+				} else {
+					throw new NotImplementedException();
+				}
+			}
+		}
+		
+		public bool CanEnterContainer(PlacementOperation operation)
+		{
+			return false;
+		}
+		
+		public void EnterContainer(PlacementOperation operation)
+		{
+			throw new NotImplementedException();
+		}
+	}
+}

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/ModelTools.cs

@@ -44,6 +44,20 @@ namespace ICSharpCode.WpfDesign.Designer
 			return 0;
 		}
 		
+		/// <summary>
+		/// Gets if the specified design item is in the document it belongs to.
+		/// </summary>
+		/// <returns>True for live objects, false for deleted objects.</returns>
+		public static bool IsInDocument(DesignItem item)
+		{
+			DesignItem rootItem = item.Context.RootItem;
+			while (item != null) {
+				if (item == rootItem) return true;
+				item = item.Parent;
+			}
+			return false;
+		}
+		
 		/// <summary>
 		/// Gets if the specified components can be deleted.
 		/// </summary>
@@ -60,9 +74,15 @@ namespace ICSharpCode.WpfDesign.Designer
 		/// </summary>
 		public static void DeleteComponents(ICollection<DesignItem> items)
 		{
+			DesignItem parent = Func.First(items).Parent;
 			PlacementOperation operation = PlacementOperation.Start(items, PlacementType.Delete);
 			try {
-				Func.First(items).Services.Selection.SetSelectedComponents(items, SelectionTypes.Remove);
+				ISelectionService selectionService = Func.First(items).Services.Selection;
+				selectionService.SetSelectedComponents(items, SelectionTypes.Remove);
+				// if the selection is empty after deleting some components, select the parent of the deleted component
+				if (selectionService.SelectionCount == 0 && !items.Contains(parent)) {
+					selectionService.SetSelectedComponents(new DesignItem[] { parent });
+				}
 				operation.DeleteItemsAndCommit();
 			} catch {
 				operation.Abort();

src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Project/WpfDesign.Designer.csproj

@@ -74,6 +74,7 @@
     <Compile Include="Controls\WindowClone.cs" />
     <Compile Include="DesignPanel.cs" />
     <Compile Include="Extensions\GridAdornerProvider.cs" />
+    <Compile Include="Extensions\GridPlacementSupport.cs" />
     <Compile Include="ModelTools.cs" />
     <Compile Include="Extensions\CanvasPlacementSupport.cs" />
     <Compile Include="Extensions\PanelInstanceFactory.cs" />