Merge pull request #180 from miroiu/feature/items-moved-event

Add ItemsMoved routed event to NodifyEditor to simplify undo-redo

Author: miroiu

CHANGELOG.md

@@ -17,13 +17,15 @@
 >	- Moved AllowCuttingCancellation from CuttingLine to NodifyEditor
 >	- Moved AllowDraggingCancellation from ItemContainer to NodifyEditor
 >	- Moved EditorGestures under the Nodify.Interactivity namespace
+>	- Moved Editor events under the Nodify.Events namespace
 > - Features:
 >	- Added BeginPanning, UpdatePanning, EndPanning, CancelPanning and AllowPanningCancellation to NodifyEditor and Minimap
 >	- Added MouseLocation, ZoomAtPosition and GetLocationInsideMinimap to Minimap
 >	- Added UpdateCuttingLine to NodifyEditor
 >	- Added Select, BeginSelecting, UpdateSelection, EndSelecting, CancelSelecting and AllowSelectionCancellation to NodifyEditor
 >	- Added IsDragging, BeginDragging, UpdateDragging, EndDragging and CancelDragging to NodifyEditor
 >	- Added AlignSelection and AlignContainers methods to NodifyEditor
+>	- Added ItemsMoved routed event to NodifyEditor
 >	- Added HasCustomContextMenu dependency property to NodifyEditor, ItemContainer, Connector and BaseConnection
 >	- Added Select, BeginDragging, UpdateDragging, EndDragging and CancelDragging to ItemContainer
 >	- Added PreserveSelectionOnRightClick configuration field to ItemContainer

Examples/Nodify.Playground/Editor/NodifyEditorView.xaml.cs

@@ -1,4 +1,5 @@
-using System.Windows.Controls;
+using Nodify.Events;
+using System.Windows.Controls;
 
 namespace Nodify.Playground
 {

Examples/Nodify.Shapes/Canvas/CanvasView.xaml

@@ -46,6 +46,7 @@
                              ItemsDragCompletedCommand="{Binding MoveShapesCompletedCommand}"
                              RemoveConnectionCommand="{Binding RemoveConnectionCommand}"
                              SelectionChanged="Editor_SelectionChanged"
+                             ItemsMoved="Editor_ItemsMoved"
                              MouseDown="Editor_MouseDown"
                              MouseMove="Editor_MouseMove"
                              MouseUp="Editor_MouseUp"

Examples/Nodify.Shapes/Canvas/CanvasView.xaml.cs

@@ -1,4 +1,5 @@
-using Nodify.Shapes.Canvas.UndoRedo;
+using Nodify.Events;
+using Nodify.Shapes.Canvas.UndoRedo;
 using System;
 using System.Collections.Generic;
 using System.Linq;
@@ -129,5 +130,17 @@ private void Editor_SelectionChanged(object sender, SelectionChangedEventArgs e)
                 canvasVM.UndoRedo.Record(selectNodes);
             }
         }
+
+        private void Editor_ItemsMoved(object sender, ItemsMovedEventArgs e)
+        {
+            var shapes = e.Items.Cast<ShapeViewModel>().ToList();
+
+            var canvasVM = (CanvasViewModel)DataContext;
+            using (canvasVM.UndoRedo.Batch("Move shapes"))
+            {
+                var moveShapes = new MoveShapesAction(shapes, e.Offset);
+                canvasVM.UndoRedo.Record(moveShapes);
+            }
+        }
     }
 }

Examples/Nodify.Shapes/Canvas/CanvasViewModel.cs

@@ -74,17 +74,11 @@ public CanvasViewModel()
 
         private void MoveShapesStartedHandler()
         {
-            UndoRedo.ExecuteAction(new MoveShapesAction(this));
             ShapeToolbar.Hide();
         }
 
         private void MoveShapesCompletedHandler()
         {
-            if (UndoRedo.Current is MoveShapesAction movesShapes)
-            {
-                movesShapes.SaveLocations();
-            }
-
             ShapeToolbar.Show();
         }
 

Examples/Nodify.Shapes/Canvas/UndoRedo/MoveShapesAction.cs

@@ -1,37 +1,34 @@
 using Nodify.UndoRedo;
 using System.Collections.Generic;
-using System.Linq;
 using System.Windows;
 
 namespace Nodify.Shapes.Canvas.UndoRedo
 {
     public class MoveShapesAction : IAction
     {
-        private readonly IReadOnlyCollection<ShapeViewModel> _movedShapes;
-        private readonly Dictionary<ShapeViewModel, Point> _initialLocations;
-        private Dictionary<ShapeViewModel, Point>? _finalLocations;
-
-        public MoveShapesAction(CanvasViewModel canvas)
-        {
-            _movedShapes = canvas.SelectedShapes;
-            _initialLocations = _movedShapes.ToDictionary(x => x, x => x.Location);
-        }
+        private readonly IReadOnlyCollection<ShapeViewModel> _shapes;
+        private readonly Vector _offset;
 
         public string? Label => "Move shapes";
 
-        public void Execute()
+        public MoveShapesAction(IReadOnlyCollection<ShapeViewModel> shapes, Vector offset)
         {
-            _finalLocations?.ForEach(x => x.Key.Location = x.Value);
+            _shapes = shapes;
+            _offset = offset;
         }
 
+        public void Execute()
+            => ApplyOffset(_offset);
+
         public void Undo()
-        {
-            _initialLocations.ForEach(x => x.Key.Location = x.Value);
-        }
+            => ApplyOffset(-_offset);
 
-        public void SaveLocations()
+        private void ApplyOffset(Vector offset)
         {
-            _finalLocations = _movedShapes.ToDictionary(x => x, x => x.Location);
+            foreach (var shape in _shapes)
+            {
+                shape.Location += offset;
+            }
         }
     }
 }

Examples/Nodify.Shapes/Canvas/UndoRedo/ResizeShapesAction.cs

@@ -10,23 +10,21 @@ public class ResizeShapesAction : IAction
         private readonly IReadOnlyCollection<ShapeViewModel> _resizedShapes;
         private readonly Dictionary<ShapeViewModel, Size> _initialSizes;
         private Dictionary<ShapeViewModel, Size>? _finalSizes;
-
-        // Resizing could also move the shape
-        private readonly MoveShapesAction _moveShapesAction;
+        private readonly Dictionary<ShapeViewModel, Point> _initialLocations;
+        private Dictionary<ShapeViewModel, Point>? _finalLocations;
 
         public ResizeShapesAction(CanvasViewModel canvas)
         {
             _resizedShapes = canvas.SelectedShapes;
             _initialSizes = _resizedShapes.ToDictionary(x => x, x => new Size(x.Width, x.Height));
-
-            _moveShapesAction = new MoveShapesAction(canvas);
+            _initialLocations = _resizedShapes.ToDictionary(x => x, x => x.Location);
         }
 
         public string? Label => "Resize shapes";
 
         public void Execute()
         {
-            _moveShapesAction.Execute();
+            _finalLocations?.ForEach(x => x.Key.Location = x.Value);
 
             _finalSizes?.ForEach(x =>
             {
@@ -43,13 +41,12 @@ public void Undo()
                 x.Key.Height = x.Value.Height;
             });
 
-            _moveShapesAction.Undo();
+            _initialLocations.ForEach(x => x.Key.Location = x.Value);
         }
 
         public void SaveSizes()
         {
-            _moveShapesAction.SaveLocations();
-
+            _finalLocations = _resizedShapes.ToDictionary(x => x, x => x.Location);
             _finalSizes = _resizedShapes.ToDictionary(x => x, x => new Size(x.Width, x.Height));
         }
     }

Nodify/Containers/Events/PreviewLocationChanged.cs

@@ -0,0 +1,10 @@
+using System.Windows;
+
+namespace Nodify.Events
+{
+    /// <summary>
+    /// Delegate used to notify when an <see cref="ItemContainer"/> is previewing a new location.
+    /// </summary>
+    /// <param name="newLocation">The new location.</param>
+    public delegate void PreviewLocationChanged(Point newLocation);
+}

Nodify/Containers/ItemContainer.cs

@@ -1,4 +1,5 @@
-using Nodify.Interactivity;
+using Nodify.Events;
+using Nodify.Interactivity;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Controls.Primitives;
@@ -7,12 +8,6 @@
 
 namespace Nodify
 {
-    /// <summary>
-    /// Delegate used to notify when an <see cref="ItemContainer"/> is previewing a new location.
-    /// </summary>
-    /// <param name="newLocation">The new location.</param>
-    public delegate void PreviewLocationChanged(Point newLocation);
-
     /// <summary>
     /// The container for all the items generated by the <see cref="ItemsControl.ItemsSource"/> of the <see cref="NodifyEditor"/>.
     /// </summary>

Nodify/Editor/Events/ItemsMovedEventArgs.cs

@@ -0,0 +1,43 @@
+using System;
+using System.Collections.Generic;
+using System.Windows;
+
+namespace Nodify.Events
+{
+    /// <summary>
+    /// Represents a method signature used to handle the <see cref="NodifyEditor.ItemsMovedEvent"/> routed event.
+    /// </summary>
+    /// <param name="sender">The source of the event.</param>
+    /// <param name="e">The event data containing information about the moved items and their offset.</param>
+    public delegate void ItemsMovedEventHandler(object sender, ItemsMovedEventArgs e);
+
+    /// <summary>
+    /// Provides data for the <see cref="NodifyEditor.ItemsMovedEvent"/> routed event.
+    /// </summary>
+    public class ItemsMovedEventArgs : RoutedEventArgs
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ItemsMovedEventArgs"/> class with the specified moved items and offset.
+        /// </summary>
+        /// <param name="items">The collection of items that were moved.</param>
+        /// <param name="offset">The vector representing the distance the items were moved.</param>
+        public ItemsMovedEventArgs(IReadOnlyCollection<object> items, Vector offset)
+        {
+            Items = items;
+            Offset = offset;
+        }
+
+        /// <summary>
+        /// Gets or sets the vector representing the distance the items were moved.
+        /// </summary>
+        public Vector Offset { get; set; }
+
+        /// <summary>
+        /// Gets a collection of <see cref="FrameworkElement.DataContext"/>s of the <see cref="ItemContainer"/>s associated with this event.
+        /// </summary>
+        public IReadOnlyCollection<object> Items { get; }
+
+        protected override void InvokeEventHandler(Delegate genericHandler, object genericTarget)
+            => ((ItemsMovedEventHandler)genericHandler)(genericTarget, this);
+    }
+}