Move all items relative to the cursor by performing a drag gesture

CHANGELOG.md

@@ -7,6 +7,9 @@
 >	- Added InputGroupStyle and OutputGroupStyle to Node
 >	- Added PanWithMouseWheel, PanHorizontalModifierKey and PanVerticalModifierKey to EditorGestures.Editor
 >	- Added CornerRadius dependency property to LineConnection, CircuitConnection and StepConnection
+>	- Added EditorGestures.Editor.PushItems gesture used to start pushing ItemContainers vertically or horizontally
+>	- Added PushedAreaStyle, PushedAreaOrientation and IsPushingItems dependency properties to NodifyEditor
+>	- Added NodifyEditor.SnapToGrid utility function
 > - Bugfixes:
 
 #### **Version 6.5.0**

Nodify/Connections/ConnectionsMultiSelector.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Collections;
+using System.Collections;
 using System.Collections.Specialized;
 using System.Windows;
 using System.Windows.Controls;
@@ -45,18 +44,6 @@ private bool CanSelectMultipleItemsBase
             set => base.CanSelectMultipleItems = value;
         }
 
-        /// <summary>
-        /// The <see cref="NodifyEditor"/> that owns this <see cref="ConnectionsMultiSelector"/>.
-        /// </summary>
-        public NodifyEditor Editor { get; private set; } = default!;
-
-        public override void OnApplyTemplate()
-        {
-            base.OnApplyTemplate();
-
-            Editor = this.GetParentOfType<NodifyEditor>() ?? throw new NotSupportedException($"{nameof(ConnectionsMultiSelector)} cannot be used outside the {nameof(NodifyEditor)}");
-        }
-
         protected override DependencyObject GetContainerForItemOverride()
         {
             return new ConnectionContainer(this);

Nodify/EditorGestures.cs

@@ -111,6 +111,7 @@ public NodifyEditorGestures()
             {
                 Selection = new SelectionGestures();
                 Cutting = new MouseGesture(MouseAction.LeftClick, ModifierKeys.Alt | ModifierKeys.Shift);
+                PushItems = new MouseGesture(MouseAction.LeftClick, ModifierKeys.Control | ModifierKeys.Shift);
                 Pan = new AnyGesture(new MouseGesture(MouseAction.RightClick), new MouseGesture(MouseAction.MiddleClick));
                 ZoomModifierKey = ModifierKeys.None;
                 ZoomIn = new MultiGesture(MultiGesture.Match.Any, new KeyGesture(Key.OemPlus, ModifierKeys.Control), new KeyGesture(Key.Add, ModifierKeys.Control));
@@ -145,7 +146,11 @@ public NodifyEditorGestures()
             /// <remarks>Defaults to <see cref="ModifierKeys.Shift"/>.</remarks>
             public ModifierKeys PanHorizontalModifierKey { get; set; }
 
-            /// <summary>The modifier key required to start zooming with the mouse wheel.</summary>
+            /// <summary>Gesture used to start pushing.</summary>
+            /// <remarks>Defaults to <see cref="ModifierKeys.Control"/>+<see cref="ModifierKeys.Shift"/>+<see cref="MouseAction.LeftClick"/>.</remarks>
+            public InputGestureRef PushItems { get; }
+
+            /// <summary>The key modifier required to start zooming by mouse wheel.</summary>
             /// <remarks>Defaults to <see cref="ModifierKeys.None"/>.</remarks>
             public ModifierKeys ZoomModifierKey { get; set; }
 
@@ -185,6 +190,7 @@ public void Apply(NodifyEditorGestures gestures)
                 PanWithMouseWheel = gestures.PanWithMouseWheel;
                 PanHorizontalModifierKey = gestures.PanHorizontalModifierKey;
                 PanVerticalModifierKey = gestures.PanVerticalModifierKey;
+                PushItems.Value = gestures.PushItems.Value;
             }
         }
 

Nodify/EditorStates/EditorDefaultState.cs

@@ -36,6 +36,10 @@ public override void HandleMouseDown(MouseButtonEventArgs e)
             {
                 PushState(new EditorCuttingState(Editor));
             }
+            else if (gestures.PushItems.Matches(e.Source, e))
+            {
+                PushState(new EditorPushingItemsState(Editor));
+            }
             else if (gestures.Selection.Select.Matches(e.Source, e))
             {
                 SelectionType selectionType = GetSelectionType(e);

Nodify/EditorStates/EditorPushingItemsState.cs

@@ -0,0 +1,89 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Input;
+
+namespace Nodify
+{
+    public class EditorPushingItemsState : EditorState
+    {
+        private Point _prevPosition;
+        private const int _minDragDistance = 10;
+
+        public bool Canceled { get; set; } = NodifyEditor.AllowPushItemsCancellation;
+
+        public EditorPushingItemsState(NodifyEditor editor) : base(editor)
+        {
+        }
+
+        public override void Enter(EditorState? from)
+        {
+            Canceled = false;
+
+            _prevPosition = Editor.MouseLocation;
+        }
+
+        public override void Exit()
+        {
+            if (!Editor.IsPushingItems)
+            {
+                return;
+            }
+
+            if (Canceled)
+            {
+                Editor.CancelPushingItems();
+            }
+            else
+            {
+                Editor.EndPushingItems();
+            }
+        }
+
+        public override void HandleMouseMove(MouseEventArgs e)
+        {
+            if (Editor.IsPushingItems)
+            {
+                Editor.PushItems(Editor.MouseLocation - _prevPosition);
+                _prevPosition = Editor.MouseLocation;
+            }
+            else
+            {
+                if (Math.Abs(Editor.MouseLocation.X - _prevPosition.X) >= _minDragDistance)
+                {
+                    Editor.StartPushingItems(_prevPosition, Orientation.Horizontal);
+                }
+                else if (Math.Abs(Editor.MouseLocation.Y - _prevPosition.Y) >= _minDragDistance)
+                {
+                    Editor.StartPushingItems(_prevPosition, Orientation.Vertical);
+                }
+            }
+        }
+
+        public override void HandleMouseUp(MouseButtonEventArgs e)
+        {
+            EditorGestures.NodifyEditorGestures gestures = EditorGestures.Mappings.Editor;
+            if (gestures.PushItems.Matches(e.Source, e))
+            {
+                PopState();
+            }
+            else if (NodifyEditor.AllowPushItemsCancellation && gestures.CancelAction.Matches(e.Source, e))
+            {
+                Canceled = true;
+                e.Handled = true;   // prevents opening context menu
+
+                PopState();
+            }
+        }
+
+        public override void HandleKeyUp(KeyEventArgs e)
+        {
+            EditorGestures.NodifyEditorGestures gestures = EditorGestures.Mappings.Editor;
+            if (NodifyEditor.AllowPushItemsCancellation && gestures.CancelAction.Matches(e.Source, e))
+            {
+                Canceled = true;
+                PopState();
+            }
+        }
+    }
+}

Nodify/Helpers/DraggingOptimized.cs

@@ -8,19 +8,19 @@ namespace Nodify
     /// <summary>
     /// Commits the position changes at the end of the operation. Updates the RenderTransform to preview the container position.
     /// </summary>
-    internal class DraggingOptimized : IDraggingStrategy
+    internal sealed class DraggingOptimized : IDraggingStrategy
     {
-        private readonly NodifyEditor _editor;
-        private Vector _dragAccumulator;
+        private readonly uint _gridCellSize;
         private readonly List<ItemContainer> _selectedContainers;
+        private Vector _dragAccumulator = new Vector(0, 0);
 
-        public DraggingOptimized(NodifyEditor editor)
+        public DraggingOptimized(IEnumerable<ItemContainer> containers, uint gridCellSize)
         {
-            _editor = editor;
-            _selectedContainers = _editor.SelectedContainers.Where(c => c.IsDraggable).ToList();
+            _gridCellSize = gridCellSize;
+            _selectedContainers = containers.Where(c => c.IsDraggable).ToList();
         }
 
-        public void Abort(Vector change)
+        public void Abort()
         {
             for (var i = 0; i < _selectedContainers.Count; i++)
             {
@@ -36,7 +36,7 @@ public void Abort(Vector change)
             _selectedContainers.Clear();
         }
 
-        public void End(Vector change)
+        public void End()
         {
             for (var i = 0; i < _selectedContainers.Count; i++)
             {
@@ -48,8 +48,8 @@ public void End(Vector change)
                 // Correct the final position
                 if (NodifyEditor.EnableSnappingCorrection && (r.X != 0 || r.Y != 0))
                 {
-                    result.X = (int)result.X / _editor.GridCellSize * _editor.GridCellSize;
-                    result.Y = (int)result.Y / _editor.GridCellSize * _editor.GridCellSize;
+                    result.X = (int)result.X / _gridCellSize * _gridCellSize;
+                    result.Y = (int)result.Y / _gridCellSize * _gridCellSize;
                 }
 
                 container.Location = result;
@@ -61,15 +61,10 @@ public void End(Vector change)
             _selectedContainers.Clear();
         }
 
-        public void Start(Vector change)
-        {
-            _dragAccumulator = new Vector(0, 0);
-        }
-
         public void Update(Vector change)
         {
             _dragAccumulator += change;
-            var delta = new Vector((int)_dragAccumulator.X / _editor.GridCellSize * _editor.GridCellSize, (int)_dragAccumulator.Y / _editor.GridCellSize * _editor.GridCellSize);
+            var delta = new Vector((int)_dragAccumulator.X / _gridCellSize * _gridCellSize, (int)_dragAccumulator.Y / _gridCellSize * _gridCellSize);
             _dragAccumulator -= delta;
 
             if (delta.X != 0 || delta.Y != 0)

Nodify/Helpers/DraggingSimple.cs

@@ -6,26 +6,25 @@ namespace Nodify
 {
     internal interface IDraggingStrategy
     {
-        void Start(Vector change);
         void Update(Vector change);
-        void End(Vector change);
-        void Abort(Vector change);
+        void End();
+        void Abort();
     }
 
-    internal class DraggingSimple : IDraggingStrategy
+    internal sealed class DraggingSimple : IDraggingStrategy
     {
-        private readonly NodifyEditor _editor;
-        private Vector _dragOffset;
-        private Vector _dragAccumulator;
-        private readonly IList<ItemContainer> _selectedContainers;
+        private readonly uint _gridCellSize;
+        private readonly List<ItemContainer> _selectedContainers;
+        private Vector _dragOffset = new Vector(0, 0);
+        private Vector _dragAccumulator = new Vector(0, 0);
 
-        public DraggingSimple(NodifyEditor editor)
+        public DraggingSimple(IEnumerable<ItemContainer> containers, uint gridCellSize)
         {
-            _editor = editor;
-            _selectedContainers = _editor.SelectedContainers.Where(c => c.IsDraggable).ToList();
+            _gridCellSize = gridCellSize;
+            _selectedContainers = containers.Where(c => c.IsDraggable).ToList();
         }
 
-        public void Abort(Vector change)
+        public void Abort()
         {
             for (var i = 0; i < _selectedContainers.Count; i++)
             {
@@ -36,7 +35,7 @@ public void Abort(Vector change)
             _selectedContainers.Clear();
         }
 
-        public void End(Vector change)
+        public void End()
         {
             for (var i = 0; i < _selectedContainers.Count; i++)
             {
@@ -46,8 +45,8 @@ public void End(Vector change)
                 // Correct the final position
                 if (NodifyEditor.EnableSnappingCorrection)
                 {
-                    result.X = (int)result.X / _editor.GridCellSize * _editor.GridCellSize;
-                    result.Y = (int)result.Y / _editor.GridCellSize * _editor.GridCellSize;
+                    result.X = (int)result.X / _gridCellSize * _gridCellSize;
+                    result.Y = (int)result.Y / _gridCellSize * _gridCellSize;
                 }
 
                 container.Location = result;
@@ -56,16 +55,10 @@ public void End(Vector change)
             _selectedContainers.Clear();
         }
 
-        public void Start(Vector change)
-        {
-            _dragOffset = new Vector(0, 0);
-            _dragAccumulator = new Vector(0, 0);
-        }
-
         public void Update(Vector change)
         {
             _dragAccumulator += change;
-            var delta = new Vector((int)_dragAccumulator.X / _editor.GridCellSize * _editor.GridCellSize, (int)_dragAccumulator.Y / _editor.GridCellSize * _editor.GridCellSize);
+            var delta = new Vector((int)_dragAccumulator.X / _gridCellSize * _gridCellSize, (int)_dragAccumulator.Y / _gridCellSize * _gridCellSize);
             _dragAccumulator -= delta;
 
             if (delta.X != 0 || delta.Y != 0)