Refactor Align/Stack function to use existing functionality. Also make undoable.

src/Greenshot.Base/Interfaces/ISurface.cs

@@ -38,6 +38,7 @@ namespace Greenshot.Base.Interfaces
         event SurfaceMessageEventHandler SurfaceMessage;
         event SurfaceDrawingModeEventHandler DrawingModeChanged;
         event SurfaceElementEventHandler MovingElementChanged;
+        event SurfaceExpandedEventHandler SurfaceExpanded;
 
         /// <summary>
         /// Start value of the step-labels (counts)
@@ -161,6 +162,7 @@ namespace Greenshot.Base.Interfaces
         void RemoveElement(IDrawableContainer elementToRemove, bool makeUndoable = true, bool invalidate = true, bool generateEvents = true);
 
         void SendMessageEvent(object source, SurfaceMessageTyp messageType, string message);
+        void ResizeCanvas(int left, int right, int top, int bottom);
         void ApplyBitmapEffect(IEffect effect);
         void RemoveCursor();
         bool HasCursor { get; }

src/Greenshot.Base/Interfaces/SurfaceExpandedEventHandler.cs

@@ -0,0 +1,27 @@
+/*
+ * Greenshot - a free and open source screenshot tool
+ * Copyright (C) 2007-2021 Thomas Braun, Jens Klingen, Robin Krom
+ *
+ * For more information see: https://getgreenshot.org/
+ * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+using System;
+
+namespace Greenshot.Base.Interfaces
+{
+    public delegate void SurfaceExpandedEventHandler(object sender, EventArgs e);
+}

src/Greenshot.Editor/Drawing/DrawableContainerList.cs

@@ -882,52 +882,101 @@ namespace Greenshot.Editor.Drawing
 
         public void AlignOrStack(string direction, ISurface surface, IDrawableContainer target, IDrawableContainerList parent)
         {
-            int newBackgroundWidth = 0, newBackgroundHeight = 0, imageBorder = 0, xMovement = 0, yMovement = 0;
+            // Make calculations
-            int oldImageX = 0, oldImageY = 0;
+            int left = 0, right = 0, top = 0, bottom = 0;
-            // Calculate height and width of new frame.
-            // Also calculate movement for target object and old image.
-            if (direction == "right" || direction == "left")
-            {
-                newBackgroundWidth = target.Width + surface.Image.Width;
-                newBackgroundHeight = Math.Max(surface.Image.Height, target.Height);
-                if (direction == "right")
-                    imageBorder = surface.Image.Width;
             if (direction == "left")
-                    oldImageX = target.Width;
+                left = target.Width;
-            }
+            else if (direction == "right")
+                right = target.Width;
+            else if (direction == "top")
+                top = target.Height;
+            else if (direction == "bottom")
+                bottom = target.Height;
+            
+            // Use surface function
+            surface.ResizeCanvas(left, right, top, bottom);
+
+            // Move target object
+            SnapToEdge(direction, surface, target);
+            if (direction == "left" || direction == "right")
+                SnapToEdge("top", surface, target);
             else if (direction == "top" || direction == "bottom")
-            {
+                SnapToEdge("left", surface, target);
-                newBackgroundWidth = Math.Max(surface.Image.Width, target.Width);
+            surface.DeselectAllElements();
-                newBackgroundHeight = target.Height + surface.Image.Height;
+
-                if (direction == "top")
+            //if (direction == "left")
-                    oldImageY = target.Height;
+            //{
-                if (direction == "bottom")
+            //    left = target.Width;
-                    imageBorder = surface.Image.Height;
+            //    bottom = Math.Max(target.Height - surface.Image.Height, 0);
-            }
+            //    xMovement = -target.Location.X;
-            // Create image for use as new frame.
+            //    yMovement = -target.Location.Y;
-            Bitmap newImage = new Bitmap(newBackgroundWidth, newBackgroundHeight);
+            //}
-            // Save old image.
+            //else if (direction == "right")
-            Bitmap oldImage = (Bitmap)ImageHelper.Clone(surface.Image);
+            //{
-            // Set background to new, larger frame.
+            //    right = target.Width;
-            surface.Image = newImage;
+            //    bottom = Math.Max(target.Height - surface.Image.Height, 0);
-            if (direction == "right" || direction == "left")
+            //    xMovement = surface.Image.Width - target.Location.X;
-            {
+            //    yMovement = -target.Location.Y;
-                xMovement = imageBorder - target.Location.X;
+            //}
-                yMovement = -target.Location.Y;
+            //else if (direction == "top")
-            }
+            //{
-            else if (direction == "top" || direction == "bottom")
+            //    top = target.Height;
-            {
+            //    right = Math.Max(target.Width - surface.Image.Width, 0);
-                xMovement = -target.Location.X;
+            //}
-                yMovement = imageBorder - target.Location.Y;
+            //else if (direction == "bottom")
-            }
+            //{
-            // Move object to open space
+            //    bottom = target.Height;
-            target.MoveBy(xMovement, yMovement);
+            //    right = Math.Max(target.Width - surface.Image.Width, 0);
-            // Push original image to bottom.
+            //}
-            var oldImageContainer = surface.AddImageContainer(oldImage, oldImageX, oldImageY);
+
-            IDrawableContainerList oldImageContainerList = parent.Clone();
+
-            oldImageContainerList[0] = oldImageContainer;
+
-            surface.Elements.PushElementsToBottom(oldImageContainerList);
+            //int newBackgroundWidth = 0, newBackgroundHeight = 0, imageBorder = 0;
-            //_surfaceSizeChanged(this, null);
+            //int oldImageX = 0, oldImageY = 0;
+            //// Calculate height and width of new frame.
+            //// Also calculate movement for target object and old image.
+            //if (direction == "right" || direction == "left")
+            //{
+            //    newBackgroundWidth = target.Width + surface.Image.Width;
+            //    newBackgroundHeight = Math.Max(surface.Image.Height, target.Height);
+            //    if (direction == "right")
+            //        imageBorder = surface.Image.Width;
+            //    if (direction == "left")
+            //        oldImageX = target.Width;
+            //}
+            //else if (direction == "top" || direction == "bottom")
+            //{
+            //    newBackgroundWidth = Math.Max(surface.Image.Width, target.Width);
+            //    newBackgroundHeight = target.Height + surface.Image.Height;
+            //    if (direction == "top")
+            //        oldImageY = target.Height;
+            //    if (direction == "bottom")
+            //        imageBorder = surface.Image.Height;
+            //}
+            //// Create image for use as new frame.
+            //Bitmap newImage = new Bitmap(newBackgroundWidth, newBackgroundHeight);
+            //// Save old image.
+            //Bitmap oldImage = (Bitmap)ImageHelper.Clone(surface.Image);
+            //// Set background to new, larger frame.
+            //surface.Image = newImage;
+            //if (direction == "right" || direction == "left")
+            //{
+            //    xMovement = imageBorder - target.Location.X;
+            //    yMovement = -target.Location.Y;
+            //}
+            //else if (direction == "top" || direction == "bottom")
+            //{
+            //    xMovement = -target.Location.X;
+            //    yMovement = imageBorder - target.Location.Y;
+            //}
+            //// Move object to open space
+            //target.MoveBy(xMovement, yMovement);
+            //// Push original image to bottom.
+            //var oldImageContainer = surface.AddImageContainer(oldImage, oldImageX, oldImageY);
+            //IDrawableContainerList oldImageContainerList = parent.Clone();
+            //oldImageContainerList[0] = oldImageContainer;
+            //surface.Elements.PushElementsToBottom(oldImageContainerList);
+            ////_surfaceSizeChanged(this, null);
         }
     }
 }

src/Greenshot.Editor/Drawing/Surface.cs

@@ -104,6 +104,14 @@ namespace Greenshot.Editor.Drawing
             remove => _surfaceSizeChanged -= value;
         }
 
+        [NonSerialized] private SurfaceExpandedEventHandler _surfaceExpanded;
+
+        public event SurfaceExpandedEventHandler SurfaceExpanded
+        {
+            add => _surfaceExpanded += value;
+            remove => _surfaceExpanded -= value;
+        }
+
         [NonSerialized] private SurfaceMessageEventHandler _surfaceMessage;
 
         public event SurfaceMessageEventHandler SurfaceMessage
@@ -964,6 +972,13 @@ namespace Greenshot.Editor.Drawing
             }
         }
 
+        public void ResizeCanvas(int left, int right, int top, int bottom)
+        {
+            var resizeEffect = new ResizeCanvasEffect(left, right, top, bottom);
+            ApplyBitmapEffect(resizeEffect);
+            _surfaceExpanded(this, null);
+        }
+
         /// <summary>
         /// Apply a bitmap effect to the surface
         /// </summary>

src/Greenshot.Editor/Forms/ImageEditorForm.cs

@@ -229,6 +229,7 @@ namespace Greenshot.Editor.Forms
                 _surface.MovingElementChanged += delegate { RefreshEditorControls(); };
                 _surface.DrawingModeChanged += Surface_DrawingModeChanged;
                 _surface.SurfaceSizeChanged += SurfaceSizeChanged;
+                _surface.SurfaceExpanded += SurfaceExpanded;
                 _surface.SurfaceMessage += SurfaceMessageReceived;
                 _surface.FieldAggregator.FieldChanged += FieldAggregatorFieldChanged;
                 SurfaceSizeChanged(Surface, null);
@@ -514,6 +515,14 @@ namespace Greenshot.Editor.Forms
             AlignCanvasPositionAfterResize();
         }
 
+        /// <summary>
+        /// Used when expanding the surface in one direction to accomodate shifting an object to one side.
+        /// </summary>
+        private void SurfaceExpanded(object sender, EventArgs e)
+        {
+            UpdateUndoRedoSurfaceDependencies();
+        }
+
         public ISurface Surface
         {
             get { return _surface; }