[ColorPicker] Change zoom animation behavior (#11057)

* [ColorPicker] Change zoom animation behavior
Makes the main window large enough to accommodate all zoom levels.

* [ColorPicker] Change zoom window position logic
Use PointFromScreen to calculate mouse position relative to window
This requires a "visible" window, so use opacity to fake-hide window
Window is still fully hidden when color picker closes

* [ColorPicker] Extract and modify resize behavior
Allows easier editing of animation easing/duration

* Update expect.txt

IAnimatable
IEasing

Co-authored-by: Clint Rutkas <clint@rutkas.com>

.github/actions/spell-check/expect.txt

@@ -752,6 +752,7 @@ hxx
 Hyperlink
 IAction
 IActivated
+IAnimatable
 IApp
 IApplication
 IAppx
@@ -796,6 +797,7 @@ IDrop
 idx
 IDXGI
 IDYES
+IEasing
 IEnum
 IEnumerable
 IEnumerator

src/modules/colorPicker/ColorPickerUI/Behaviors/MoveWindowBehavior.cs

@@ -1,60 +0,0 @@
-// Copyright (c) Microsoft Corporation
-// The Microsoft Corporation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-using System.Windows;
-using System.Windows.Media.Animation;
-using Microsoft.Xaml.Behaviors;
-
-namespace ColorPicker.Behaviors
-{
-    public class MoveWindowBehavior : Behavior<Window>
-    {
-        public static readonly DependencyProperty LeftProperty = DependencyProperty.Register("Left", typeof(double), typeof(MoveWindowBehavior), new PropertyMetadata(new PropertyChangedCallback(LeftPropertyChanged)));
-
-        private static void LeftPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
-        {
-            var sender = ((MoveWindowBehavior)d).AssociatedObject;
-            var move = new DoubleAnimation(sender.Left, (double)e.NewValue, new Duration(TimeSpan.FromMilliseconds(150)), FillBehavior.Stop);
-            move.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseInOut };
-            sender.BeginAnimation(Window.LeftProperty, move, HandoffBehavior.Compose);
-        }
-
-        public static readonly DependencyProperty TopProperty = DependencyProperty.Register("Top", typeof(double), typeof(MoveWindowBehavior), new PropertyMetadata(new PropertyChangedCallback(TopPropertyChanged)));
-
-        private static void TopPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
-        {
-            var sender = ((MoveWindowBehavior)d).AssociatedObject;
-            var move = new DoubleAnimation(sender.Top, (double)e.NewValue, new Duration(TimeSpan.FromMilliseconds(150)), FillBehavior.Stop);
-            move.EasingFunction = new CubicEase() { EasingMode = EasingMode.EaseInOut };
-            sender.BeginAnimation(Window.TopProperty, move, HandoffBehavior.Compose);
-        }
-
-        public double Left
-        {
-            get
-            {
-                return (double)GetValue(LeftProperty);
-            }
-
-            set
-            {
-                SetValue(LeftProperty, value);
-            }
-        }
-
-        public double Top
-        {
-            get
-            {
-                return (double)GetValue(TopProperty);
-            }
-
-            set
-            {
-                SetValue(TopProperty, value);
-            }
-        }
-    }
-}

src/modules/colorPicker/ColorPickerUI/Behaviors/ResizeBehavior.cs

@@ -11,20 +11,55 @@ namespace ColorPicker.Behaviors
 {
     public class ResizeBehavior : Behavior<FrameworkElement>
     {
+        // animation behavior variables
+        // used when size is getting bigger
+        private static readonly TimeSpan _animationTime = TimeSpan.FromMilliseconds(200);
+        private static readonly IEasingFunction _easeFunction = new SineEase() { EasingMode = EasingMode.EaseOut };
+
+        // used when size is getting smaller
+        private static readonly TimeSpan _animationTimeSmaller = _animationTime;
+        private static readonly IEasingFunction _easeFunctionSmaller = new QuadraticEase() { EasingMode = EasingMode.EaseIn };
+
+        private static void CustomAnimation(DependencyProperty prop, IAnimatable sender, double fromValue, double toValue)
+        {
+            // if the animation is to/from a value of 0, it will cancel the current animation
+            DoubleAnimation move = null;
+            if (toValue > 0 && fromValue > 0)
+            {
+                // if getting bigger
+                if (fromValue < toValue)
+                {
+                    move = new DoubleAnimation(fromValue, toValue, new Duration(_animationTime), FillBehavior.Stop)
+                    {
+                        EasingFunction = _easeFunction,
+                    };
+                }
+                else
+                {
+                    move = new DoubleAnimation(fromValue, toValue, new Duration(_animationTimeSmaller), FillBehavior.Stop)
+                    {
+                        EasingFunction = _easeFunctionSmaller,
+                    };
+                }
+            }
+
+            // HandoffBehavior must be SnapshotAndReplace
+            // Compose does not allow cancellation
+            sender.BeginAnimation(prop, move, HandoffBehavior.SnapshotAndReplace);
+        }
+
         public static readonly DependencyProperty WidthProperty = DependencyProperty.Register("Width", typeof(double), typeof(ResizeBehavior), new PropertyMetadata(new PropertyChangedCallback(WidthPropertyChanged)));
 
         private static void WidthPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
             var sender = ((ResizeBehavior)d).AssociatedObject;
-            var move = new DoubleAnimation(sender.Width, (double)e.NewValue, new Duration(TimeSpan.FromMilliseconds(150)), FillBehavior.Stop);
-            move.Completed += (s, e1) =>
-            {
-                sender.BeginAnimation(FrameworkElement.WidthProperty, null);
-                sender.Width = (double)e.NewValue;
-            };
 
-            move.EasingFunction = new QuadraticEase() { EasingMode = EasingMode.EaseOut };
-            sender.BeginAnimation(FrameworkElement.WidthProperty, move, HandoffBehavior.Compose);
+            var fromValue = sender.Width;
+            var toValue = (double)e.NewValue;
+
+            // setting Width before animation prevents jumping
+            sender.Width = toValue;
+            CustomAnimation(FrameworkElement.WidthProperty, sender, fromValue, toValue);
         }
 
         public static readonly DependencyProperty HeightProperty = DependencyProperty.Register("Height", typeof(double), typeof(ResizeBehavior), new PropertyMetadata(new PropertyChangedCallback(HeightPropertyChanged)));
@@ -32,15 +67,13 @@ namespace ColorPicker.Behaviors
         private static void HeightPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
             var sender = ((ResizeBehavior)d).AssociatedObject;
-            var move = new DoubleAnimation(sender.Height, (double)e.NewValue, new Duration(TimeSpan.FromMilliseconds(150)), FillBehavior.Stop);
-            move.Completed += (s, e1) =>
-            {
-                sender.BeginAnimation(FrameworkElement.HeightProperty, null);
-                sender.Height = (double)e.NewValue;
-            };
 
-            move.EasingFunction = new QuadraticEase() { EasingMode = EasingMode.EaseOut };
-            sender.BeginAnimation(FrameworkElement.HeightProperty, move, HandoffBehavior.Compose);
+            var fromValue = sender.Height;
+            var toValue = (double)e.NewValue;
+
+            // setting Height before animation prevents jumping
+            sender.Height = toValue;
+            CustomAnimation(FrameworkElement.HeightProperty, sender, fromValue, toValue);
         }
 
         public double Width

src/modules/colorPicker/ColorPickerUI/Helpers/ZoomWindowHelper.cs

@@ -18,33 +18,27 @@ namespace ColorPicker.Helpers
     [Export(typeof(ZoomWindowHelper))]
     public class ZoomWindowHelper
     {
-        private const int ZoomWindowChangeDelayInMS = 50;
         private const int ZoomFactor = 2;
         private const int BaseZoomImageSize = 50;
         private const int MaxZoomLevel = 4;
         private const int MinZoomLevel = 0;
 
+        private static readonly Bitmap _bmp = new Bitmap(BaseZoomImageSize, BaseZoomImageSize, PixelFormat.Format32bppArgb);
+        private static readonly Graphics _graphics = Graphics.FromImage(_bmp);
+
         private readonly IZoomViewModel _zoomViewModel;
         private readonly AppStateHandler _appStateHandler;
-        private readonly IThrottledActionInvoker _throttledActionInvoker;
 
         private int _currentZoomLevel;
         private int _previousZoomLevel;
 
         private ZoomWindow _zoomWindow;
 
-        private double _lastLeft;
-        private double _lastTop;
-
-        private double _previousScaledX;
-        private double _previousScaledY;
-
         [ImportingConstructor]
-        public ZoomWindowHelper(IZoomViewModel zoomViewModel, AppStateHandler appStateHandler, IThrottledActionInvoker throttledActionInvoker)
+        public ZoomWindowHelper(IZoomViewModel zoomViewModel, AppStateHandler appStateHandler)
         {
             _zoomViewModel = zoomViewModel;
             _appStateHandler = appStateHandler;
-            _throttledActionInvoker = throttledActionInvoker;
             _appStateHandler.AppClosed += AppStateHandler_AppClosed;
             _appStateHandler.AppHidden += AppStateHandler_AppClosed;
         }
@@ -73,7 +67,7 @@ namespace ColorPicker.Helpers
         {
             _currentZoomLevel = 0;
             _previousZoomLevel = 0;
-            HideZoomWindow();
+            HideZoomWindow(true);
         }
 
         private void SetZoomImage(System.Windows.Point point)
@@ -89,28 +83,17 @@ namespace ColorPicker.Helpers
             {
                 var x = (int)point.X - (BaseZoomImageSize / 2);
                 var y = (int)point.Y - (BaseZoomImageSize / 2);
-                var rect = new Rectangle(x, y, BaseZoomImageSize, BaseZoomImageSize);
 
-                using (var bmp = new Bitmap(rect.Width, rect.Height, PixelFormat.Format32bppArgb))
-                {
-                    var g = Graphics.FromImage(bmp);
-                    g.CopyFromScreen(rect.Left, rect.Top, 0, 0, bmp.Size, CopyPixelOperation.SourceCopy);
+                _graphics.CopyFromScreen(x, y, 0, 0, _bmp.Size, CopyPixelOperation.SourceCopy);
 
-                    var bitmapImage = BitmapToImageSource(bmp);
-
-                    _zoomViewModel.ZoomArea = bitmapImage;
-                    _zoomViewModel.ZoomFactor = 1;
-                }
+                _zoomViewModel.ZoomArea = BitmapToImageSource(_bmp);
             }
             else
             {
-                var enlarge = (_currentZoomLevel - _previousZoomLevel) > 0 ? true : false;
-                var currentZoomFactor = enlarge ? ZoomFactor : 1.0 / ZoomFactor;
-
-                _zoomViewModel.ZoomFactor *= currentZoomFactor;
+                _zoomViewModel.ZoomFactor = Math.Pow(ZoomFactor, _currentZoomLevel - 1);
             }
 
-            ShowZoomWindow((int)point.X, (int)point.Y);
+            ShowZoomWindow(point);
         }
 
         private static BitmapSource BitmapToImageSource(Bitmap bitmap)
@@ -130,84 +113,67 @@ namespace ColorPicker.Helpers
             }
         }
 
-        private void HideZoomWindow()
+        private void HideZoomWindow(bool fully = false)
         {
             if (_zoomWindow != null)
             {
-                _zoomWindow.Hide();
+                _zoomWindow.Opacity = 0;
+                _zoomViewModel.DesiredWidth = 0;
+                _zoomViewModel.DesiredHeight = 0;
+
+                if (fully)
+                {
+                    _zoomWindow.Hide();
+                }
             }
         }
 
-        private void ShowZoomWindow(int x, int y)
+        private void ShowZoomWindow(System.Windows.Point point)
         {
-            if (_zoomWindow == null)
+            _zoomWindow ??= new ZoomWindow
             {
-                _zoomWindow = new ZoomWindow();
-                _zoomWindow.Content = _zoomViewModel;
-                _zoomWindow.Loaded += ZoomWindow_Loaded;
-                _zoomWindow.IsVisibleChanged += ZoomWindow_IsVisibleChanged;
-            }
+                Content = _zoomViewModel,
+                Opacity = 0,
+            };
 
-            // we just started zooming, remember where we opened zoom window
-            if (_currentZoomLevel == 1 && _previousZoomLevel == 0)
-            {
-                var dpi = MonitorResolutionHelper.GetCurrentMonitorDpi();
-                _previousScaledX = x / dpi.DpiScaleX;
-                _previousScaledY = y / dpi.DpiScaleY;
-            }
-
-            _lastLeft = Math.Floor(_previousScaledX - (BaseZoomImageSize * Math.Pow(ZoomFactor, _currentZoomLevel - 1) / 2));
-            _lastTop = Math.Floor(_previousScaledY - (BaseZoomImageSize * Math.Pow(ZoomFactor, _currentZoomLevel - 1) / 2));
-
-            var justShown = false;
             if (!_zoomWindow.IsVisible)
             {
-                _zoomWindow.Left = _lastLeft;
-                _zoomWindow.Top = _lastTop;
-                _zoomViewModel.Height = BaseZoomImageSize;
-                _zoomViewModel.Width = BaseZoomImageSize;
                 _zoomWindow.Show();
-                justShown = true;
+            }
+
+            if (_zoomWindow.Opacity < 0.5)
+            {
+                var halfWidth = _zoomWindow.Width / 2;
+                var halfHeight = _zoomWindow.Height / 2;
+
+                // usually takes 1-3 iterations to converge
+                // 5 is just an arbitrary limit to prevent infinite loops
+                for (var i = 0; i < 5; i++)
+                {
+                    // mouse position relative to top left of _zoomWindow
+                    var scaledPoint = _zoomWindow.PointFromScreen(point);
+
+                    var diffX = scaledPoint.X - halfWidth;
+                    var diffY = scaledPoint.Y - halfHeight;
+
+                    // minimum difference that is considered important
+                    const double minDiff = 0.05;
+                    if (Math.Abs(diffX) < minDiff && Math.Abs(diffY) < minDiff)
+                    {
+                        break;
+                    }
+
+                    _zoomWindow.Left += diffX;
+                    _zoomWindow.Top += diffY;
+                }
 
                 // make sure color picker window is on top of just opened zoom window
                 AppStateHandler.SetTopMost();
+                _zoomWindow.Opacity = 1;
             }
 
-            // dirty hack - sometimes when we just show a window on a second monitor with different DPI,
-            // window position is not set correctly on a first time, we need to "ping" it again to make it appear on the proper location
-            if (justShown)
-            {
-                _zoomWindow.Left = _lastLeft + 1;
-                _zoomWindow.Top = _lastTop + 1;
-                SessionEventHelper.Event.ZoomUsed = true;
-            }
-
-            _throttledActionInvoker.ScheduleAction(
-            () =>
-            {
-                _zoomWindow.DesiredLeft = _lastLeft;
-                _zoomWindow.DesiredTop = _lastTop;
-                _zoomViewModel.DesiredHeight = BaseZoomImageSize * _zoomViewModel.ZoomFactor;
-                _zoomViewModel.DesiredWidth = BaseZoomImageSize * _zoomViewModel.ZoomFactor;
-            },
-            ZoomWindowChangeDelayInMS);
-        }
-
-        private void ZoomWindow_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
-        {
-            // need to set at this point again, to avoid issues moving between screens with different scaling
-            if ((bool)e.NewValue)
-            {
-                _zoomWindow.Left = _lastLeft;
-                _zoomWindow.Top = _lastTop;
-            }
-        }
-
-        private void ZoomWindow_Loaded(object sender, RoutedEventArgs e)
-        {
-            // need to call it again at load time, because it does was not dpi aware at the first time of Show() call
-            _zoomWindow.Left = _lastLeft;
-            _zoomWindow.Top = _lastTop;
+            _zoomViewModel.DesiredHeight = BaseZoomImageSize * _zoomViewModel.ZoomFactor;
+            _zoomViewModel.DesiredWidth = BaseZoomImageSize * _zoomViewModel.ZoomFactor;
         }
 
         private void AppStateHandler_AppClosed(object sender, EventArgs e)

src/modules/colorPicker/ColorPickerUI/Views/ZoomView.xaml

@@ -11,6 +11,8 @@
              Focusable="False">
 
     <Border x:Name="WindowBorder"
+            HorizontalAlignment="Center"
+            VerticalAlignment="Center"
             BorderBrush="{DynamicResource WindowBorderBrush}"
             Margin="12"
             BorderThickness="1"

src/modules/colorPicker/ColorPickerUI/ZoomWindow.xaml

@@ -8,7 +8,6 @@
         mc:Ignorable="d"
         Title="Zoom window"
         WindowStyle="None"
-        SizeToContent="WidthAndHeight"
         Topmost="True"
         AllowsTransparency="True"
         Background="Transparent"
@@ -17,6 +16,5 @@
         Focusable="False">
     <e:Interaction.Behaviors>
         <behaviors:CloseZoomWindowBehavior/>
-        <behaviors:MoveWindowBehavior Left="{Binding DesiredLeft, Mode=TwoWay}" Top="{Binding DesiredTop}"/>
     </e:Interaction.Behaviors>
 </Window>

src/modules/colorPicker/ColorPickerUI/ZoomWindow.xaml.cs

@@ -10,50 +10,16 @@ namespace ColorPicker
     /// <summary>
     /// Interaction logic for ZoomWindow.xaml
     /// </summary>
-    public partial class ZoomWindow : Window, INotifyPropertyChanged
+    public partial class ZoomWindow : Window
     {
-        private double _left;
-        private double _top;
-
         public ZoomWindow()
         {
             InitializeComponent();
             DataContext = this;
-        }
 
-        public double DesiredLeft
-        {
-            get
-            {
-                return _left;
-            }
-
-            set
-            {
-                _left = value;
-                NotifyPropertyChanged(nameof(DesiredLeft));
-            }
-        }
-
-        public double DesiredTop
-        {
-            get
-            {
-                return _top;
-            }
-
-            set
-            {
-                _top = value;
-                NotifyPropertyChanged(nameof(DesiredTop));
-            }
-        }
-
-        public event PropertyChangedEventHandler PropertyChanged;
-
-        private void NotifyPropertyChanged(string propertyName)
-        {
-            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
+            // must be large enough to fit max zoom
+            Width = 500;
+            Height = 500;
         }
     }
 }