Touch and press effect is improved

Author: AgustinBonilla

MaterialDesignControls.nuspec

@@ -2,7 +2,7 @@
 <package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
    <metadata minClientVersion="2.8.1">
        <id>Plugin.MaterialDesignControls</id>
-       <version>1.4.0</version>
+       <version>1.4.1</version>
        <title>MaterialDesignControls Plugin for Xamarin Forms</title>
        <authors>Horus</authors>
        <owners>AgustinBonillaHorus</owners>

README.md

@@ -165,24 +165,7 @@ public class MyControl : ContentView, ITouchAndPressEffectConsumer
 {
     public void ConsumeEvent(EventType gestureType)
     {
-        switch (gestureType)
-        {
-            case EventType.Pressing:
-                Task.Run(async () =>
-                {
-                    await this.ScaleTo(0.90, 100);
-                });
-                break;
-            case EventType.Cancelled:
-            case EventType.Released:
-                Task.Run(async () =>
-                {
-                    await this.ScaleTo(1, 100);
-                });
-                break;
-            default:
-                throw new ArgumentOutOfRangeException(nameof(gestureType), gestureType, null);
-        }
+        TouchAndPressAnimation.Animate(this, gestureType);
     }
 }
 ```

example/ExampleMaterialDesignControls/Pages/MaterialButtonPage.xaml

@@ -15,10 +15,12 @@
                 <material:MaterialOutlineButton IsEnabled="false" Text="Cancel" Command="{Binding TapCommand}" CornerRadius="20" CommandParameter="Canceled" />
                 <material:MaterialFlatButton IsEnabled="false" Text="Delete" Icon="delete.png" DisabledIcon="delete.png" Command="{Binding TapCommand}" CommandParameter="Deleted" />
 
-                <Label Text="Animations" HorizontalTextAlignment="Center" />
+                <Label Text="Animations" HorizontalTextAlignment="Center" Margin="0,40,0,0" />
                 <material:MaterialButton Animation="None" Text="None" ToUpper="True" />
                 <material:MaterialButton Animation="Fade" AnimationParameter="0.6" Text="Fade" ToUpper="True" />
+                <material:MaterialButton Animation="Fade" AnimationParameter="0.2" Text="Fade" ToUpper="True" />
                 <material:MaterialButton Animation="Scale" AnimationParameter="0.98" Text="Scale" ToUpper="True" />
+                <material:MaterialButton Animation="Scale" AnimationParameter="0.7" Text="Scale" ToUpper="True" />
             </StackLayout>
         </ScrollView>
     </ContentPage.Content>

src/MaterialDesignControls.Android/Effects/TouchAndPressEffect.cs

@@ -35,6 +35,10 @@ protected override void OnDetached()
             }
         }
 
+        private float? firstX;
+        private float? firstY;
+        private bool ignored;
+
         private void OnViewOnTouch(object sender, View.TouchEventArgs e)
         {
             switch (e.Event.ActionMasked)
@@ -60,6 +64,28 @@ private void OnViewOnTouch(object sender, View.TouchEventArgs e)
                 case MotionEventActions.Mask:
                     break;
                 case MotionEventActions.Move:
+                    var motionEvent = e.Event as MotionEvent;
+
+                    if (motionEvent != null)
+                    {
+                        var x = motionEvent.GetX();
+                        var y = motionEvent.GetY();
+
+                        if (!this.firstX.HasValue || !this.firstY.HasValue)
+                        {
+                            this.firstX = x;
+                            this.firstY = y;
+                        }
+
+                        var maxDelta = 10;
+                        var deltaX = Math.Abs(x - this.firstX.Value);
+                        var deltaY = Math.Abs(y - this.firstY.Value);
+                        if (!this.ignored && (deltaX > maxDelta || deltaY > maxDelta))
+                        {
+                            this.ignored = true;
+                            _touchAndPressEffectConsumer?.ConsumeEvent(EventType.Ignored);
+                        }
+                    }
                     break;
                 case MotionEventActions.Outside:
                     break;
@@ -87,6 +113,13 @@ private void OnViewOnTouch(object sender, View.TouchEventArgs e)
                 default:
                     throw new ArgumentOutOfRangeException();
             }
+
+            if (e.Event.ActionMasked != MotionEventActions.Move)
+            {
+                this.ignored = false;
+                this.firstX = null;
+                this.firstY = null;
+            }
         }
     }
 }

src/MaterialDesignControls.iOS/Effects/TouchAndPressEffect.cs

@@ -81,6 +81,12 @@ public override void TouchesCancelled(NSSet touches, UIEvent evt)
                 base.TouchesCancelled(touches, evt);
                 _touchAndPressEffectConsumer.ConsumeEvent(EventType.Cancelled);
             }
+
+            public override void IgnoreTouch(UITouch touch, UIEvent forEvent)
+            {
+                base.IgnoreTouch(touch, forEvent);
+                _touchAndPressEffectConsumer.ConsumeEvent(EventType.Ignored);
+            }
         }
     }
 }

src/MaterialDesignControls/Animations/TouchAndPressAnimation.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Threading.Tasks;
+using Xamarin.Forms;
+
+namespace Plugin.MaterialDesignControls.Animations
+{
+    public static class TouchAndPressAnimation
+    {
+        public static void Animate(View view, EventType gestureType)
+        {
+            var touchAndPressEffectConsumer = view as ITouchAndPressEffectConsumer;
+
+            switch (gestureType)
+            {
+                case EventType.Pressing:
+                    SetAnimation(view, touchAndPressEffectConsumer);
+                    break;
+                case EventType.Cancelled:
+                case EventType.Released:
+                    if (view.IsEnabled && touchAndPressEffectConsumer.Command != null && touchAndPressEffectConsumer.Command.CanExecute(touchAndPressEffectConsumer.CommandParameter))
+                    {
+                        touchAndPressEffectConsumer.Command.Execute(touchAndPressEffectConsumer.CommandParameter);
+                    }
+
+                    RestoreAnimation(view, touchAndPressEffectConsumer);
+                    break;
+                case EventType.Ignored:
+                    RestoreAnimation(view, touchAndPressEffectConsumer);
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException(nameof(gestureType), gestureType, null);
+            }
+        }
+
+        private static void SetAnimation(View view, ITouchAndPressEffectConsumer touchAndPressEffectConsumer)
+        {
+            if (touchAndPressEffectConsumer.Animation != AnimationTypes.None && view.IsEnabled && (touchAndPressEffectConsumer.Command == null || touchAndPressEffectConsumer.Command.CanExecute(touchAndPressEffectConsumer.CommandParameter)))
+            {
+                Task.Run(async () =>
+                {
+                    if (touchAndPressEffectConsumer.Animation == AnimationTypes.Fade)
+                    {
+                        await view.FadeTo(touchAndPressEffectConsumer.AnimationParameter.HasValue ? touchAndPressEffectConsumer.AnimationParameter.Value : 0.6, 100);
+                    }
+                    else
+                    {
+                        await view.ScaleTo(touchAndPressEffectConsumer.AnimationParameter.HasValue ? touchAndPressEffectConsumer.AnimationParameter.Value : 0.95, 100);
+                    }
+                });
+            }
+        }
+
+        private static void RestoreAnimation(View view, ITouchAndPressEffectConsumer touchAndPressEffectConsumer)
+        {
+            if (touchAndPressEffectConsumer.Animation != AnimationTypes.None)
+            {
+                Task.Run(async () =>
+                {
+                    if (touchAndPressEffectConsumer.Animation == AnimationTypes.Fade)
+                    {
+                        await view.FadeTo(1, 100);
+                    }
+                    else
+                    {
+                        await view.ScaleTo(1, 100);
+                    }
+                });
+            }
+        }
+    }
+}
+

src/MaterialDesignControls/Controls/MaterialButton.cs

@@ -2,6 +2,7 @@
 using System.Runtime.CompilerServices;
 using System.Threading.Tasks;
 using System.Windows.Input;
+using Plugin.MaterialDesignControls.Animations;
 using Xamarin.Forms;
 
 namespace Plugin.MaterialDesignControls
@@ -346,49 +347,7 @@ protected override void OnPropertyChanged([CallerMemberName] string propertyName
 
         public void ConsumeEvent(EventType gestureType)
         {
-            switch (gestureType)
-            {
-                case EventType.Pressing:
-                    if (this.Animation != AnimationTypes.None && this.IsEnabled && (this.Command == null || this.Command.CanExecute(this.CommandParameter)))
-                    {
-                        Task.Run(async () =>
-                        {
-                            if (this.Animation == AnimationTypes.Fade)
-                            {
-                                await this.FadeTo(this.AnimationParameter.HasValue ? this.AnimationParameter.Value : 0.6, 100);
-                            }
-                            else
-                            {
-                                await this.ScaleTo(this.AnimationParameter.HasValue ? this.AnimationParameter.Value : 0.95, 100);
-                            }
-                        });
-                    }
-                    break;
-                case EventType.Cancelled:
-                case EventType.Released:
-                    if (this.IsEnabled && this.Command != null && this.Command.CanExecute(this.CommandParameter))
-                    {
-                        this.Command.Execute(this.CommandParameter);
-                    }
-
-                    if (this.Animation != AnimationTypes.None)
-                    {
-                        Task.Run(async () =>
-                        {
-                            if (this.Animation == AnimationTypes.Fade)
-                            {
-                                await this.FadeTo(1, 100);
-                            }
-                            else
-                            {
-                                await this.ScaleTo(1, 100);
-                            }
-                        });
-                    }
-                    break;
-                default:
-                    throw new ArgumentOutOfRangeException(nameof(gestureType), gestureType, null);
-            }
+            TouchAndPressAnimation.Animate(this, gestureType);
         }
 
         #endregion Methods

src/MaterialDesignControls/Effects/TouchAndPressEffect.cs

@@ -1,18 +1,26 @@
 using System;
+using System.Threading.Tasks;
+using System.Windows.Input;
 using Xamarin.Forms;
 
 namespace Plugin.MaterialDesignControls
 {
     public interface ITouchAndPressEffectConsumer
     {
         void ConsumeEvent(EventType gestureType);
+        ICommand Command { get; set; }
+        object CommandParameter { get; set; }
+        bool IsEnabled { get; set; }
+        AnimationTypes Animation { get; set; }
+        double? AnimationParameter { get; set; }
     }
 
     public enum EventType
     {
         Pressing,
         Released,
-        Cancelled
+        Cancelled,
+        Ignored
     }
 
     public class TouchAndPressEffect : RoutingEffect

src/MaterialDesignControls/MaterialDesignControls.csproj

@@ -98,6 +98,7 @@
     <Compile Include="Animations\ShakeAnimation.cs" />
     <Compile Include="Effects\TouchAndPressEffect.cs" />
     <Compile Include="AnimationTypes.cs" />
+    <Compile Include="Animations\TouchAndPressAnimation.cs" />
   </ItemGroup>
 
   <ItemGroup Condition=" $(TargetFramework.StartsWith('netstandard')) ">