[Android] Restore pinch gestures and fix listview item selection

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla24574.cs

@@ -1,30 +1,35 @@
 using System;
-
 using Xamarin.Forms.CustomAttributes;
 using Xamarin.Forms.Internals;
 #if UITEST
+using Xamarin.Forms.Core.UITests;
 using Xamarin.UITest;
 using NUnit.Framework;
 #endif
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif
+
 	[Preserve (AllMembers = true)]
 	[Issue (IssueTracker.Bugzilla, 24574, "Tap Double Tap")]
-	public class Issue24574 : TestContentPage // or TestMasterDetailPage, etc ...
+	public class Issue24574 : TestContentPage 
 	{
 		protected override void Init ()
 		{
 			var label = new Label {
 				AutomationId = "TapLabel",
-				Text = "123" 
+				Text = "123",
+				FontSize = 50
 			};
 
-			var rec = new TapGestureRecognizer () { NumberOfTapsRequired = 1 };
+			var rec = new TapGestureRecognizer { NumberOfTapsRequired = 1 };
 			rec.Tapped += (s, e) => { label.Text = "Single"; };
 			label.GestureRecognizers.Add (rec);
 
-			rec = new TapGestureRecognizer () { NumberOfTapsRequired = 2 };
+			rec = new TapGestureRecognizer { NumberOfTapsRequired = 2 };
 			rec.Tapped += (s, e) => { label.Text = "Double"; };
 			label.GestureRecognizers.Add (rec);
 
@@ -33,7 +38,7 @@ protected override void Init ()
 
 #if UITEST
 		[Test]
-		public void Issue1Test ()
+		public void TapThenDoubleTap ()
 		{
 			RunningApp.Screenshot ("I am at Issue 24574");
 

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla25943.cs

@@ -11,9 +11,11 @@ namespace Xamarin.Forms.Controls.Issues
 {
 #if UITEST
     [Category(UITestCategories.InputTransparent)]
+    [Category(UITestCategories.Gestures)]
 #endif
     [Preserve(AllMembers = true)]
-    [Issue(IssueTracker.Bugzilla, 25943, "[Android] TapGestureRecognizer does not work with a nested StackLayout", PlatformAffected.Android)]
+    [Issue(IssueTracker.Bugzilla, 25943, 
+		"[Android] TapGestureRecognizer does not work with a nested StackLayout", PlatformAffected.Android)]
     public class Bugzilla25943 : TestContentPage
     {
         Label _result;

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla35477.cs

@@ -3,11 +3,16 @@
 
 #if UITEST
 using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
 using Xamarin.UITest.Queries;
 #endif
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif
+
 	[Preserve (AllMembers = true)]
 	[Issue (IssueTracker.Bugzilla, 35477, "Tapped event does not fire when added to Frame in Android AppCompat",
 		PlatformAffected.Android)]

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla36703.cs

@@ -4,12 +4,19 @@
 #if UITEST
 using Xamarin.UITest;
 using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
 #endif
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+	[Category(UITestCategories.IsEnabled)]
+#endif
+
 	[Preserve(AllMembers = true)]
-	[Issue(IssueTracker.Bugzilla, 36703, "TapGestureRecognizer inside initially disable Image will never fire Tapped event", PlatformAffected.All)]
+	[Issue(IssueTracker.Bugzilla, 36703, 
+		"TapGestureRecognizer inside initially disable Image will never fire Tapped event", PlatformAffected.All)]
 	public class Bugzilla36703 : TestContentPage
 	{
 		const string TestImage = "testimage";
@@ -22,7 +29,9 @@ protected override void Init()
 			var image = new Image { Source = "coffee.png", IsEnabled = false, AutomationId = TestImage };
 			var button = new Button { Text = $"Toggle IsEnabled (now {image.IsEnabled})", AutomationId = Toggle };
 			var resultLabel = new Label { Text = "Testing..."};
-			var instructions = new Label { Text = $"Tap the image. The '{Testing}' label should remain unchanged. Tap the 'Toggle IsEnabled' button. Now tap the image again. The {Testing} Label should change its text to {Success}." };
+			var instructions = new Label { Text = $"Tap the image. The '{Testing}' label should remain unchanged. " 
+				+ $"Tap the 'Toggle IsEnabled' button. Now tap the image again." 
+				+ $" The {Testing} Label should change its text to {Success}." };
 
 			button.Clicked += (sender, args) =>
 			{

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla39530.cs

@@ -9,6 +9,10 @@
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif
+
 	[Preserve (AllMembers = true)]
 	[Issue (IssueTracker.Bugzilla, 39530, "Frames do not handle pan or pinch gestures under AppCompat", PlatformAffected.Android)]
 	public class Bugzilla39530 : TestContentPage

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla39768.cs

@@ -5,10 +5,15 @@
 #if UITEST
 using Xamarin.UITest;
 using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
 #endif
 
 namespace Xamarin.Forms.Controls
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif
+
 	[Preserve(AllMembers = true)]
 	[Issue(IssueTracker.Bugzilla, 39768, "PanGestureRecognizer sometimes won't fire completed event when dragging very slowly")]
 	public class Bugzilla39768 : TestContentPage

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla44044.cs

@@ -6,10 +6,15 @@
 #if UITEST
 using Xamarin.UITest;
 using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
 #endif
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif
+
 	[Preserve(AllMembers = true)]
 	[Issue(IssueTracker.Bugzilla, 44044, "TabbedPage steals swipe gestures", PlatformAffected.Android)]
 	public class Bugzilla44044 : TestTabbedPage

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla46363.cs

@@ -10,13 +10,20 @@
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+	[Category(UITestCategories.ListView)]
+	[Category(UITestCategories.Cells)]
+#endif
+
 	[Preserve(AllMembers = true)]
 	[Issue(IssueTracker.Bugzilla, 46363, "TapGestureRecognizer blocks List View Context Actions", PlatformAffected.Android)]
 	public class Bugzilla46363 : TestContentPage
 	{
 		const string Target = "Two";
 		const string ContextAction = "Context Action";
 		const string TapSuccess = "Tap Success";
+		const string TapFailure = "Tap command executed more than once";
 		const string ContextSuccess = "Context Menu Success";
 		const string Testing = "Testing";
 
@@ -25,7 +32,7 @@ public class Bugzilla46363 : TestContentPage
 
 		protected override void Init()
 		{
-			var list = new List<string> { "One", Target, "Two", "Three" };
+			var list = new List<string> { "One", Target, "Three", "Four" };
 
 			var lv = new ListView
 			{
@@ -38,7 +45,15 @@ protected override void Init()
 
 			s_tapCommand = new Command(() =>
 			{
-				result.Text = TapSuccess;
+				if (result.Text == TapSuccess || result.Text == TapFailure)
+				{
+					// We want this test to fail if the tap command is executed more than once
+					result.Text = TapFailure;
+				}
+				else
+				{
+					result.Text = TapSuccess;
+				}
 			});
 
 			s_contextCommand = new Command(() =>

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla46458.cs

@@ -98,7 +98,7 @@ protected override void Init()
 
 #if UITEST
 		[Test]
-		public void Issue1Test()
+		public void GridIsEnabled()
 		{
 			RunningApp.WaitForElement(q => q.Marked("entry"));
 			RunningApp.Tap(q => q.Marked("entry"));

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla55912.cs

@@ -4,11 +4,16 @@
 using Xamarin.Forms.Internals;
 #if UITEST
 using NUnit.Framework;
+using Xamarin.Forms.Core.UITests;
 
 #endif
 
 namespace Xamarin.Forms.Controls.Issues
 {
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif
+
 	[Preserve(AllMembers = true)]
 	[Issue(IssueTracker.Bugzilla, 55912, "Tap event not always propagated to containing Grid/StackLayout",
 		PlatformAffected.Android)]

Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Bugzilla57515.cs

@@ -0,0 +1,147 @@
+using Xamarin.Forms.CustomAttributes;
+using Xamarin.Forms.Internals;
+using System;
+#if UITEST
+using Xamarin.UITest;
+using Xamarin.Forms.Core.UITests;
+using NUnit.Framework;
+#endif
+
+namespace Xamarin.Forms.Controls.Issues
+{
+#if UITEST
+	[Category(UITestCategories.Gestures)]
+#endif 
+	[Preserve(AllMembers = true)]
+	[Issue(IssueTracker.Bugzilla, 57515, "PinchGestureRecognizer not getting called on Android ", PlatformAffected.Android)]
+	public class Bugzilla57515 : TestContentPage
+	{
+		const string ZoomImage = "zoomImg";
+		const string ZoomContainer = "zoomContainer";
+
+		protected override void Init()
+		{
+			var layout = new Grid
+			{
+				RowDefinitions = new RowDefinitionCollection
+				{
+					new RowDefinition { Height = 80 },
+					new RowDefinition { Height = GridLength.Star }
+				}
+			};
+
+			var scaleLabel = new Label();
+			layout.Children.Add(scaleLabel);
+
+			var pinchToZoomContainer = new PinchToZoomContainer
+			{
+				Margin = new Thickness(80),
+				AutomationId = ZoomContainer,
+				Content = new Image
+				{
+					AutomationId = ZoomImage,
+					Source = ImageSource.FromFile("oasis.jpg")
+				}
+			};
+
+			Grid.SetRow(pinchToZoomContainer, 1);
+			layout.Children.Add(pinchToZoomContainer);
+
+			scaleLabel.BindingContext = pinchToZoomContainer;
+			scaleLabel.SetBinding(Label.TextProperty, new Binding("CurrentScale"));
+
+			Content = layout;
+		}
+
+		class PinchToZoomContainer : ContentView
+		{
+			public static readonly BindableProperty CurrentScaleProperty = 
+				BindableProperty.Create("CurrentScale", typeof(double), typeof(PinchToZoomContainer), 1.0);
+
+			public double CurrentScale
+			{
+				get { return (double)GetValue(CurrentScaleProperty); }
+				set { SetValue(CurrentScaleProperty, value); }
+			}
+
+			double startScale = 1;
+			double xOffset = 0;
+			double yOffset = 0;
+
+			public PinchToZoomContainer()
+			{
+				var pinchGesture = new PinchGestureRecognizer();
+				pinchGesture.PinchUpdated += OnPinchUpdated;
+				GestureRecognizers.Add(pinchGesture);
+			}
+
+			void OnPinchUpdated(object sender, PinchGestureUpdatedEventArgs e)
+			{
+				if (e.Status == GestureStatus.Started)
+				{
+					// Store the current scale factor applied to the wrapped user interface element,
+					// and zero the components for the center point of the translate transform.
+					startScale = Content.Scale;
+					Content.AnchorX = 0;
+					Content.AnchorY = 0;
+				}
+				if (e.Status == GestureStatus.Running)
+				{
+					// Calculate the scale factor to be applied.
+					CurrentScale += (e.Scale - 1) * startScale;
+					CurrentScale = Math.Max(1, CurrentScale);
+
+					// The ScaleOrigin is in relative coordinates to the wrapped user interface element,
+					// so get the X pixel coordinate.
+					double renderedX = Content.X + xOffset;
+					double deltaX = renderedX / Width;
+					double deltaWidth = Width / (Content.Width * startScale);
+					double originX = (e.ScaleOrigin.X - deltaX) * deltaWidth;
+
+					// The ScaleOrigin is in relative coordinates to the wrapped user interface element,
+					// so get the Y pixel coordinate.
+					double renderedY = Content.Y + yOffset;
+					double deltaY = renderedY / Height;
+					double deltaHeight = Height / (Content.Height * startScale);
+					double originY = (e.ScaleOrigin.Y - deltaY) * deltaHeight;
+
+					// Calculate the transformed element pixel coordinates.
+					double targetX = xOffset - (originX * Content.Width) * (CurrentScale - startScale);
+					double targetY = yOffset - (originY * Content.Height) * (CurrentScale - startScale);
+
+					// Apply translation based on the change in origin.
+					Content.TranslationX = targetX.Clamp(-Content.Width * (CurrentScale - 1), 0);
+					Content.TranslationY = targetY.Clamp(-Content.Height * (CurrentScale - 1), 0);
+
+					// Apply scale factor
+					Content.Scale = CurrentScale;
+				}
+				if (e.Status == GestureStatus.Completed)
+				{
+					// Store the translation delta's of the wrapped user interface element.
+					xOffset = Content.TranslationX;
+					yOffset = Content.TranslationY;
+				}
+			}
+		}
+
+#if UITEST
+		[Test]
+		public void Bugzilla57515Test()
+		{
+			RunningApp.WaitForElement(ZoomContainer);
+			RunningApp.WaitForElement("1");
+			RunningApp.PinchToZoomIn(ZoomContainer);
+			RunningApp.WaitForNoElement("1"); // The scale should have changed during the zoom
+		}
+#endif
+	}
+
+	public static class DoubleExtensions
+	{
+		public static double Clamp(this double self, double min, double max)
+		{
+			return Math.Min(max, Math.Max(self, min));
+		}
+	}
+}