1 files changed, 276 insertions, 0 deletions
diff --git a/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue2411.cs b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue2411.cs
new file mode 100644
index 00000000..9221803b
--- /dev/null
+++ b/Xamarin.Forms.Controls.Issues/Xamarin.Forms.Controls.Issues.Shared/Issue2411.cs
@@ -0,0 +1,276 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xamarin.Forms.CustomAttributes;
+
+#if UITEST
+using NUnit.Framework;
+using Xamarin.UITest;
+#endif
+
+namespace Xamarin.Forms.Controls.TestCasesPages
+{
+	[Preserve (AllMembers=true)]
+	[Issue (IssueTracker.Github, 2411, "ListView.ScrollTo not working in TabbedPage", PlatformAffected.Android)]
+	public class Issue2411 : TestTabbedPage
+	{
+		protected override void Init ()
+		{
+			Children.Add (new XamarinListViewScrollToBugPage1 ());
+			Children.Add (new XamarinListViewScrollToBugPage2 ());
+			Children.Add (new XamarinListViewScrollToBugPage3 ());
+		}
+
+#if UITEST
+		[Test]
+#if __ANDROID__
+		[Ignore ("Appearing event is tied to virtualization in TabbedPage for Material")]
+#endif
+		[Issue (IssueTracker.Github, 2411, "ScrollToPositon.MakeVisible not called every time TabbedPage", PlatformAffected.Android)]
+		public void Issue2411ScrollToPositionMakeVisible ()
+		{
+			RunningApp.WaitForElement (q => q.Marked ("99 99 99 99 99 99"));
+			RunningApp.Screenshot ("ScrollTo working correctly");
+			RunningApp.Tap (q => q.Marked ("Crash in ScrollToPosition.End"));
+			RunningApp.Screenshot ("On Second Tab");
+			RunningApp.WaitForElement (q => q.Marked ("2 0 0 0 0 0 0"));
+			RunningApp.Tap (q => q.Marked ("Scroll To in OnAppearing"));
+			RunningApp.Screenshot ("On First Tab");
+			RunningApp.WaitForElement (q => q.Marked ("99 99 99 99 99 99"));
+
+			var listViewBound = RunningApp.Query (q => q.Marked ("listView"))[0].Rect;
+			Xamarin.Forms.Core.UITests.Gestures.ScrollForElement (RunningApp, "* marked:'0 0 0 0 0 0'", new Xamarin.Forms.Core.UITests.Drag (listViewBound, Xamarin.Forms.Core.UITests.Drag.Direction.TopToBottom, Xamarin.Forms.Core.UITests.Drag.DragLength.Long));
+			RunningApp.Screenshot ("Scrolled to Top");
+
+			RunningApp.Tap (q => q.Marked ("Crash in ScrollToPosition.End"));
+			RunningApp.Screenshot ("On Second Tab");
+			RunningApp.WaitForElement (q => q.Marked ("2 0 0 0 0 0 0"));
+			RunningApp.Tap (q => q.Marked ("Scroll To in OnAppearing"));
+			RunningApp.Screenshot ("On First Tab");
+			RunningApp.WaitForElement (q => q.Marked ("99 99 99 99 99 99"));
+		}
+
+		[Test]
+		[Issue (IssueTracker.Github, 2411, "ScrollToPositon.End crashing in TabbedPage", PlatformAffected.Android)]
+		public void Issue2411ScrollToPositionEndCrash ()
+		{
+			RunningApp.Tap (q => q.Marked ("Crash in ScrollToPosition.End"));
+			RunningApp.Screenshot ("On Second Tab");
+			RunningApp.Tap (q => q.Marked ("Scroll To in OnAppearing"));
+			RunningApp.Screenshot ("On First Tab");
+			RunningApp.Tap (q => q.Marked ("Crash in ScrollToPosition.End"));
+			RunningApp.Screenshot ("On Second Tab Again");
+			RunningApp.Tap (q => q.Marked ("ScrollToPosition.End End - Not animated"));
+			RunningApp.WaitForElement (q => q.Marked ("2 99 99 99 99 99 99"));
+		}
+
+		[Test]
+		[Issue (IssueTracker.Github, 2411, "ScrollToPositon.End crashing in TabbedPage", PlatformAffected.Android)]
+		public void Issue2411ScrollToPositionWrongOnUneven ()
+		{
+			RunningApp.Tap (q => q.Marked ("Crash in ScrollToPosition.End"));
+			RunningApp.Tap (q => q.Marked ("Scroll To in OnAppearing Uneven"));
+			RunningApp.Screenshot ("On Third Tab");
+			RunningApp.WaitForElement (q => q.Marked ("99 99 99 99 99 99"));
+		}
+#endif
+	}
+
+	[Preserve (AllMembers = true)]
+	internal class ListObj
+	{
+		public string Name { get; set; }
+	}
+
+	[Preserve (AllMembers = true)]
+	public class CellTemplateScrollTo : ViewCell
+	{
+		public CellTemplateScrollTo ()
+		{
+			Label cellLabel = new Label () {
+				HorizontalOptions = LayoutOptions.FillAndExpand,
+			};
+
+			cellLabel.SetBinding (Label.TextProperty, new Binding ("Name", BindingMode.OneWay));
+
+			StackLayout root = new StackLayout () {
+				Children = {
+					cellLabel
+				}
+			};
+
+			View = root;
+		}
+	}
+
+	[Preserve (AllMembers = true)]
+	public class CellTemplateScrollToUneven : CellTemplateScrollTo
+	{
+		public CellTemplateScrollToUneven () 
+		{
+
+			Height = 60 + new Random().Next(10, 100);
+		}
+	}
+
+	[Preserve (AllMembers = true)]
+	public class XamarinListViewScrollToBugPage1 : ContentPage
+	{
+		ListView _listView;
+		ObservableCollection<ListObj> _collection = new ObservableCollection<ListObj> ();
+
+		public XamarinListViewScrollToBugPage1 ()
+		{
+			Title = "Scroll To in OnAppearing";
+
+			for (int i = 0; i < 100; i++) {
+				var item = new ListObj { Name = string.Format ("{0} {0} {0} {0} {0} {0}", i) };
+				_collection.Add (item);
+			}
+
+			_listView = new ListView {
+				ItemsSource = _collection,
+				ItemTemplate = new DataTemplate (typeof(CellTemplateScrollTo))
+			};
+
+			_listView.AutomationId = "listView";
+
+			Content = new StackLayout {
+				Children = {
+					_listView
+				}
+			};
+		}
+
+		protected override void OnAppearing ()
+		{
+			base.OnAppearing ();
+			_listView.ScrollTo (_collection.Last(), ScrollToPosition.MakeVisible, false);
+		}
+	}
+
+	[Preserve (AllMembers = true)]	
+	public class XamarinListViewScrollToBugPage2 : ContentPage
+	{
+		ListView _listView;
+		ObservableCollection<ListObj> _collection = new ObservableCollection<ListObj> ();
+
+		public XamarinListViewScrollToBugPage2 ()
+		{
+			Title = "Crash in ScrollToPosition.End";
+
+			for (int i = 0; i < 100; i++) {
+				var item = new ListObj { Name = string.Format ("2 {0} {0} {0} {0} {0} {0}", i) };
+				_collection.Add (item);
+			}
+
+			_listView = new ListView {
+				ItemsSource = _collection,
+				ItemTemplate = new DataTemplate (typeof(CellTemplateScrollTo))
+			};
+
+			var endButton = new Button {
+				Text = "ScrollToPosition.End End - Not animated",
+				Command = new Command (() => {
+					_listView.ScrollTo (_collection.Last(), ScrollToPosition.End, false);
+				})
+			};
+
+			var endButtonAnimated = new Button {
+				Text = "ScrollToPosition.MakeVisible End - Animated",
+				Command = new Command (() => {
+					_listView.ScrollTo (_collection.Last(), ScrollToPosition.MakeVisible, true);
+				})
+			};
+
+			Content = new StackLayout {
+				Children = {
+					endButton,
+					endButtonAnimated,
+					_listView
+				}
+			};
+		}
+	}
+
+	public class XamarinListViewScrollToBugPage3 : ContentPage
+	{
+		ListView _listView;
+		ObservableCollection<ListObj> _collection = new ObservableCollection<ListObj> ();
+		int _i =0;
+		public XamarinListViewScrollToBugPage3 ()
+		{
+			Title = "Scroll To in OnAppearing Uneven";
+
+			for (_i = 0; _i < 100; _i++) {
+				var item = new ListObj { Name = string.Format ("{0} {0} {0} {0} {0} {0}", _i) };
+				_collection.Add (item);
+			}
+
+			var btnAdd = new Button {
+				Text = "Add item",
+				WidthRequest = 100
+			};
+			btnAdd.Clicked += BtnAddOnClicked;
+
+			var btnBottom = new Button {
+				Text = "Scroll to end",
+				WidthRequest = 100
+			};
+			btnBottom.Clicked += BtnBottomOnClicked;
+
+			var btnPanel = new StackLayout {
+				Orientation = StackOrientation.Horizontal,
+				HorizontalOptions = LayoutOptions.Center,
+				Children = {
+					btnAdd,
+					btnBottom
+				}
+			};
+
+			_listView = new ListView {
+				ItemsSource = _collection,
+				BackgroundColor = Color.Transparent,
+				VerticalOptions = LayoutOptions.FillAndExpand,
+				HasUnevenRows = true,
+				ItemTemplate = new DataTemplate (typeof(CellTemplateScrollToUneven))
+			};
+			_listView.TakePerformanceHit = true;
+			_listView.ItemTapped += (sender, e) => ((ListView)sender).SelectedItem = null;
+
+			_listView.AutomationId = "listView";
+
+			Content = new StackLayout {
+				Children = {
+					btnPanel,
+					_listView
+				}
+			};
+		}
+
+		protected override void OnAppearing ()
+		{
+			base.OnAppearing ();
+			_listView.ScrollTo (_collection.Last(), ScrollToPosition.MakeVisible, false);
+		}
+
+		void BtnBottomOnClicked(object sender, EventArgs e)
+		{
+			var item = _collection.Last();
+			_listView.ScrollTo(item, ScrollToPosition.End, true);
+		}
+
+		void BtnAddOnClicked(object sender, EventArgs eventArgs)
+		{
+			var str = string.Format("Item {0}", _i++);
+			var item = new ListObj { Name = string.Format ("{0} {0} {0} {0} {0} {0}", _i) };
+			_collection.Add(item);
+
+			_listView.ScrollTo(item, ScrollToPosition.End, true);
+		}
+	}
+}