Initial import

1 files changed, 302 insertions, 0 deletions

diff --git a/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs b/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs
new file mode 100644
index 00000000..f0e6dc73
--- /dev/null
+++ b/Xamarin.Forms.Platform.Android/Renderers/NavigationRenderer.cs
@@ -0,0 +1,302 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Android.Views;
+using AButton = Android.Widget.Button;
+using AView = Android.Views.View;
+using AndroidAnimation = Android.Animation;
+
+namespace Xamarin.Forms.Platform.Android
+{
+	public class NavigationRenderer : VisualElementRenderer<NavigationPage>
+	{
+		static ViewPropertyAnimator s_currentAnimation;
+
+		Page _current;
+		Page _exitingPage;
+
+		public NavigationRenderer()
+		{
+			AutoPackage = false;
+		}
+
+		public Task<bool> PopToRootAsync(Page page, bool animated = true)
+		{
+			return OnPopToRootAsync(page, animated);
+		}
+
+		public Task<bool> PopViewAsync(Page page, bool animated = true)
+		{
+			return OnPopViewAsync(page, animated);
+		}
+
+		public Task<bool> PushViewAsync(Page page, bool animated = true)
+		{
+			return OnPushAsync(page, animated);
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			if (disposing)
+			{
+				foreach (VisualElement child in Element.InternalChildren)
+				{
+					IVisualElementRenderer renderer = Platform.GetRenderer(child);
+					if (renderer != null)
+						renderer.Dispose();
+				}
+
+				if (Element != null)
+				{
+					Element.PushRequested -= OnPushed;
+					Element.PopRequested -= OnPopped;
+					Element.PopToRootRequested -= OnPoppedToRoot;
+					Element.InsertPageBeforeRequested -= OnInsertPageBeforeRequested;
+					Element.RemovePageRequested -= OnRemovePageRequested;
+				}
+			}
+
+			base.Dispose(disposing);
+		}
+
+		protected override void OnAttachedToWindow()
+		{
+			base.OnAttachedToWindow();
+			Element.SendAppearing();
+		}
+
+		protected override void OnDetachedFromWindow()
+		{
+			base.OnDetachedFromWindow();
+			Element.SendDisappearing();
+		}
+
+		protected override void OnElementChanged(ElementChangedEventArgs<NavigationPage> e)
+		{
+			base.OnElementChanged(e);
+
+			if (e.OldElement != null)
+			{
+				NavigationPage oldNav = e.OldElement;
+				oldNav.PushRequested -= OnPushed;
+				oldNav.PopRequested -= OnPopped;
+				oldNav.PopToRootRequested -= OnPoppedToRoot;
+				oldNav.InsertPageBeforeRequested -= OnInsertPageBeforeRequested;
+				oldNav.RemovePageRequested -= OnRemovePageRequested;
+
+				RemoveAllViews();
+			}
+
+			NavigationPage nav = e.NewElement;
+			nav.PushRequested += OnPushed;
+			nav.PopRequested += OnPopped;
+			nav.PopToRootRequested += OnPoppedToRoot;
+			nav.InsertPageBeforeRequested += OnInsertPageBeforeRequested;
+			nav.RemovePageRequested += OnRemovePageRequested;
+
+			// If there is already stuff on the stack we need to push it
+			nav.StackCopy.Reverse().ForEach(p => PushViewAsync(p, false));
+		}
+
+		protected override void OnLayout(bool changed, int l, int t, int r, int b)
+		{
+			base.OnLayout(changed, l, t, r, b);
+
+			for (var i = 0; i < ChildCount; i++)
+				GetChildAt(i).Layout(0, 0, r - l, b - t);
+		}
+
+		protected virtual Task<bool> OnPopToRootAsync(Page page, bool animated)
+		{
+			return SwitchContentAsync(page, animated, true);
+		}
+
+		protected virtual Task<bool> OnPopViewAsync(Page page, bool animated)
+		{
+			Page pageToShow = Element.StackCopy.Skip(1).FirstOrDefault();
+			if (pageToShow == null)
+				return Task.FromResult(false);
+
+			return SwitchContentAsync(pageToShow, animated, true);
+		}
+
+		protected virtual Task<bool> OnPushAsync(Page view, bool animated)
+		{
+			return SwitchContentAsync(view, animated);
+		}
+
+		void InsertPageBefore(Page page, Page before)
+		{
+		}
+
+		void OnInsertPageBeforeRequested(object sender, NavigationRequestedEventArgs e)
+		{
+			InsertPageBefore(e.Page, e.BeforePage);
+		}
+
+		void OnPopped(object sender, NavigationRequestedEventArgs e)
+		{
+			e.Task = PopViewAsync(e.Page, e.Animated);
+		}
+
+		void OnPoppedToRoot(object sender, NavigationRequestedEventArgs e)
+		{
+			e.Task = PopToRootAsync(e.Page, e.Animated);
+		}
+
+		void OnPushed(object sender, NavigationRequestedEventArgs e)
+		{
+			e.Task = PushViewAsync(e.Page, e.Animated);
+		}
+
+		void OnRemovePageRequested(object sender, NavigationRequestedEventArgs e)
+		{
+			RemovePage(e.Page);
+		}
+
+		void RemovePage(Page page)
+		{
+			IVisualElementRenderer rendererToRemove = Platform.GetRenderer(page);
+			PageContainer containerToRemove = rendererToRemove == null ? null : (PageContainer)rendererToRemove.ViewGroup.Parent;
+
+			containerToRemove.RemoveFromParent();
+
+			if (rendererToRemove != null)
+			{
+				rendererToRemove.ViewGroup.RemoveFromParent();
+				rendererToRemove.Dispose();
+			}
+
+			containerToRemove?.Dispose();
+
+			Device.StartTimer(TimeSpan.FromMilliseconds(0), () =>
+			{
+				((Platform)Element.Platform).UpdateNavigationTitleBar();
+				return false;
+			});
+		}
+
+		Task<bool> SwitchContentAsync(Page view, bool animated, bool removed = false)
+		{
+			Context.HideKeyboard(this);
+
+			IVisualElementRenderer rendererToAdd = Platform.GetRenderer(view);
+			bool existing = rendererToAdd != null;
+			if (!existing)
+				Platform.SetRenderer(view, rendererToAdd = Platform.CreateRenderer(view));
+
+			Page pageToRemove = _current;
+			IVisualElementRenderer rendererToRemove = pageToRemove == null ? null : Platform.GetRenderer(pageToRemove);
+			PageContainer containerToRemove = rendererToRemove == null ? null : (PageContainer)rendererToRemove.ViewGroup.Parent;
+			PageContainer containerToAdd = (PageContainer)rendererToAdd.ViewGroup.Parent ?? new PageContainer(Context, rendererToAdd);
+
+			containerToAdd.SetWindowBackground();
+
+			_current = view;
+
+			((Platform)Element.Platform).NavAnimationInProgress = true;
+
+			var tcs = new TaskCompletionSource<bool>();
+
+			if (animated)
+			{
+				if (s_currentAnimation != null)
+					s_currentAnimation.Cancel();
+
+				if (removed)
+				{
+					// animate out
+					if (containerToAdd.Parent != this)
+						AddView(containerToAdd, Element.LogicalChildren.IndexOf(rendererToAdd.Element));
+					else
+						((Page)rendererToAdd.Element).SendAppearing();
+					containerToAdd.Visibility = ViewStates.Visible;
+
+					if (containerToRemove != null)
+					{
+						Action<AndroidAnimation.Animator> done = a =>
+						{
+							containerToRemove.Visibility = ViewStates.Gone;
+							containerToRemove.Alpha = 1;
+							containerToRemove.ScaleX = 1;
+							containerToRemove.ScaleY = 1;
+							RemoveView(containerToRemove);
+
+							tcs.TrySetResult(true);
+							((Platform)Element.Platform).NavAnimationInProgress = false;
+
+							VisualElement removedElement = rendererToRemove.Element;
+							rendererToRemove.Dispose();
+							if (removedElement != null)
+								Platform.SetRenderer(removedElement, null);
+						};
+
+						// should always happen
+						s_currentAnimation = containerToRemove.Animate().Alpha(0).ScaleX(0.8f).ScaleY(0.8f).SetDuration(250).SetListener(new GenericAnimatorListener { OnEnd = a =>
+						{
+							s_currentAnimation = null;
+							done(a);
+						},
+							OnCancel = done });
+					}
+				}
+				else
+				{
+					bool containerAlreadyAdded = containerToAdd.Parent == this;
+					// animate in
+					if (!containerAlreadyAdded)
+						AddView(containerToAdd);
+					else
+						((Page)rendererToAdd.Element).SendAppearing();
+
+					if (existing)
+						Element.ForceLayout();
+
+					containerToAdd.Alpha = 0;
+					containerToAdd.ScaleX = containerToAdd.ScaleY = 0.8f;
+					containerToAdd.Visibility = ViewStates.Visible;
+					s_currentAnimation = containerToAdd.Animate().Alpha(1).ScaleX(1).ScaleY(1).SetDuration(250).SetListener(new GenericAnimatorListener { OnEnd = a =>
+					{
+						if (containerToRemove != null && containerToRemove.Handle != IntPtr.Zero)
+						{
+							containerToRemove.Visibility = ViewStates.Gone;
+							if (pageToRemove != null)
+								pageToRemove.SendDisappearing();
+						}
+						s_currentAnimation = null;
+						tcs.TrySetResult(true);
+						((Platform)Element.Platform).NavAnimationInProgress = false;
+					} });
+				}
+			}
+			else
+			{
+				// just do it fast
+				if (containerToRemove != null)
+				{
+					if (removed)
+						RemoveView(containerToRemove);
+					else
+						containerToRemove.Visibility = ViewStates.Gone;
+				}
+
+				if (containerToAdd.Parent != this)
+					AddView(containerToAdd);
+				else
+					((Page)rendererToAdd.Element).SendAppearing();
+
+				if (containerToRemove != null && !removed)
+					pageToRemove.SendDisappearing();
+
+				if (existing)
+					Element.ForceLayout();
+
+				containerToAdd.Visibility = ViewStates.Visible;
+				tcs.SetResult(true);
+				((Platform)Element.Platform).NavAnimationInProgress = false;
+			}
+
+			return tcs.Task;
+		}
+	}
+}
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