[TabbedPage] Enable TabbedPage to add or remove tabs

    TASK=TCAPI-2494
    - Allow TabbedPage to add or remove tabs

Change-Id: I38d39a1c34b8bcb1b301af89277ee270163d8a29

1 files changed, 111 insertions, 23 deletions

diff --git a/Xamarin.Forms.Platform.Tizen/Renderers/TabbedPageRenderer.cs b/Xamarin.Forms.Platform.Tizen/Renderers/TabbedPageRenderer.cs
index 3af1b341..9d9283e1 100644
--- a/Xamarin.Forms.Platform.Tizen/Renderers/TabbedPageRenderer.cs
+++ b/Xamarin.Forms.Platform.Tizen/Renderers/TabbedPageRenderer.cs
@@ -1,12 +1,12 @@
 using System.Collections.Generic;
+using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Linq;
+using Xamarin.Forms.PlatformConfiguration.TizenSpecific;
 using ElmSharp;
 using EToolbarItem = ElmSharp.ToolbarItem;
 using EToolbarItemEventArgs = ElmSharp.ToolbarItemEventArgs;
 using EColor = ElmSharp.Color;
-using Xamarin.Forms.PlatformConfiguration.TizenSpecific;
-using Xamarin.Forms.Internals;
 
 namespace Xamarin.Forms.Platform.Tizen
 {
@@ -17,10 +17,12 @@ namespace Xamarin.Forms.Platform.Tizen
 		Scroller _scroller;
 		Toolbar _toolbar;
 		Dictionary<EToolbarItem, Page> _itemToItemPage = new Dictionary<EToolbarItem, Page>();
+		List<EToolbarItem> _toolbarItemList = new List<EToolbarItem>();
+		bool _isResettingToolbarItems = false;
 
 		public TabbedPageRenderer()
 		{
-			RegisterPropertyHandler(TabbedPage.TitleProperty, UpdateTitle);
+			RegisterPropertyHandler(Page.TitleProperty, UpdateTitle);
 			RegisterPropertyHandler("CurrentPage", CurrentPageChanged);
 			RegisterPropertyHandler(TabbedPage.BarBackgroundColorProperty, UpdateBarBackgroundColor);
 		}
@@ -97,6 +99,15 @@ namespace Xamarin.Forms.Platform.Tizen
 				UpdateTitle();
 			}
 
+			if (e.OldElement != null)
+			{
+				Element.PagesChanged -= OnElementPagesChanged;
+			}
+			if (e.NewElement != null)
+			{
+				Element.PagesChanged += OnElementPagesChanged;
+			}
+
 			base.OnElementChanged(e);
 		}
 
@@ -104,6 +115,7 @@ namespace Xamarin.Forms.Platform.Tizen
 		{
 			if (disposing)
 			{
+				Element.PagesChanged -= OnElementPagesChanged;
 				if (_outterLayout != null)
 				{
 					_outterLayout.Unrealize();
@@ -149,21 +161,15 @@ namespace Xamarin.Forms.Platform.Tizen
 				index++;
 			}
 			_innerBox.MinimumWidth = Element.Children.Count * bound.Width;
+			if (_toolbar.SelectedItem == null)
+				return;
 			int currentPage = MultiPage<Page>.GetIndex(_itemToItemPage[_toolbar.SelectedItem]);
 			_scroller.ScrollTo(currentPage, 0, true);
 		}
 
 		void OnItemPageScrolled(object sender, System.EventArgs e)
 		{
-			Page newPage = Element.GetPageByIndex(_scroller.HorizontalPageIndex);
-			foreach (var pair in _itemToItemPage)
-			{
-				if (pair.Value == newPage)
-				{
-					pair.Key.IsSelected = true;
-					return;
-				}
-			}
+			_toolbarItemList[_scroller.HorizontalPageIndex].IsSelected = true;
 		}
 
 		void UpdateBarBackgroundColor()
@@ -205,33 +211,115 @@ namespace Xamarin.Forms.Platform.Tizen
 			}
 		}
 
-		void FillToolbarAndContents()
+		void OnElementPagesChanged(object sender, NotifyCollectionChangedEventArgs e)
 		{
-			//add items to toolbar
-			foreach (Page child in Element.Children)
+			switch (e.Action)
+			{
+				case NotifyCollectionChangedAction.Add:
+					AddToolbarItems(e);
+					break;
+				case NotifyCollectionChangedAction.Remove:
+					RemoveToolbarItems(e);
+					break;
+				default:
+					ResetToolbarItems();
+					break;
+			}
+		}
+
+		void AddToolbarItems(NotifyCollectionChangedEventArgs e)
+		{
+			int index = e.NewStartingIndex < 0 ? _toolbar.ItemsCount : e.NewStartingIndex;
+			foreach (Page item in e.NewItems)
+			{
+				AddToolbarItem(item, index++);
+			}
+		}
+
+		EToolbarItem AddToolbarItem(Page newItem, int index)
+		{
+			EToolbarItem toolbarItem;
+			if (index == 0)
 			{
-				EToolbarItem toolbarItem = _toolbar.Append(child.Title, string.IsNullOrEmpty(child.Icon) ? null : ResourcePath.GetPath(child.Icon));
-				if (Element.BarBackgroundColor != Color.Default)
+				toolbarItem = _toolbar.Prepend(newItem.Title, string.IsNullOrEmpty(newItem.Icon) ? null : ResourcePath.GetPath(newItem.Icon));
+			}
+			else
+			{
+				toolbarItem = _toolbar.InsertAfter(_toolbarItemList[index - 1], newItem.Title, string.IsNullOrEmpty(newItem.Icon) ? null : ResourcePath.GetPath(newItem.Icon));
+			}
+			_toolbarItemList.Insert(index, toolbarItem);
+			_itemToItemPage.Add(toolbarItem, newItem);
+
+			if (Element.BarBackgroundColor != Color.Default)
+			{
+				toolbarItem.SetPartColor("bg", _toolbar.BackgroundColor);
+			}
+
+			var childContent = Platform.GetOrCreateRenderer(newItem).NativeView;
+			_innerBox.PackEnd(childContent);
+
+			newItem.PropertyChanged += OnPageTitleChanged;
+
+			return toolbarItem;
+		}
+
+		void RemoveToolbarItems(NotifyCollectionChangedEventArgs e)
+		{
+			foreach (Page item in e.OldItems)
+			{
+				RemoveToolbarItem(item);
+			}
+		}
+
+		void RemoveToolbarItem(Page oldItem)
+		{
+			foreach (var pair in _itemToItemPage)
+			{
+				if (pair.Value == oldItem)
 				{
-					toolbarItem.SetPartColor("bg", _toolbar.BackgroundColor);
+					pair.Value.PropertyChanged -= OnPageTitleChanged;
+					_toolbarItemList.Remove(pair.Key);
+					_itemToItemPage.Remove(pair.Key);
+					pair.Key.Delete();
+					return;
 				}
-				_itemToItemPage.Add(toolbarItem, child);
+			}
+		}
+
+		void ResetToolbarItems()
+		{
+			_isResettingToolbarItems = true;
+			foreach(var pair in _itemToItemPage)
+			{
+				pair.Value.PropertyChanged -= OnPageTitleChanged;
+				pair.Key.Delete();
+			}
+			_itemToItemPage.Clear();
+			_toolbarItemList.Clear();
+
+			FillToolbarAndContents();
+			_isResettingToolbarItems = false;
+		}
 
-				var childContent = Platform.GetOrCreateRenderer(child).NativeView;
-				_innerBox.PackEnd(childContent);
+		void FillToolbarAndContents()
+		{
+			int index = 0;
+			//add items to toolbar
+			foreach (Page child in Element.Children)
+			{
+				EToolbarItem toolbarItem = AddToolbarItem(child, index++);
 
 				if (Element.CurrentPage == child)
 				{
 					//select item on the toolbar and fill content
 					toolbarItem.IsSelected = true;
 				}
-				child.PropertyChanged += OnPageTitleChanged;
 			}
 		}
 
 		void OnToolbarItemSelected(object sender, EToolbarItemEventArgs e)
 		{
-			if (_toolbar.SelectedItem == null)
+			if (_toolbar.SelectedItem == null || _isResettingToolbarItems)
 				return;
 
 			var oldPage = Element.CurrentPage;