Platform Specifics (#301)

* Playing around with how the platform specifics interfaces etc. might work

* Sample implementation of iOS navigation translucency

* Very slightly reduced code

* Better vendor stuff

* Drop single-implemenation interfaces

* Generics on NavigationPage

* On-demand vendor stuff

* Remove functionally duplicate classes and make ControlGallery work again

* Namespace all the things. XAML test.

* Can use Effect to attach platform specific

* Attach Effect on PropertyChanging for XAML support!

* Rename IConfigPlatform interfaces for readability

* Some renaming to match the documents

* Split class files

* Clear out test-only code

* Re-namespace

* Added On method to rendered Elements

* Allow for removal of platform suffix, convenience methods on specific platforms

* Creating a gallery page for specifics

* Add rudimentary Platform Specifics gallery; make CollapseStyle work on UWP;
Add CollapsedPaneWidth specific property

* Toolbar now working with both collapse styles

* MDP now displaying Content title; toolbar routing around title

* Add a gallery for the iOS NavigationPage stuff

* Add Navigation Page as detail page to verify it works with new Toolbar options

* Make titlebar/toolbar background colors consistent

* ToolbarPlacement now working on NavigationPage

* Toolbar Placement working for tabbed and nav pages

* Fix bug where phone doesn't get default toolbar placement on start

* [Core] Add PS WindowSoftInputModeAdjust

[Core] Make Application extendable

* Toolbar placement now working on Nav, Tabbed, and Master pages on desktop/phone

Remove unnecessary style indirection

Fix build errors

* [A] Add PlatformConfigurationExtensions

* SetSoftInputMode test page

* [A] SetSoftInputMode

Known issue: Status bar color does not work in AdjustResize mode

* [Core] Add PS Blur

* [iOS] Configure renderer for blur

* Add test page

* Move to blur VisualElement for broader support

* Move test pages to gallery

* Update docs

* Use lazy initializer for PlatformConfigurationRegistry

11 files changed, 645 insertions, 2 deletions

diff --git a/Xamarin.Forms.Controls/App.cs b/Xamarin.Forms.Controls/App.cs
index af7e999c..c6480040 100644
--- a/Xamarin.Forms.Controls/App.cs
+++ b/Xamarin.Forms.Controls/App.cs
@@ -3,7 +3,8 @@ using System.Collections.Generic;
 using System.IO;
 using System.Reflection;
 using System.Threading.Tasks;
-using Xamarin.Forms.Controls.Issues;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.WindowsSpecific;
 
 namespace Xamarin.Forms.Controls
 {
@@ -34,7 +35,6 @@ namespace Xamarin.Forms.Controls
 
 		protected override void OnAppLinkRequestReceived(Uri uri)
 		{
-
 			var appDomain = "http://" + AppName.ToLowerInvariant() + "/";
 
 			if (!uri.ToString().ToLowerInvariant().StartsWith(appDomain))
diff --git a/Xamarin.Forms.Controls/CoreGallery.cs b/Xamarin.Forms.Controls/CoreGallery.cs
index dc3217ca..7986a45c 100644
--- a/Xamarin.Forms.Controls/CoreGallery.cs
+++ b/Xamarin.Forms.Controls/CoreGallery.cs
@@ -220,6 +220,7 @@ namespace Xamarin.Forms.Controls
 		public CorePageView (Page rootPage, NavigationBehavior navigationBehavior = NavigationBehavior.PushAsync)
 		{
 			var pages = new List<Page> {
+				new PlatformSpecificsGallery() {Title = "Platform Specifics"},
 				new AppLinkPageGallery {Title = "App Link Page Gallery"},
 				new NestedNativeControlGalleryPage {Title = "Nested Native Controls Gallery"},
 				new CellForceUpdateSizeGalleryPage {Title = "Cell Force Update Size Gallery"},
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/ApplicationAndroid.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/ApplicationAndroid.cs
new file mode 100644
index 00000000..4290adff
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/ApplicationAndroid.cs
@@ -0,0 +1,40 @@
+using System.Windows.Input;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.AndroidSpecific;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+	public class ApplicationAndroid : ContentPage
+	{
+		public ApplicationAndroid(ICommand restore)
+		{
+			var restoreButton = new Button { Text = "Back To Gallery" };
+			restoreButton.Clicked += (sender, args) => restore.Execute(null);
+
+			var button1 = GetButton(WindowSoftInputModeAdjust.Pan);
+			var button2 = GetButton(WindowSoftInputModeAdjust.Resize);
+			var buttons = new StackLayout { Orientation = StackOrientation.Horizontal, Children = { button1, button2 }, VerticalOptions = LayoutOptions.Start };
+			var entry = new Entry { Text = "1", VerticalOptions = LayoutOptions.Center, HorizontalOptions = LayoutOptions.StartAndExpand };
+			var layout = new RelativeLayout
+			{
+				VerticalOptions = LayoutOptions.StartAndExpand,
+				HorizontalOptions = LayoutOptions.Center,
+			};
+			layout.Children.Add(buttons, yConstraint: Xamarin.Forms.Constraint.RelativeToParent(parent => { return parent.Y; }));
+			layout.Children.Add(entry, yConstraint: Xamarin.Forms.Constraint.RelativeToParent(parent => { return parent.Height - 100; }));
+
+			Content = layout;
+			Title = "Application Features";
+		}
+
+		static Button GetButton(WindowSoftInputModeAdjust value)
+		{
+			var button = new Button { Text = value.ToString(), Margin = 20 };
+			button.Clicked += (sender, args) =>
+			{
+				Application.Current.On<Android>().UseWindowSoftInputModeAdjust(value);
+			};
+			return button;
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/MasterDetailPageWindows.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/MasterDetailPageWindows.cs
new file mode 100644
index 00000000..d862c167
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/MasterDetailPageWindows.cs
@@ -0,0 +1,192 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Windows.Input;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.WindowsSpecific;
+using static Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries.WindowsPlatformSpecificsGalleryHelpers;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+    public class MasterDetailPageWindows : MasterDetailPage
+	{
+		public MasterDetailPageWindows(ICommand restore)
+		{
+			On<Windows>()
+				.SetCollapseStyle(CollapseStyle.Partial);
+			MasterBehavior = MasterBehavior.Popover;
+
+			var master = new ContentPage { Title = "Master Detail Page" };
+			var masterContent = new StackLayout { Spacing = 10, Margin = new Thickness(0, 10, 5, 0) };
+			var detail = new ContentPage { Title = "This is the detail page's Title" };
+
+			// Build the navigation pane items
+			var navItems = new List<NavItem>
+			{
+				new NavItem("Display Alert", "\uE171", new Command(() => DisplayAlert("Alert", "This is an alert", "OK"))),
+				new NavItem("Return To Gallery", "\uE106", restore),
+				new NavItem("Save", "\uE105", new Command(() => DisplayAlert("Save", "Fake save dialog", "OK"))),
+				new NavItem("Audio", "\uE189", new Command(() => DisplayAlert("Audio", "Never gonna give you up...", "OK"))),
+				new NavItem("Set Detail to Navigation Page", "\uE16F", new Command(() => Detail = CreateNavigationPage())),
+				new NavItem("Set Detail to Content Page", "\uE160", new Command(() => Detail = detail)),
+			};
+
+			var navList = new NavList(navItems);
+
+			// And add them to the navigation pane's content
+			masterContent.Children.Add(navList);
+			master.Content = masterContent;
+			
+			var detailContent = new StackLayout { VerticalOptions = LayoutOptions.Fill, HorizontalOptions = LayoutOptions.Fill };
+			detailContent.Children.Add(new Label
+			{
+				Text = "Platform Features",
+				FontAttributes = FontAttributes.Bold,
+				HorizontalTextAlignment = TextAlignment.Center,
+				VerticalTextAlignment = TextAlignment.Center
+			});
+
+			detailContent.Children.Add(CreateCollapseStyleChanger(this));
+			detailContent.Children.Add(CreateToolbarPlacementChanger(this));
+			detailContent.Children.Add(CreateCollapseWidthAdjuster(this));
+			detailContent.Children.Add(CreateAddRemoveToolBarItemButtons(this));
+
+			detail.Content = detailContent;
+
+			Master = master;
+
+			AddToolBarItems(this);
+
+			Detail = detail;
+		}
+
+		static Layout CreateCollapseStyleChanger(MasterDetailPage page)
+		{
+			Type enumType = typeof(CollapseStyle);
+
+			return CreateChanger(enumType,
+				Enum.GetName(enumType, page.On<Windows>().GetCollapseStyle()),
+				picker =>
+				{
+					page.On<Windows>().SetCollapseStyle((CollapseStyle)Enum.Parse(enumType, picker.Items[picker.SelectedIndex]));
+				},
+				"Select Collapse Style");
+		}
+
+		static Layout CreateCollapseWidthAdjuster(MasterDetailPage page)
+		{
+			var adjustCollapseWidthLabel = new Label
+			{
+				Text = "Adjust Collapsed Width",
+				VerticalTextAlignment = TextAlignment.Center,
+				VerticalOptions = LayoutOptions.Center
+			};
+			var adjustCollapseWidthEntry = new Entry { Text = page.On<Windows>().CollapsedPaneWidth().ToString() };
+			var adjustCollapseWidthButton = new Button { Text = "Change", BackgroundColor = Color.Gray };
+			adjustCollapseWidthButton.Clicked += (sender, args) =>
+			{
+				double newWidth;
+				if (double.TryParse(adjustCollapseWidthEntry.Text, out newWidth))
+				{
+					page.On<Windows>().CollapsedPaneWidth(newWidth);
+				}
+			};
+
+			var adjustCollapsedWidthSection = new StackLayout
+			{
+				HorizontalOptions = LayoutOptions.Center,
+				Orientation = StackOrientation.Horizontal,
+				Children = { adjustCollapseWidthLabel, adjustCollapseWidthEntry, adjustCollapseWidthButton }
+			};
+
+			return adjustCollapsedWidthSection;
+		}
+
+		public class NavItem
+		{
+			public NavItem(string text, string icon, ICommand command)
+			{
+				Text = text;
+				Icon = icon;
+				Command = command;
+			}
+
+			public ICommand Command { get; set; }
+
+			public string Icon { get; set; }
+
+			public string Text { get; set; }
+		}
+
+		public class NavList : ListView
+		{
+			public NavList(IEnumerable<NavItem> items)
+			{
+				ItemsSource = items;
+				ItemTapped += (sender, args) => (args.Item as NavItem)?.Command.Execute(null);
+
+				ItemTemplate = new DataTemplate(() =>
+				{
+					var grid = new Grid();
+					grid.ColumnDefinitions.Add(new ColumnDefinition { Width = 48 });
+					grid.ColumnDefinitions.Add(new ColumnDefinition { Width = 200 });
+
+					grid.Margin = new Thickness(0, 10, 0, 10);
+
+					var text = new Label
+					{
+						VerticalOptions = LayoutOptions.Fill
+					};
+					text.SetBinding(Label.TextProperty, "Text");
+
+					var glyph = new Label
+					{
+						FontFamily = "Segoe MDL2 Assets",
+						FontSize = 24,
+						HorizontalTextAlignment = TextAlignment.Center
+					};
+
+					glyph.SetBinding(Label.TextProperty, "Icon");
+
+					grid.Children.Add(glyph);
+					grid.Children.Add(text);
+
+					Grid.SetColumn(glyph, 0);
+					Grid.SetColumn(text, 1);
+
+					grid.WidthRequest = 48;
+
+					var cell = new ViewCell
+					{
+						View = grid
+					};
+
+					return cell;
+				});
+			}
+		}
+
+		static NavigationPage CreateNavigationPage()
+		{
+			var page = new NavigationPage { Title = "This is the Navigation Page Title" };
+
+			page.PushAsync(CreateNavSubPage());
+
+			return page;
+		}
+
+		static ContentPage CreateNavSubPage()
+		{
+			var page = new ContentPage();
+
+			var label = new Label { Text = "This is content in a nav page" };
+			var button = new Button() { Text = "Push Another Page"};
+
+			button.Clicked += (sender, args) => page.Navigation.PushAsync(CreateNavSubPage());
+
+			page.Content = new StackLayout { Children = { label, button } };
+
+			return page;
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/NavigationPageWindows.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/NavigationPageWindows.cs
new file mode 100644
index 00000000..1143678b
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/NavigationPageWindows.cs
@@ -0,0 +1,68 @@
+using System.Windows.Input;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+	public class NavigationPageWindows : NavigationPage
+	{
+		public NavigationPageWindows(ICommand restore)
+		{
+			PushAsync(CreateRoot(restore));
+			WindowsPlatformSpecificsGalleryHelpers.AddToolBarItems(this);
+		}
+
+		ContentPage CreateRoot(ICommand restore)
+		{
+			var page = new ContentPage { Title = "Content Page Title" };
+
+			var content = new StackLayout
+			{
+				VerticalOptions = LayoutOptions.Fill,
+				HorizontalOptions = LayoutOptions.Fill
+			};
+			content.Children.Add(new Label
+			{
+				Text = "Navigation Page Windows Features",
+				FontAttributes = FontAttributes.Bold,
+				HorizontalTextAlignment = TextAlignment.Center,
+				VerticalTextAlignment = TextAlignment.Center
+			});
+
+			content.Children.Add(WindowsPlatformSpecificsGalleryHelpers.CreateToolbarPlacementChanger(this));
+			content.Children.Add(WindowsPlatformSpecificsGalleryHelpers.CreateAddRemoveToolBarItemButtons(this));
+
+			var restoreButton = new Button { Text = "Back To Gallery" };
+			restoreButton.Clicked += (sender, args) => restore.Execute(null);
+			content.Children.Add(restoreButton);
+
+			var navButton = new Button { Text = "Push Page (with no title)" };
+			navButton.Clicked += (sender, args) => PushAsync(CreatePageWithNoTitle());
+			content.Children.Add(navButton);
+
+			page.Content = content;
+
+			return page;
+		}
+
+		ContentPage CreatePageWithNoTitle()
+		{
+			var page = new ContentPage {  };
+
+			var content = new StackLayout
+			{
+				VerticalOptions = LayoutOptions.Fill,
+				HorizontalOptions = LayoutOptions.Fill
+			};
+			content.Children.Add(new Label
+			{
+				Text = "Page 2",
+				FontAttributes = FontAttributes.Bold,
+				HorizontalTextAlignment = TextAlignment.Center,
+				VerticalTextAlignment = TextAlignment.Center
+			});
+
+			page.Content = content;
+
+			return page;
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/NavigationPageiOS.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/NavigationPageiOS.cs
new file mode 100644
index 00000000..92f278bb
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/NavigationPageiOS.cs
@@ -0,0 +1,40 @@
+using System.Windows.Input;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+	public class NavigationPageiOS : NavigationPage
+	{
+		public static NavigationPageiOS Create(ICommand restore)
+		{
+			var restoreButton = new Button { Text = "Back To Gallery" };
+			restoreButton.Clicked += (sender, args) => restore.Execute(null);
+
+			var translucentToggleButton = new Button { Text = "Toggle Translucent NavBar" };
+
+			var content = new ContentPage
+			{
+				Title = "Navigation Page Features",
+				Content = new StackLayout
+				{
+					VerticalOptions = LayoutOptions.Center,
+					HorizontalOptions = LayoutOptions.Center,
+					Children = { translucentToggleButton, restoreButton }
+				}
+			};
+
+			var navPage = new NavigationPageiOS(content, restore);
+
+			translucentToggleButton.Clicked += (sender, args) => navPage.On<iOS>().SetIsNavigationBarTranslucent(!navPage.On<iOS>().IsNavigationBarTranslucent());
+
+			return navPage;
+		}
+
+		public NavigationPageiOS(Page root, ICommand restore) : base(root)
+		{
+			BackgroundColor = Color.Pink;
+			On<iOS>().EnableTranslucentNavigationBar();
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/TabbedPageWindows.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/TabbedPageWindows.cs
new file mode 100644
index 00000000..11b5d8c4
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/TabbedPageWindows.cs
@@ -0,0 +1,65 @@
+using System.Windows.Input;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+	public class TabbedPageWindows : TabbedPage
+	{
+		public TabbedPageWindows(ICommand restore)
+		{
+			Children.Add(CreateFirstPage(restore));
+			Children.Add(CreateSecondPage());
+			WindowsPlatformSpecificsGalleryHelpers.AddToolBarItems(this);
+		}
+
+		ContentPage CreateFirstPage(ICommand restore)
+		{
+			var page = new ContentPage { Title = "Content Page Title" };
+
+			var content = new StackLayout
+			{
+				VerticalOptions = LayoutOptions.Fill,
+				HorizontalOptions = LayoutOptions.Fill
+			};
+			content.Children.Add(new Label
+			{
+				Text = "Tabbed Page Windows Features",
+				FontAttributes = FontAttributes.Bold,
+				HorizontalTextAlignment = TextAlignment.Center,
+				VerticalTextAlignment = TextAlignment.Center
+			});
+
+			content.Children.Add(WindowsPlatformSpecificsGalleryHelpers.CreateToolbarPlacementChanger(this));
+			content.Children.Add(WindowsPlatformSpecificsGalleryHelpers.CreateAddRemoveToolBarItemButtons(this));
+
+			var restoreButton = new Button { Text = "Back To Gallery" };
+			restoreButton.Clicked += (sender, args) => restore.Execute(null);
+			content.Children.Add(restoreButton);
+
+			page.Content = content;
+
+			return page;
+		}
+
+		static Page CreateSecondPage()
+		{
+			var cp = new ContentPage { Title = "Second Content Page" };
+
+			var content = new StackLayout
+			{
+				VerticalOptions = LayoutOptions.Fill,
+				HorizontalOptions = LayoutOptions.Fill
+			};
+			content.Children.Add(new Label
+			{
+				Text = "Page 2",
+				FontAttributes = FontAttributes.Bold,
+				HorizontalTextAlignment = TextAlignment.Center,
+				VerticalTextAlignment = TextAlignment.Center
+			});
+
+			cp.Content = content;
+
+			return cp;
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/VisualElementiOS.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/VisualElementiOS.cs
new file mode 100644
index 00000000..410d9157
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/VisualElementiOS.cs
@@ -0,0 +1,34 @@
+using System.Windows.Input;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.iOSSpecific;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+	public class VisualElementiOS : ContentPage
+	{
+		public VisualElementiOS(ICommand restore)
+		{
+			var restoreButton = new Button { Text = "Back To Gallery" };
+			restoreButton.Clicked += (sender, args) => restore.Execute(null);
+
+			var image = new Image { Source = ImageSource.FromFile("crimson.jpg") };
+			var box = new BoxView { HeightRequest = 300, WidthRequest = 600 };
+			box.On<iOS>().UseBlurEffect(BlurEffectStyle.Light);
+			Button button1 = GetButton(box, BlurEffectStyle.None);
+			Button button2 = GetButton(box, BlurEffectStyle.ExtraLight);
+			Button button3 = GetButton(box, BlurEffectStyle.Light);
+			Button button4 = GetButton(box, BlurEffectStyle.Dark);
+			var buttons = new StackLayout { Orientation = StackOrientation.Horizontal, Children = { button1, button2, button3, button4 } };
+
+			Content = new StackLayout { Children = { buttons, new AbsoluteLayout { Children = { image, box } } } };
+			Title = "Visual Element Features";
+		}
+
+		Button GetButton(BoxView box, BlurEffectStyle value)
+		{
+			var button1 = new Button { Text = value.ToString(), Margin = 25 };
+			button1.Clicked += (s, e) => { box.On<iOS>().UseBlurEffect(value); };
+			return button1;
+		}
+	}
+}
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/WindowsPlatformSpecificsGalleryHelpers.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/WindowsPlatformSpecificsGalleryHelpers.cs
new file mode 100644
index 00000000..08371919
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGalleries/WindowsPlatformSpecificsGalleryHelpers.cs
@@ -0,0 +1,141 @@
+using System;
+using System.Linq;
+using Xamarin.Forms.PlatformConfiguration;
+using Xamarin.Forms.PlatformConfiguration.WindowsSpecific;
+
+namespace Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries
+{
+    internal static class WindowsPlatformSpecificsGalleryHelpers
+    {
+        const string CommandBarActionTitle = "Hey!";
+        const string CommandBarActionMessage = "Command Bar Item Clicked";
+        const string CommandBarActionDismiss = "OK";
+
+        public static void AddToolBarItems(Page page)
+        {
+            Action action = () => page.DisplayAlert(CommandBarActionTitle, CommandBarActionMessage, CommandBarActionDismiss);
+
+            var tb1 = new ToolbarItem("Primary 1", "coffee.png", action, ToolbarItemOrder.Primary)
+            {
+                IsEnabled = true,
+                AutomationId = "toolbaritem_primary1"
+            };
+
+            var tb2 = new ToolbarItem("Primary 2", "coffee.png", action, ToolbarItemOrder.Primary)
+            {
+                IsEnabled = true,
+                AutomationId = "toolbaritem_primary2"
+            };
+
+            var tb3 = new ToolbarItem("Seconday 1", "coffee.png", action, ToolbarItemOrder.Secondary)
+            {
+                IsEnabled = true,
+                AutomationId = "toolbaritem_secondary3"
+            };
+
+            var tb4 = new ToolbarItem("Secondary 2", "coffee.png", action, ToolbarItemOrder.Secondary)
+            {
+                IsEnabled = true,
+                AutomationId = "toolbaritem_secondary4"
+            };
+
+            page.ToolbarItems.Add(tb1);
+            page.ToolbarItems.Add(tb2);
+            page.ToolbarItems.Add(tb3);
+            page.ToolbarItems.Add(tb4);
+        }
+
+        public static Layout CreateChanger(Type enumType, string defaultOption, Action<Picker> selectedIndexChanged, string label)
+        {
+            var picker = new Picker();
+            string[] options = Enum.GetNames(enumType);
+            foreach (string option in options)
+            {
+                picker.Items.Add(option);
+            }
+
+            picker.SelectedIndex = options.IndexOf(defaultOption);
+
+            picker.SelectedIndexChanged += (sender, args) =>
+            {
+                selectedIndexChanged(picker);
+            };
+
+            var changerLabel = new Label { Text = label, VerticalOptions = LayoutOptions.Center };
+
+            var layout = new Grid
+            {
+                HorizontalOptions = LayoutOptions.Center,
+                ColumnDefinitions = new ColumnDefinitionCollection
+                {
+                    new ColumnDefinition { Width = 150 },
+                    new ColumnDefinition { Width = 100 }
+                },
+                Children = { changerLabel, picker }
+            };
+
+            Grid.SetColumn(changerLabel, 0);
+            Grid.SetColumn(picker, 1);
+
+            return layout;
+        }
+
+        public static Layout CreateToolbarPlacementChanger(Page page)
+        {
+            Type enumType = typeof(ToolbarPlacement);
+
+            return CreateChanger(enumType,
+                Enum.GetName(enumType, page.On<Windows>().GetToolbarPlacement()),
+                picker =>
+                {
+                    page.On<Windows>().SetToolbarPlacement((ToolbarPlacement)Enum.Parse(enumType, picker.Items[picker.SelectedIndex]));
+                }, "Select Toolbar Placement");
+        }
+
+        public static Layout CreateAddRemoveToolBarItemButtons(Page page)
+        {
+            var layout = new StackLayout { Orientation = StackOrientation.Vertical, HorizontalOptions = LayoutOptions.Center };
+            layout.Children.Add(new Label { Text = "Toolbar Items:" });
+
+            var buttonLayout = new StackLayout
+            {
+                Orientation = StackOrientation.Horizontal,
+                HorizontalOptions = LayoutOptions.Center
+            };
+
+            layout.Children.Add(buttonLayout);
+
+            var addPrimary = new Button { Text = "Add Primary", BackgroundColor = Color.Gray };
+            var addSecondary = new Button { Text = "Add Secondary", BackgroundColor = Color.Gray };
+            var remove = new Button { Text = "Remove", BackgroundColor = Color.Gray };
+
+            buttonLayout.Children.Add(addPrimary);
+            buttonLayout.Children.Add(addSecondary);
+            buttonLayout.Children.Add(remove);
+
+            Action action = () => page.DisplayAlert(CommandBarActionTitle, CommandBarActionMessage, CommandBarActionDismiss);
+
+            addPrimary.Clicked += (sender, args) =>
+            {
+                int index = page.ToolbarItems.Count(item => item.Order == ToolbarItemOrder.Primary) + 1;
+                page.ToolbarItems.Add(new ToolbarItem($"Primary {index}", "coffee.png", action, ToolbarItemOrder.Primary));
+            };
+
+            addSecondary.Clicked += (sender, args) =>
+            {
+                int index = page.ToolbarItems.Count(item => item.Order == ToolbarItemOrder.Secondary) + 1;
+                page.ToolbarItems.Add(new ToolbarItem($"Secondary {index}", "coffee.png", action, ToolbarItemOrder.Secondary));
+            };
+
+            remove.Clicked += (sender, args) =>
+            {
+                if (page.ToolbarItems.Any())
+                {
+                    page.ToolbarItems.RemoveAt(0);
+                }
+            };
+
+            return layout;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGallery.cs b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGallery.cs
new file mode 100644
index 00000000..67465da1
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/PlatformSpecificsGallery.cs
@@ -0,0 +1,54 @@
+using Xamarin.Forms.Controls.GalleryPages.PlatformSpecificsGalleries;
+
+namespace Xamarin.Forms.Controls
+{
+	public class PlatformSpecificsGallery : ContentPage
+	{
+		Page _originalRoot;
+
+		public PlatformSpecificsGallery()
+		{
+			var mdpWindowsButton = new Button { Text = "Master Detail Page (Windows)" };
+			var npWindowsButton = new Button { Text = "Navigation Page (Windows)" };
+			var tbWindowsButton = new Button { Text = "Tabbed Page (Windows)" };
+			var navpageiOSButton = new Button() { Text = "Navigation Page (iOS)" };
+			var viselemiOSButton = new Button() { Text = "Visual Element (iOS)" };
+			var appAndroidButton = new Button() { Text = "Application (Android)" };
+
+			mdpWindowsButton.Clicked += (sender, args) => { SetRoot(new MasterDetailPageWindows(new Command(RestoreOriginal))); };
+			npWindowsButton.Clicked += (sender, args) => { SetRoot(new NavigationPageWindows(new Command(RestoreOriginal))); };
+			tbWindowsButton.Clicked += (sender, args) => { SetRoot(new TabbedPageWindows(new Command(RestoreOriginal))); };
+			navpageiOSButton.Clicked += (sender, args) => { SetRoot(NavigationPageiOS.Create(new Command(RestoreOriginal))); };
+			viselemiOSButton.Clicked += (sender, args) => { SetRoot(new VisualElementiOS(new Command(RestoreOriginal))); };
+			appAndroidButton.Clicked += (sender, args) => { SetRoot(new ApplicationAndroid(new Command(RestoreOriginal))); };
+
+			Content = new StackLayout
+			{
+				Children = { mdpWindowsButton, npWindowsButton, tbWindowsButton, navpageiOSButton, viselemiOSButton, appAndroidButton }
+			};
+		}
+
+		void SetRoot(Page page)
+		{
+			var app = Application.Current as App;
+			if (app == null)
+			{
+				return;
+			}
+
+			_originalRoot = app.MainPage;
+			app.SetMainPage(page);
+		}
+
+		void RestoreOriginal()
+		{
+			if (_originalRoot == null)
+			{
+				return;
+			}
+
+			var app = Application.Current as App;
+			app?.SetMainPage(_originalRoot);
+		}
+	}
+}
\ No newline at end of file
diff --git a/Xamarin.Forms.Controls/Xamarin.Forms.Controls.csproj b/Xamarin.Forms.Controls/Xamarin.Forms.Controls.csproj
index ade7cd16..825d157d 100644
--- a/Xamarin.Forms.Controls/Xamarin.Forms.Controls.csproj
+++ b/Xamarin.Forms.Controls/Xamarin.Forms.Controls.csproj
@@ -99,8 +99,16 @@
       <DependentUpon>ControlTemplateXamlPage.xaml</DependentUpon>
     </Compile>
     <Compile Include="GalleryPages\LayoutPerformanceGallery.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\MasterDetailPageWindows.cs" />
     <Compile Include="GalleryPages\NavigationPropertiesGallery.cs" />
     <Compile Include="ControlGalleryPages\ListViewSelectionColor.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\NavigationPageiOS.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\NavigationPageWindows.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\ApplicationAndroid.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\TabbedPageWindows.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\VisualElementiOS.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGalleries\WindowsPlatformSpecificsGalleryHelpers.cs" />
+    <Compile Include="GalleryPages\PlatformSpecificsGallery.cs" />
     <Compile Include="LegacyRepro\Page1.xaml.cs">
       <DependentUpon>Page1.xaml</DependentUpon>
     </Compile>