bottom navigation tab page on android

src/Android/Android.csproj

@@ -73,6 +73,10 @@
   <ItemGroup>
     <Reference Include="Mono.Android" />
     <Reference Include="Mono.Android.Export" />
+    <Reference Include="Naxam.Ittianyu.BottomNavExtension, Version=1.2.2.0, Culture=neutral, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>.\Naxam.Ittianyu.BottomNavExtension.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.IO.Compression" />
@@ -924,5 +928,8 @@
   <ItemGroup>
     <AndroidResource Include="Resources\drawable-xxxhdpi\refresh_selected.png" />
   </ItemGroup>
+  <ItemGroup>
+    <AndroidResource Include="Resources\drawable\bottom_nav_bg.xml" />
+  </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\Android\Xamarin.Android.CSharp.targets" />
 </Project>

src/Android/Controls/ExtendedTabbedPageRenderer.cs

@@ -2,94 +2,427 @@
 using Bit.Android.Controls;
 using Bit.App.Controls;
 using Xamarin.Forms;
+using Com.Ittianyu.Bottomnavigationviewex;
 using Xamarin.Forms.Platform.Android;
-using Android.Support.Design.Widget;
-using Xamarin.Forms.Platform.Android.AppCompat;
-using System.Reflection;
-using System.Linq;
+using RelativeLayout = Android.Widget.RelativeLayout;
+using Platform = Xamarin.Forms.Platform.Android.Platform;
 using Android.Content;
+using Android.Views;
+using Android.Widget;
+using Android.Support.Design.Internal;
+using System.IO;
+using System.Linq;
+using System.ComponentModel;
+using Android.Support.Design.Widget;
 
 [assembly: ExportRenderer(typeof(ExtendedTabbedPage), typeof(ExtendedTabbedPageRenderer))]
 namespace Bit.Android.Controls
 {
-    public class ExtendedTabbedPageRenderer : TabbedPageRenderer, TabLayout.IOnTabSelectedListener
+    public class ExtendedTabbedPageRenderer : VisualElementRenderer<ExtendedTabbedPage>,
+        BottomNavigationView.IOnNavigationItemSelectedListener
     {
-        private TabLayout _tabLayout;
+        public static bool ShouldUpdateSelectedIcon;
+        public static Action<IMenuItem, FileImageSource, bool> MenuItemIconSetter;
+        public static float? BottomBarHeight = 50;
+
+        private RelativeLayout _rootLayout;
+        private FrameLayout _pageContainer;
+        private BottomNavigationViewEx _bottomNav;
+        private readonly int _barId;
+
+        public static global::Android.Graphics.Color? BackgroundColor;
 
         public ExtendedTabbedPageRenderer(Context context)
             : base(context)
-        { }
+        {
+            AutoPackage = false;
+            _barId = GenerateViewId();
+        }
 
-        protected override void OnElementChanged(ElementChangedEventArgs<TabbedPage> e)
+        IPageController TabbedController => Element as IPageController;
+        public int LastSelectedIndex { get; internal set; }
+
+        public bool OnNavigationItemSelected(IMenuItem item)
+        {
+            this.SwitchPage(item);
+            return true;
+        }
+
+        internal void SetupTabItems()
+        {
+            this.SetupTabItems(_bottomNav);
+        }
+
+        internal void SetupBottomBar()
+        {
+            _bottomNav = this.SetupBottomBar(_rootLayout, _bottomNav, _barId);
+        }
+
+        public static readonly Action<IMenuItem, FileImageSource, bool> DefaultMenuItemIconSetter = (menuItem, icon, selected) =>
+        {
+            var tabIconId = ResourceUtils.IdFromTitle(icon, ResourceManager.DrawableClass);
+            menuItem.SetIcon(tabIconId);
+        };
+
+        protected override void OnElementChanged(ElementChangedEventArgs<ExtendedTabbedPage> e)
         {
             base.OnElementChanged(e);
-            var view = (ExtendedTabbedPage)Element;
 
-            var field = typeof(ExtendedTabbedPageRenderer).BaseType.GetField("_tabLayout",
-                BindingFlags.Instance | BindingFlags.NonPublic);
-            _tabLayout = field?.GetValue(this) as TabLayout;
-            if(_tabLayout != null)
+            if(e.OldElement != null)
             {
-                var tab = _tabLayout.GetTabAt(0);
-                SetSelectedTabIcon(tab, Element.Children[0].Icon, true);
-            }
+                e.OldElement.ChildAdded -= PagesChanged;
+                e.OldElement.ChildRemoved -= PagesChanged;
+                e.OldElement.ChildrenReordered -= PagesChanged;
             }
 
-        void TabLayout.IOnTabSelectedListener.OnTabSelected(TabLayout.Tab tab)
-        {
-            if(Element == null)
+            if(e.NewElement == null)
             {
                 return;
             }
 
-            var selectedIndex = tab.Position;
-            var child = Element.Children[selectedIndex];
-            if(Element.Children.Count > selectedIndex && selectedIndex >= 0)
+            UpdateIgnoreContainerAreas();
+
+            if(_rootLayout == null)
             {
-                Element.CurrentPage = Element.Children[selectedIndex];
+                SetupNativeView();
             }
 
-            SetSelectedTabIcon(tab, child.Icon, true);
+            this.HandlePagesChanged();
+            SwitchContent(Element.CurrentPage);
+
+            Element.ChildAdded += PagesChanged;
+            Element.ChildRemoved += PagesChanged;
+            Element.ChildrenReordered += PagesChanged;
         }
 
-        void TabLayout.IOnTabSelectedListener.OnTabUnselected(TabLayout.Tab tab)
+        protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
         {
-            var child = Element.Children[tab.Position];
-            SetSelectedTabIcon(tab, child.Icon, false);
+            base.OnElementPropertyChanged(sender, e);
+            if(e.PropertyName == nameof(TabbedPage.CurrentPage))
+            {
+                SwitchContent(Element.CurrentPage);
+            }
         }
 
-        private void SetSelectedTabIcon(TabLayout.Tab tab, string icon, bool selected)
+        void PagesChanged(object sender, EventArgs e)
         {
-            if(string.IsNullOrEmpty(icon))
+            this.HandlePagesChanged();
+        }
+
+        protected override void OnAttachedToWindow()
+        {
+            base.OnAttachedToWindow();
+            TabbedController?.SendAppearing();
+        }
+
+        protected override void OnDetachedFromWindow()
+        {
+            base.OnDetachedFromWindow();
+            TabbedController?.SendDisappearing();
+        }
+
+        protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
+        {
+            var width = right - left;
+            var height = bottom - top;
+
+            base.OnLayout(changed, left, top, right, bottom);
+            if(width <= 0 || height <= 0)
             {
                 return;
             }
 
-            if(selected)
+            this.Layout(width, height);
+        }
+
+        protected override void Dispose(bool disposing)
         {
-                var selectedIcon = string.Format("{0}_selected", icon.Replace(".png", string.Empty));
-                var selectedResource = IdFromTitle(selectedIcon, ResourceManager.DrawableClass);
-                if(selectedResource != 0)
+            if(disposing)
+            {
+                Element.ChildAdded -= PagesChanged;
+                Element.ChildRemoved -= PagesChanged;
+                Element.ChildrenReordered -= PagesChanged;
+
+                if(_rootLayout != null)
+                {
+                    RemoveAllViews();
+                    foreach(Page pageToRemove in Element.Children)
+                    {
+                        var pageRenderer = Platform.GetRenderer(pageToRemove);
+                        if(pageRenderer != null)
+                        {
+                            pageRenderer.View.RemoveFromParent();
+                            pageRenderer.Dispose();
+                        }
+                    }
+
+                    if(_bottomNav != null)
+                    {
+                        _bottomNav.SetOnNavigationItemSelectedListener(null);
+                        _bottomNav.Dispose();
+                        _bottomNav = null;
+                    }
+                    _rootLayout.Dispose();
+                    _rootLayout = null;
+                }
+            }
+
+            base.Dispose(disposing);
+        }
+
+        internal void SetupNativeView()
+        {
+            _rootLayout = this.CreateRoot(_barId, GenerateViewId(), out _pageContainer);
+            AddView(_rootLayout);
+        }
+
+        void SwitchContent(Page page)
+        {
+            this.ChangePage(_pageContainer, page);
+        }
+
+        void UpdateIgnoreContainerAreas()
+        {
+            foreach(var child in Element.Children)
+            {
+                child.IgnoresContainerArea = false;
+            }
+        }
+    }
+
+    internal static class TabExtensions
+    {
+        public static Rectangle CreateRect(this Context context, int width, int height)
+        {
+            return new Rectangle(0, 0, context.FromPixels(width), context.FromPixels(height));
+        }
+
+        public static void HandlePagesChanged(this ExtendedTabbedPageRenderer renderer)
+        {
+            renderer.SetupBottomBar();
+            renderer.SetupTabItems();
+
+            if(renderer.Element.Children.Count == 0)
             {
-                    tab.SetIcon(selectedResource);
                 return;
             }
+
+            EnsureTabIndex(renderer);
         }
 
-            var resource = IdFromTitle(icon, ResourceManager.DrawableClass);
-            tab.SetIcon(resource);
-        }
-
-        private int IdFromTitle(string title, Type type)
+        static void EnsureTabIndex(ExtendedTabbedPageRenderer renderer)
         {
-            var name = System.IO.Path.GetFileNameWithoutExtension(title);
-            return GetId(type, name);
+            var rootLayout = (RelativeLayout)renderer.GetChildAt(0);
+            var bottomNav = (BottomNavigationViewEx)rootLayout.GetChildAt(1);
+            var menu = (BottomNavigationMenu)bottomNav.Menu;
+
+            var itemIndex = menu.FindItemIndex(bottomNav.SelectedItemId);
+            var pageIndex = renderer.Element.Children.IndexOf(renderer.Element.CurrentPage);
+            if(pageIndex >= 0 && pageIndex != itemIndex && pageIndex < bottomNav.ItemCount)
+            {
+                var menuItem = menu.GetItem(pageIndex);
+                bottomNav.SelectedItemId = menuItem.ItemId;
+
+                if(ExtendedTabbedPageRenderer.ShouldUpdateSelectedIcon && ExtendedTabbedPageRenderer.MenuItemIconSetter != null)
+                {
+                    ExtendedTabbedPageRenderer.MenuItemIconSetter?.Invoke(menuItem, renderer.Element.CurrentPage.Icon, true);
+
+                    if(renderer.LastSelectedIndex != pageIndex)
+                    {
+                        var lastSelectedPage = renderer.Element.Children[renderer.LastSelectedIndex];
+                        var lastSelectedMenuItem = menu.GetItem(renderer.LastSelectedIndex);
+                        ExtendedTabbedPageRenderer.MenuItemIconSetter?.Invoke(lastSelectedMenuItem, lastSelectedPage.Icon, false);
+                        renderer.LastSelectedIndex = pageIndex;
+                    }
+                }
+            }
         }
 
-        private int GetId(Type type, string propertyName)
+        public static void SwitchPage(this ExtendedTabbedPageRenderer renderer, IMenuItem item)
+        {
+            var rootLayout = (RelativeLayout)renderer.GetChildAt(0);
+            var bottomNav = (BottomNavigationViewEx)rootLayout.GetChildAt(1);
+            var menu = (BottomNavigationMenu)bottomNav.Menu;
+
+            var index = menu.FindItemIndex(item.ItemId);
+            var pageIndex = index % renderer.Element.Children.Count;
+            var currentPageIndex = renderer.Element.Children.IndexOf(renderer.Element.CurrentPage);
+
+            if(currentPageIndex != pageIndex)
+            {
+                renderer.Element.CurrentPage = renderer.Element.Children[pageIndex];
+            }
+        }
+
+        public static void Layout(this ExtendedTabbedPageRenderer renderer, int width, int height)
+        {
+            var rootLayout = (RelativeLayout)renderer.GetChildAt(0);
+            var bottomNav = (BottomNavigationViewEx)rootLayout.GetChildAt(1);
+
+            var Context = renderer.Context;
+
+            rootLayout.Measure(MakeMeasureSpec(width, MeasureSpecMode.Exactly),
+                MakeMeasureSpec(height, MeasureSpecMode.AtMost));
+
+            ((IPageController)renderer.Element).ContainerArea =
+                Context.CreateRect(rootLayout.MeasuredWidth, rootLayout.GetChildAt(0).MeasuredHeight);
+
+            rootLayout.Measure(MakeMeasureSpec(width, MeasureSpecMode.Exactly),
+                MakeMeasureSpec(height, MeasureSpecMode.Exactly));
+            rootLayout.Layout(0, 0, rootLayout.MeasuredWidth, rootLayout.MeasuredHeight);
+
+            if(renderer.Element.Children.Count == 0)
+            {
+                return;
+            }
+
+            int tabsHeight = bottomNav.MeasuredHeight;
+
+            var item = (ViewGroup)bottomNav.GetChildAt(0);
+            item.Measure(MakeMeasureSpec(width, MeasureSpecMode.Exactly),
+                MakeMeasureSpec(tabsHeight, MeasureSpecMode.Exactly));
+
+            item.Layout(0, 0, width, tabsHeight);
+            int item_w = width / item.ChildCount;
+            for(int i = 0; i < item.ChildCount; i++)
+            {
+                var frame = (FrameLayout)item.GetChildAt(i);
+                frame.Measure(MakeMeasureSpec(item_w, MeasureSpecMode.Exactly),
+                    MakeMeasureSpec(tabsHeight, MeasureSpecMode.Exactly));
+                frame.Layout(i * item_w, 0, i * item_w + item_w, tabsHeight);
+            }
+        }
+
+        public static void SetupTabItems(this ExtendedTabbedPageRenderer renderer, BottomNavigationViewEx bottomNav)
+        {
+            var element = renderer.Element;
+            var menu = (BottomNavigationMenu)bottomNav.Menu;
+            menu.ClearAll();
+
+            var tabsCount = Math.Min(element.Children.Count, bottomNav.MaxItemCount);
+            for(int i = 0; i < tabsCount; i++)
+            {
+                var page = element.Children[i];
+                var menuItem = menu.Add(0, i, 0, page.Title);
+                var setter = ExtendedTabbedPageRenderer.MenuItemIconSetter ?? ExtendedTabbedPageRenderer.DefaultMenuItemIconSetter;
+                setter.Invoke(menuItem, page.Icon, renderer.LastSelectedIndex == i);
+            }
+
+            if(element.Children.Count > 0)
+            {
+                bottomNav.EnableShiftingMode(false);
+                bottomNav.EnableItemShiftingMode(false);
+                bottomNav.EnableAnimation(false);
+                bottomNav.SetTextVisibility(false);
+                bottomNav.SetIconsMarginTop(30);
+                bottomNav.SetBackgroundResource(Resource.Drawable.bottom_nav_bg);
+
+                var stateList = new global::Android.Content.Res.ColorStateList(
+                    new int[][] {
+                        new int[] { global::Android.Resource.Attribute.StateChecked },
+                        new int[] { global::Android.Resource.Attribute.StateEnabled}
+                    },
+                    new int[] {
+                        element.TintColor.ToAndroid(), // Selected
+                        Color.FromHex("A1A1A1").ToAndroid() // Normal
+                    });
+
+                bottomNav.ItemIconTintList = stateList;
+            }
+        }
+
+        public static BottomNavigationViewEx SetupBottomBar(this ExtendedTabbedPageRenderer renderer,
+            global::Android.Widget.RelativeLayout rootLayout, BottomNavigationViewEx bottomNav, int barId)
+        {
+            if(bottomNav != null)
+            {
+                rootLayout.RemoveView(bottomNav);
+                bottomNav.SetOnNavigationItemSelectedListener(null);
+            }
+
+            var barParams = new global::Android.Widget.RelativeLayout.LayoutParams(
+                ViewGroup.LayoutParams.MatchParent,
+                ExtendedTabbedPageRenderer.BottomBarHeight.HasValue ?
+                (int)rootLayout.Context.ToPixels(ExtendedTabbedPageRenderer.BottomBarHeight.Value) :
+                ViewGroup.LayoutParams.WrapContent);
+            barParams.AddRule(LayoutRules.AlignParentBottom);
+            bottomNav = new BottomNavigationViewEx(rootLayout.Context)
+            {
+                LayoutParameters = barParams,
+                Id = barId
+            };
+            if(ExtendedTabbedPageRenderer.BackgroundColor.HasValue)
+            {
+                bottomNav.SetBackgroundColor(ExtendedTabbedPageRenderer.BackgroundColor.Value);
+            }
+
+            bottomNav.SetOnNavigationItemSelectedListener(renderer);
+            rootLayout.AddView(bottomNav, 1, barParams);
+
+            return bottomNav;
+        }
+
+        public static void ChangePage(this ExtendedTabbedPageRenderer renderer, FrameLayout pageContainer, Page page)
+        {
+            renderer.Context.HideKeyboard(renderer);
+            if(page == null)
+            {
+                return;
+            }
+
+            if(Platform.GetRenderer(page) == null)
+            {
+                Platform.SetRenderer(page, Platform.CreateRendererWithContext(page, renderer.Context));
+            }
+
+            var pageContent = Platform.GetRenderer(page).View;
+            pageContainer.AddView(pageContent);
+            if(pageContainer.ChildCount > 1)
+            {
+                pageContainer.RemoveViewAt(0);
+            }
+
+            EnsureTabIndex(renderer);
+        }
+
+        public static RelativeLayout CreateRoot(this ExtendedTabbedPageRenderer renderer, int barId, int pageContainerId, out FrameLayout pageContainer)
+        {
+            var rootLayout = new RelativeLayout(renderer.Context)
+            {
+                LayoutParameters = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent),
+            };
+
+            var pageParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent);
+            pageParams.AddRule(LayoutRules.Above, barId);
+            pageContainer = new FrameLayout(renderer.Context)
+            {
+                LayoutParameters = pageParams,
+                Id = pageContainerId
+            };
+
+            rootLayout.AddView(pageContainer, 0, pageParams);
+            return rootLayout;
+        }
+
+        private static int MakeMeasureSpec(int size, MeasureSpecMode mode)
+        {
+            return size + (int)mode;
+        }
+    }
+
+    public static class ResourceUtils
+    {
+        public static int IdFromTitle(string title, Type type)
+        {
+            var name = Path.GetFileNameWithoutExtension(title);
+            var id = GetId(type, name);
+            return id;
+        }
+
+        public static int GetId(Type type, string propertyName)
         {
             var props = type.GetFields();
-            var prop = props.FirstOrDefault(p => p.Name == propertyName);
+            var prop = props.Select(p => p).FirstOrDefault(p => p.Name == propertyName);
             if(prop != null)
             {
                 return (int)prop.GetValue(type);

src/Android/Resources/drawable/bottom_nav_bg.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+  <item>
+    <shape android:shape="rectangle">
+      <solid android:color="#D2D6DF" />
+    </shape>
+  </item>
+  <item android:top="1dp">
+    <shape android:shape="rectangle">
+      <solid android:color="#F5F5F7" />
+    </shape>
+  </item>
+</layer-list>