feature: custom dynamic tab icon

Pixiview.iOS/Renderers/AppShellRenderer.cs

@@ -32,7 +32,7 @@ namespace Pixiview.iOS.Renderers
 
         protected override IShellTabBarAppearanceTracker CreateTabBarAppearanceTracker()
         {
-            return new AppShellTabBarAppearanceTracker();
+            return new AppShellTabBarAppearanceTracker((AppShell)Element);
         }
 
         protected override IShellNavBarAppearanceTracker CreateNavBarAppearanceTracker()

Pixiview.iOS/Renderers/AppShellSection/AppAppearanceTracker.cs

@@ -1,4 +1,5 @@
-using CoreGraphics;
+using System.Linq;
+using CoreGraphics;
 using UIKit;
 using Xamarin.Forms;
 using Xamarin.Forms.Platform.iOS;
@@ -99,6 +100,14 @@ namespace Pixiview.iOS.Renderers.AppShellSection
         UIColor _defaultTint;
         UIColor _defaultUnselectedTint;
 
+        private readonly AppShell appShell;
+        private bool initIcons;
+
+        public AppShellTabBarAppearanceTracker(AppShell shell)
+        {
+            appShell = shell;
+        }
+
         public void ResetAppearance(UITabBarController controller)
         {
             if (_defaultTint == null)
@@ -118,6 +127,34 @@ namespace Pixiview.iOS.Renderers.AppShellSection
             var tintColor = appearanceElement.EffectiveTabBarForegroundColor; // appearanceElement.EffectiveTabBarTitleColor;
 
             var tabBar = controller.TabBar;
+            if (tabBar.Items != null && !initIcons)
+            {
+                initIcons = true;
+                var sources = appShell.CurrentItem.Items.Select(i => (FontImageSource)i.Icon).ToArray();
+                var images = new UIImage[sources.Length];
+                var handler = new FontImageSourceHandler();
+                for (var i = 0; i < images.Length; i++)
+                {
+                    var font = sources[i];
+                    if (font != null)
+                    {
+                        images[i] = handler.LoadImageAsync(new FontImageSource
+                        {
+                            FontFamily = "FontAwesome5Pro-Solid",
+                            Glyph = font.Glyph,
+                            Size = font.Size
+                        }).Result;
+                    }
+                }
+                for (var i = 0; i < tabBar.Items.Length; i++)
+                {
+                    var image = images[i];
+                    if (image != null)
+                    {
+                        tabBar.Items[i].SelectedImage = image;
+                    }
+                }
+            }
 
             if (_defaultTint == null)
             {