Skia.Android refactorng

src/Skia/Perspex.Skia.Android.TestApp/MainActivity.cs

@@ -23,7 +23,7 @@ namespace Perspex.Skia.Android.TestApp
             SetContentView(new MainView(this));
         }
 
-        class MainView : SkiaView
+        class MainView : SkiaRenderView
         {
             float _radians = 0;
             public MainView(Activity context) : base(context)

src/Skia/Perspex.Skia.Android/AndroidRenderTarget.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using Android.App;
+using Android.Content;
+using Android.OS;
+using Android.Runtime;
+using Android.Views;
+using Android.Widget;
+using Perspex.Media;
+using Perspex.Platform;
+
+namespace Perspex.Skia
+{
+    class RenderTarget : IRenderTarget
+    {
+        private IntPtr _currentRenderTarget = IntPtr.Zero;
+        private Surface _currentSurface = null;
+        private SurfaceView _view = null;
+
+        public RenderTarget(IPlatformHandle handle)
+        {
+            _view = (SurfaceView) handle;
+        }
+
+        public void Dispose()
+        {
+            if (_currentRenderTarget != IntPtr.Zero)
+            {
+                MethodTable.Instance.DisposeRenderTarget(_currentRenderTarget);
+                _currentRenderTarget = IntPtr.Zero;
+                GC.SuppressFinalize(this);
+            }
+        }
+
+        ~RenderTarget()
+        {
+            Dispose();
+        }
+
+        public DrawingContext CreateDrawingContext()
+        {
+            var surface = _view.Holder.Surface;
+            if (surface == null)
+                throw new InvalidOperationException("Surface isn't available");
+            if (_currentSurface != surface)
+            {
+                _currentSurface = null;
+                if (_currentRenderTarget != IntPtr.Zero)
+                {
+                    MethodTable.Instance.DisposeRenderTarget(_currentRenderTarget);
+                    _currentRenderTarget = IntPtr.Zero;
+                }
+
+                _currentRenderTarget = MethodTable.Instance.CreateWindowRenderTarget(surface.Handle);
+                _currentSurface = surface;
+            }
+            return new DrawingContext(
+                new DrawingContextImpl(MethodTable.Instance.RenderTargetCreateRenderingContext(_currentRenderTarget)));
+        }
+    }
+}

src/Skia/Perspex.Skia.Android/Perspex.Skia.Android.csproj

@@ -82,7 +82,9 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="AndroidRenderTarget.cs" />
     <Compile Include="MethodTable.cs" />
+    <Compile Include="SkiaRenderView.cs" />
     <Compile Include="SkiaView.cs" />
   </ItemGroup>
   <ItemGroup>

src/Skia/Perspex.Skia.Android/SkiaRenderView.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using Android.App;
+using Android.Content;
+using Android.OS;
+using Android.Runtime;
+using Android.Views;
+using Android.Widget;
+using Perspex.Media;
+using Perspex.Platform;
+
+namespace Perspex.Skia.Android
+{
+    public abstract class SkiaRenderView : SkiaView
+    {
+        private IRenderTarget _renderTarget;
+
+        public SkiaRenderView(Activity context) : base(context)
+        {
+            _renderTarget =
+                PerspexLocator.Current.GetService<IPlatformRenderInterface>()
+                    .CreateRenderer(this);
+        }
+
+        protected override void Draw()
+        {
+            if (_renderTarget == null)
+                return;
+            using (var ctx = _renderTarget.CreateDrawingContext())
+                OnRender(ctx);
+        }
+
+        protected abstract void OnRender(DrawingContext ctx);
+
+    }
+}

src/Skia/Perspex.Skia.Android/SkiaView.cs

@@ -16,7 +16,7 @@ using Perspex.Platform;
 
 namespace Perspex.Skia.Android
 {
-    public abstract class SkiaView : SurfaceView, ISurfaceHolderCallback
+    public abstract class SkiaView : SurfaceView, ISurfaceHolderCallback, IPlatformHandle
     {
         private readonly Activity _context;
         bool _invalidateQueued;
@@ -27,7 +27,6 @@ namespace Perspex.Skia.Android
             SkiaPlatform.Initialize();
             Holder.AddCallback(this);
         }
-        private IRenderTarget _renderTarget;
 
         public override void Invalidate()
         {
@@ -65,27 +64,15 @@ namespace Perspex.Skia.Android
         public void SurfaceCreated(ISurfaceHolder holder)
         {
             Log.Info("PERSPEX", "Surface Created");
-            _renderTarget =
-                PerspexLocator.Current.GetService<IPlatformRenderInterface>()
-                    .CreateRenderer(new PlatformHandle(holder.Surface.Handle, "Surface"));
             Draw();
         }
 
         public void SurfaceDestroyed(ISurfaceHolder holder)
         {
             Log.Info("PERSPEX", "Surface Destroyed");
-            _renderTarget.Dispose();
-            _renderTarget = null;
         }
 
-        void Draw()
-        {
-            if(_renderTarget == null)
-                return;
-            using (var ctx = _renderTarget.CreateDrawingContext())
-                OnRender(ctx);
-        }
-
-        protected abstract void OnRender(DrawingContext ctx);
+        protected abstract void Draw();
+        public string HandleDescriptor => "SurfaceView";
     }
 }

src/Skia/Perspex.Skia/MethodTable.cs

@@ -12,7 +12,7 @@ namespace Perspex.Skia
         [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
         public delegate IntPtr _CreateWindowRenderTarget(IntPtr nativeHandle);
 
-        public _CreateWindowRenderTarget CreateWindowWindowRenderTarget;
+        public _CreateWindowRenderTarget CreateWindowRenderTarget;
 
         [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
         public delegate IntPtr _RenderTargetCreateRenderingContext(IntPtr target);

src/Skia/Perspex.Skia/PlatformRenderInterface.cs

@@ -60,6 +60,6 @@ namespace Perspex.Skia
         }
 
         public IRenderTarget CreateRenderer(IPlatformHandle handle) 
-            => new RenderTarget(MethodTable.Instance.CreateWindowWindowRenderTarget(handle.Handle));
+            => new RenderTarget(handle);
     }
 }

src/Skia/Perspex.Skia/RenderTarget.cs

@@ -7,9 +7,10 @@ using Perspex.Platform;
 
 namespace Perspex.Skia
 {
+#if !__ANDROID__
     class RenderTarget : PerspexHandleHolder, IRenderTarget
     {
-        public RenderTarget(IntPtr handle) : base(handle)
+        public RenderTarget(IPlatformHandle handle) : base(MethodTable.Instance.CreateWindowRenderTarget(handle.Handle))
         {
         }
 
@@ -22,4 +23,5 @@ namespace Perspex.Skia
                     new DrawingContextImpl(MethodTable.Instance.RenderTargetCreateRenderingContext(Handle)));
         }
     }
+#endif
 }