Update Linear/RadialGradientBrushImpl

Fixed formatting, dispose of GradientStopCollection; however they're
still
leaking massively.

src/Windows/Perspex.Direct2D1/Media/LinearGradientBrushImpl.cs

@@ -1,11 +1,7 @@
 // Copyright (c) The Perspex Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace Perspex.Direct2D1.Media
 {
@@ -16,17 +12,40 @@ namespace Perspex.Direct2D1.Media
             SharpDX.Direct2D1.RenderTarget target,
             Size destinationSize)
         {
-            var gradientStops = brush.GradientStops.Select(s => new SharpDX.Direct2D1.GradientStop { Color = s.Color.ToDirect2D(), Position = (float)s.Offset }).ToArray();
+            if (brush.GradientStops.Count == 0)
+            {
+                return;
+            }
 
-            Point startPoint = brush.StartPoint.ToPixels(destinationSize);
-            Point endPoint = brush.EndPoint.ToPixels(destinationSize);
+            var gradientStops = brush.GradientStops.Select(s => new SharpDX.Direct2D1.GradientStop
+            {
+                Color = s.Color.ToDirect2D(),
+                Position = (float)s.Offset
+            }).ToArray();
+
+            var startPoint = brush.StartPoint.ToPixels(destinationSize);
+            var endPoint = brush.EndPoint.ToPixels(destinationSize);
 
             PlatformBrush = new SharpDX.Direct2D1.LinearGradientBrush(
                 target,
-                new SharpDX.Direct2D1.LinearGradientBrushProperties { StartPoint = startPoint.ToSharpDX(), EndPoint = endPoint.ToSharpDX() },
-                new SharpDX.Direct2D1.BrushProperties { Opacity = (float)brush.Opacity, Transform = target.Transform },
+                new SharpDX.Direct2D1.LinearGradientBrushProperties
+                {
+                    StartPoint = startPoint.ToSharpDX(),
+                    EndPoint = endPoint.ToSharpDX()
+                },
+                new SharpDX.Direct2D1.BrushProperties
+                {
+                    Opacity = (float)brush.Opacity,
+                    Transform = target.Transform
+                },
                 new SharpDX.Direct2D1.GradientStopCollection(target, gradientStops, brush.SpreadMethod.ToDirect2D())
             );
         }
+
+        public override void Dispose()
+        {
+            ((SharpDX.Direct2D1.LinearGradientBrush)PlatformBrush)?.GradientStopCollection.Dispose();
+            base.Dispose();
+        }
     }
 }

src/Windows/Perspex.Direct2D1/Media/RadialGradientBrushImpl.cs

@@ -1,11 +1,7 @@
 // Copyright (c) The Perspex Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
-using System;
-using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace Perspex.Direct2D1.Media
 {
@@ -16,20 +12,46 @@ namespace Perspex.Direct2D1.Media
             SharpDX.Direct2D1.RenderTarget target,
             Size destinationSize)
         {
-            var gradientStops = brush.GradientStops.Select(s => new SharpDX.Direct2D1.GradientStop { Color = s.Color.ToDirect2D(), Position = (float)s.Offset }).ToArray();
+            if (brush.GradientStops.Count == 0)
+            {
+                return;
+            }
 
-            Point centerPoint = brush.Center.ToPixels(destinationSize);
-            Point GradientOriginOffset = brush.GradientOrigin.ToPixels(destinationSize);
+            var gradientStops = brush.GradientStops.Select(s => new SharpDX.Direct2D1.GradientStop
+            {
+                Color = s.Color.ToDirect2D(),
+                Position = (float)s.Offset
+            }).ToArray();
+
+            var centerPoint = brush.Center.ToPixels(destinationSize);
+            var GradientOriginOffset = brush.GradientOrigin.ToPixels(destinationSize);
+            
             // Note: Direct2D supports RadiusX and RadiusY but Cairo backend supports only Radius property
-            double radiusX = brush.Radius;
-            double radiusY = brush.Radius;
+            var radiusX = brush.Radius;
+            var radiusY = brush.Radius;
 
             PlatformBrush = new SharpDX.Direct2D1.RadialGradientBrush(
                 target,
-                new SharpDX.Direct2D1.RadialGradientBrushProperties { Center = centerPoint.ToSharpDX(), GradientOriginOffset = GradientOriginOffset.ToSharpDX(), RadiusX = (float)radiusX, RadiusY = (float)radiusY },
-                new SharpDX.Direct2D1.BrushProperties { Opacity = (float)brush.Opacity, Transform = target.Transform },
+                new SharpDX.Direct2D1.RadialGradientBrushProperties
+                {
+                    Center = centerPoint.ToSharpDX(),
+                    GradientOriginOffset = GradientOriginOffset.ToSharpDX(),
+                    RadiusX = (float)radiusX,
+                    RadiusY = (float)radiusY
+                },
+                new SharpDX.Direct2D1.BrushProperties
+                {
+                    Opacity = (float)brush.Opacity,
+                    Transform = target.Transform
+                },
                 new SharpDX.Direct2D1.GradientStopCollection(target, gradientStops, brush.SpreadMethod.ToDirect2D())
             );
         }
+
+        public override void Dispose()
+        {
+            ((SharpDX.Direct2D1.RadialGradientBrush)PlatformBrush)?.GradientStopCollection.Dispose();
+            base.Dispose();
+        }
     }
 }