Standardize ImageBrush usage

src/Avalonia.Controls.ColorPicker/ColorSlider/ColorSlider.cs

@@ -102,7 +102,7 @@ namespace Avalonia.Controls.Primitives
 
                 if (bitmap != null)
                 {
-                    Background = ColorHelpers.BitmapToBrushAsync(bitmap, pixelWidth, pixelHeight);
+                    Background = new ImageBrush(ColorHelpers.CreateBitmapFromPixelData(bitmap, pixelWidth, pixelHeight));
                 }
             }
         }

src/Avalonia.Controls.ColorPicker/ColorSpectrum/ColorSpectrum.cs

@@ -1059,8 +1059,8 @@ namespace Avalonia.Controls.Primitives
 
                 ColorSpectrumComponents components2 = Components;
 
-                WriteableBitmap minBitmap = ColorHelpers.CreateBitmapFromPixelData(pixelWidth, pixelHeight, bgraMinPixelData);
-                WriteableBitmap maxBitmap = ColorHelpers.CreateBitmapFromPixelData(pixelWidth, pixelHeight, bgraMaxPixelData);
+                WriteableBitmap minBitmap = ColorHelpers.CreateBitmapFromPixelData(bgraMinPixelData, pixelWidth, pixelHeight);
+                WriteableBitmap maxBitmap = ColorHelpers.CreateBitmapFromPixelData(bgraMaxPixelData, pixelWidth, pixelHeight);
 
                 switch (components2)
                 {
@@ -1076,10 +1076,10 @@ namespace Avalonia.Controls.Primitives
                     case ColorSpectrumComponents.ValueSaturation:
                     case ColorSpectrumComponents.SaturationValue:
                         _hueRedBitmap = minBitmap;
-                        _hueYellowBitmap = ColorHelpers.CreateBitmapFromPixelData(pixelWidth, pixelHeight, bgraMiddle1PixelData);
-                        _hueGreenBitmap = ColorHelpers.CreateBitmapFromPixelData(pixelWidth, pixelHeight, bgraMiddle2PixelData);
-                        _hueCyanBitmap = ColorHelpers.CreateBitmapFromPixelData(pixelWidth, pixelHeight, bgraMiddle3PixelData);
-                        _hueBlueBitmap = ColorHelpers.CreateBitmapFromPixelData(pixelWidth, pixelHeight, bgraMiddle4PixelData);
+                        _hueYellowBitmap = ColorHelpers.CreateBitmapFromPixelData(bgraMiddle1PixelData, pixelWidth, pixelHeight);
+                        _hueGreenBitmap = ColorHelpers.CreateBitmapFromPixelData(bgraMiddle2PixelData, pixelWidth, pixelHeight);
+                        _hueCyanBitmap = ColorHelpers.CreateBitmapFromPixelData(bgraMiddle3PixelData, pixelWidth, pixelHeight);
+                        _hueBlueBitmap = ColorHelpers.CreateBitmapFromPixelData(bgraMiddle4PixelData, pixelWidth, pixelHeight);
                         _huePurpleBitmap = maxBitmap;
                         break;
                 }

src/Avalonia.Controls.ColorPicker/Helpers/ColorHelpers.cs

@@ -5,6 +5,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
 using Avalonia.Layout;
@@ -640,16 +641,16 @@ namespace Avalonia.Controls.Primitives
         }
 
         /// <summary>
-        /// 
+        /// Converts the given raw BGRA pre-multiplied alpha pixel data into a bitmap.
         /// </summary>
+        /// <param name="bgraPixelData">The bitmap (in raw BGRA pre-multiplied alpha pixels).</param>
         /// <param name="pixelWidth">The pixel width of the bitmap.</param>
         /// <param name="pixelHeight">The pixel height of the bitmap.</param>
-        /// <param name="bgraPixelData"></param>
-        /// <returns></returns>
+        /// <returns>A new <see cref="WriteableBitmap"/>.</returns>
         public static WriteableBitmap CreateBitmapFromPixelData(
+            IList<byte> bgraPixelData,
             int pixelWidth,
-            int pixelHeight,
-            List<byte> bgraPixelData)
+            int pixelHeight)
         {
             // Standard may need to change on some devices
             Vector dpi = new Vector(96, 96);
@@ -669,50 +670,6 @@ namespace Avalonia.Controls.Primitives
             return bitmap;
         }
 
-        /// <summary>
-        /// Converts the given bitmap (in raw BGRA pre-multiplied alpha pixels) into an image brush
-        /// that can be used in the UI.
-        /// </summary>
-        /// <param name="bgraPixelData">The bitmap (in raw BGRA pre-multiplied alpha pixels)
-        /// to convert to a brush.</param>
-        /// <param name="pixelWidth">The pixel width of the bitmap.</param>
-        /// <param name="pixelHeight">The pixel height of the bitmap.</param>
-        /// <returns>A new <see cref="ImageBrush"/>.</returns>
-        public static IBrush? BitmapToBrushAsync(
-            byte[] bgraPixelData,
-            int pixelWidth,
-            int pixelHeight)
-        {
-            if (bgraPixelData.Length == 0 ||
-                (pixelWidth == 0 &&
-                 pixelHeight == 0))
-            {
-                return null;
-            }
-
-            // Standard may need to change on some devices
-            Vector dpi = new Vector(96, 96);
-
-            var bitmap = new WriteableBitmap(
-                new PixelSize(pixelWidth, pixelHeight),
-                dpi,
-                PixelFormat.Bgra8888,
-                AlphaFormat.Premul);
-
-            // Warning: This is highly questionable
-            using (var frameBuffer = bitmap.Lock())
-            {
-                Marshal.Copy(bgraPixelData, 0, frameBuffer.Address, bgraPixelData.Length);
-            }
-
-            var brush = new ImageBrush(bitmap)
-            {
-                Stretch = Stretch.None
-            };
-
-            return brush;
-        }
-
         /// <summary>
         /// Gets the relative (perceptual) luminance/brightness of the given color.
         /// 1 is closer to white while 0 is closer to black.