Add a test for text align (#1207)

binding/Binding/SKImage.cs

@@ -253,8 +253,9 @@ namespace SkiaSharp
 			if (bitmap == null)
 				throw new ArgumentNullException (nameof (bitmap));
 
-			var handle = SkiaApi.sk_image_new_from_bitmap (bitmap.Handle);
-			return GetObject<SKImage> (handle);
+			var image = GetObject<SKImage> (SkiaApi.sk_image_new_from_bitmap (bitmap.Handle));
+			GC.KeepAlive (bitmap);
+			return image;
 		}
 
 		// create a new image from a GPU texture

tests/Tests/SKCanvasTest.cs

@@ -1,6 +1,5 @@
 using System;
 using System.IO;
-using System.Linq;
 using System.Xml.Linq;
 using Xunit;
 
@@ -470,5 +469,46 @@ namespace SkiaSharp.Tests
 				Assert.Equal("80", rect.Attribute("height")?.Value);
 			}
 		}
+
+		[SkippableTheory]
+		[InlineData(SKTextAlign.Left, 300)]
+		[InlineData(SKTextAlign.Center, 162)]
+		[InlineData(SKTextAlign.Right, 23)]
+		public void TextAlignMovesTextPosition(SKTextAlign align, int offset)
+		{
+			var font = Path.Combine(PathToFonts, "segoeui.ttf");
+			using var tf = SKTypeface.FromFile(font);
+
+			using var bitmap = new SKBitmap(600, 200);
+			using var canvas = new SKCanvas(bitmap);
+
+			canvas.Clear(SKColors.White);
+
+			using var paint = new SKPaint();
+			paint.Typeface = tf;
+			paint.IsAntialias = true;
+			paint.TextSize = 64;
+			paint.Color = SKColors.Black;
+
+			paint.TextAlign = align;
+			canvas.DrawText("SkiaSharp", 300, 100, paint);
+
+			// [S]kia[S]har[p]
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 6, 66));
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 28, 87));
+			Assert.Equal(SKColors.White, bitmap.GetPixel(offset + 28, 66));
+			Assert.Equal(SKColors.White, bitmap.GetPixel(offset + 6, 87));
+
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 120, 66));
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 142, 87));
+			Assert.Equal(SKColors.White, bitmap.GetPixel(offset + 142, 66));
+			Assert.Equal(SKColors.White, bitmap.GetPixel(offset + 120, 87));
+
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 246, 70));
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 246, 113));
+			Assert.Equal(SKColors.Black, bitmap.GetPixel(offset + 271, 83));
+			Assert.Equal(SKColors.White, bitmap.GetPixel(offset + 258, 83));
+			Assert.Equal(SKColors.White, bitmap.GetPixel(offset + 258, 113));
+		}
 	}
 }