Disposing surfaces representing merged images in exporters

Pinta.Core/ImageFormats/GdkPixbufFormat.cs

@@ -25,6 +25,7 @@
 // THE SOFTWARE.
 
 using System;
+using Cairo;
 using GdkPixbuf;
 
 namespace Pinta.Core;
@@ -49,7 +50,7 @@ public Document Import (Gio.File file)
 
 		Layer layer = newDocument.Layers.AddNewLayer (file.GetDisplayName ());
 
-		using Cairo.Context g = new (layer.Surface);
+		using Context g = new (layer.Surface);
 
 		g.DrawPixbuf (effectiveBuffer, PointD.Zero);
 
@@ -67,7 +68,11 @@ private static Pixbuf ReadPixbuf (Gio.File file)
 		}
 	}
 
-	protected virtual void DoSave (Pixbuf pb, Gio.File file, string fileType, Gtk.Window parent)
+	protected virtual void DoSave (
+		Pixbuf pb,
+		Gio.File file,
+		string fileType,
+		Gtk.Window parent)
 	{
 		using Gio.OutputStream stream = file.Replace ();
 		try {
@@ -80,10 +85,13 @@ protected virtual void DoSave (Pixbuf pb, Gio.File file, string fileType, Gtk.Wi
 		}
 	}
 
-	public void Export (Document document, Gio.File file, Gtk.Window parent)
+	public void Export (
+		Document document,
+		Gio.File file,
+		Gtk.Window parent)
 	{
-		Cairo.ImageSurface surf = document.GetFlattenedImage ();
-		using Pixbuf pb = surf.ToPixbuf ();
+		using ImageSurface flattenedImage = document.GetFlattenedImage ();
+		using Pixbuf pb = flattenedImage.ToPixbuf ();
 		DoSave (pb, file, filetype, parent);
 	}
 }

Pinta.Core/ImageFormats/NetpbmPortablePixmap.cs

@@ -11,13 +11,13 @@ public sealed class NetpbmPortablePixmap : IImageExporter
 	public void Export (ImageSurface flattenedImage, Stream outputStream)
 	{
 		using StreamWriter writer = new (outputStream, Encoding.ASCII) {
-			NewLine = "\n" // Always use LF endings to generate the same output on every platform and simplify unit tests
+			NewLine = "\n", // Always use LF endings to generate the same output on every platform and simplify unit tests
 		};
 		Size imageSize = flattenedImage.GetSize ();
 		ReadOnlySpan<ColorBgra> pixelData = flattenedImage.GetReadOnlyPixelData ();
 		writer.WriteLine ("P3"); // Magic number for text-based portable pixmap format
 		writer.WriteLine ($"{imageSize.Width} {imageSize.Height}");
-		writer.WriteLine ("255");
+		writer.WriteLine (byte.MaxValue);
 		for (int row = 0; row < imageSize.Height; row++) {
 			int rowStart = row * imageSize.Width;
 			int rowEnd = rowStart + imageSize.Width;
@@ -35,9 +35,12 @@ public void Export (ImageSurface flattenedImage, Stream outputStream)
 		writer.Close ();
 	}
 
-	public void Export (Document document, Gio.File file, Window parent)
+	public void Export (
+		Document document,
+		Gio.File file,
+		Window parent)
 	{
-		ImageSurface flattenedImage = document.GetFlattenedImage ();
+		using ImageSurface flattenedImage = document.GetFlattenedImage ();
 		using GioStream outputStream = new (file.Replace ());
 		Export (flattenedImage, outputStream);
 	}

Pinta.Core/ImageFormats/TgaExporter.cs

@@ -56,8 +56,7 @@ private record struct TgaHeader (
 		ushort imageWidth,  // Image Width
 		ushort imageHeight, // Image Height
 		byte pixelDepth,    // Pixel Depth
-		byte imageDesc      // Image Descriptor
-	)
+		byte imageDesc)     // Image Descriptor
 	{
 		public readonly void WriteTo (BinaryWriter output)
 		{
@@ -87,11 +86,14 @@ public readonly void WriteTo (BinaryWriter output)
 
 	// For now, we only export in uncompressed ARGB32 format. If someone requests this functionality,
 	// we can always add more through an export dialog.
-	public void Export (Document document, Gio.File file, Gtk.Window parent)
+	public void Export (
+		Document document,
+		Gio.File file,
+		Gtk.Window parent)
 	{
-		ImageSurface surf = document.GetFlattenedImage (); // Assumes the surface is in ARGB32 format
-		using var file_stream = new GioStream (file.Replace ());
-		using var writer = new BinaryWriter (file_stream);
+		using ImageSurface flattenedImage = document.GetFlattenedImage (); // Assumes the surface is in ARGB32 format
+		using GioStream file_stream = new (file.Replace ());
+		using BinaryWriter writer = new (file_stream);
 
 		TgaHeader header = new (
 			idLength: (byte) (ImageIdField.Length + 1),
@@ -102,21 +104,21 @@ public void Export (Document document, Gio.File file, Gtk.Window parent)
 			cmapEntrySize: 0,
 			xOrigin: 0,
 			yOrigin: 0,
-			imageWidth: (ushort) surf.Width,
-			imageHeight: (ushort) surf.Height,
+			imageWidth: (ushort) flattenedImage.Width,
+			imageHeight: (ushort) flattenedImage.Height,
 			pixelDepth: 32,
-			imageDesc: 8 // 32-bit, lower-left origin, which is weird but hey...
-		);
+			imageDesc: 8); // 32-bit, lower-left origin, which is weird but hey...
+
 		header.WriteTo (writer);
 
 		writer.Write (ImageIdField);
 
-		Span<byte> data = surf.GetData ();
+		Span<byte> data = flattenedImage.GetData ();
 
 		// It just so happens that the Cairo ARGB32 internal representation matches
 		// the TGA format, except vertically-flipped. In little-endian, of course.
-		for (int y = surf.Height - 1; y >= 0; y--)
-			writer.Write (data.Slice (surf.Stride * y, surf.Stride));
+		for (int y = flattenedImage.Height - 1; y >= 0; y--)
+			writer.Write (data.Slice (flattenedImage.Stride * y, flattenedImage.Stride));
 
 	}
 }