Hook up preview image & create save button

The save button is currently non-functional.

SpritePacker-GUI/MainWindow.cs

@@ -6,6 +6,9 @@ using Gtk;
 using Ext.SilentorBit;
 using System.Drawing.Imaging;
 using System.Runtime.ExceptionServices;
+using System.Drawing;
+using System.IO;
+using System.Text;
 
 namespace SpritePacker.GUI
 {
@@ -19,6 +22,9 @@ namespace SpritePacker.GUI
 
 		private Button openImageButton;
 		private Button removeImageButton;
+		private Button saveResultButton;
+
+		private Gtk.Image previewImage;
 
 		private SpritePacker spritePacker = new SpritePacker();
 
@@ -62,6 +68,7 @@ namespace SpritePacker.GUI
 			VBox rightPanel = new VBox(false, 0) { MarginLeft = 5 };
 			Frame leftPanelFrame = new Frame("Sprites") { Child = leftPanel, Margin = 10, MarginRight = 5 };
 			Frame rightPanelFrame = new Frame("Preview") { Child = rightPanel, Margin = 10, MarginLeft = 5 };
+			previewImage = new Gtk.Image() { Margin = 10 };
 
 			// Create the file selector filter
 			spriteListSelectorFilter = new FileFilter() { Name = "Images" };
@@ -84,6 +91,7 @@ namespace SpritePacker.GUI
 
 			openImageButton = new Button("Add Sprites") { Margin = 10, MarginTop = 0, MarginBottom = 0 };
 			removeImageButton = new Button("Remove Selected Sprites") { Margin = 10, MarginTop = 0, MarginBottom = 0 };
+			saveResultButton = new Button("Save Result") { Margin = 10 };
 			openImageButton.Released += (object sender, EventArgs e) => {
 				ResponseType response = (ResponseType)spriteListSelector.Run();
 				spriteListSelector.Hide();
@@ -107,6 +115,11 @@ namespace SpritePacker.GUI
 				foreach(Sprite currentSprite in spritePacker.CurrentSprites)
 					spriteListDisplay.AddItem(currentSprite);
 			};
+			saveResultButton.Released += (object sender, EventArgs e) => {
+				Console.WriteLine("Save image button clicked");
+			};
+
+			updatePreviewImage();
 
 			// Populate the control button row
 			controlButtonRow.PackStart(openImageButton, true, false, 0);
@@ -116,6 +129,10 @@ namespace SpritePacker.GUI
 			leftPanel.PackStart(controlButtonRow, false, false, 5);
 			leftPanel.PackStart(spriteListDisplay, true, true, 0);
 
+			// Populate the right panel
+			rightPanel.PackStart(previewImage, true, false, 10);
+			rightPanel.PackStart(saveResultButton, false, false, 10);
+
 			// Pack the master container
 			masterContainer.PackStart(leftPanelFrame, true, true, 0);
 			masterContainer.PackStart(rightPanelFrame, true, true, 0);
@@ -124,7 +141,7 @@ namespace SpritePacker.GUI
 			Add(masterContainer);
 		}
 
-		void Action_AddSprite(string[] selectedFilenames)
+		private void Action_AddSprite(string[] selectedFilenames)
 		{
 			foreach (string filename in selectedFilenames)
 			{
@@ -132,6 +149,28 @@ namespace SpritePacker.GUI
 				spritePacker.Add(nextSprite);
 				spriteListDisplay.AddItem(nextSprite);
 			}
+			updatePreviewImage();
+		}
+
+		private void updatePreviewImage()
+		{
+			// TODO: Add an option to call this method manually instead of automatically
+			spritePacker.Arrange();
+
+			using(Bitmap newPreviewImage = spritePacker.GenerateImage())
+			using(MemoryStream newPreviewImageData = new MemoryStream())
+			{
+				// If the new preview image is null, then we shouldn't bother continuing
+				if (newPreviewImage == null)
+					return;
+
+				Bitmap resizedPreviewImage = SBRLUtilities.ImageTools.ResizeImage(newPreviewImage, new Size(512, 512));
+
+				resizedPreviewImage.Save(newPreviewImageData, ImageFormat.Png);
+				previewImage.Pixbuf = new Gdk.Pixbuf(newPreviewImageData.ToArray());
+			}
+
+			Console.WriteLine("Updated preview image");
 		}
 	}
 }

SpritePacker/SBRLUtilities/ResizeImage.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+
+namespace SpritePacker.SBRLUtilities
+{
+	public static partial class ImageTools
+	{
+		/// <summary>
+		/// Resizes a <c>Bitmap</c> such that it fits within the target dimensions.
+		/// </summary>
+		/// <param name="sourceImage">The image to resize.</param>
+		/// <param name="targetBox">The target dimensions.</param>
+		/// <returns>The resized image.</returns>
+		public static Bitmap ResizeImage(Bitmap sourceImage, Size targetBox)
+		{
+			float scaleFactor = Math.Min(
+				targetBox.Width / (float)sourceImage.Width,
+				targetBox.Height / (float)sourceImage.Height
+			);
+			Size thumbnailSize = new Size(
+				(int)(sourceImage.Width * scaleFactor),
+				(int)(sourceImage.Height * scaleFactor)
+			);
+
+			Bitmap resultImage = new Bitmap(thumbnailSize.Width, thumbnailSize.Height);
+
+			using (Graphics context = Graphics.FromImage(resultImage)) {
+				context.CompositingMode = CompositingMode.SourceCopy;
+				context.InterpolationMode = InterpolationMode.HighQualityBicubic;
+				context.DrawImage(sourceImage, new Rectangle(
+					Point.Empty,
+					thumbnailSize
+				));
+			}
+
+			return resultImage;
+		}
+	}
+}
+

SpritePacker/SpritePacker.cs

@@ -197,6 +197,7 @@ namespace SpritePacker
 		/// <summary>
 		/// Generates an image that contains all the currently added sprites.
 		/// You probably want to call Arrage() before calling this method.
+		/// Returns <c>null</c> if you haven't added any sprites to the SpritePacker yet.
 		/// </summary>
 		/// <returns>The generated image.</returns>
 		public Bitmap GenerateImage()
@@ -211,6 +212,9 @@ namespace SpritePacker
 					imageSize.X = spr.Right;
 			}
 
+			if (imageSize.IsEmpty)
+				return null;
+
 			Bitmap finalImage = new Bitmap(imageSize.X, imageSize.Y, PixelFormat.Format32bppArgb);
 			finalImage.MakeTransparent();
 			using (Graphics context = Graphics.FromImage(finalImage))

SpritePacker/SpritePacker.csproj

@@ -36,6 +36,10 @@
     <Compile Include="Sprite.cs" />
     <Compile Include="SpritePacker.cs" />
     <Compile Include="Utilities.cs" />
+    <Compile Include="SBRLUtilities\ResizeImage.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
+  <ItemGroup>
+    <Folder Include="SBRLUtilities\" />
+  </ItemGroup>
 </Project>