Improvements over Image, Bitmap and Icon classes (#9)

* fix test name

* redefine Image class based on SKBitmap and add missing props/methods; Image class will be the base class of Bitmap class

* make Bitmap inherit from Image class and add missing props/methods

* init HorizontalResolution/VerticalResolution props with default resolution

* add missing props/methods in Icon class according to new defintiion of Bitmap class

* take the largest icon by default (and not the lowest) as System.Drawing does; fix constructor by copy

* add test for Bitmap.MakeTransparent method

* fix Icon.ExtractAssociatedIcon to take the largest icon

* fix ExtractIcon to consider size prior to index

* add ExtractIcon test cases

* implement Image.GetBounds, add GraphicsUnit enum

* fix typo in Color.Transparent

* add ImageLockMode enum

* add PixelFormat enum; implement PixelFormat in Bitmap/Image classes

* add RotateFlipType enum, implement Image.RotateFlip method

* remove unused parameter from ToPixelFormat

* add ImageFlags enum, add Image.Flags basic implementation

* minor fix on PixelFormat property's summary

* mark Bitmap.SetResolution as not supported

* add Image.GetThumbnailImage

* add ColorPalette class, implement Image.Palette property

* minor improvement

* add image test cases

* fix Dispose pattern

* make Bitmap/Icon sealed

* Fix typo.

* Fix summary open tag declaration

* Rename properties to match naming convention.

* define Image as abstract

* remove Bitmap destructor (aleady defined in Image class)

* remove CreateInstance method (just use Bitmap constructor)

* add using directive for temp Image instances

* simplify SKRect to SKRectI

* Define GetResourceStream in Image class (instead of Bitmap class)

* fix Bitmap(Type,string) description

* define Svg class, remove SKBitmap references from Image class and use them on Bitmap class

* define SV as sealed

* Rename m_Image to InnerImage for property naming consistency.

---------

Co-authored-by: Fede Azzato <fedeazzato@gmail.com>

src/Common/GraphicsUnit.cs

@@ -0,0 +1,42 @@
+namespace GeneXus.Drawing;
+
+/// <summary>
+///  Specifies the unit of measure for the given data.
+/// </summary>
+public enum GraphicsUnit
+{
+	/// <summary>
+	///  Specifies the world unit as the unit of measure.
+	/// </summary>
+	World = 0,
+
+	/// <summary>
+	///  Specifies 1/75 inch as the unit of measure.
+	/// </summary>
+	Display = 1,
+
+	/// <summary>
+	///  Specifies a device pixel as the unit of measure.
+	/// </summary>
+	Pixel = 2,
+
+	/// <summary>
+	///  Specifies a printer's point (1/72 inch) as the unit of measure.
+	/// </summary>
+	Point = 3,
+
+	/// <summary>
+	///  Specifies the inch as the unit of measure.
+	/// </summary>
+	Inch = 4,
+
+	/// <summary>
+	///  Specifies the document unit (1/300 inch) as the unit of measure.
+	/// </summary>
+	Document = 5,
+
+	/// <summary>
+	///  Specifies the millimeter as the unit of measure.
+	/// </summary>
+	Millimeter = 6
+}

src/Common/Icon.cs

@@ -2,16 +2,17 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using GeneXus.Drawing.Imaging;
 using SkiaSharp;
 
 namespace GeneXus.Drawing;
 
 [Serializable]
-public class Icon : IDisposable, ICloneable
+public sealed class Icon : IDisposable, ICloneable
 {
 	internal readonly Bitmap m_bitmap;
 	internal readonly List<IconEntry> m_entries;
-	internal int m_index { get; private set; } = 0;
+	internal int EntryIndex { get; private set; }
 
 	private Icon(Bitmap bitmap, List<IconEntry> entries, float width, float height)
 	{
@@ -30,21 +31,21 @@ private Icon(Bitmap bitmap, List<IconEntry> entries, float width, float height)
 			if (diff >= pivot)
 				continue;
 			pivot = diff;
-			m_index = i;
+			EntryIndex = i;
 		}
 	}
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref='Icon'/> class from a  <see cref='Bitmap'/> instance.
 	/// </summary>
 	public Icon(Bitmap bitmap)
-		: this(bitmap, new List<IconEntry>().Append(new IconEntry { Width = (byte)bitmap.Width, Height = (byte)bitmap.Height }).ToList(), int.MinValue, int.MinValue) { }
+		: this(bitmap, new() { new IconEntry { Width = (byte)bitmap.Width, Height = (byte)bitmap.Height } }, -1, -1) { }
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref='Icon'/> class from the specified file name.
 	/// </summary>
 	public Icon(string filename)
-		: this(filename, int.MinValue, int.MinValue) { }
+		: this(filename, byte.MaxValue, byte.MaxValue) { }
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref='Icon'/> class of the specified <see cref='Size'/> from the specified file.
@@ -62,7 +63,7 @@ public Icon(string filename, float width, float height)
 	/// Initializes a new instance of the <see cref='Icon'/> class from the specified data stream.
 	/// </summary>
 	public Icon(Stream stream)
-		: this(stream, int.MinValue, int.MinValue) { }
+		: this(stream, byte.MaxValue, byte.MaxValue) { }
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref='Icon'/> class of the specified size from the specified stream.
@@ -80,7 +81,7 @@ public Icon(Stream stream, float width, float height)
 	/// Initializes a new instance of the <see cref='Icon'/> class by copy.
 	/// </summary>
 	public Icon(Icon original)
-		: this(original, int.MinValue, int.MinValue) { }
+		: this(original, original.Width, original.Height) { }
 
 	/// <summary>
 	/// Initializes a new instance of the <see cref='Icon'/> class by copy and attempts to find a version of the
@@ -99,7 +100,7 @@ public Icon(Icon original, float width, float height)
 	/// <summary>
 	///  Cleans up resources for this <see cref='Icon'/>.
 	/// </summary>
-	~Icon() => Dispose();
+	~Icon() => Dispose(false);
 
 	/// <summary>
 	/// Creates a human-readable string that represents this <see cref='Icon'/>.
@@ -112,7 +113,13 @@ public Icon(Icon original, float width, float height)
 	/// <summary>
 	///  Cleans up resources for this <see cref='Icon'/>.
 	/// </summary>
-	public void Dispose() => m_bitmap.Dispose();
+	public void Dispose()
+	{
+		GC.SuppressFinalize(this);
+		Dispose(true);
+	}
+
+	private void Dispose(bool disposing) => m_bitmap.Dispose();
 
 	#endregion
 
@@ -134,34 +141,91 @@ public object Clone()
 	#region Properties
 
 	/// <summary>
-	///  Gets the width of this <see cref='Icon'/>.
+	///  Gets the Windows handle for this <see cref='Icon'/>. This is not a copy of the handle; do not free it.
 	/// </summary>
-	public int Width => m_entries[m_index].Width;
+	public IntPtr Handle => m_bitmap.Handle;
 
 	/// <summary>
 	///  Gets the height of this <see cref='Icon'/>.
 	/// </summary>
-	public int Height => m_entries[m_index].Height;
+	public int Height => m_entries[EntryIndex].Height;
 
 	/// <summary>
 	///  Gets the size of this <see cref='Icon'/>.
 	/// </summary>
 	public Size Size => new(Width, Height);
 
+	/// <summary>
+	///  Gets the width of this <see cref='Icon'/>.
+	/// </summary>
+	public int Width => m_entries[EntryIndex].Width;
+
+	#endregion
+
+
+	#region Factory
+
+	/// <summary>
+	///  Creates a GDI+ <see cref='Icon'/> from the specified Windows handle to an icon (HICON).
+	/// </summary>
+	public static Icon FromHandle(IntPtr handle)
+	{
+		var info = new SKImageInfo(100, 100);
+		var skBitmap = new SKBitmap();
+		skBitmap.InstallPixels(info, handle, info.RowBytes);
+		var bitmap = new Bitmap(skBitmap, ImageFormat.Ico);
+		return new Icon(bitmap);
+	}
+
 	#endregion
 
 
 	#region Methods
 
 	/// <summary>
-	///  Converts this <see cref='Icon'/> to a <see cref='Bitmap'/>.
+	///  Returns an icon representation of an image that is contained in the specified file.
+	/// </summary>
+	public static Icon ExtractAssociatedIcon(string filePath)
+		=> ExtractIcon(filePath, -1); // NOTE: https://stackoverflow.com/a/37419253
+
+	/// <summary>
+	///  Extracts a specified icon from the given <paramref name="filePath"/>.
 	/// </summary>
-	public Bitmap ToBitmap() => new(m_Resized);
+	public static Icon ExtractIcon(string filePath, int id, bool smallIcon = false)
+		=> ExtractIcon(filePath, id, smallIcon ? 8 : ushort.MaxValue);
+
+	/// <summary>
+	///  Extracts a specified icon from the given <paramref name="filePath"/> and specified size.
+	/// </summary>
+	public static Icon ExtractIcon(string filePath, int id, int size)
+	{
+		if (size is <= 0 or > ushort.MaxValue)
+			throw new ArgumentOutOfRangeException(nameof(size));
+
+		if (new[] { ".dll", ".exe" }.Contains(Path.GetExtension(filePath)))
+			throw new ArgumentException("portable executable (PE) file format is not supported.", nameof(filePath));
+
+		var icon = new Icon(filePath, size, size);
+		if (icon.Width == size && icon.Height == size)
+			id = int.MaxValue; // set to undefined
+
+		if (id >= 0 && id < icon.m_entries.Count) 
+			icon.EntryIndex = id; // set defined index
+
+		return icon;
+	}
 
 	/// <summary>
 	///  Saves this <see cref='Icon'/> to the specified output <see cref='Stream'/>.
 	/// </summary>
-	public void Save(Stream stream) => new Bitmap(m_Resized).Save(stream, SKEncodedImageFormat.Png, 100);
+	public void Save(Stream stream)
+		=> ToBitmap().Save(stream, ImageFormat.Png, 100);
+
+	/// <summary>
+	///  Converts this <see cref='Icon'/> to a <see cref='Bitmap'/>.
+	/// </summary>
+	public Bitmap ToBitmap()
+		=> new(Resized, ImageFormat.Png);
 
 	#endregion
 
@@ -214,11 +278,11 @@ private static List<IconEntry> ReadIco(Stream stream)
 		return entries;
 	}
 
-	private SKBitmap m_Resized
+	private SKBitmap Resized
 	{
 		get
 		{
-			var original = m_bitmap.Clone() as Bitmap ?? throw new Exception("Cloning bitmap failed");
+			var original = m_bitmap.Clone() as Bitmap ?? throw new Exception("cloning bitmap failed.");
 			var resized = new SKBitmap(Width, Height);
 			original.m_bitmap.ScalePixels(resized, SKFilterQuality.High);
 			return resized;