Add IImageDecoder overloads

Adds overloads the the Image.Load(..) methods that take an IImageDecoder.

src/ImageSharp/Image.Decode.cs

@@ -19,25 +19,12 @@ namespace ImageSharp
     /// </summary>
     public sealed partial class Image
     {
-        /// <summary>
+        private static IImageFormat DiscoverFormat(Stream stream, IDecoderOptions options, Configuration config)
-        /// Decodes the image stream to the current image.
-        /// </summary>
-        /// <typeparam name="TColor">The pixel format.</typeparam>
-        /// <param name="stream">The stream.</param>
-        /// <param name="options">The options for the decoder.</param>
-        /// <param name="config">the configuration.</param>
-        /// <param name="img">The decoded image</param>
-        /// <returns>
-        ///  [true] if can successfull decode the image otherwise [false].
-        /// </returns>
-        private static bool Decode<TColor>(Stream stream, IDecoderOptions options, Configuration config, out Image<TColor> img)
-            where TColor : struct, IPixel<TColor>
         {
-            img = null;
             int maxHeaderSize = config.MaxHeaderSize;
             if (maxHeaderSize <= 0)
             {
-                return false;
+                return null;
             }
 
             IImageFormat format;
@@ -54,14 +41,31 @@ namespace ImageSharp
                 ArrayPool<byte>.Shared.Return(header);
             }
 
+            return format;
+        }
+
+        /// <summary>
+        /// Decodes the image stream to the current image.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="stream">The stream.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <param name="config">the configuration.</param>
+        /// <returns>
+        ///  The decoded image
+        /// </returns>
+        private static Image<TColor> Decode<TColor>(Stream stream, IDecoderOptions options, Configuration config)
+        where TColor : struct, IPixel<TColor>
+        {
+            IImageFormat format = DiscoverFormat(stream, options, config);
             if (format == null)
             {
-                return false;
+                return null;
             }
 
-            img = format.Decoder.Decode<TColor>(stream, options);
+            Image<TColor> img = format.Decoder.Decode<TColor>(stream, options);
             img.CurrentImageFormat = format;
-            return true;
+            return img;
         }
     }
 }

src/ImageSharp/Image.FromBytes.cs

@@ -29,7 +29,7 @@ namespace ImageSharp
         /// <returns>The image</returns>
         public static Image Load(byte[] data)
         {
-            return Load(data, null, null);
+            return Load(data, null, (Configuration)null);
         }
 
         /// <summary>
@@ -60,6 +60,20 @@ namespace ImageSharp
             return Load(data, null, config);
         }
 
+        /// <summary>
+        /// Loads the image from the given byte array.
+        /// </summary>
+        /// <param name="data">The byte array containing image data.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image Load(byte[] data, IImageDecoder decoder)
+        {
+            return Load(data, decoder, null);
+        }
+
         /// <summary>
         /// Loads the image from the given byte array.
         /// </summary>
@@ -78,6 +92,24 @@ namespace ImageSharp
             }
         }
 
+        /// <summary>
+        /// Loads the image from the given byte array.
+        /// </summary>
+        /// <param name="data">The byte array containing image data.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image Load(byte[] data, IImageDecoder decoder, IDecoderOptions options)
+        {
+            using (MemoryStream ms = new MemoryStream(data))
+            {
+                return Load(ms, decoder, options);
+            }
+        }
+
         /// <summary>
         /// Loads the image from the given byte array.
         /// </summary>
@@ -90,7 +122,7 @@ namespace ImageSharp
         public static Image<TColor> Load<TColor>(byte[] data)
             where TColor : struct, IPixel<TColor>
         {
-            return Load<TColor>(data, null, null);
+            return Load<TColor>(data, null, (Configuration)null);
         }
 
         /// <summary>
@@ -125,6 +157,22 @@ namespace ImageSharp
             return Load<TColor>(data, null, config);
         }
 
+        /// <summary>
+        /// Loads the image from the given byte array.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="data">The byte array containing image data.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image<TColor> Load<TColor>(byte[] data, IImageDecoder decoder)
+            where TColor : struct, IPixel<TColor>
+        {
+            return Load<TColor>(data, decoder, null);
+        }
+
         /// <summary>
         /// Loads the image from the given byte array.
         /// </summary>
@@ -144,5 +192,25 @@ namespace ImageSharp
                 return Load<TColor>(ms, options, config);
             }
         }
+
+        /// <summary>
+        /// Loads the image from the given byte array.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="data">The byte array containing image data.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image<TColor> Load<TColor>(byte[] data, IImageDecoder decoder, IDecoderOptions options)
+            where TColor : struct, IPixel<TColor>
+        {
+            using (MemoryStream ms = new MemoryStream(data))
+            {
+                return Load<TColor>(ms, decoder, options);
+            }
+        }
     }
 }

src/ImageSharp/Image.FromFile.cs

@@ -30,7 +30,7 @@ namespace ImageSharp
         /// <returns>The image</returns>
         public static Image Load(string path)
         {
-            return Load(path, null, null);
+            return Load(path, null, (Configuration)null);
         }
 
         /// <summary>
@@ -61,6 +61,35 @@ namespace ImageSharp
             return Load(path, null, config);
         }
 
+        /// <summary>
+        /// Loads the image from the given file.
+        /// </summary>
+        /// <param name="path">The file path to the image.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image Load(string path, IImageDecoder decoder)
+        {
+            return Load(path, decoder, null);
+        }
+
+        /// <summary>
+        /// Loads the image from the given file.
+        /// </summary>
+        /// <param name="path">The file path to the image.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image Load(string path, IImageDecoder decoder, IDecoderOptions options)
+        {
+            return new Image(Load<Color>(path, decoder, options));
+        }
+
         /// <summary>
         /// Loads the image from the given file.
         /// </summary>
@@ -88,7 +117,7 @@ namespace ImageSharp
         public static Image<TColor> Load<TColor>(string path)
             where TColor : struct, IPixel<TColor>
         {
-            return Load<TColor>(path, null, null);
+            return Load<TColor>(path, null, (Configuration)null);
         }
 
         /// <summary>
@@ -123,6 +152,22 @@ namespace ImageSharp
             return Load<TColor>(path, null, config);
         }
 
+        /// <summary>
+        /// Loads the image from the given file.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="path">The file path to the image.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image<TColor> Load<TColor>(string path, IImageDecoder decoder)
+            where TColor : struct, IPixel<TColor>
+        {
+            return Load<TColor>(path, decoder, null);
+        }
+
         /// <summary>
         /// Loads the image from the given file.
         /// </summary>
@@ -143,6 +188,27 @@ namespace ImageSharp
                 return Load<TColor>(s, options, config);
             }
         }
+
+        /// <summary>
+        /// Loads the image from the given file.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="path">The file path to the image.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image<TColor> Load<TColor>(string path, IImageDecoder decoder, IDecoderOptions options)
+            where TColor : struct, IPixel<TColor>
+        {
+            Configuration config = Configuration.Default;
+            using (Stream s = config.FileSystem.OpenRead(path))
+            {
+                return Load<TColor>(s, decoder, options);
+            }
+        }
     }
 #endif
 }

src/ImageSharp/Image.FromStream.cs

@@ -29,7 +29,7 @@ namespace ImageSharp
         /// <returns>The image</returns>
         public static Image Load(Stream stream)
         {
-            return Load(stream, null, null);
+            return Load(stream, null, (Configuration)null);
         }
 
         /// <summary>
@@ -60,6 +60,20 @@ namespace ImageSharp
             return Load(stream, null, config);
         }
 
+        /// <summary>
+        /// Loads the image from the given stream.
+        /// </summary>
+        /// <param name="stream">The stream containing image information.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image Load(Stream stream, IImageDecoder decoder)
+        {
+            return Load(stream, decoder, null);
+        }
+
         /// <summary>
         /// Loads the image from the given stream.
         /// </summary>
@@ -75,6 +89,21 @@ namespace ImageSharp
             return new Image(Load<Color>(stream, options, config));
         }
 
+        /// <summary>
+        /// Loads the image from the given stream.
+        /// </summary>
+        /// <param name="stream">The stream containing image information.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image Load(Stream stream, IImageDecoder decoder, IDecoderOptions options)
+        {
+            return new Image(Load<Color>(stream, decoder, options));
+        }
+
         /// <summary>
         /// Loads the image from the given stream.
         /// </summary>
@@ -87,7 +116,7 @@ namespace ImageSharp
         public static Image<TColor> Load<TColor>(Stream stream)
             where TColor : struct, IPixel<TColor>
         {
-            return Load<TColor>(stream, null, null);
+            return Load<TColor>(stream, null, (Configuration)null);
         }
 
         /// <summary>
@@ -122,6 +151,39 @@ namespace ImageSharp
             return Load<TColor>(stream, null, config);
         }
 
+        /// <summary>
+        /// Loads the image from the given stream.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="stream">The stream containing image information.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image<TColor> Load<TColor>(Stream stream, IImageDecoder decoder)
+            where TColor : struct, IPixel<TColor>
+        {
+            return Load<TColor>(stream, decoder, null);
+        }
+
+        /// <summary>
+        /// Loads the image from the given stream.
+        /// </summary>
+        /// <typeparam name="TColor">The pixel format.</typeparam>
+        /// <param name="stream">The stream containing image information.</param>
+        /// <param name="decoder">The decoder.</param>
+        /// <param name="options">The options for the decoder.</param>
+        /// <exception cref="NotSupportedException">
+        /// Thrown if the stream is not readable nor seekable.
+        /// </exception>
+        /// <returns>The image</returns>
+        public static Image<TColor> Load<TColor>(Stream stream, IImageDecoder decoder, IDecoderOptions options)
+            where TColor : struct, IPixel<TColor>
+        {
+            return WithSeekableStream(stream, s => decoder.Decode<TColor>(s, options));
+        }
+
         /// <summary>
         /// Loads the image from the given stream.
         /// </summary>
@@ -138,11 +200,29 @@ namespace ImageSharp
         {
             config = config ?? Configuration.Default;
 
-            if (!config.ImageFormats.Any())
+            Image<TColor> img = WithSeekableStream(stream, s =>
+            {
+                return Decode<TColor>(stream, options, config);
+            });
+
+            if (img != null)
+            {
+                return img;
+            }
+
+            StringBuilder stringBuilder = new StringBuilder();
+            stringBuilder.AppendLine("Image cannot be loaded. Available formats:");
+
+            foreach (IImageFormat format in config.ImageFormats)
             {
-                throw new InvalidOperationException("No image formats have been configured.");
+                stringBuilder.AppendLine("-" + format);
             }
 
+            throw new NotSupportedException(stringBuilder.ToString());
+        }
+
+        private static T WithSeekableStream<T>(Stream stream, Func<Stream, T> action)
+        {
             if (!stream.CanRead)
             {
                 throw new NotSupportedException("Cannot read from the stream.");
@@ -150,10 +230,7 @@ namespace ImageSharp
 
             if (stream.CanSeek)
             {
-                if (Decode(stream, options, config, out Image<TColor> img))
+                return action(stream);
-                {
-                    return img;
-                }
             }
             else
             {
@@ -163,22 +240,9 @@ namespace ImageSharp
                     stream.CopyTo(ms);
                     ms.Position = 0;
 
-                    if (Decode(ms, options, config, out Image<TColor> img))
+                    return action(stream);
-                    {
-                        return img;
-                    }
                 }
             }
-
-            StringBuilder stringBuilder = new StringBuilder();
-            stringBuilder.AppendLine("Image cannot be loaded. Available formats:");
-
-            foreach (IImageFormat format in config.ImageFormats)
-            {
-                stringBuilder.AppendLine("-" + format);
-            }
-
-            throw new NotSupportedException(stringBuilder.ToString());
         }
     }
 }

tests/ImageSharp.Tests/Image/ImageLoadTests.cs

@@ -66,6 +66,9 @@ namespace ImageSharp.Tests
 
             this.FilePath = Guid.NewGuid().ToString();
             this.fileSystem.Setup(x => x.OpenRead(this.FilePath)).Returns(this.DataStream);
+
+            TestFileSystem.RegisterGloablTestFormat();
+            TestFileSystem.Global.AddFile(this.FilePath, this.DataStream);
         }
 
         [Fact]
@@ -157,6 +160,50 @@ namespace ImageSharp.Tests
             this.localDecoder.Verify(x => x.Decode<Color>(stream, this.decoderOptions));
         }
 
+
+
+        [Fact]
+        public void LoadFromStreamWithDecoder()
+        {
+            Stream stream = new MemoryStream();
+            Image img = Image.Load(stream, this.localDecoder.Object);
+
+            Assert.NotNull(img);
+            this.localDecoder.Verify(x => x.Decode<Color>(stream, null));
+        }
+
+        [Fact]
+        public void LoadFromStreamWithTypeAndDecoder()
+        {
+            Stream stream = new MemoryStream();
+            Image<Color> img = Image.Load<Color>(stream, this.localDecoder.Object);
+
+            Assert.NotNull(img);
+            Assert.Equal(this.returnImage, img);
+            this.localDecoder.Verify(x => x.Decode<Color>(stream, null));
+        }
+
+        [Fact]
+        public void LoadFromStreamWithDecoderAndOptions()
+        {
+            Stream stream = new MemoryStream();
+            Image img = Image.Load(stream, this.localDecoder.Object, this.decoderOptions);
+
+            Assert.NotNull(img);
+            this.localDecoder.Verify(x => x.Decode<Color>(stream, this.decoderOptions));
+        }
+
+        [Fact]
+        public void LoadFromStreamWithTypeAndDecoderAndOptions()
+        {
+            Stream stream = new MemoryStream();
+            Image<Color> img = Image.Load<Color>(stream, this.localDecoder.Object, this.decoderOptions);
+
+            Assert.NotNull(img);
+            Assert.Equal(this.returnImage, img);
+            this.localDecoder.Verify(x => x.Decode<Color>(stream, this.decoderOptions));
+        }
+
         [Fact]
         public void LoadFromBytes()
         {
@@ -246,7 +293,50 @@ namespace ImageSharp.Tests
             this.localDecoder.Verify(x => x.Decode<Color>(It.IsAny<Stream>(), this.decoderOptions));
             Assert.Equal(this.DataStream.ToArray(), this.DecodedData);
         }
-        
+
+
+        [Fact]
+        public void LoadFromBytesWithDecoder()
+        {
+            Image img = Image.Load(this.DataStream.ToArray(), this.localDecoder.Object);
+
+            Assert.NotNull(img);
+            this.localDecoder.Verify(x => x.Decode<Color>(It.IsAny<Stream>(), null));
+            Assert.Equal(this.DataStream.ToArray(), this.DecodedData);
+        }
+
+        [Fact]
+        public void LoadFromBytesWithTypeAndDecoder()
+        {
+            Image<Color> img = Image.Load<Color>(this.DataStream.ToArray(), this.localDecoder.Object);
+
+            Assert.NotNull(img);
+            Assert.Equal(this.returnImage, img);
+            this.localDecoder.Verify(x => x.Decode<Color>(It.IsAny<Stream>(), null));
+            Assert.Equal(this.DataStream.ToArray(), this.DecodedData);
+        }
+
+        [Fact]
+        public void LoadFromBytesWithDecoderAndOptions()
+        {
+            Image img = Image.Load(this.DataStream.ToArray(), this.localDecoder.Object, this.decoderOptions);
+
+            Assert.NotNull(img);
+            this.localDecoder.Verify(x => x.Decode<Color>(It.IsAny<Stream>(), this.decoderOptions));
+            Assert.Equal(this.DataStream.ToArray(), this.DecodedData);
+        }
+
+        [Fact]
+        public void LoadFromBytesWithTypeAndDecoderAndOptions()
+        {
+            Image<Color> img = Image.Load<Color>(this.DataStream.ToArray(), this.localDecoder.Object, this.decoderOptions);
+
+            Assert.NotNull(img);
+            Assert.Equal(this.returnImage, img);
+            this.localDecoder.Verify(x => x.Decode<Color>(It.IsAny<Stream>(), this.decoderOptions));
+            Assert.Equal(this.DataStream.ToArray(), this.DecodedData);
+        }
+
         [Fact]
         public void LoadFromFile()
         {
@@ -324,7 +414,7 @@ namespace ImageSharp.Tests
         [Fact]
         public void LoadFromFileWithTypeAndConfigAndOptions()
         {
-            Image<Color> img = Image.Load<Color>(FilePath, this.decoderOptions, this.LocalConfiguration);
+            Image<Color> img = Image.Load<Color>(this.FilePath, this.decoderOptions, this.LocalConfiguration);
 
             Assert.NotNull(img);
             Assert.Equal(this.returnImage, img);
@@ -332,6 +422,45 @@ namespace ImageSharp.Tests
             this.localDecoder.Verify(x => x.Decode<Color>(this.DataStream, this.decoderOptions));
         }
 
+
+        [Fact]
+        public void LoadFromFileWithDecoder()
+        {
+            Image img = Image.Load(this.FilePath, this.localDecoder.Object);
+
+            Assert.NotNull(img);
+            this.localDecoder.Verify(x => x.Decode<Color>(this.DataStream, null));
+        }
+
+        [Fact]
+        public void LoadFromFileWithTypeAndDecoder()
+        {
+            Image<Color> img = Image.Load<Color>(this.FilePath, this.localDecoder.Object);
+
+            Assert.NotNull(img);
+            Assert.Equal(this.returnImage, img);
+            this.localDecoder.Verify(x => x.Decode<Color>(this.DataStream, null));
+        }
+
+        [Fact]
+        public void LoadFromFileWithDecoderAndOptions()
+        {
+            Image img = Image.Load(this.FilePath, this.localDecoder.Object, this.decoderOptions);
+
+            Assert.NotNull(img);
+            this.localDecoder.Verify(x => x.Decode<Color>(this.DataStream, this.decoderOptions));
+        }
+
+        [Fact]
+        public void LoadFromFileWithTypeAndDecoderAndOptions()
+        {
+            Image<Color> img = Image.Load<Color>(this.FilePath, this.localDecoder.Object, this.decoderOptions);
+
+            Assert.NotNull(img);
+            Assert.Equal(this.returnImage, img);
+            this.localDecoder.Verify(x => x.Decode<Color>(this.DataStream, this.decoderOptions));
+        }
+
         public void Dispose()
         {
             // clean up the global object;

tests/ImageSharp.Tests/TestFileSystem.cs

@@ -0,0 +1,72 @@
+// <copyright file="TestFileSystem.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp.Tests
+{
+    using System;
+    using System.Collections.Concurrent;
+    using System.Collections.Generic;
+    using System.IO;
+    using System.Linq;
+    using System.Reflection;
+    using ImageSharp.Formats;
+    using Xunit;
+
+    /// <summary>
+    /// A test image file.
+    /// </summary>
+    public class TestFileSystem : ImageSharp.IO.IFileSystem
+    {
+
+        public static TestFileSystem Global { get; } = new TestFileSystem();
+
+        public static void RegisterGloablTestFormat()
+        {
+            Configuration.Default.FileSystem = Global;
+        }
+
+        Dictionary<string, Stream> fileSystem = new Dictionary<string, Stream>(StringComparer.OrdinalIgnoreCase);
+
+        public void AddFile(string path, Stream data)
+        {
+            fileSystem.Add(path, data);
+        }
+
+        public Stream Create(string path)
+        {
+            MemoryStream stream = new MemoryStream();
+            lock (fileSystem)
+            {
+                if (fileSystem.ContainsKey(path))
+                {
+                    fileSystem[path] = stream;
+                }
+                else
+                {
+                    fileSystem.Add(path, stream);
+                }
+            }
+            return stream;
+        }
+
+
+        public Stream OpenRead(string path)
+        {
+            lock (fileSystem)
+            {
+                if (fileSystem.ContainsKey(path))
+                {
+
+                    Stream stream =  fileSystem[path];
+                    stream.Position = 0;
+                    return stream;
+                }
+            }
+
+            return File.OpenRead(path);
+        }
+    }
+}
+