Add support for the decoding of jpeg2000

.gitignore

@@ -2,3 +2,4 @@
 *.rs.bk
 /Cargo.lock
 /target/
+.DS_Store

Cargo.toml

@@ -11,6 +11,8 @@ readme = "README.md"
 [dependencies]
 byteorder = "1"
 png = { version = "0.16", optional = true }
+jpeg2k = "0.6.6"
+
 
 [features]
 default = ["pngio"]

README.md

@@ -54,13 +54,6 @@ The table below indicates which types are currently supported; see
 https://en.wikipedia.org/wiki/Apple_Icon_Image_format#Icon_types for more
 information about each type.
 
-The biggest limitation at this time is that a number of the newer icon types
-can be encoded with either PNG or JPEG 2000 data, but this library does not yet
-support JPEG 2000; attempting to decode such an icon will result an an error
-value being returned (although you can still decode other icons from the same
-ICNS file).  The reason for this is that I don't currently know of any JPEG
-2000 libraries for Rust; if one exists, please feel free to file a bug or send
-a pull request.
 
 | OSType | Description                             | Supported? |
 |--------|-----------------------------------------|------------|
@@ -85,17 +78,17 @@ a pull request.
 | `h8mk` | 48×48 8-bit mask                        | Yes        |
 | `it32` | 128×128 24-bit icon                     | Yes        |
 | `t8mk` | 128×128 8-bit mask                      | Yes        |
-| `icp4` | 16x16 32-bit PNG/JP2 icon               | PNG only   |
-| `icp5` | 32x32 32-bit PNG/JP2 icon               | PNG only   |
-| `icp6` | 64x64 32-bit PNG/JP2 icon               | PNG only   |
-| `ic07` | 128x128 32-bit PNG/JP2 icon             | PNG only   |
-| `ic08` | 256×256 32-bit PNG/JP2 icon             | PNG only   |
-| `ic09` | 512×512 32-bit PNG/JP2 icon             | PNG only   |
-| `ic10` | 512x512@2x "retina" 32-bit PNG/JP2 icon | PNG only   |
-| `ic11` | 16x16@2x "retina" 32-bit PNG/JP2 icon   | PNG only   |
-| `ic12` | 32x32@2x "retina" 32-bit PNG/JP2 icon   | PNG only   |
-| `ic13` | 128x128@2x "retina" 32-bit PNG/JP2 icon | PNG only   |
-| `ic14` | 256x256@2x "retina" 32-bit PNG/JP2 icon | PNG only   |
+| `icp4` | 16x16 32-bit PNG/JP2 icon               | Yes        |
+| `icp5` | 32x32 32-bit PNG/JP2 icon               | Yes        |
+| `icp6` | 64x64 32-bit PNG/JP2 icon               | Yes        |
+| `ic07` | 128x128 32-bit PNG/JP2 icon             | Yes        |
+| `ic08` | 256×256 32-bit PNG/JP2 icon             | Yes        |
+| `ic09` | 512×512 32-bit PNG/JP2 icon             | Yes        |
+| `ic10` | 512x512@2x "retina" 32-bit PNG/JP2 icon | Yes        |
+| `ic11` | 16x16@2x "retina" 32-bit PNG/JP2 icon   | Yes        |
+| `ic12` | 32x32@2x "retina" 32-bit PNG/JP2 icon   | Yes        |
+| `ic13` | 128x128@2x "retina" 32-bit PNG/JP2 icon | Yes        |
+| `ic14` | 256x256@2x "retina" 32-bit PNG/JP2 icon | Yes        |
 
 ## License
 

src/element.rs

@@ -111,14 +111,41 @@ impl IconElement {
         let width = icon_type.pixel_width();
         let height = icon_type.pixel_width();
         match icon_type.encoding() {
-            #[cfg(feature = "pngio")]
             Encoding::JP2PNG => {
+                let image: Image;
                 if self.data.starts_with(&JPEG_2000_FILE_MAGIC_NUMBER) {
-                    let msg = "element to be decoded contains JPEG 2000 \
-                               data, which is not yet supported";
-                    return Err(Error::new(ErrorKind::InvalidInput, msg));
+                    let j2k_image = match jpeg2k::Image::from_bytes(&self.data) {
+                        Ok(image) => image,
+                        Err(e) => {
+                            return Err(io::Error::new(
+                                io::ErrorKind::InvalidData,
+                                e,
+                            ))
+                        }
+                    };
+                    let alpha_default = 255u8; // Full opacity
+                    let pixels =
+                        j2k_image.get_pixels(Some(alpha_default)).map_err(
+                            |e| io::Error::new(io::ErrorKind::InvalidData, e),
+                        )?;
+
+                    let pixel_format = match pixels.format {
+                        jpeg2k::ImageFormat::L8 => PixelFormat::Gray,
+                        jpeg2k::ImageFormat::La8 => PixelFormat::GrayAlpha,
+                        jpeg2k::ImageFormat::Rgb8 => PixelFormat::RGB,
+                        jpeg2k::ImageFormat::Rgba8 => PixelFormat::RGBA,
+                    };
+
+                    image = Image::from_data(
+                        pixel_format,
+                        pixels.width,
+                        pixels.height,
+                        pixels.data,
+                    )?;
+                } else {
+                    image = Image::read_png(io::Cursor::new(&self.data))?;
                 }
-                let image = Image::read_png(io::Cursor::new(&self.data))?;
+
                 if image.width() != width || image.height() != height {
                     let msg = format!("decoded PNG has wrong dimensions \
                                        ({}x{} instead of {}x{})",

src/lib.rs

@@ -84,16 +84,9 @@
 //!
 //! # Limitations
 //!
-//! The ICNS format allows some icon types to be encoded either as PNG data or
-//! as JPEG 2000 data; however, when encoding icons, this library always uses
-//! PNG format, and when decoding icons, it cannot decode JPEG 2000 icons at
-//! all (it will detect the JPEG 2000 header and return an error).  The reason
-//! for this is the apparent lack of JPEG 2000 libraries for Rust; if this ever
-//! changes, please feel free to file a bug or a send a pull request.
-//!
-//! Additionally, this library does not yet support many of the older icon
+//! This library does not yet support many of the older icon
 //! types used by earlier versions of Mac OS (such as `ICN#`, a 32x32 black and
-//! white icon).  Again, pull requests (with suitable tests) are welcome.
+//! white icon). Pull requests (with suitable tests) are welcome.
 //!
 //! # Example usage
 //!

tests/golden.rs

@@ -74,6 +74,24 @@ fn encode_ic11() {
     encoder_test("32x32.png", IconType::RGBA32_16x16_2x, "ic11.icns");
 }
 
+#[test]
+fn decode_ic13() {
+    decoder_test("ic13.icns", IconType::RGBA32_128x128_2x, "256x256.png");
+}
+
+#[test]
+fn decode_ic08(){
+    decoder_test("ic08.icns", IconType::RGBA32_256x256, "256x256.png");
+}
+
+#[test]
+fn decode_jpeg2000_256x256() {
+    decoder_test("loom.icns", IconType::RGBA32_512x512, "loom-512x512.png");
+}
+
+
+
+
 fn decoder_test(icns_name: &str, icon_type: IconType, png_name: &str) {
     let family = load_icns_file(icns_name).unwrap();
     let image = family.get_icon_with_type(icon_type).unwrap();