LibGfx: Initial support for ICO image files.

This adds support for loading the first image from ICO format images only if they are PNG encoded.
This is useful for loading favicons, which are sometimes PNGs with an ICO extension and sometimes actual ICO files.
In particular we can now load the favicon from new.ycombinator.com

Libraries/LibGfx/Bitmap.cpp

@@ -33,6 +33,7 @@
 #include <LibGfx/GIFLoader.h>
 #include <LibGfx/PBMLoader.h>
 #include <LibGfx/PNGLoader.h>
+#include <LibGfx/ICOLoader.h>
 #include <LibGfx/ShareableBitmap.h>
 #include <fcntl.h>
 #include <stdio.h>

Libraries/LibGfx/Bitmap.h

@@ -37,7 +37,8 @@
     __ENUMERATE_IMAGE_FORMAT(pbm, ".pbm") \
     __ENUMERATE_IMAGE_FORMAT(png, ".png") \
     __ENUMERATE_IMAGE_FORMAT(gif, ".gif") \
-    __ENUMERATE_IMAGE_FORMAT(bmp, ".bmp")
+    __ENUMERATE_IMAGE_FORMAT(bmp, ".bmp") \
+    __ENUMERATE_IMAGE_FORMAT(ico, ".ico")
 
 namespace Gfx {
 

Libraries/LibGfx/CMakeLists.txt

@@ -9,6 +9,7 @@ set(SOURCES
     FloatRect.cpp
     Font.cpp
     GIFLoader.cpp
+    ICOLoader.cpp
     ImageDecoder.cpp
     Painter.cpp
     Palette.cpp

Libraries/LibGfx/ICOLoader.cpp

@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) 2020, Paul Roukema <roukemap@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/BufferStream.h>
+#include <AK/ByteBuffer.h>
+#include <AK/LexicalPath.h>
+#include <AK/MappedFile.h>
+#include <AK/NonnullOwnPtrVector.h>
+#include <LibGfx/ICOLoader.h>
+#include <LibGfx/PNGLoader.h>
+#include <LibM/math.h>
+#include <stdio.h>
+#include <string.h>
+
+//#define ICO_DEBUG
+
+namespace Gfx {
+
+// FIXME: This is in little-endian order. Maybe need a NetworkOrdered<T> equivalent eventually.
+struct ICONDIR {
+    u16 must_be_0;
+    u16 must_be_1;
+    u16 image_count;
+};
+static_assert(sizeof(ICONDIR) == 6);
+
+struct ICONDIRENTRY {
+    u8 width;
+    u8 height;
+    u8 color_count;
+    u8 reserved_0;
+    u16 planes;
+    u16 bits_per_pixel;
+    u32 size;
+    u32 offset;
+};
+static_assert(sizeof(ICONDIRENTRY) == 16);
+
+struct ImageDescriptor {
+    u16 width;
+    u16 height;
+    size_t offset;
+    size_t size;
+    RefPtr<Gfx::Bitmap> bitmap;
+};
+
+struct ICOLoadingContext {
+    enum State {
+        NotDecoded = 0,
+        Error,
+        DirectoryDecoded,
+        BitmapDecoded
+    };
+    State state { NotDecoded };
+    const u8* data { nullptr };
+    size_t data_size { 0 };
+    Vector<ImageDescriptor> images;
+};
+
+RefPtr<Gfx::Bitmap> load_ico(const StringView& path)
+{
+    MappedFile mapped_file(path);
+    if (!mapped_file.is_valid())
+        return nullptr;
+    ICOImageDecoderPlugin decoder((const u8*)mapped_file.data(), mapped_file.size());
+    auto bitmap = decoder.bitmap();
+    if (bitmap)
+        bitmap->set_mmap_name(String::format("Gfx::Bitmap [%dx%d] - Decoded ICO: %s", bitmap->width(), bitmap->height(), LexicalPath::canonicalized_path(path).characters()));
+    return bitmap;
+}
+
+RefPtr<Gfx::Bitmap> load_ico_from_memory(const u8* data, size_t length)
+{
+    ICOImageDecoderPlugin decoder(data, length);
+    auto bitmap = decoder.bitmap();
+    if (bitmap)
+        bitmap->set_mmap_name(String::format("Gfx::Bitmap [%dx%d] - Decoded ICO: <memory>", bitmap->width(), bitmap->height()));
+    return bitmap;
+}
+
+static Optional<size_t> decode_ico_header(BufferStream& stream)
+{
+    ICONDIR header;
+    stream.read_raw((uint8_t*)&header, sizeof(header));
+    if (stream.handle_read_failure())
+        return {};
+
+    if (header.must_be_0 != 0 || header.must_be_1 != 1)
+        return {};
+    return { header.image_count };
+}
+
+static Optional<ImageDescriptor> decode_ico_direntry(BufferStream& stream)
+{
+    ICONDIRENTRY entry;
+    stream.read_raw((uint8_t*)&entry, sizeof(entry));
+    if (stream.handle_read_failure())
+        return {};
+
+    ImageDescriptor desc = { entry.width, entry.height, entry.offset, entry.size, nullptr };
+    if (desc.width == 0)
+        desc.width = 256;
+    if (desc.height == 0)
+        desc.height = 256;
+
+    return { desc };
+}
+
+static bool load_ico_directory(ICOLoadingContext& context)
+{
+    auto buffer = ByteBuffer::wrap(context.data, context.data_size);
+    auto stream = BufferStream(buffer);
+    auto image_count = decode_ico_header(stream);
+    if (!image_count.has_value() || image_count.value() == 0) {
+        return false;
+    }
+
+    for (size_t i = 0; i < image_count.value(); ++i) {
+        auto maybe_desc = decode_ico_direntry(stream);
+        if (!maybe_desc.has_value()) {
+#ifdef ICO_DEBUG
+            printf("load_ico_directory: error loading entry: %lu\n", i);
+#endif
+            return false;
+        }
+
+        auto& desc = maybe_desc.value();
+        if (desc.offset + desc.size < desc.offset // detect integer overflow
+            || (desc.offset + desc.size) > context.data_size) {
+#ifdef ICO_DEBUG
+            printf("load_ico_directory: offset: %lu size: %lu doesn't fit in ICO size: %lu\n",
+                desc.offset, desc.size, context.data_size);
+#endif
+            return false;
+        }
+#ifdef ICO_DEBUG
+        printf("load_ico_directory: index %lu width: %u height: %u offset: %lu size: %lu\n",
+            i, desc.width, desc.height, desc.offset, desc.size);
+#endif
+        context.images.append(desc);
+    }
+    return true;
+}
+
+static bool load_ico_bitmap(ICOLoadingContext& context, size_t index)
+{
+    if (context.state < ICOLoadingContext::State::DirectoryDecoded) {
+        if (!load_ico_directory(context)) {
+            context.state = ICOLoadingContext::State::Error;
+            return false;
+        }
+        context.state = ICOLoadingContext::State::DirectoryDecoded;
+    }
+    if (index >= context.images.size()) {
+        return false;
+    }
+
+    ImageDescriptor& desc = context.images[index];
+
+    PNGImageDecoderPlugin png_decoder(context.data + desc.offset, desc.size);
+    if (png_decoder.sniff()) {
+        desc.bitmap = png_decoder.bitmap();
+        if (!desc.bitmap) {
+#ifdef ICO_DEBUG
+            printf("load_ico_bitmap: failed to load PNG encoded image index: %lu\n", index);
+#endif
+            return false;
+        }
+        return true;
+    } else {
+        dbg() << "load_ico_bitmap: image index: " << index << " must be BMP encoded, not implemented\n";
+        return false;
+    }
+}
+
+ICOImageDecoderPlugin::ICOImageDecoderPlugin(const u8* data, size_t size)
+{
+    m_context = make<ICOLoadingContext>();
+    m_context->data = data;
+    m_context->data_size = size;
+}
+
+ICOImageDecoderPlugin::~ICOImageDecoderPlugin() { }
+
+IntSize ICOImageDecoderPlugin::size()
+{
+    if (m_context->state == ICOLoadingContext::State::Error) {
+        return {};
+    }
+
+    if (m_context->state < ICOLoadingContext::State::DirectoryDecoded) {
+        if (!load_ico_directory(*m_context)) {
+            m_context->state = ICOLoadingContext::State::Error;
+            return {};
+        }
+        m_context->state = ICOLoadingContext::State::DirectoryDecoded;
+    }
+
+    return { m_context->images[0].width, m_context->images[0].height };
+}
+
+RefPtr<Gfx::Bitmap> ICOImageDecoderPlugin::bitmap()
+{
+    if (m_context->state == ICOLoadingContext::State::Error)
+        return nullptr;
+
+    if (m_context->state < ICOLoadingContext::State::BitmapDecoded) {
+        // NOTE: This forces the chunk decoding to happen.
+        bool success = load_ico_bitmap(*m_context, 0);
+        if (!success) {
+            m_context->state = ICOLoadingContext::State::Error;
+            return nullptr;
+        }
+        m_context->state = ICOLoadingContext::State::BitmapDecoded;
+    }
+
+    ASSERT(m_context->images[0].bitmap);
+    return m_context->images[0].bitmap;
+}
+
+void ICOImageDecoderPlugin::set_volatile()
+{
+    if (m_context->images[0].bitmap)
+        m_context->images[0].bitmap->set_volatile();
+}
+
+bool ICOImageDecoderPlugin::set_nonvolatile()
+{
+    if (!m_context->images[0].bitmap)
+        return false;
+    return m_context->images[0].bitmap->set_nonvolatile();
+}
+
+bool ICOImageDecoderPlugin::sniff()
+{
+    auto buffer = ByteBuffer::wrap(m_context->data, m_context->data_size);
+    BufferStream stream(buffer);
+    return decode_ico_header(stream).has_value();
+}
+
+bool ICOImageDecoderPlugin::is_animated()
+{
+    return false;
+}
+
+size_t ICOImageDecoderPlugin::loop_count()
+{
+    return 0;
+}
+
+size_t ICOImageDecoderPlugin::frame_count()
+{
+    return 1;
+}
+
+ImageFrameDescriptor ICOImageDecoderPlugin::frame(size_t i)
+{
+    if (i > 0) {
+        return { bitmap(), 0 };
+    }
+    return {};
+}
+
+}

Libraries/LibGfx/ICOLoader.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2020, Paul Roukema <roukemap@gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibGfx/Bitmap.h>
+#include <LibGfx/ImageDecoder.h>
+
+namespace Gfx {
+
+RefPtr<Gfx::Bitmap> load_ico(const StringView& path);
+RefPtr<Gfx::Bitmap> load_ico_from_memory(const u8*, size_t);
+
+struct ICOLoadingContext;
+
+class ICOImageDecoderPlugin final : public ImageDecoderPlugin {
+public:
+    virtual ~ICOImageDecoderPlugin() override;
+    ICOImageDecoderPlugin(const u8*, size_t);
+
+    virtual IntSize size() override;
+    virtual RefPtr<Gfx::Bitmap> bitmap() override;
+    virtual void set_volatile() override;
+    [[nodiscard]] virtual bool set_nonvolatile() override;
+    virtual bool sniff() override;
+    virtual bool is_animated() override;
+    virtual size_t loop_count() override;
+    virtual size_t frame_count() override;
+    virtual ImageFrameDescriptor frame(size_t i) override;
+
+private:
+    OwnPtr<ICOLoadingContext> m_context;
+};
+
+}

Libraries/LibGfx/ImageDecoder.cpp

@@ -27,6 +27,7 @@
 #include <LibGfx/ImageDecoder.h>
 #include <LibGfx/BMPLoader.h>
 #include <LibGfx/GIFLoader.h>
+#include <LibGfx/ICOLoader.h>
 #include <LibGfx/PBMLoader.h>
 #include <LibGfx/PNGLoader.h>
 
@@ -50,6 +51,10 @@ ImageDecoder::ImageDecoder(const u8* data, size_t size)
     if (m_plugin->sniff())
         return;
 
+    m_plugin = make<ICOImageDecoderPlugin>(data, size);
+    if (m_plugin->sniff())
+        return;
+
     m_plugin = nullptr;
 }