1 files changed, 125 insertions, 0 deletions
diff --git a/image/decoders/nsIconDecoder.cpp b/image/decoders/nsIconDecoder.cpp
new file mode 100644
index 0000000000..c4ed8b7b06
--- /dev/null
+++ b/image/decoders/nsIconDecoder.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIconDecoder.h"
+#include "RasterImage.h"
+#include "SurfacePipeFactory.h"
+#include "gfxPlatform.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace image {
+
+static const uint32_t ICON_HEADER_SIZE = 4;
+
+nsIconDecoder::nsIconDecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::To(State::HEADER, ICON_HEADER_SIZE),
+             Transition::TerminateSuccess()),
+      mBytesPerRow()  // set by ReadHeader()
+{
+  // Nothing to do
+}
+
+nsIconDecoder::~nsIconDecoder() {}
+
+LexerResult nsIconDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                    IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(aIterator, aOnResume,
+                    [=](State aState, const char* aData, size_t aLength) {
+                      switch (aState) {
+                        case State::HEADER:
+                          return ReadHeader(aData);
+                        case State::ROW_OF_PIXELS:
+                          return ReadRowOfPixels(aData, aLength);
+                        case State::FINISH:
+                          return Finish();
+                        default:
+                          MOZ_CRASH("Unknown State");
+                      }
+                    });
+}
+
+LexerTransition<nsIconDecoder::State> nsIconDecoder::ReadHeader(
+    const char* aData) {
+  // Grab the width and height.
+  uint8_t width = uint8_t(aData[0]);
+  uint8_t height = uint8_t(aData[1]);
+  SurfaceFormat format = SurfaceFormat(aData[2]);
+  bool transform = bool(aData[3]);
+
+  // FIXME(aosmond): On OSX we get the icon in device space and already
+  // premultiplied, so we can't support the surface flags with icons right now.
+  SurfacePipeFlags pipeFlags = SurfacePipeFlags();
+  if (transform) {
+    if (mCMSMode == CMSMode::All) {
+      mTransform = GetCMSsRGBTransform(format);
+    }
+
+    if (!(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA)) {
+      pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+    }
+  }
+
+  // The input is 32bpp, so we expect 4 bytes of data per pixel.
+  mBytesPerRow = width * 4;
+
+  // Post our size to the superclass.
+  PostSize(width, height);
+
+  // Icons have alpha.
+  PostHasTransparency();
+
+  // If we're doing a metadata decode, we're done.
+  if (IsMetadataDecode()) {
+    return Transition::TerminateSuccess();
+  }
+
+  MOZ_ASSERT(!mImageData, "Already have a buffer allocated?");
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), FullFrame(), format, SurfaceFormat::OS_RGBA,
+      /* aAnimParams */ Nothing(), mTransform, pipeFlags);
+  if (!pipe) {
+    return Transition::TerminateFailure();
+  }
+
+  mPipe = std::move(*pipe);
+
+  MOZ_ASSERT(mImageData, "Should have a buffer now");
+
+  return Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
+}
+
+LexerTransition<nsIconDecoder::State> nsIconDecoder::ReadRowOfPixels(
+    const char* aData, size_t aLength) {
+  MOZ_ASSERT(aLength % 4 == 0, "Rows should contain a multiple of four bytes");
+
+  auto result = mPipe.WriteBuffer(reinterpret_cast<const uint32_t*>(aData));
+  MOZ_ASSERT(result != WriteState::FAILURE);
+
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (invalidRect) {
+    PostInvalidation(invalidRect->mInputSpaceRect,
+                     Some(invalidRect->mOutputSpaceRect));
+  }
+
+  return result == WriteState::FINISHED
+             ? Transition::To(State::FINISH, 0)
+             : Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
+}
+
+LexerTransition<nsIconDecoder::State> nsIconDecoder::Finish() {
+  PostFrameStop();
+  PostDecodeDone();
+
+  return Transition::TerminateSuccess();
+}
+
+}  // namespace image
+}  // namespace mozilla