1 files changed, 346 insertions, 0 deletions
diff --git a/image/MultipartImage.cpp b/image/MultipartImage.cpp
new file mode 100644
index 0000000000..59aa24aafe
--- /dev/null
+++ b/image/MultipartImage.cpp
@@ -0,0 +1,346 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "MultipartImage.h"
+
+#include "imgINotificationObserver.h"
+
+namespace mozilla {
+
+using gfx::IntSize;
+using gfx::SourceSurface;
+
+namespace image {
+
+///////////////////////////////////////////////////////////////////////////////
+// Helpers
+///////////////////////////////////////////////////////////////////////////////
+
+class NextPartObserver : public IProgressObserver
+{
+public:
+  MOZ_DECLARE_REFCOUNTED_TYPENAME(NextPartObserver)
+  NS_INLINE_DECL_REFCOUNTING(NextPartObserver, override)
+
+  explicit NextPartObserver(MultipartImage* aOwner)
+    : mOwner(aOwner)
+  {
+    MOZ_ASSERT(mOwner);
+  }
+
+  void BeginObserving(Image* aImage)
+  {
+    MOZ_ASSERT(aImage);
+    mImage = aImage;
+
+    RefPtr<ProgressTracker> tracker = mImage->GetProgressTracker();
+    tracker->AddObserver(this);
+  }
+
+  void BlockUntilDecodedAndFinishObserving()
+  {
+    // Use GetFrame() to block until our image finishes decoding.
+    RefPtr<SourceSurface> surface =
+      mImage->GetFrame(imgIContainer::FRAME_CURRENT,
+                       imgIContainer::FLAG_SYNC_DECODE);
+
+    // GetFrame() should've sent synchronous notifications that would have
+    // caused us to call FinishObserving() (and null out mImage) already. If for
+    // some reason it didn't, we should do so here.
+    if (mImage) {
+      FinishObserving();
+    }
+  }
+
+  virtual void Notify(int32_t aType,
+                      const nsIntRect* aRect = nullptr) override
+  {
+    if (!mImage) {
+      // We've already finished observing the last image we were given.
+      return;
+    }
+
+    if (aType == imgINotificationObserver::FRAME_COMPLETE) {
+      FinishObserving();
+    }
+  }
+
+  virtual void OnLoadComplete(bool aLastPart) override
+  {
+    if (!mImage) {
+      // We've already finished observing the last image we were given.
+      return;
+    }
+
+    // Retrieve the image's intrinsic size.
+    int32_t width = 0;
+    int32_t height = 0;
+    mImage->GetWidth(&width);
+    mImage->GetHeight(&height);
+
+    // Request decoding at the intrinsic size.
+    mImage->RequestDecodeForSize(IntSize(width, height),
+                                 imgIContainer::DECODE_FLAGS_DEFAULT);
+
+    // If there's already an error, we may never get a FRAME_COMPLETE
+    // notification, so go ahead and notify our owner right away.
+    RefPtr<ProgressTracker> tracker = mImage->GetProgressTracker();
+    if (tracker->GetProgress() & FLAG_HAS_ERROR) {
+      FinishObserving();
+    }
+  }
+
+  // Other notifications are ignored.
+  virtual void BlockOnload() override { }
+  virtual void UnblockOnload() override { }
+  virtual void SetHasImage() override { }
+  virtual bool NotificationsDeferred() const override { return false; }
+  virtual void SetNotificationsDeferred(bool) override { }
+
+private:
+  virtual ~NextPartObserver() { }
+
+  void FinishObserving()
+  {
+    MOZ_ASSERT(mImage);
+
+    RefPtr<ProgressTracker> tracker = mImage->GetProgressTracker();
+    tracker->RemoveObserver(this);
+    mImage = nullptr;
+
+    mOwner->FinishTransition();
+  }
+
+  MultipartImage* mOwner;
+  RefPtr<Image> mImage;
+};
+
+
+///////////////////////////////////////////////////////////////////////////////
+// Implementation
+///////////////////////////////////////////////////////////////////////////////
+
+MultipartImage::MultipartImage(Image* aFirstPart)
+  : ImageWrapper(aFirstPart)
+  , mDeferNotifications(false)
+{
+  mNextPartObserver = new NextPartObserver(this);
+}
+
+void
+MultipartImage::Init()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mTracker, "Should've called SetProgressTracker() by now");
+
+  // Start observing the first part.
+  RefPtr<ProgressTracker> firstPartTracker =
+    InnerImage()->GetProgressTracker();
+  firstPartTracker->AddObserver(this);
+  InnerImage()->IncrementAnimationConsumers();
+}
+
+MultipartImage::~MultipartImage()
+{
+  // Ask our ProgressTracker to drop its weak reference to us.
+  mTracker->ResetImage();
+}
+
+NS_IMPL_ISUPPORTS_INHERITED0(MultipartImage, ImageWrapper)
+
+void
+MultipartImage::BeginTransitionToPart(Image* aNextPart)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aNextPart);
+
+  if (mNextPart) {
+    // Let the decoder catch up so we don't drop frames.
+    mNextPartObserver->BlockUntilDecodedAndFinishObserving();
+    MOZ_ASSERT(!mNextPart);
+  }
+
+  mNextPart = aNextPart;
+
+  // Start observing the next part; we'll complete the transition when
+  // NextPartObserver calls FinishTransition.
+  mNextPartObserver->BeginObserving(mNextPart);
+  mNextPart->IncrementAnimationConsumers();
+}
+
+static Progress
+FilterProgress(Progress aProgress)
+{
+  // Filter out onload blocking notifications, since we don't want to block
+  // onload for multipart images.
+  return aProgress & ~(FLAG_ONLOAD_BLOCKED | FLAG_ONLOAD_UNBLOCKED);
+}
+
+void
+MultipartImage::FinishTransition()
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mNextPart, "Should have a next part here");
+
+  RefPtr<ProgressTracker> newCurrentPartTracker =
+    mNextPart->GetProgressTracker();
+  if (newCurrentPartTracker->GetProgress() & FLAG_HAS_ERROR) {
+    // This frame has an error; drop it.
+    mNextPart = nullptr;
+
+    // We still need to notify, though.
+    mTracker->ResetForNewRequest();
+    RefPtr<ProgressTracker> currentPartTracker =
+      InnerImage()->GetProgressTracker();
+    mTracker
+      ->SyncNotifyProgress(FilterProgress(currentPartTracker->GetProgress()));
+
+    return;
+  }
+
+  // Stop observing the current part.
+  {
+    RefPtr<ProgressTracker> currentPartTracker =
+      InnerImage()->GetProgressTracker();
+    currentPartTracker->RemoveObserver(this);
+  }
+
+  // Make the next part become the current part.
+  mTracker->ResetForNewRequest();
+  SetInnerImage(mNextPart);
+  mNextPart = nullptr;
+  newCurrentPartTracker->AddObserver(this);
+
+  // Finally, send all the notifications for the new current part and send a
+  // FRAME_UPDATE notification so that observers know to redraw.
+  mTracker
+    ->SyncNotifyProgress(FilterProgress(newCurrentPartTracker->GetProgress()),
+                         GetMaxSizedIntRect());
+}
+
+already_AddRefed<imgIContainer>
+MultipartImage::Unwrap()
+{
+  // Although we wrap another image, we don't allow callers to unwrap as. As far
+  // as external code is concerned, MultipartImage is atomic.
+  nsCOMPtr<imgIContainer> image = this;
+  return image.forget();
+}
+
+already_AddRefed<ProgressTracker>
+MultipartImage::GetProgressTracker()
+{
+  MOZ_ASSERT(mTracker);
+  RefPtr<ProgressTracker> tracker = mTracker;
+  return tracker.forget();
+}
+
+void
+MultipartImage::SetProgressTracker(ProgressTracker* aTracker)
+{
+  MOZ_ASSERT(aTracker);
+  MOZ_ASSERT(!mTracker);
+  mTracker = aTracker;
+}
+
+nsresult
+MultipartImage::OnImageDataAvailable(nsIRequest* aRequest,
+                                     nsISupports* aContext,
+                                     nsIInputStream* aInStr,
+                                     uint64_t aSourceOffset,
+                                     uint32_t aCount)
+{
+  // Note that this method is special in that we forward it to the next part if
+  // one exists, and *not* the current part.
+
+  // We may trigger notifications that will free mNextPart, so keep it alive.
+  RefPtr<Image> nextPart = mNextPart;
+  if (nextPart) {
+    nextPart->OnImageDataAvailable(aRequest, aContext, aInStr,
+                                   aSourceOffset, aCount);
+  } else {
+    InnerImage()->OnImageDataAvailable(aRequest, aContext, aInStr,
+                                       aSourceOffset, aCount);
+  }
+
+  return NS_OK;
+}
+
+nsresult
+MultipartImage::OnImageDataComplete(nsIRequest* aRequest,
+                                    nsISupports* aContext,
+                                    nsresult aStatus,
+                                    bool aLastPart)
+{
+  // Note that this method is special in that we forward it to the next part if
+  // one exists, and *not* the current part.
+
+  // We may trigger notifications that will free mNextPart, so keep it alive.
+  RefPtr<Image> nextPart = mNextPart;
+  if (nextPart) {
+    nextPart->OnImageDataComplete(aRequest, aContext, aStatus, aLastPart);
+  } else {
+    InnerImage()->OnImageDataComplete(aRequest, aContext, aStatus, aLastPart);
+  }
+
+  return NS_OK;
+}
+
+void
+MultipartImage::Notify(int32_t aType, const nsIntRect* aRect /* = nullptr*/)
+{
+  if (aType == imgINotificationObserver::SIZE_AVAILABLE) {
+    mTracker->SyncNotifyProgress(FLAG_SIZE_AVAILABLE);
+  } else if (aType == imgINotificationObserver::FRAME_UPDATE) {
+    mTracker->SyncNotifyProgress(NoProgress, *aRect);
+  } else if (aType == imgINotificationObserver::FRAME_COMPLETE) {
+    mTracker->SyncNotifyProgress(FLAG_FRAME_COMPLETE);
+  } else if (aType == imgINotificationObserver::LOAD_COMPLETE) {
+    mTracker->SyncNotifyProgress(FLAG_LOAD_COMPLETE);
+  } else if (aType == imgINotificationObserver::DECODE_COMPLETE) {
+    mTracker->SyncNotifyProgress(FLAG_DECODE_COMPLETE);
+  } else if (aType == imgINotificationObserver::DISCARD) {
+    mTracker->OnDiscard();
+  } else if (aType == imgINotificationObserver::UNLOCKED_DRAW) {
+    mTracker->OnUnlockedDraw();
+  } else if (aType == imgINotificationObserver::IS_ANIMATED) {
+    mTracker->SyncNotifyProgress(FLAG_IS_ANIMATED);
+  } else if (aType == imgINotificationObserver::HAS_TRANSPARENCY) {
+    mTracker->SyncNotifyProgress(FLAG_HAS_TRANSPARENCY);
+  } else {
+    NS_NOTREACHED("Notification list should be exhaustive");
+  }
+}
+
+void
+MultipartImage::OnLoadComplete(bool aLastPart)
+{
+  Progress progress = FLAG_LOAD_COMPLETE;
+  if (aLastPart) {
+    progress |= FLAG_LAST_PART_COMPLETE;
+  }
+  mTracker->SyncNotifyProgress(progress);
+}
+
+void
+MultipartImage::SetHasImage()
+{
+  mTracker->OnImageAvailable();
+}
+
+bool
+MultipartImage::NotificationsDeferred() const
+{
+  return mDeferNotifications;
+}
+
+void
+MultipartImage::SetNotificationsDeferred(bool aDeferNotifications)
+{
+  mDeferNotifications = aDeferNotifications;
+}
+
+} // namespace image
+} // namespace mozilla