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/* -*- 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/. */
// A class that handles style system image loads (other image loads are handled
// by the nodes in the content tree).
#ifndef mozilla_css_ImageLoader_h___
#define mozilla_css_ImageLoader_h___
#include "mozilla/CORSMode.h"
#include "nsClassHashtable.h"
#include "nsHashKeys.h"
#include "nsIFrame.h"
#include "nsIReflowCallback.h"
#include "nsTArray.h"
#include "imgIRequest.h"
#include "imgINotificationObserver.h"
#include "mozilla/Attributes.h"
class imgIContainer;
class nsPresContext;
class nsIURI;
class nsIPrincipal;
namespace mozilla {
struct MediaFeatureChange;
namespace dom {
class Document;
}
namespace css {
/**
* NOTE: All methods must be called from the main thread unless otherwise
* specified.
*/
class ImageLoader final {
public:
static void Init();
static void Shutdown();
// We also associate flags alongside frames in the request-to-frames hashmap.
// These are used for special handling of events for requests.
typedef uint32_t FrameFlags;
enum {
REQUEST_REQUIRES_REFLOW = 1u << 0,
REQUEST_HAS_BLOCKED_ONLOAD = 1u << 1,
};
explicit ImageLoader(dom::Document* aDocument) : mDocument(aDocument) {
MOZ_ASSERT(mDocument);
}
NS_INLINE_DECL_REFCOUNTING(ImageLoader)
void DropDocumentReference();
void AssociateRequestToFrame(imgIRequest* aRequest, nsIFrame* aFrame,
FrameFlags aFlags);
void DisassociateRequestFromFrame(imgIRequest* aRequest, nsIFrame* aFrame);
void DropRequestsForFrame(nsIFrame* aFrame);
void SetAnimationMode(uint16_t aMode);
// The prescontext for this ImageLoader's document. We need it to be passed
// in because this can be called during presentation destruction after the
// presshell pointer on the document has been cleared.
void ClearFrames(nsPresContext* aPresContext);
// Triggers an image load.
static already_AddRefed<imgRequestProxy> LoadImage(
const StyleComputedImageUrl&, dom::Document&);
// Usually, only one style value owns a given proxy. However, we have a hack
// to share image proxies in chrome documents under some circumstances. We
// need to keep track of this so that we don't stop tracking images too early.
//
// In practice it shouldn't matter as these chrome images are mostly static,
// but it is always good to keep sanity.
static void NoteSharedLoad(imgRequestProxy*);
// Undoes what `LoadImage` does.
static void UnloadImage(imgRequestProxy*);
// This is called whenever an image we care about notifies the
// GlobalImageObserver.
void Notify(imgIRequest*, int32_t aType, const nsIntRect* aData);
private:
// Called when we stop caring about a given request.
void DeregisterImageRequest(imgIRequest*, nsPresContext*);
// This callback is used to unblock document onload after a reflow
// triggered from an image load.
struct ImageReflowCallback final : public nsIReflowCallback {
RefPtr<ImageLoader> mLoader;
WeakFrame mFrame;
nsCOMPtr<imgIRequest> const mRequest;
ImageReflowCallback(ImageLoader* aLoader, nsIFrame* aFrame,
imgIRequest* aRequest)
: mLoader(aLoader), mFrame(aFrame), mRequest(aRequest) {}
bool ReflowFinished() override;
void ReflowCallbackCanceled() override;
};
~ImageLoader() = default;
// We need to be able to look up the frames associated with a request (for
// delivering notifications) and the requests associated with a frame (when
// the frame goes away). Thus we maintain hashtables going both ways. These
// should always be in sync.
struct FrameWithFlags {
explicit FrameWithFlags(nsIFrame* aFrame) : mFrame(aFrame), mFlags(0) {
MOZ_ASSERT(mFrame);
}
nsIFrame* const mFrame;
FrameFlags mFlags;
};
// A helper class to compare FrameWithFlags by comparing mFrame and
// ignoring mFlags.
class FrameOnlyComparator {
public:
bool Equals(const FrameWithFlags& aElem1,
const FrameWithFlags& aElem2) const {
return aElem1.mFrame == aElem2.mFrame;
}
bool LessThan(const FrameWithFlags& aElem1,
const FrameWithFlags& aElem2) const {
return aElem1.mFrame < aElem2.mFrame;
}
};
typedef nsTArray<FrameWithFlags> FrameSet;
typedef nsTArray<nsCOMPtr<imgIRequest>> RequestSet;
typedef nsClassHashtable<nsISupportsHashKey, FrameSet> RequestToFrameMap;
typedef nsClassHashtable<nsPtrHashKey<nsIFrame>, RequestSet>
FrameToRequestMap;
nsPresContext* GetPresContext();
void RequestPaintIfNeeded(FrameSet* aFrameSet, imgIRequest* aRequest,
bool aForcePaint);
void UnblockOnloadIfNeeded(nsIFrame* aFrame, imgIRequest* aRequest);
void RequestReflowIfNeeded(FrameSet* aFrameSet, imgIRequest* aRequest);
void RequestReflowOnFrame(FrameWithFlags* aFwf, imgIRequest* aRequest);
void OnSizeAvailable(imgIRequest* aRequest, imgIContainer* aImage);
void OnFrameComplete(imgIRequest* aRequest);
void OnImageIsAnimated(imgIRequest* aRequest);
void OnFrameUpdate(imgIRequest* aRequest);
void OnLoadComplete(imgIRequest* aRequest);
// Helpers for DropRequestsForFrame / DisassociateRequestFromFrame above.
void RemoveRequestToFrameMapping(imgIRequest* aRequest, nsIFrame* aFrame);
void RemoveFrameToRequestMapping(imgIRequest* aRequest, nsIFrame* aFrame);
// A map of imgIRequests to the nsIFrames that are using them.
RequestToFrameMap mRequestToFrameMap;
// A map of nsIFrames to the imgIRequests they use.
FrameToRequestMap mFrameToRequestMap;
// A weak pointer to our document. Nulled out by DropDocumentReference.
dom::Document* mDocument;
};
} // namespace css
} // namespace mozilla
#endif /* mozilla_css_ImageLoader_h___ */
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