gecko-dev/layout/style/ImageLoader.h

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5.8 KiB
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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 nsIFrame;
class nsIDocument;
class nsPresContext;
class nsIURI;
class nsIPrincipal;
namespace mozilla {
namespace css {
struct ImageValue;
class ImageLoader final : public imgINotificationObserver
{
public:
// 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_REQUESTED_REFLOW = 1u << 1,
REQUEST_HAS_BLOCKED_ONLOAD = 1u << 2
};
typedef mozilla::css::ImageValue Image;
explicit ImageLoader(nsIDocument* aDocument)
: mDocument(aDocument),
mInClone(false)
{
MOZ_ASSERT(mDocument);
}
NS_DECL_ISUPPORTS
NS_DECL_IMGINOTIFICATIONOBSERVER
void DropDocumentReference();
void MaybeRegisterCSSImage(Image* aImage);
void DeregisterCSSImage(Image* aImage);
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);
void LoadImage(nsIURI* aURI, nsIPrincipal* aPrincipal, nsIURI* aReferrer,
Image* aCSSValue, CORSMode aCorsMode);
void DestroyRequest(imgIRequest* aRequest);
void FlushUseCounters();
private:
// 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() {}
// 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 nsTHashtable<nsPtrHashKey<Image> > ImageHashSet;
typedef nsClassHashtable<nsISupportsHashKey,
FrameSet> RequestToFrameMap;
typedef nsClassHashtable<nsPtrHashKey<nsIFrame>,
RequestSet> FrameToRequestMap;
void AddImage(Image* aCSSImage);
void RemoveImage(Image* aCSSImage);
nsPresContext* GetPresContext();
void DoRedraw(FrameSet* aFrameSet, bool aForcePaint);
void UnblockOnloadIfNeeded(nsIFrame* aFrame, imgIRequest* aRequest);
void RequestReflowIfNeeded(FrameSet* aFrameSet, imgIRequest* aRequest);
void RequestReflowOnFrame(FrameWithFlags* aFwf, imgIRequest* aRequest);
nsresult OnSizeAvailable(imgIRequest* aRequest, imgIContainer* aImage);
nsresult OnFrameComplete(imgIRequest* aRequest);
nsresult OnImageIsAnimated(imgIRequest* aRequest);
nsresult OnFrameUpdate(imgIRequest* aRequest);
nsresult 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.
nsIDocument* mDocument;
// The set of all nsCSSValue::Images (whether they're associated a frame or
// not). We'll need this when we go away to remove any requests associated
// with our document from those Images.
ImageHashSet mImages;
// Are we cloning? If so, ignore any notifications we get.
bool mInClone;
};
} // namespace css
} // namespace mozilla
#endif /* mozilla_css_ImageLoader_h___ */