70 lines
2.0 KiB
C++
70 lines
2.0 KiB
C++
/* -*- Mode: C++; tab-width: 8; 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/. */
|
|
|
|
/* table of images used in a document, for batch locking/unlocking and
|
|
* animating */
|
|
|
|
#ifndef mozilla_dom_ImageTracker
|
|
#define mozilla_dom_ImageTracker
|
|
|
|
#include "imgIRequest.h"
|
|
#include "nsDataHashtable.h"
|
|
#include "nsHashKeys.h"
|
|
|
|
class imgIRequest;
|
|
|
|
namespace mozilla {
|
|
namespace dom {
|
|
|
|
/*
|
|
* Image Tracking
|
|
*
|
|
* Style and content images register their imgIRequests with their document's
|
|
* image tracker, so that we can efficiently tell all descendant images when
|
|
* they are and are not visible. When an image is on-screen, we want to call
|
|
* LockImage() on it so that it doesn't do things like discarding frame data
|
|
* to save memory. The PresShell informs its document's image tracker whether
|
|
* its images should be locked or not via SetLockingState().
|
|
*
|
|
* See bug 512260.
|
|
*/
|
|
class ImageTracker
|
|
{
|
|
public:
|
|
ImageTracker();
|
|
ImageTracker(const ImageTracker&) = delete;
|
|
ImageTracker& operator=(const ImageTracker&) = delete;
|
|
|
|
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ImageTracker)
|
|
|
|
nsresult Add(imgIRequest* aImage);
|
|
|
|
enum { REQUEST_DISCARD = 0x1 };
|
|
nsresult Remove(imgIRequest* aImage, uint32_t aFlags = 0);
|
|
|
|
// Makes the images on this document locked/unlocked. By default, the locking
|
|
// state is unlocked/false.
|
|
nsresult SetLockingState(bool aLocked);
|
|
|
|
// Makes the images on this document capable of having their animation
|
|
// active or suspended. An Image will animate as long as at least one of its
|
|
// owning Documents needs it to animate; otherwise it can suspend.
|
|
void SetAnimatingState(bool aAnimating);
|
|
|
|
void RequestDiscardAll();
|
|
|
|
private:
|
|
~ImageTracker();
|
|
|
|
nsDataHashtable<nsPtrHashKey<imgIRequest>, uint32_t> mImages;
|
|
bool mLocking;
|
|
bool mAnimating;
|
|
};
|
|
|
|
} // namespace dom
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_dom_ImageTracker
|