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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
/* table of images used in a document, for batch locking/unlocking and
* animating */
#include "ImageTracker.h"
#include "imgIContainer.h"
#include "imgIRequest.h"
#include "mozilla/Preferences.h"
#include "nsXULAppAPI.h"
namespace mozilla::dom {
ImageTracker::ImageTracker() = default;
ImageTracker::~ImageTracker() { SetLockingState(false); }
nsresult ImageTracker::Add(imgIRequest* aImage) {
MOZ_ASSERT(aImage);
const nsresult rv = mImages.WithEntryHandle(aImage, [&](auto&& entry) {
nsresult rv = NS_OK;
if (entry) {
// The image is already in the hashtable. Increment its count.
uint32_t oldCount = entry.Data();
MOZ_ASSERT(oldCount > 0, "Entry in the image tracker with count 0!");
entry.Data() = oldCount + 1;
} else {
// A new entry was inserted - set the count to 1.
entry.Insert(1);
// If we're locking images, lock this image too.
if (mLocking) {
rv = aImage->LockImage();
}
// If we're animating images, request that this image be animated too.
if (mAnimating) {
nsresult rv2 = aImage->IncrementAnimationConsumers();
rv = NS_SUCCEEDED(rv) ? rv2 : rv;
}
}
return rv;
});
return rv;
}
nsresult ImageTracker::Remove(imgIRequest* aImage, uint32_t aFlags) {
NS_ENSURE_ARG_POINTER(aImage);
// Get the old count. It should exist and be > 0.
if (auto entry = mImages.Lookup(aImage)) {
MOZ_ASSERT(entry.Data() > 0, "Entry in the image tracker with count 0!");
// If the count becomes zero, remove it from the tracker.
if (--entry.Data() == 0) {
entry.Remove();
} else {
return NS_OK;
}
} else {
MOZ_ASSERT_UNREACHABLE("Removing image that wasn't in the tracker!");
return NS_OK;
}
nsresult rv = NS_OK;
// Now that we're no longer tracking this image, unlock it if we'd
// previously locked it.
if (mLocking) {
rv = aImage->UnlockImage();
}
// If we're animating images, remove our request to animate this one.
if (mAnimating) {
nsresult rv2 = aImage->DecrementAnimationConsumers();
rv = NS_SUCCEEDED(rv) ? rv2 : rv;
}
if (aFlags & REQUEST_DISCARD) {
// Request that the image be discarded if nobody else holds a lock on it.
// Do this even if !mLocking, because even if we didn't just unlock
// this image, it might still be a candidate for discarding.
aImage->RequestDiscard();
}
return rv;
}
void ImageTracker::SetLockingState(bool aLocked) {
// If there's no change, there's nothing to do.
if (mLocking == aLocked) {
return;
}
// Otherwise, iterate over our images and perform the appropriate action.
for (imgIRequest* image : mImages.Keys()) {
if (aLocked) {
image->LockImage();
} else {
image->UnlockImage();
}
}
// Update state.
mLocking = aLocked;
}
void ImageTracker::SetAnimatingState(bool aAnimating) {
// If there's no change, there's nothing to do.
if (mAnimating == aAnimating) return;
// Otherwise, iterate over our images and perform the appropriate action.
for (imgIRequest* image : mImages.Keys()) {
if (aAnimating) {
image->IncrementAnimationConsumers();
} else {
image->DecrementAnimationConsumers();
}
}
// Update state.
mAnimating = aAnimating;
}
void ImageTracker::RequestDiscardAll() {
for (imgIRequest* image : mImages.Keys()) {
image->RequestDiscard();
}
}
void ImageTracker::MediaFeatureValuesChangedAllDocuments(
const MediaFeatureChange& aChange) {
// Inform every content image used in the document that media feature values
// have changed. If the same image is used in multiple places, then we can
// end up informing them multiple times. Theme changes are rare though and we
// don't bother trying to ensure we only do this once per image.
//
// Pull the images out into an array and iterate over them, in case the
// image notifications do something that ends up modifying the table.
nsTArray<nsCOMPtr<imgIContainer>> images;
for (imgIRequest* req : mImages.Keys()) {
nsCOMPtr<imgIContainer> image;
req->GetImage(getter_AddRefs(image));
if (!image) {
continue;
}
images.AppendElement(image->Unwrap());
}
for (imgIContainer* image : images) {
image->MediaFeatureValuesChangedAllDocuments(aChange);
}
}
} // namespace mozilla::dom