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// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/tab_contents/web_contents_collection.h"
#include "base/check.h"
#include "base/memory/raw_ptr.h"
#include "content/public/browser/web_contents_observer.h"
class WebContentsCollection::ForwardingWebContentsObserver
: public content::WebContentsObserver {
public:
ForwardingWebContentsObserver(content::WebContents* web_contents,
WebContentsCollection::Observer* observer,
WebContentsCollection* collection)
: content::WebContentsObserver(web_contents),
observer_(observer),
collection_(collection) {}
private:
// WebContentsObserver:
void WebContentsDestroyed() override {
// Deletes `this`. Do no add any code after this line.
collection_->WebContentsDestroyed(web_contents());
}
void PrimaryMainFrameRenderProcessGone(
base::TerminationStatus status) override {
observer_->RenderProcessGone(web_contents(), status);
}
void DidFinishNavigation(
content::NavigationHandle* navigation_handle) override {
observer_->DidFinishNavigation(web_contents(), navigation_handle);
}
void DidStartLoading() override {
observer_->DidStartLoading(web_contents());
}
// The observer that callbacks should forward to, annotating the
// web contents they were fired in.
raw_ptr<WebContentsCollection::Observer> observer_;
// The collection this observer belongs to, needed to cleanup observer
// lifetime.
raw_ptr<WebContentsCollection> collection_;
};
WebContentsCollection::WebContentsCollection(
WebContentsCollection::Observer* observer)
: observer_(observer) {}
WebContentsCollection::~WebContentsCollection() = default;
void WebContentsCollection::StartObserving(content::WebContents* web_contents) {
if (web_contents_observers_.find(web_contents) !=
web_contents_observers_.end())
return;
auto emplace_result = web_contents_observers_.emplace(
web_contents, std::make_unique<ForwardingWebContentsObserver>(
web_contents, observer_, this));
DCHECK(emplace_result.second);
}
void WebContentsCollection::StopObserving(content::WebContents* web_contents) {
web_contents_observers_.erase(web_contents);
}
void WebContentsCollection::WebContentsDestroyed(
content::WebContents* web_contents) {
web_contents_observers_.erase(web_contents);
// We invoke the observer callback here rather than in
// `ForwardingWebContentsObserver` to ensure that calling `RemoveObserver()`
// during `WebContentsCollection::Observer::WebContentsDestroyed()` does not
// cause a heap-use-after-free.
observer_->WebContentsDestroyed(web_contents);
}
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