gecko-dev/dom/base/ResizeObserverController.h
Simon Giesecke 1e6ec7ec86 Bug 1656117 - Reduce include dependencies on nsRefreshDriver.h. r=mstange
The abstract observer base classes are moved to a separate header file
nsRefreshObservers.h and the includes are adjusted accordingly.

Some method implementations are moved to the corresponding implementation files
to avoid the need to include the nsRefreshDriver.h file in the header.

Differential Revision: https://phabricator.services.mozilla.com/D85764
2020-08-04 21:17:50 +00:00

143 lines
4.0 KiB
C++

/* -*- 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/. */
#ifndef mozilla_dom_ResizeObserverController_h
#define mozilla_dom_ResizeObserverController_h
#include "mozilla/dom/ResizeObserver.h"
#include "mozilla/TimeStamp.h"
#include "nsRefreshObservers.h"
#include "nsTObserverArray.h"
class nsRefreshDriver;
namespace mozilla {
class PresShell;
namespace dom {
class Document;
class ResizeObserverController;
/**
* ResizeObserverNotificationHelper will trigger ResizeObserver notifications
* by registering with the Refresh Driver.
*/
class ResizeObserverNotificationHelper final : public nsARefreshObserver {
public:
NS_INLINE_DECL_REFCOUNTING(ResizeObserverNotificationHelper, override)
explicit ResizeObserverNotificationHelper(ResizeObserverController* aOwner)
: mOwner(aOwner), mRegistered(false) {
MOZ_ASSERT(mOwner, "Need a non-null owner");
}
MOZ_CAN_RUN_SCRIPT void WillRefresh(TimeStamp aTime) override;
nsRefreshDriver* GetRefreshDriver() const;
void Register();
void Unregister();
bool IsRegistered() const { return mRegistered; }
void DetachFromOwner() { mOwner = nullptr; }
private:
virtual ~ResizeObserverNotificationHelper();
ResizeObserverController* mOwner;
bool mRegistered;
};
/**
* ResizeObserverController contains the list of ResizeObservers and controls
* the flow of notification.
*/
class ResizeObserverController final {
public:
explicit ResizeObserverController(Document* aDocument)
: mDocument(aDocument),
mResizeObserverNotificationHelper(
new ResizeObserverNotificationHelper(this)) {
MOZ_ASSERT(mDocument, "Need a non-null document");
}
// Methods for supporting cycle-collection
void Traverse(nsCycleCollectionTraversalCallback& aCb);
void Unlink();
void AddSizeOfIncludingThis(nsWindowSizes&) const;
void ShellDetachedFromDocument();
void AddResizeObserver(ResizeObserver& aObserver) {
MOZ_ASSERT(!mResizeObservers.Contains(&aObserver));
mResizeObservers.AppendElement(&aObserver);
}
void RemoveResizeObserver(ResizeObserver& aObserver) {
MOZ_ASSERT(mResizeObservers.Contains(&aObserver));
mResizeObservers.RemoveElement(&aObserver);
}
/**
* Schedule the notification via ResizeObserverNotificationHelper refresh
* observer.
*/
void ScheduleNotification();
/**
* Notify all ResizeObservers by gathering and broadcasting all active
* observations.
*/
MOZ_CAN_RUN_SCRIPT void Notify();
PresShell* GetPresShell() const { return mDocument->GetPresShell(); }
~ResizeObserverController();
private:
/**
* Calls GatherActiveObservations(aDepth) for all ResizeObservers in this
* controller. All observations in each ResizeObserver with element's depth
* more than aDepth will be gathered.
*/
void GatherAllActiveObservations(uint32_t aDepth);
/**
* Calls BroadcastActiveObservations() for all ResizeObservers in this
* controller. It also returns the shallowest depth of observed target
* elements with active observations from all ResizeObservers or
* numeric_limits<uint32_t>::max() if there aren't any active observations
* at all.
*/
MOZ_CAN_RUN_SCRIPT uint32_t BroadcastAllActiveObservations();
/**
* Returns whether there is any ResizeObserver that has active observations.
*/
bool HasAnyActiveObservations() const;
/**
* Returns whether there is any ResizeObserver that has skipped observations.
*/
bool HasAnySkippedObservations() const;
// Raw pointer is OK because mDocument strongly owns us & hence must outlive
// us.
Document* const mDocument;
RefPtr<ResizeObserverNotificationHelper> mResizeObserverNotificationHelper;
nsTArray<RefPtr<ResizeObserver>> mResizeObservers;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_ResizeObserverController_h