gecko-dev/image/IProgressObserver.h
Emilio Cobos Álvarez ff61891772 Bug 1653011 - Simplify and make WeakPtr<Derived> usable and compact. r=froydnj,sg,geckoview-reviewers,jgilbert,kvark,snorp
Having two classes in the inheritance chain inherit from SupportsWeakPtr
now won't compile, but you can use WeakPtr<Derived> when any base class
inherits from SupportsWeakPtr.

Differential Revision: https://phabricator.services.mozilla.com/D83674
2020-07-23 14:51:46 +00:00

58 lines
1.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; 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/. */
#ifndef mozilla_image_IProgressObserver_h
#define mozilla_image_IProgressObserver_h
#include "mozilla/WeakPtr.h"
#include "nsISupports.h"
#include "nsRect.h"
class nsIEventTarget;
namespace mozilla {
namespace image {
/**
* An interface for observing changes to image state, as reported by
* ProgressTracker.
*
* This is the ImageLib-internal version of imgINotificationObserver,
* essentially, with implementation details that code outside of ImageLib
* shouldn't see.
*
* XXX(seth): It's preferable to avoid adding anything to this interface if
* possible. In the long term, it would be ideal to get to a place where we can
* just use the imgINotificationObserver interface internally as well.
*/
class IProgressObserver : public SupportsWeakPtr {
public:
// Subclasses may or may not be XPCOM classes, so we just require that they
// implement AddRef and Release.
NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
// imgINotificationObserver methods:
virtual void Notify(int32_t aType, const nsIntRect* aRect = nullptr) = 0;
virtual void OnLoadComplete(bool aLastPart) = 0;
// Other, internal-only methods:
virtual void SetHasImage() = 0;
virtual bool NotificationsDeferred() const = 0;
virtual void MarkPendingNotify() = 0;
virtual void ClearPendingNotify() = 0;
virtual already_AddRefed<nsIEventTarget> GetEventTarget() const {
return nullptr;
}
protected:
virtual ~IProgressObserver() = default;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_IProgressObserver_h