image/IProgressObserver.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef mozilla_image_IProgressObserver_h
   7 #define mozilla_image_IProgressObserver_h
   8
   9 #include "mozilla/WeakPtr.h"
  10 #include "nsISupports.h"
  11 #include "nsRect.h"
  12
  13 namespace mozilla {
  14 namespace image {
  15
  16 /**
  17  * An interface for observing changes to image state, as reported by
  18  * ProgressTracker.
  19  *
  20  * This is the ImageLib-internal version of imgINotificationObserver,
  21  * essentially, with implementation details that code outside of ImageLib
  22  * shouldn't see.
  23  *
  24  * XXX(seth): It's preferable to avoid adding anything to this interface if
  25  * possible.  In the long term, it would be ideal to get to a place where we can
  26  * just use the imgINotificationObserver interface internally as well.
  27  */
  28 class IProgressObserver : public SupportsWeakPtr {
  29  public:
  30   // Subclasses may or may not be XPCOM classes, so we just require that they
  31   // implement AddRef and Release.
  32   NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
  33
  34   // imgINotificationObserver methods:
  35   virtual void Notify(int32_t aType, const nsIntRect* aRect = nullptr) = 0;
  36   virtual void OnLoadComplete(bool aLastPart) = 0;
  37
  38   // Other, internal-only methods:
  39   virtual void SetHasImage() = 0;
  40   virtual bool NotificationsDeferred() const = 0;
  41   virtual void MarkPendingNotify() = 0;
  42   virtual void ClearPendingNotify() = 0;
  43
  44  protected:
  45   virtual ~IProgressObserver() = default;
  46 };
  47
  48 }  // namespace image
  49 }  // namespace mozilla
  50
  51 #endif  // mozilla_image_IProgressObserver_h