dom/media/webvtt/WebVTTListener.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_dom_WebVTTLoadListener_h
   7 #define mozilla_dom_WebVTTLoadListener_h
   8
   9 #include "nsIWebVTTListener.h"
  10 #include "nsIStreamListener.h"
  11 #include "nsIChannelEventSink.h"
  12 #include "nsIInterfaceRequestor.h"
  13 #include "nsCOMPtr.h"
  14 #include "nsCycleCollectionParticipant.h"
  15
  16 class nsIWebVTTParserWrapper;
  17
  18 namespace mozilla::dom {
  19
  20 class HTMLTrackElement;
  21
  22 class WebVTTListener final : public nsIWebVTTListener,
  23                              public nsIStreamListener,
  24                              public nsIChannelEventSink,
  25                              public nsIInterfaceRequestor {
  26   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  27   NS_DECL_NSIWEBVTTLISTENER
  28   NS_DECL_NSIREQUESTOBSERVER
  29   NS_DECL_NSISTREAMLISTENER
  30   NS_DECL_NSICHANNELEVENTSINK
  31   NS_DECL_NSIINTERFACEREQUESTOR
  32
  33   NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(WebVTTListener, nsIStreamListener)
  34
  35  public:
  36   explicit WebVTTListener(HTMLTrackElement* aElement);
  37
  38   /**
  39    * Loads the WebVTTListener. Must call this in order for the listener to be
  40    * ready to parse data that is passed to it.
  41    */
  42   nsresult LoadResource();
  43
  44   /**
  45    * When this listener is not going to be used anymore, its owner should take
  46    * a responsibility to call `Cancel()` to prevent this listener making any
  47    * changes for the track element.
  48    */
  49   bool IsCanceled() const;
  50   void Cancel();
  51
  52  private:
  53   ~WebVTTListener();
  54
  55   // List of error codes returned from the WebVTT parser that we care about.
  56   enum ErrorCodes { BadSignature = 0 };
  57   static nsresult ParseChunk(nsIInputStream* aInStream, void* aClosure,
  58                              const char* aFromSegment, uint32_t aToOffset,
  59                              uint32_t aCount, uint32_t* aWriteCount);
  60
  61   RefPtr<HTMLTrackElement> mElement;
  62   nsCOMPtr<nsIWebVTTParserWrapper> mParserWrapper;
  63   nsresult mParserWrapperError;
  64   bool mCancel = false;
  65 };
  66
  67 }  // namespace mozilla::dom
  68
  69 #endif  // mozilla_dom_WebVTTListener_h