gecko/content/media/WebVTTLoadListener.h

90 lines
3.0 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_dom_WebVTTLoadListener_h
#define mozilla_dom_WebVTTLoadListener_h
#include "nsIStreamListener.h"
#include "nsIChannelEventSink.h"
#include "nsIInterfaceRequestor.h"
#include "nsIObserver.h"
#include "nsAutoPtr.h"
#include "nsAutoRef.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/dom/HTMLTrackElement.h"
struct webvtt_parser_t;
struct webvtt_cue;
typedef int webvtt_error;
template <>
class nsAutoRefTraits<webvtt_parser_t> : public nsPointerRefTraits<webvtt_parser_t>
{
public:
static void Release(webvtt_parser_t* aParser) {
// Call parser dtor here.
}
};
namespace mozilla {
namespace dom {
/**
* Class that manages the libwebvtt parsing library and functions as an
* interface between Gecko and libwebvtt.
*
* Currently it's only designed to work with an HTMLTrackElement. The
* HTMLTrackElement controls the lifetime of the WebVTTLoadListener.
*
* The workflow of this class is as follows:
* - Gets Loaded via an HTMLTrackElement class.
* - As the HTMLTrackElement class gets new data WebVTTLoadListener's
* OnDataAvailable() function is called and data is passed to the libwebvtt
* parser.
* - When the libwebvtt parser has finished a cue it will call the callbacks
* that are exposed by the WebVTTLoadListener -- OnParsedCueWebVTTCallBack or
* OnReportErrorWebVTTCallBack if it has encountered an error.
* - When it has returned a cue successfully the WebVTTLoadListener will create
* a new TextTrackCue and add it to the HTMLTrackElement's TextTrack.
*/
class WebVTTLoadListener MOZ_FINAL : public nsIStreamListener,
public nsIChannelEventSink,
public nsIInterfaceRequestor
{
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_NSIREQUESTOBSERVER
NS_DECL_NSISTREAMLISTENER
NS_DECL_NSICHANNELEVENTSINK
NS_DECL_NSIINTERFACEREQUESTOR
NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(WebVTTLoadListener,
nsIStreamListener)
public:
WebVTTLoadListener(HTMLTrackElement* aElement);
~WebVTTLoadListener();
// Loads the libwebvtt parser. Must call this function in order to the
// WebVTTLoadListener to be ready to accept data.
nsresult LoadResource();
private:
static NS_METHOD ParseChunk(nsIInputStream* aInStream, void* aClosure,
const char* aFromSegment, uint32_t aToOffset,
uint32_t aCount, uint32_t* aWriteCount);
nsRefPtr<HTMLTrackElement> mElement;
nsAutoRef<webvtt_parser_t> mParser;
void OnParsedCue(webvtt_cue* aCue);
int OnReportError(uint32_t aLine, uint32_t aCol, webvtt_error aError);
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_WebVTTLoadListener_h