gecko-dev/dom/media/TextTrackList.cpp

/* -*- 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/. */

#include "mozilla/dom/TextTrackList.h"

#include "mozilla/DebugOnly.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/TextTrackListBinding.h"
#include "mozilla/dom/TrackEvent.h"
#include "nsThreadUtils.h"
#include "nsGlobalWindow.h"
#include "mozilla/dom/TextTrackCue.h"
#include "mozilla/dom/TextTrackManager.h"

namespace mozilla {
namespace dom {

NS_IMPL_CYCLE_COLLECTION_INHERITED(TextTrackList, DOMEventTargetHelper,
                                   mTextTracks, mTextTrackManager)

NS_IMPL_ADDREF_INHERITED(TextTrackList, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(TextTrackList, DOMEventTargetHelper)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextTrackList)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

TextTrackList::TextTrackList(nsPIDOMWindowInner* aOwnerWindow)
    : DOMEventTargetHelper(aOwnerWindow) {}

TextTrackList::TextTrackList(nsPIDOMWindowInner* aOwnerWindow,
                             TextTrackManager* aTextTrackManager)
    : DOMEventTargetHelper(aOwnerWindow),
      mTextTrackManager(aTextTrackManager) {}

TextTrackList::~TextTrackList() = default;

void TextTrackList::GetShowingCues(nsTArray<RefPtr<TextTrackCue>>& aCues) {
  // Only Subtitles and Captions can show on the screen.
  nsTArray<RefPtr<TextTrackCue>> cues;
  for (uint32_t i = 0; i < Length(); i++) {
    if (mTextTracks[i]->Mode() == TextTrackMode::Showing &&
        (mTextTracks[i]->Kind() == TextTrackKind::Subtitles ||
         mTextTracks[i]->Kind() == TextTrackKind::Captions)) {
      mTextTracks[i]->GetActiveCueArray(cues);
      aCues.AppendElements(cues);
    }
  }
}

JSObject* TextTrackList::WrapObject(JSContext* aCx,
                                    JS::Handle<JSObject*> aGivenProto) {
  return TextTrackList_Binding::Wrap(aCx, this, aGivenProto);
}

TextTrack* TextTrackList::IndexedGetter(uint32_t aIndex, bool& aFound) {
  aFound = aIndex < mTextTracks.Length();
  if (!aFound) {
    return nullptr;
  }
  return mTextTracks[aIndex];
}

TextTrack* TextTrackList::operator[](uint32_t aIndex) {
  return mTextTracks.SafeElementAt(aIndex, nullptr);
}

already_AddRefed<TextTrack> TextTrackList::AddTextTrack(
    TextTrackKind aKind, const nsAString& aLabel, const nsAString& aLanguage,
    TextTrackMode aMode, TextTrackReadyState aReadyState,
    TextTrackSource aTextTrackSource, const CompareTextTracks& aCompareTT) {
  RefPtr<TextTrack> track =
      new TextTrack(GetOwner(), this, aKind, aLabel, aLanguage, aMode,
                    aReadyState, aTextTrackSource);
  AddTextTrack(track, aCompareTT);
  return track.forget();
}

void TextTrackList::AddTextTrack(TextTrack* aTextTrack,
                                 const CompareTextTracks& aCompareTT) {
  if (mTextTracks.Contains(aTextTrack)) {
    return;
  }
  if (mTextTracks.InsertElementSorted(aTextTrack, aCompareTT)) {
    aTextTrack->SetTextTrackList(this);
    CreateAndDispatchTrackEventRunner(aTextTrack,
                                      NS_LITERAL_STRING("addtrack"));
  }
}

TextTrack* TextTrackList::GetTrackById(const nsAString& aId) {
  nsAutoString id;
  for (uint32_t i = 0; i < Length(); i++) {
    mTextTracks[i]->GetId(id);
    if (aId.Equals(id)) {
      return mTextTracks[i];
    }
  }
  return nullptr;
}

void TextTrackList::RemoveTextTrack(TextTrack* aTrack) {
  if (mTextTracks.RemoveElement(aTrack)) {
    CreateAndDispatchTrackEventRunner(aTrack, NS_LITERAL_STRING("removetrack"));
  }
}

class TrackEventRunner : public Runnable {
 public:
  TrackEventRunner(TextTrackList* aList, Event* aEvent)
      : Runnable("dom::TrackEventRunner"), mList(aList), mEvent(aEvent) {}

  NS_IMETHOD Run() override { return mList->DispatchTrackEvent(mEvent); }

  RefPtr<TextTrackList> mList;

 private:
  RefPtr<Event> mEvent;
};

nsresult TextTrackList::DispatchTrackEvent(Event* aEvent) {
  return DispatchTrustedEvent(aEvent);
}

void TextTrackList::CreateAndDispatchChangeEvent() {
  MOZ_ASSERT(NS_IsMainThread());
  nsPIDOMWindowInner* win = GetOwner();
  if (!win) {
    return;
  }

  RefPtr<Event> event = NS_NewDOMEvent(this, nullptr, nullptr);

  event->InitEvent(NS_LITERAL_STRING("change"), false, false);
  event->SetTrusted(true);

  nsCOMPtr<nsIRunnable> eventRunner = new TrackEventRunner(this, event);
  nsGlobalWindowInner::Cast(win)->Dispatch(TaskCategory::Other,
                                           eventRunner.forget());
}

void TextTrackList::CreateAndDispatchTrackEventRunner(
    TextTrack* aTrack, const nsAString& aEventName) {
  DebugOnly<nsresult> rv;
  nsCOMPtr<nsIEventTarget> target = GetMainThreadEventTarget();
  if (!target) {
    // If we are not able to get the main-thread object we are shutting down.
    return;
  }

  TrackEventInit eventInit;
  eventInit.mTrack.SetValue().SetAsTextTrack() = aTrack;
  RefPtr<TrackEvent> event =
      TrackEvent::Constructor(this, aEventName, eventInit);

  // Dispatch the TrackEvent asynchronously.
  rv = target->Dispatch(do_AddRef(new TrackEventRunner(this, event)),
                        NS_DISPATCH_NORMAL);

  // If we are shutting down this can file but it's still ok.
  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "Dispatch failed");
}

HTMLMediaElement* TextTrackList::GetMediaElement() {
  if (mTextTrackManager) {
    return mTextTrackManager->mMediaElement;
  }
  return nullptr;
}

void TextTrackList::SetTextTrackManager(TextTrackManager* aTextTrackManager) {
  mTextTrackManager = aTextTrackManager;
}

void TextTrackList::SetCuesInactive() {
  for (uint32_t i = 0; i < Length(); i++) {
    mTextTracks[i]->SetCuesInactive();
  }
}

bool TextTrackList::AreTextTracksLoaded() {
  // Return false if any texttrack is not loaded.
  for (uint32_t i = 0; i < Length(); i++) {
    if (!mTextTracks[i]->IsLoaded()) {
      return false;
    }
  }
  return true;
}

nsTArray<RefPtr<TextTrack>>& TextTrackList::GetTextTrackArray() {
  return mTextTracks;
}

}  // namespace dom
}  // namespace mozilla