gecko-dev/dom/media/TextTrackCue.cpp

259 строки
7.8 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/. */
#include "mozilla/dom/HTMLTrackElement.h"
#include "mozilla/dom/TextTrackCue.h"
#include "mozilla/dom/TextTrackList.h"
#include "mozilla/dom/TextTrackRegion.h"
#include "nsComponentManagerUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "unicode/ubidi.h"
extern mozilla::LazyLogModule gTextTrackLog;
#define LOG(msg, ...) \
MOZ_LOG(gTextTrackLog, LogLevel::Debug, \
("TextTrackCue=%p, " msg, this, ##__VA_ARGS__))
namespace mozilla {
namespace dom {
NS_IMPL_CYCLE_COLLECTION_INHERITED(TextTrackCue, DOMEventTargetHelper,
mDocument, mTrack, mTrackElement,
mDisplayState, mRegion)
NS_IMPL_ADDREF_INHERITED(TextTrackCue, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(TextTrackCue, DOMEventTargetHelper)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(TextTrackCue)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
StaticRefPtr<nsIWebVTTParserWrapper> TextTrackCue::sParserWrapper;
// Set default value for cue, spec https://w3c.github.io/webvtt/#model-cues
void TextTrackCue::SetDefaultCueSettings() {
mPositionIsAutoKeyword = true;
// Spec https://www.w3.org/TR/webvtt1/#webvtt-cue-position-automatic-alignment
mPositionAlign = PositionAlignSetting::Auto;
mSize = 100.0;
mPauseOnExit = false;
mSnapToLines = true;
mLineIsAutoKeyword = true;
mAlign = AlignSetting::Center;
mLineAlign = LineAlignSetting::Start;
mVertical = DirectionSetting::_empty;
mActive = false;
}
TextTrackCue::TextTrackCue(nsPIDOMWindowInner* aOwnerWindow, double aStartTime,
double aEndTime, const nsAString& aText,
ErrorResult& aRv)
: DOMEventTargetHelper(aOwnerWindow),
mText(aText),
mStartTime(aStartTime),
mEndTime(aEndTime),
mPosition(0.0),
mLine(0.0),
mReset(false, "TextTrackCue::mReset"),
mHaveStartedWatcher(false),
mWatchManager(
this, GetOwnerGlobal()->AbstractMainThreadFor(TaskCategory::Other)) {
LOG("create TextTrackCue");
SetDefaultCueSettings();
MOZ_ASSERT(aOwnerWindow);
if (NS_FAILED(StashDocument())) {
aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
}
}
TextTrackCue::TextTrackCue(nsPIDOMWindowInner* aOwnerWindow, double aStartTime,
double aEndTime, const nsAString& aText,
HTMLTrackElement* aTrackElement, ErrorResult& aRv)
: DOMEventTargetHelper(aOwnerWindow),
mText(aText),
mStartTime(aStartTime),
mEndTime(aEndTime),
mTrackElement(aTrackElement),
mPosition(0.0),
mLine(0.0),
mReset(false, "TextTrackCue::mReset"),
mHaveStartedWatcher(false),
mWatchManager(
this, GetOwnerGlobal()->AbstractMainThreadFor(TaskCategory::Other)) {
LOG("create TextTrackCue");
SetDefaultCueSettings();
MOZ_ASSERT(aOwnerWindow);
if (NS_FAILED(StashDocument())) {
aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
}
}
TextTrackCue::~TextTrackCue() {}
/** Save a reference to our creating document so we don't have to
* keep getting it from our window.
*/
nsresult TextTrackCue::StashDocument() {
nsPIDOMWindowInner* window = GetOwner();
if (!window) {
return NS_ERROR_NO_INTERFACE;
}
mDocument = window->GetDoc();
if (!mDocument) {
return NS_ERROR_NOT_AVAILABLE;
}
return NS_OK;
}
already_AddRefed<DocumentFragment> TextTrackCue::GetCueAsHTML() {
// mDocument may be null during cycle collector shutdown.
// See bug 941701.
if (!mDocument) {
return nullptr;
}
if (!sParserWrapper) {
nsresult rv;
nsCOMPtr<nsIWebVTTParserWrapper> parserWrapper =
do_CreateInstance(NS_WEBVTTPARSERWRAPPER_CONTRACTID, &rv);
if (NS_FAILED(rv)) {
return mDocument->CreateDocumentFragment();
}
sParserWrapper = parserWrapper;
ClearOnShutdown(&sParserWrapper);
}
nsPIDOMWindowInner* window = mDocument->GetInnerWindow();
if (!window) {
return mDocument->CreateDocumentFragment();
}
RefPtr<DocumentFragment> frag;
sParserWrapper->ConvertCueToDOMTree(window, this, getter_AddRefs(frag));
if (!frag) {
return mDocument->CreateDocumentFragment();
}
return frag.forget();
}
void TextTrackCue::SetTrackElement(HTMLTrackElement* aTrackElement) {
mTrackElement = aTrackElement;
}
JSObject* TextTrackCue::WrapObject(JSContext* aCx,
JS::Handle<JSObject*> aGivenProto) {
return VTTCue_Binding::Wrap(aCx, this, aGivenProto);
}
TextTrackRegion* TextTrackCue::GetRegion() { return mRegion; }
void TextTrackCue::SetRegion(TextTrackRegion* aRegion) {
if (mRegion == aRegion) {
return;
}
mRegion = aRegion;
mReset = true;
}
double TextTrackCue::ComputedLine() {
// See spec https://w3c.github.io/webvtt/#cue-computed-line
if (!mLineIsAutoKeyword && !mSnapToLines && (mLine < 0.0 || mLine > 100.0)) {
return 100.0;
} else if (!mLineIsAutoKeyword) {
return mLine;
} else if (mLineIsAutoKeyword && !mSnapToLines) {
return 100.0;
} else if (!mTrack || !mTrack->GetTextTrackList() ||
!mTrack->GetTextTrackList()->GetMediaElement()) {
return -1.0;
}
RefPtr<TextTrackList> trackList = mTrack->GetTextTrackList();
bool dummy;
uint32_t showingTracksNum = 0;
for (uint32_t idx = 0; idx < trackList->Length(); idx++) {
RefPtr<TextTrack> track = trackList->IndexedGetter(idx, dummy);
if (track->Mode() == TextTrackMode::Showing) {
showingTracksNum++;
}
if (mTrack == track) {
break;
}
}
return (-1.0) * showingTracksNum;
}
double TextTrackCue::ComputedPosition() {
// See spec https://w3c.github.io/webvtt/#cue-computed-position
if (!mPositionIsAutoKeyword) {
return mPosition;
}
if (ComputedPositionAlign() == PositionAlignSetting::Line_left) {
return 0.0;
}
if (ComputedPositionAlign() == PositionAlignSetting::Line_right) {
return 100.0;
}
return 50.0;
}
PositionAlignSetting TextTrackCue::ComputedPositionAlign() {
// See spec https://w3c.github.io/webvtt/#cue-computed-position-alignment
if (mPositionAlign != PositionAlignSetting::Auto) {
return mPositionAlign;
} else if (mAlign == AlignSetting::Left) {
return PositionAlignSetting::Line_left;
} else if (mAlign == AlignSetting::Right) {
return PositionAlignSetting::Line_right;
} else if (mAlign == AlignSetting::Start) {
return IsTextBaseDirectionLTR() ? PositionAlignSetting::Line_left
: PositionAlignSetting::Line_right;
} else if (mAlign == AlignSetting::End) {
return IsTextBaseDirectionLTR() ? PositionAlignSetting::Line_right
: PositionAlignSetting::Line_left;
}
return PositionAlignSetting::Center;
}
bool TextTrackCue::IsTextBaseDirectionLTR() const {
// The returned result by `ubidi_getBaseDirection` might be `neutral` if the
// text only contains netural charaters. In this case, we would treat its
// base direction as LTR.
return ubidi_getBaseDirection(mText.BeginReading(), mText.Length()) !=
UBIDI_RTL;
}
void TextTrackCue::NotifyDisplayStatesChanged() {
if (!mReset) {
return;
}
if (!mTrack || !mTrack->GetTextTrackList() ||
!mTrack->GetTextTrackList()->GetMediaElement()) {
return;
}
mTrack->GetTextTrackList()
->GetMediaElement()
->NotifyCueDisplayStatesChanged();
}
void TextTrackCue::SetActive(bool aActive) {
if (mActive == aActive) {
return;
}
LOG("TextTrackCue, SetActive=%d", aActive);
mActive = aActive;
mDisplayState = mActive ? mDisplayState : nullptr;
if (mTrack) {
mTrack->NotifyCueActiveStateChanged(this);
}
}
} // namespace dom
} // namespace mozilla