third_party/WebKit/Source/core/html/HTMLTrackElement.cpp

   1 /*
   2  * Copyright (C) 2011 Google Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "core/html/HTMLTrackElement.h"
  28
  29 #include "core/HTMLNames.h"
  30 #include "core/dom/Document.h"
  31 #include "core/events/Event.h"
  32 #include "core/frame/csp/ContentSecurityPolicy.h"
  33 #include "core/html/HTMLMediaElement.h"
  34 #include "core/html/track/LoadableTextTrack.h"
  35 #include "platform/Logging.h"
  36
  37 namespace blink {
  38
  39 using namespace HTMLNames;
  40
  41 #if !LOG_DISABLED
  42 static String urlForLoggingTrack(const KURL& url)
  43 {
  44     static const unsigned maximumURLLengthForLogging = 128;
  45
  46     if (url.string().length() < maximumURLLengthForLogging)
  47         return url.string();
  48     return url.string().substring(0, maximumURLLengthForLogging) + "...";
  49 }
  50 #endif
  51
  52 inline HTMLTrackElement::HTMLTrackElement(Document& document)
  53     : HTMLElement(trackTag, document)
  54     , m_loadTimer(this, &HTMLTrackElement::loadTimerFired)
  55 {
  56     WTF_LOG(Media, "HTMLTrackElement::HTMLTrackElement - %p", this);
  57 }
  58
  59 DEFINE_NODE_FACTORY(HTMLTrackElement)
  60
  61 HTMLTrackElement::~HTMLTrackElement()
  62 {
  63 #if !ENABLE(OILPAN)
  64     if (m_track)
  65         m_track->clearTrackElement();
  66 #endif
  67 }
  68
  69 Node::InsertionNotificationRequest HTMLTrackElement::insertedInto(ContainerNode* insertionPoint)
  70 {
  71     WTF_LOG(Media, "HTMLTrackElement::insertedInto");
  72
  73     // Since we've moved to a new parent, we may now be able to load.
  74     scheduleLoad();
  75
  76     HTMLElement::insertedInto(insertionPoint);
  77     HTMLMediaElement* parent = mediaElement();
  78     if (insertionPoint == parent)
  79         parent->didAddTrackElement(this);
  80     return InsertionDone;
  81 }
  82
  83 void HTMLTrackElement::removedFrom(ContainerNode* insertionPoint)
  84 {
  85     if (!parentNode() && isHTMLMediaElement(*insertionPoint))
  86         toHTMLMediaElement(insertionPoint)->didRemoveTrackElement(this);
  87     HTMLElement::removedFrom(insertionPoint);
  88 }
  89
  90 void HTMLTrackElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
  91 {
  92     if (name == srcAttr) {
  93         if (!value.isEmpty())
  94             scheduleLoad();
  95         else if (m_track)
  96             m_track->removeAllCues();
  97
  98     // 4.8.10.12.3 Sourcing out-of-band text tracks
  99     // As the kind, label, and srclang attributes are set, changed, or removed, the text track must update accordingly...
 100     } else if (name == kindAttr) {
 101         track()->setKind(value.lower());
 102     } else if (name == labelAttr) {
 103         track()->setLabel(value);
 104     } else if (name == srclangAttr) {
 105         track()->setLanguage(value);
 106     } else if (name == idAttr) {
 107         track()->setId(value);
 108     }
 109
 110     HTMLElement::parseAttribute(name, value);
 111 }
 112
 113 const AtomicString& HTMLTrackElement::kind()
 114 {
 115     return track()->kind();
 116 }
 117
 118 void HTMLTrackElement::setKind(const AtomicString& kind)
 119 {
 120     setAttribute(kindAttr, kind);
 121 }
 122
 123 LoadableTextTrack* HTMLTrackElement::ensureTrack()
 124 {
 125     if (!m_track) {
 126         // kind, label and language are updated by parseAttribute
 127         m_track = LoadableTextTrack::create(this);
 128     }
 129     return m_track.get();
 130 }
 131
 132 TextTrack* HTMLTrackElement::track()
 133 {
 134     return ensureTrack();
 135 }
 136
 137 bool HTMLTrackElement::isURLAttribute(const Attribute& attribute) const
 138 {
 139     return attribute.name() == srcAttr || HTMLElement::isURLAttribute(attribute);
 140 }
 141
 142 void HTMLTrackElement::scheduleLoad()
 143 {
 144     WTF_LOG(Media, "HTMLTrackElement::scheduleLoad");
 145
 146     // 1. If another occurrence of this algorithm is already running for this text track and its track element,
 147     // abort these steps, letting that other algorithm take care of this element.
 148     if (m_loadTimer.isActive())
 149         return;
 150
 151     // 2. If the text track's text track mode is not set to one of hidden or showing, abort these steps.
 152     if (ensureTrack()->mode() != TextTrack::hiddenKeyword() && ensureTrack()->mode() != TextTrack::showingKeyword())
 153         return;
 154
 155     // 3. If the text track's track element does not have a media element as a parent, abort these steps.
 156     if (!mediaElement())
 157         return;
 158
 159     // 4. Run the remainder of these steps in parallel, allowing whatever caused these steps to run to continue.
 160     m_loadTimer.startOneShot(0, FROM_HERE);
 161
 162     // 5. Top: Await a stable state. The synchronous section consists of the following steps. (The steps in the
 163     // synchronous section are marked with [X])
 164     // FIXME: We use a timer to approximate a "stable state" - i.e. this is not 100% per spec.
 165 }
 166
 167 void HTMLTrackElement::loadTimerFired(Timer<HTMLTrackElement>*)
 168 {
 169     WTF_LOG(Media, "HTMLTrackElement::loadTimerFired");
 170
 171     // 6. [X] Set the text track readiness state to loading.
 172     setReadyState(LOADING);
 173
 174     // 7. [X] Let URL be the track URL of the track element.
 175     KURL url = getNonEmptyURLAttribute(srcAttr);
 176
 177     // 8. [X] If the track element's parent is a media element then let CORS mode be the state of the parent media
 178     // element's crossorigin content attribute. Otherwise, let CORS mode be No CORS.
 179     const AtomicString& corsMode = mediaElementCrossOriginAttribute();
 180
 181     // 9. End the synchronous section, continuing the remaining steps in parallel.
 182
 183     // 10. If URL is not the empty string, perform a potentially CORS-enabled fetch of URL, with the mode being CORS
 184     // mode, the origin being the origin of the track element's node document, and the default origin behaviour set to
 185     // fail.
 186     if (!canLoadUrl(url)) {
 187         didCompleteLoad(Failure);
 188         return;
 189     }
 190
 191     if (url == m_url) {
 192         ASSERT(m_loader);
 193         switch (m_loader->loadState()) {
 194         case TextTrackLoader::Idle:
 195         case TextTrackLoader::Loading:
 196             // If loading of the resource from this URL is in progress, return early.
 197             break;
 198         case TextTrackLoader::Finished:
 199             didCompleteLoad(Success);
 200             break;
 201         case TextTrackLoader::Failed:
 202             didCompleteLoad(Failure);
 203             break;
 204         default:
 205             ASSERT_NOT_REACHED();
 206         }
 207         return;
 208     }
 209
 210     m_url = url;
 211
 212     if (m_loader)
 213         m_loader->cancelLoad();
 214
 215     m_loader = TextTrackLoader::create(*this, document());
 216     if (!m_loader->load(m_url, corsMode))
 217         didCompleteLoad(Failure);
 218 }
 219
 220 bool HTMLTrackElement::canLoadUrl(const KURL& url)
 221 {
 222     HTMLMediaElement* parent = mediaElement();
 223     if (!parent)
 224         return false;
 225
 226     if (url.isEmpty())
 227         return false;
 228
 229     if (!document().contentSecurityPolicy()->allowMediaFromSource(url)) {
 230         WTF_LOG(Media, "HTMLTrackElement::canLoadUrl(%s) -> rejected by Content Security Policy", urlForLoggingTrack(url).utf8().data());
 231         return false;
 232     }
 233
 234     return true;
 235 }
 236
 237 void HTMLTrackElement::didCompleteLoad(LoadStatus status)
 238 {
 239     // 10. ... (continued)
 240
 241     // If the fetching algorithm fails for any reason (network error, the server returns an error code, a cross-origin
 242     // check fails, etc), or if URL is the empty string, then queue a task to first change the text track readiness
 243     // state to failed to load and then fire a simple event named error at the track element. This task must use the DOM
 244     // manipulation task source.
 245     //
 246     // (Note: We don't "queue a task" here because this method will only be called from a timer - m_loadTimer or
 247     // TextTrackLoader::m_cueLoadTimer - which should be a reasonable, and hopefully non-observable, approximation of
 248     // the spec text. I.e we could consider this to be run from the "networking task source".)
 249     //
 250     // If the fetching algorithm does not fail, but the type of the resource is not a supported text track format, or
 251     // the file was not successfully processed (e.g. the format in question is an XML format and the file contained a
 252     // well-formedness error that the XML specification requires be detected and reported to the application), then the
 253     // task that is queued by the networking task source in which the aforementioned problem is found must change the
 254     // text track readiness state to failed to load and fire a simple event named error at the track element.
 255     if (status == Failure) {
 256         setReadyState(TRACK_ERROR);
 257         dispatchEvent(Event::create(EventTypeNames::error));
 258         return;
 259     }
 260
 261     // If the fetching algorithm does not fail, and the file was successfully processed, then the final task that is
 262     // queued by the networking task source, after it has finished parsing the data, must change the text track
 263     // readiness state to loaded, and fire a simple event named load at the track element.
 264     setReadyState(LOADED);
 265     dispatchEvent(Event::create(EventTypeNames::load));
 266 }
 267
 268 void HTMLTrackElement::newCuesAvailable(TextTrackLoader* loader)
 269 {
 270     ASSERT_UNUSED(loader, m_loader == loader);
 271     ASSERT(m_track);
 272
 273     HeapVector<Member<TextTrackCue>> newCues;
 274     m_loader->getNewCues(newCues);
 275
 276     m_track->addListOfCues(newCues);
 277 }
 278
 279 void HTMLTrackElement::newRegionsAvailable(TextTrackLoader* loader)
 280 {
 281     ASSERT_UNUSED(loader, m_loader == loader);
 282     ASSERT(m_track);
 283
 284     HeapVector<Member<VTTRegion>> newRegions;
 285     m_loader->getNewRegions(newRegions);
 286
 287     m_track->addRegions(newRegions);
 288 }
 289
 290 void HTMLTrackElement::cueLoadingCompleted(TextTrackLoader* loader, bool loadingFailed)
 291 {
 292     ASSERT_UNUSED(loader, m_loader == loader);
 293
 294     didCompleteLoad(loadingFailed ? Failure : Success);
 295 }
 296
 297 // NOTE: The values in the TextTrack::ReadinessState enum must stay in sync with those in HTMLTrackElement::ReadyState.
 298 static_assert(HTMLTrackElement::NONE == static_cast<HTMLTrackElement::ReadyState>(TextTrack::NotLoaded), "HTMLTrackElement::NONE should be in sync with TextTrack::NotLoaded");
 299 static_assert(HTMLTrackElement::LOADING == static_cast<HTMLTrackElement::ReadyState>(TextTrack::Loading), "HTMLTrackElement::LOADING should be in sync with TextTrack::Loading");
 300 static_assert(HTMLTrackElement::LOADED == static_cast<HTMLTrackElement::ReadyState>(TextTrack::Loaded), "HTMLTrackElement::LOADED should be in sync with TextTrack::Loaded");
 301 static_assert(HTMLTrackElement::TRACK_ERROR == static_cast<HTMLTrackElement::ReadyState>(TextTrack::FailedToLoad), "HTMLTrackElement::TRACK_ERROR should be in sync with TextTrack::FailedToLoad");
 302
 303 void HTMLTrackElement::setReadyState(ReadyState state)
 304 {
 305     ensureTrack()->setReadinessState(static_cast<TextTrack::ReadinessState>(state));
 306     if (HTMLMediaElement* parent = mediaElement())
 307         return parent->textTrackReadyStateChanged(m_track.get());
 308 }
 309
 310 HTMLTrackElement::ReadyState HTMLTrackElement::readyState()
 311 {
 312     return static_cast<ReadyState>(ensureTrack()->readinessState());
 313 }
 314
 315 const AtomicString& HTMLTrackElement::mediaElementCrossOriginAttribute() const
 316 {
 317     if (HTMLMediaElement* parent = mediaElement())
 318         return parent->fastGetAttribute(HTMLNames::crossoriginAttr);
 319
 320     return nullAtom;
 321 }
 322
 323 HTMLMediaElement* HTMLTrackElement::mediaElement() const
 324 {
 325     Element* parent = parentElement();
 326     if (isHTMLMediaElement(parent))
 327         return toHTMLMediaElement(parent);
 328     return nullptr;
 329 }
 330
 331 DEFINE_TRACE(HTMLTrackElement)
 332 {
 333     visitor->trace(m_track);
 334     visitor->trace(m_loader);
 335     HTMLElement::trace(visitor);
 336 }
 337
 338 }