Detect change on video/viewport intersection when rendered remotely

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

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 110 matching lines @@
 using namespace HTMLNames;
 
 using WeakMediaElementSet = HeapHashSet<WeakMember<HTMLMediaElement>>;
 using DocumentElementSetMap =
     HeapHashMap<WeakMember<Document>, Member<WeakMediaElementSet>>;
 
 namespace {
 
 constexpr float kMostlyFillViewportThreshold = 0.85f;
 constexpr double kMostlyFillViewportBecomeStableSeconds = 5;
+constexpr double kCheckViewportIntersectionIntervalInSeconds = 1;

[ojan, 2016/12/14 00:39:08]

Naming nit: Other variables leave out the "In", e.g. see the one in the line
above.

[xjz, 2016/12/14 00:55:05]

Done.

 
 enum MediaControlsShow {
   MediaControlsShowAttribute = 0,
   MediaControlsShowFullscreen,
   MediaControlsShowNoScript,
   MediaControlsShowNotShown,
   MediaControlsShowMax
 };
 
 String urlForLoggingMedia(const KURL& url) {
@@ skipping 222 matching lines @@
       ActiveScriptWrappable(this),
       ActiveDOMObject(&document),
       m_loadTimer(this, &HTMLMediaElement::loadTimerFired),
       m_progressEventTimer(this, &HTMLMediaElement::progressEventTimerFired),
       m_playbackProgressTimer(this,
                               &HTMLMediaElement::playbackProgressTimerFired),
       m_audioTracksTimer(this, &HTMLMediaElement::audioTracksTimerFired),
       m_viewportFillDebouncerTimer(
           this,
           &HTMLMediaElement::viewportFillDebouncerTimerFired),
+      m_checkViewportIntersectionTimer(
+          this,
+          &HTMLMediaElement::checkViewportIntersectionTimerFired),
       m_playedTimeRanges(),
       m_asyncEventQueue(GenericEventQueue::create(this)),
       m_playbackRate(1.0f),
       m_defaultPlaybackRate(1.0f),
       m_networkState(kNetworkEmpty),
       m_readyState(kHaveNothing),
       m_readyStateMaximum(kHaveNothing),
       m_volume(1.0f),
       m_lastSeekTime(0),
       m_previousProgressTime(std::numeric_limits<double>::max()),
@@ skipping 2043 matching lines @@
 void HTMLMediaElement::startPlaybackProgressTimer() {
   if (m_playbackProgressTimer.isActive())
     return;
 
   m_previousProgressTime = WTF::currentTime();
   m_playbackProgressTimer.startRepeating(maxTimeupdateEventFrequency,
                                          BLINK_FROM_HERE);
 }
 
 void HTMLMediaElement::playbackProgressTimerFired(TimerBase*) {
-  checkViewportIntersectionChanged();
-
   if (!std::isnan(m_fragmentEndTime) && currentTime() >= m_fragmentEndTime &&
       getDirectionOfPlayback() == Forward) {
     m_fragmentEndTime = std::numeric_limits<double>::quiet_NaN();
     if (!m_paused) {
       UseCounter::count(document(),
                         UseCounter::HTMLMediaElementPauseAtFragmentEnd);
       // changes paused to true and fires a simple event named pause at the
       // media element.
       pauseInternal();
     }
@@ skipping 820 matching lines @@
       addPlayedRange(m_lastSeekTime, time);
   }
 
   if (layoutObject())
     layoutObject()->updateFromElement();
 }
 
 void HTMLMediaElement::stopPeriodicTimers() {
   m_progressEventTimer.stop();
   m_playbackProgressTimer.stop();
+  m_checkViewportIntersectionTimer.stop();
 }
 
 void HTMLMediaElement::
     clearMediaPlayerAndAudioSourceProviderClientWithoutLocking() {
   getAudioSourceProvider().setClient(nullptr);
   if (m_webMediaPlayer) {
     m_audioSourceProvider.wrap(nullptr);
     m_webMediaPlayer.reset();
   }
 }
@@ skipping 738 matching lines @@
 }
 
 DEFINE_TRACE(HTMLMediaElement::AudioClientImpl) {
   visitor->trace(m_client);
 }
 
 DEFINE_TRACE(HTMLMediaElement::AudioSourceProviderImpl) {
   visitor->trace(m_client);
 }
 
-void HTMLMediaElement::checkViewportIntersectionChanged() {
-  // TODO(xjz): Early return if we not in tab mirroring.
+void HTMLMediaElement::enableMonitorViewportIntersection(bool enable) {
+  if (enable && !m_checkViewportIntersectionTimer.isActive()) {
+    m_checkViewportIntersectionTimer.startRepeating(
+        kCheckViewportIntersectionIntervalInSeconds, BLINK_FROM_HERE);
+  } else if (!enable) {
+    m_checkViewportIntersectionTimer.stop();
+  }
+}
 
+void HTMLMediaElement::checkViewportIntersectionTimerFired(TimerBase*) {
   IntersectionGeometry geometry(
       document().frame()->localFrameRoot()->document(), this, Vector<Length>(),
       IntersectionGeometry::ReportRootBounds::kShouldReportRootBounds);
   geometry.computeGeometry();
   IntRect intersectRect = geometry.intersectionIntRect();
   if (m_currentIntersectRect == intersectRect)
     return;
 
   m_currentIntersectRect = intersectRect;
   // Reset on any intersection change, since this indicates the user is
@@ skipping 16 matching lines @@
       kMostlyFillViewportBecomeStableSeconds, BLINK_FROM_HERE);
 }
 
 void HTMLMediaElement::viewportFillDebouncerTimerFired(TimerBase*) {
   m_mostlyFillingViewport = true;
   if (m_webMediaPlayer)
     m_webMediaPlayer->becameDominantVisibleContent(m_mostlyFillingViewport);
 }
 
 }  // namespace blink