third_party/WebKit/Source/core/html/AutoplayExperimentHelper.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef AutoplayExperimentHelper_h
   6 #define AutoplayExperimentHelper_h
   7
   8 #include "core/html/AutoplayExperimentConfig.h"
   9 #include "core/page/Page.h"
  10 #include "platform/Timer.h"
  11 #include "platform/geometry/IntRect.h"
  12
  13 namespace blink {
  14 class Document;
  15 class HTMLMediaElement;
  16 class EventListener;
  17
  18 // These values are used for a histogram. Do not reorder.
  19 enum AutoplayMetrics {
  20     // Media element with autoplay seen.
  21     AutoplayMediaFound = 0,
  22     // Autoplay enabled and user stopped media play at any point.
  23     AutoplayPaused = 1,
  24     // Autoplay enabled but user bailed out on media play early.
  25     AutoplayBailout = 2,
  26     // Autoplay disabled but user manually started media.
  27     AutoplayManualStart = 3,
  28     // Autoplay was (re)enabled through a user-gesture triggered load()
  29     AutoplayEnabledThroughLoad = 4,
  30     // Autoplay disabled by sandbox flags.
  31     AutoplayDisabledBySandbox = 5,
  32
  33     // These metrics indicate "no gesture detected, but the gesture
  34     // requirement was overridden by experiment".  They do not include cases
  35     // where no user gesture is required (!m_userGestureRequiredForPlay).
  36
  37     // User gesture requirement was bypassed, and playback started, during
  38     // initial load via the autoplay flag.  If playback was deferred due to
  39     // visibility requirements, then this does not apply.
  40     GesturelessPlaybackStartedByAutoplayFlagImmediately = 6,
  41
  42     // User gesture requirement was bypassed, and playback started, when
  43     // the play() method was called.  If playback is deferred due to
  44     // visibility requirements, then this does not apply.
  45     GesturelessPlaybackStartedByPlayMethodImmediately = 7,
  46
  47     // User gesture requirement was bypassed, and playback started, after
  48     // an element with the autoplay flag moved into the viewport.  Playback
  49     // was deferred earlier due to visibility requirements.
  50     GesturelessPlaybackStartedByAutoplayFlagAfterScroll = 8,
  51
  52     // User gesture requirement was bypassed, and playback started, after
  53     // an element on which the play() method was called was moved into the
  54     // viewport.  Playback had been deferred due to visibility requirements.
  55     GesturelessPlaybackStartedByPlayMethodAfterScroll = 9,
  56
  57     // play() failed to play due to gesture requirement.
  58     PlayMethodFailed = 10,
  59
  60     // Some play, whether user initiated or not, started.
  61     AnyPlaybackStarted = 11,
  62     // Some play, whether user initiated or not, paused.
  63     AnyPlaybackPaused = 12,
  64     // Some playback, whether user initiated or not, bailed out early.
  65     AnyPlaybackBailout = 13,
  66
  67     // This enum value must be last.
  68     NumberOfAutoplayMetrics,
  69 };
  70
  71 class AutoplayExperimentHelper {
  72 public:
  73     AutoplayExperimentHelper(HTMLMediaElement&);
  74     ~AutoplayExperimentHelper();
  75
  76     void becameReadyToPlay();
  77     void playMethodCalled();
  78     void pauseMethodCalled();
  79     void mutedChanged();
  80     void positionChanged();
  81
  82 private:
  83     // Return true if any only if this player meets (most) of the eligibility
  84     // requirements for the experiment to override the need for a user
  85     // gesture.  This includes everything except the visibility test.
  86     bool isEligible() const;
  87
  88     // Set the muted flag on the media if we're in an experiment mode that
  89     // requires it, else do nothing.
  90     void muteIfNeeded();
  91
  92     // Maybe override the requirement for a user gesture, and start playing
  93     // autoplay media.  Returns true if only if it starts playback.
  94     bool maybeStartPlaying();
  95
  96     // Configure internal state to record that the autoplay experiment is
  97     // going to start playback.  This doesn't actually start playback, since
  98     // there are several different cases.
  99     void prepareToPlay(AutoplayMetrics);
 100
 101     // Return our media element's document.
 102     Document& document() const;
 103
 104     inline bool enabled(AutoplayExperimentConfig::Mode mode) const
 105     {
 106         return ((int)m_mode) & ((int)mode);
 107     }
 108
 109 private:
 110     HTMLMediaElement& m_element;
 111
 112     AutoplayExperimentConfig::Mode m_mode;
 113
 114     // Autoplay experiment state.
 115     // True if we've received a play() without a pause().
 116     bool m_playPending : 1;
 117
 118     friend class Internals;
 119 };
 120
 121 } // namespace blink
 122
 123 #endif // AutoplayExperimentHelper_h