Allow HTMLMediaElement.currentTime to be set before the transition to HAVE_METADATA

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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 306 matching lines @@
     , m_defaultPlaybackRate(1.0f)
     , m_networkState(NETWORK_EMPTY)
     , m_readyState(HAVE_NOTHING)
     , m_readyStateMaximum(HAVE_NOTHING)
     , m_volume(1.0f)
     , m_lastSeekTime(0)
     , m_previousProgressTime(std::numeric_limits<double>::max())
     , m_duration(std::numeric_limits<double>::quiet_NaN())
     , m_lastTimeUpdateEventWallTime(0)
     , m_lastTimeUpdateEventMovieTime(std::numeric_limits<double>::max())
+    , m_defaultPlaybackStartPosition(0)
     , m_loadState(WaitingForSource)
     , m_deferredLoadState(NotDeferred)
     , m_deferredLoadTimer(this, &HTMLMediaElement::deferredLoadTimerFired)
     , m_webLayer(0)
     , m_preload(MediaPlayer::Auto)
     , m_displayMode(Unknown)
     , m_cachedTime(MediaPlayer::invalidTime())
     , m_cachedTimeWallClockUpdateTime(0)
     , m_minimumWallClockTimeToCacheMediaTime(0)
     , m_fragmentStartTime(MediaPlayer::invalidTime())
@@ skipping 1478 matching lines @@
         prepareMediaFragmentURI();
 
         selectInitialTracksIfNecessary();
 
         m_duration = duration();
         scheduleEvent(EventTypeNames::durationchange);
 
         if (isHTMLVideoElement())
             scheduleEvent(EventTypeNames::resize);
         scheduleEvent(EventTypeNames::loadedmetadata);
+
+        if (m_defaultPlaybackStartPosition > 0) {

[philipj_slow, 2014/09/02 13:03:31]

This looks like the correct place for this logic, but per spec there's a jumped
flag that will prevent the media fragment URI handling from kicking in. We need
a test for setting currentTime to e.g. 1 on a resource with #t=2, verifying that
we end up at currentTime 1 and not 2. I don't think the existing code will do
this. Fixing that should also allow you to remove m_fragmentStartTime.

[amogh.bihani, 2014/09/02 13:39:54]

Acknowledged.

+            seek(m_defaultPlaybackStartPosition, IGNORE_EXCEPTION);
+            m_defaultPlaybackStartPosition = 0;
+        }
+
         if (hasMediaControls())
             mediaControls()->reset();
         if (renderer())
             renderer()->updateFromElement();
     }
 
     bool shouldUpdateDisplayState = false;
 
     if (m_readyState >= HAVE_CURRENT_DATA && oldState < HAVE_CURRENT_DATA && !m_haveFiredLoadedData) {
         m_haveFiredLoadedData = true;
@@ skipping 86 matching lines @@
     if (loadIsDeferred())
         startDeferredLoad();
 }
 
 void HTMLMediaElement::seek(double time, ExceptionState& exceptionState)
 {
     WTF_LOG(Media, "HTMLMediaElement::seek(%f)", time);
 
     // 4.8.10.9 Seeking
 
-    // 1 - If the media element's readyState is HAVE_NOTHING, then raise an InvalidStateError exception.
+    // 1 - If the media element's readyState is HAVE_NOTHING, then set the default playback start
+    // position to that time.
     if (m_readyState == HAVE_NOTHING) {
-        exceptionState.throwDOMException(InvalidStateError, "The element's readyState is HAVE_NOTHING.");
+        m_defaultPlaybackStartPosition = time;

[philipj_slow, 2014/09/02 13:03:31]

This should be moved to setCurrentTime, per "if the media element's readyState
is HAVE_NOTHING, then it must set the media element's default playback start
position to the new value"

[amogh.bihani, 2014/09/02 13:39:54]

Acknowledged.

         return;
     }
 
     // If the media engine has been told to postpone loading data, let it go ahead now.
     if (m_preload < MediaPlayer::Auto && m_readyState < HAVE_FUTURE_DATA)
         prepareToPlay();
 
     // Get the current time before setting m_seeking, m_lastSeekTime is returned once it is set.
     refreshCachedTime();
     double now = currentTime();
@@ skipping 124 matching lines @@
 }
 
 // playback state
 double HTMLMediaElement::currentTime() const
 {
 #if LOG_CACHED_TIME_WARNINGS
     static const double minCachedDeltaForWarning = 0.01;
 #endif
 
     if (m_readyState == HAVE_NOTHING)
-        return 0;
+        return m_defaultPlaybackStartPosition;

[philipj_slow, 2014/09/02 13:03:31]

The spec says "return the media element's default playback start position,
unless that is zero" so "if (m_defaultPlaybackStartPosition) return
m_defaultPlaybackStartPosition;" would be appropriate. If that can only happen
while readyState is HAVE_NOTHING, you can assert that.

[amogh.bihani, 2014/09/02 13:39:54]

Ok, I'll do that. I thought that its value is set to zero in constructor, so if
it is not set to anything else, we will be returning zero.

 
     if (m_seeking) {
         WTF_LOG(Media, "HTMLMediaElement::currentTime - seeking, returning %f", m_lastSeekTime);
         return m_lastSeekTime;
     }
 
     if (m_cachedTime != MediaPlayer::invalidTime() && m_paused) {
 #if LOG_CACHED_TIME_WARNINGS
         double delta = m_cachedTime - webMediaPlayer()->currentTime();
         if (delta > minCachedDeltaForWarning)
             WTF_LOG(Media, "HTMLMediaElement::currentTime - WARNING, cached time is %f seconds off of media time when paused", delta);
 #endif
         return m_cachedTime;
     }
 
     refreshCachedTime();
 
     return m_cachedTime;
 }
 
 void HTMLMediaElement::setCurrentTime(double time, ExceptionState& exceptionState)
 {
     if (m_mediaController) {
         exceptionState.throwDOMException(InvalidStateError, "The element is slaved to a MediaController.");
         return;
     }
+
+    if (m_networkState == NETWORK_EMPTY) {
+        exceptionState.throwDOMException(InvalidStateError, "There is no media attached.");

[philipj_slow, 2014/09/02 13:03:31]

This condition is not in the spec, why is it needed?

[amogh.bihani, 2014/09/02 13:39:54]

Oh Sorry! I got confused with this line "Test that seeking video with no 'src'
attribute throws an INVALID_STATE_ERR exception." in the video-seek-no-src
layout test and presumed that when there is not src attribute, then
InvalidStateError has to be thrown. I'll change this.

+        return;
+    }
+
     seek(time, exceptionState);
 }
 
 double HTMLMediaElement::duration() const
 {
     // FIXME: remove m_player check once we figure out how m_player is going
     // out of sync with readystate. m_player is cleared but readystate is not set
     // to HAVE_NOTHING
     if (!m_player || m_readyState < HAVE_METADATA)
         return std::numeric_limits<double>::quiet_NaN();
@@ skipping 1874 matching lines @@
 
 #if ENABLE(WEB_AUDIO)
 void HTMLMediaElement::clearWeakMembers(Visitor* visitor)
 {
     if (!visitor->isAlive(m_audioSourceNode) && audioSourceProvider())
         audioSourceProvider()->setClient(0);
 }
 #endif
 
 }