Move text track active list management to CueTimeline

Source/core/html/track/CueTimeline.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CueTimeline_h
+#define CueTimeline_h
+
+#include "core/html/track/TextTrackCue.h"
+#include "core/html/track/vtt/VTTCue.h"
+#include "platform/PODIntervalTree.h"
+#include "platform/heap/Handle.h"
+#include "wtf/Vector.h"
+
+namespace blink {
+
+class HTMLMediaElement;
+class TextTrackCueList;
+
+typedef PODIntervalTree<double, TextTrackCue*> CueIntervalTree;
+typedef CueIntervalTree::IntervalType CueInterval;
+typedef Vector<CueInterval> CueList;
+
+// This class manages the timeline and rendering updates of cues associated
+// with TextTracks. Owned by a HTMLMediaElement.
+class CueTimeline : public NoBaseWillBeGarbageCollectedFinalized<CueTimeline> {
+public:
+    CueTimeline(HTMLMediaElement&);
+
+    void addCues(TextTrack*, const TextTrackCueList*);
+    void addCue(TextTrack*, PassRefPtrWillBeRawPtr<TextTrackCue>);
+    void removeCues(TextTrack*, const TextTrackCueList*);
+    void removeCue(TextTrack*, PassRefPtrWillBeRawPtr<TextTrackCue>);
+
+    void updateActiveCues(double);
+
+    bool ignoreUpdateRequests() const { return m_ignoreUpdate > 0; }
+    void beginIgnoringUpdateRequests();
+    void endIgnoringUpdateRequests();
+
+    CueList currentlyActiveCues() const { return m_currentlyActiveCues; }
+
+    DECLARE_TRACE();
+
+private:
+    HTMLMediaElement& mediaElement() const { return *m_mediaElement; }
+
+    RawPtrWillBeMember<HTMLMediaElement> m_mediaElement;
+
+    CueIntervalTree m_cueTree;
+
+    CueList m_currentlyActiveCues;
+    double m_lastUpdateTime;
+
+    int m_ignoreUpdate;
+};
+
+class TrackDisplayUpdateScope {
+    STACK_ALLOCATED();
+public:
+    TrackDisplayUpdateScope(CueTimeline& cueTimeline)
+    {
+        m_cueTimeline = &cueTimeline;
+        m_cueTimeline->beginIgnoringUpdateRequests();
+    }
+    ~TrackDisplayUpdateScope()
+    {
+        ASSERT(m_cueTimeline);
+        m_cueTimeline->endIgnoringUpdateRequests();
+    }
+
+private:
+    RawPtrWillBeMember<CueTimeline> m_cueTimeline;
+};
+
+#ifndef NDEBUG
+// Template specializations required by PodIntervalTree in debug mode.
+template <>
+struct ValueToString<double> {
+    static String string(const double value)
+    {
+        return String::number(value);
+    }
+};
+
+template <>
+struct ValueToString<TextTrackCue*> {
+    static String string(TextTrackCue* const& cue)
+    {
+        return cue->toString();
+    }
+};
+#endif
+
+} // namespace blink
+
+#endif // CueTimeline_h