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      1 /*
      2  * Copyright (C) 2013 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 are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef VTTRegion_h
     32 #define VTTRegion_h
     33 
     34 #include "core/dom/ContextLifecycleObserver.h"
     35 #include "core/html/track/TextTrack.h"
     36 #include "platform/Timer.h"
     37 #include "platform/geometry/FloatPoint.h"
     38 #include "wtf/PassOwnPtr.h"
     39 #include "wtf/RefCounted.h"
     40 
     41 namespace WebCore {
     42 
     43 class ExceptionState;
     44 class HTMLDivElement;
     45 class VTTCueBox;
     46 
     47 class VTTRegion : public RefCounted<VTTRegion> {
     48 public:
     49     static PassRefPtr<VTTRegion> create()
     50     {
     51         return adoptRef(new VTTRegion());
     52     }
     53 
     54     virtual ~VTTRegion();
     55 
     56     TextTrack* track() const { return m_track; }
     57     void setTrack(TextTrack*);
     58 
     59     const String& id() const { return m_id; }
     60     void setId(const String&);
     61 
     62     double width() const { return m_width; }
     63     void setWidth(double, ExceptionState&);
     64 
     65     long height() const { return m_heightInLines; }
     66     void setHeight(long, ExceptionState&);
     67 
     68     double regionAnchorX() const { return m_regionAnchor.x(); }
     69     void setRegionAnchorX(double, ExceptionState&);
     70 
     71     double regionAnchorY() const { return m_regionAnchor.y(); }
     72     void setRegionAnchorY(double, ExceptionState&);
     73 
     74     double viewportAnchorX() const { return m_viewportAnchor.x(); }
     75     void setViewportAnchorX(double, ExceptionState&);
     76 
     77     double viewportAnchorY() const { return m_viewportAnchor.y(); }
     78     void setViewportAnchorY(double, ExceptionState&);
     79 
     80     const AtomicString scroll() const;
     81     void setScroll(const AtomicString&, ExceptionState&);
     82 
     83     void updateParametersFromRegion(VTTRegion*);
     84 
     85     const String& regionSettings() const { return m_settings; }
     86     void setRegionSettings(const String&);
     87 
     88     bool isScrollingRegion() { return m_scroll; }
     89 
     90     PassRefPtr<HTMLDivElement> getDisplayTree(Document&);
     91 
     92     void appendVTTCueBox(PassRefPtr<VTTCueBox>);
     93     void displayLastVTTCueBox();
     94     void willRemoveVTTCueBox(VTTCueBox*);
     95 
     96 private:
     97     VTTRegion();
     98 
     99     void prepareRegionDisplayTree();
    100 
    101     // The timer is needed to continue processing when cue scrolling ended.
    102     void startTimer();
    103     void stopTimer();
    104     void scrollTimerFired(Timer<VTTRegion>*);
    105 
    106     enum RegionSetting {
    107         None,
    108         Id,
    109         Width,
    110         Height,
    111         RegionAnchor,
    112         ViewportAnchor,
    113         Scroll
    114     };
    115     RegionSetting getSettingFromString(const String&);
    116     void parseSettingValue(RegionSetting, const String&);
    117     void parseSetting(const String&, unsigned*);
    118 
    119     static const AtomicString& textTrackCueContainerShadowPseudoId();
    120     static const AtomicString& textTrackCueContainerScrollingClass();
    121     static const AtomicString& textTrackRegionShadowPseudoId();
    122 
    123     String m_id;
    124     String m_settings;
    125     double m_width;
    126     unsigned m_heightInLines;
    127     FloatPoint m_regionAnchor;
    128     FloatPoint m_viewportAnchor;
    129     bool m_scroll;
    130 
    131     // The cue container is the container that is scrolled up to obtain the
    132     // effect of scrolling cues when this is enabled for the regions.
    133     RefPtr<HTMLDivElement> m_cueContainer;
    134     RefPtr<HTMLDivElement> m_regionDisplayTree;
    135 
    136     // The member variable track can be a raw pointer as it will never
    137     // reference a destroyed TextTrack, as this member variable
    138     // is cleared in the TextTrack destructor and it is generally
    139     // set/reset within the addRegion and removeRegion methods.
    140     TextTrack* m_track;
    141 
    142     // Keep track of the current numeric value of the css "top" property.
    143     double m_currentTop;
    144 
    145     // The timer is used to display the next cue line after the current one has
    146     // been displayed. It's main use is for scrolling regions and it triggers as
    147     // soon as the animation for rolling out one line has finished, but
    148     // currently it is used also for non-scrolling regions to use a single
    149     // code path.
    150     Timer<VTTRegion> m_scrollTimer;
    151 };
    152 
    153 } // namespace WebCore
    154 #endif
    155