Source/WebCore/page/CaptionUserPreferencesMac.mm - chromium/blink - Git at Google

 /*
  * Copyright (C) 2012 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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import "config.h"

 #if ENABLE(VIDEO_TRACK)

 #import "CaptionUserPreferencesMac.h"

 #import "ColorMac.h"
 #import "DOMWrapperWorld.h"
 #import "FloatConversion.h"
 #import "KURL.h"
 #import "PageGroup.h"
 #import "TextTrackCue.h"
 #import "UserStyleSheetTypes.h"
 #import "WebCoreSystemInterface.h"
 #import <wtf/RetainPtr.h>
 #import <wtf/text/StringBuilder.h>

 using namespace std;

 namespace WebCore {

 static void userCaptionPreferencesChangedNotificationCallback(CFNotificationCenterRef, void* observer, CFStringRef, const void *, CFDictionaryRef)
 {
     static_cast<CaptionUserPreferencesMac*>(observer)->captionPreferencesChanged();
 }


 CaptionUserPreferencesMac::CaptionUserPreferencesMac(PageGroup* group)
     : CaptionUserPreferences(group)
     , m_listeningForPreferenceChanges(false)
 {
 }

 CaptionUserPreferencesMac::~CaptionUserPreferencesMac()
 {
     if (wkCaptionAppearanceGetSettingsChangedNotification())
         CFNotificationCenterRemoveObserver(CFNotificationCenterGetLocalCenter(), this, wkCaptionAppearanceGetSettingsChangedNotification(), NULL);
 }

 bool CaptionUserPreferencesMac::userHasCaptionPreferences() const
 {
     return wkCaptionAppearanceHasUserPreferences();
 }

 bool CaptionUserPreferencesMac::userPrefersCaptions() const
 {
     return wkCaptionAppearanceShowCaptionsWhenAvailable();
 }

 void CaptionUserPreferencesMac::registerForCaptionPreferencesChangedCallbacks(CaptionPreferencesChangedListener* listener)
 {
     ASSERT(!m_captionPreferenceChangeListeners.contains(listener));

     if (!wkCaptionAppearanceGetSettingsChangedNotification())
         return;

     if (!m_listeningForPreferenceChanges) {
         m_listeningForPreferenceChanges = true;
         CFNotificationCenterAddObserver (CFNotificationCenterGetLocalCenter(), this, userCaptionPreferencesChangedNotificationCallback, wkCaptionAppearanceGetSettingsChangedNotification(), NULL, CFNotificationSuspensionBehaviorCoalesce);
         updateCaptionStyleSheetOveride();
     }

     m_captionPreferenceChangeListeners.add(listener);
 }

 void CaptionUserPreferencesMac::unregisterForCaptionPreferencesChangedCallbacks(CaptionPreferencesChangedListener* listener)
 {
     if (wkCaptionAppearanceGetSettingsChangedNotification())
         m_captionPreferenceChangeListeners.remove(listener);
 }

 Color CaptionUserPreferencesMac::captionsWindowColor() const
 {
     RetainPtr<CGColorRef> color(AdoptCF, wkCaptionAppearanceCopyWindowColor());
     Color windowColor(color.get());
     if (!windowColor.isValid())
         windowColor = Color::transparent;

     CGFloat opacity;
     if (wkCaptionAppearanceGetWindowOpacity(&opacity))
         return Color(windowColor.red(), windowColor.green(), windowColor.blue(), static_cast<int>(opacity * 255));

     if (!color)
         return Color();

     return windowColor;
 }

 Color CaptionUserPreferencesMac::captionsBackgroundColor() const
 {
     // This default value must be the same as the one specified in mediaControls.css for -webkit-media-text-track-past-nodes
     // and webkit-media-text-track-future-nodes.
     DEFINE_STATIC_LOCAL(Color, defaultBackgroundColor, (Color(0, 0, 0, 0.8 * 255)));

     RetainPtr<CGColorRef> color(AdoptCF, wkCaptionAppearanceCopyBackgroundColor());
     Color backgroundColor(color.get());
     if (!backgroundColor.isValid()) {
         backgroundColor = defaultBackgroundColor;
     }

     CGFloat opacity;
     if (wkCaptionAppearanceGetBackgroundOpacity(&opacity))
         return Color(backgroundColor.red(), backgroundColor.green(), backgroundColor.blue(), static_cast<int>(opacity * 255));

     if (!color)
         return Color();

     return backgroundColor;
 }

 Color CaptionUserPreferencesMac::captionsTextColor() const
 {
     RetainPtr<CGColorRef> color(AdoptCF, wkCaptionAppearanceCopyForegroundColor());
     Color textColor(color.get());
     if (!textColor.isValid()) {
         // This default value must be the same as the one specified in mediaControls.css for -webkit-media-text-track-container.
         textColor = Color::white;
     }

     CGFloat opacity;
     if (wkCaptionAppearanceGetForegroundOpacity(&opacity))
         return Color(textColor.red(), textColor.green(), textColor.blue(), static_cast<int>(opacity * 255));

     if (!color)
         return Color();

     return textColor;
 }

 Color CaptionUserPreferencesMac::captionsEdgeColorForTextColor(const Color& textColor) const
 {
     int distanceFromWhite = differenceSquared(textColor, Color::white);
     int distanceFromBlack = differenceSquared(textColor, Color::black);

     if (distanceFromWhite < distanceFromBlack)
         return textColor.dark();

     return textColor.light();
 }

 String CaptionUserPreferencesMac::cssPropertyWithTextEdgeColor(CSSPropertyID id, const String& value, const Color& textColor) const
 {
     StringBuilder builder;

     builder.append(getPropertyNameString(id));
     builder.append(':');
     builder.append(value);
     builder.append(' ');
     builder.append(captionsEdgeColorForTextColor(textColor).serialized());
     builder.append(';');

     return builder.toString();
 }

 String CaptionUserPreferencesMac::cssColorProperty(CSSPropertyID id, const Color& color) const
 {
     StringBuilder builder;

     builder.append(getPropertyNameString(id));
     builder.append(':');
     builder.append(color.serialized());
     builder.append(';');

     return builder.toString();
 }

 String CaptionUserPreferencesMac::captionsTextEdgeStyle() const
 {
     DEFINE_STATIC_LOCAL(const String, edgeStyleRaised, (" -.05em -.05em 0 ", String::ConstructFromLiteral));
     DEFINE_STATIC_LOCAL(const String, edgeStyleDepressed, (" .05em .05em 0 ", String::ConstructFromLiteral));
     DEFINE_STATIC_LOCAL(const String, edgeStyleDropShadow, (" .075em .075em 0 ", String::ConstructFromLiteral));
     DEFINE_STATIC_LOCAL(const String, edgeStyleUniform, (" .03em ", String::ConstructFromLiteral));

     Color color = captionsTextColor();
     if (!color.isValid())
         color.setNamedColor("black");
     color = captionsEdgeColorForTextColor(color);

     wkCaptionTextEdgeStyle textEdgeStyle = static_cast<wkCaptionTextEdgeStyle>(wkCaptionAppearanceGetTextEdgeStyle());
     switch (textEdgeStyle) {
         case wkCaptionTextEdgeStyleUndefined:
         case wkCaptionTextEdgeStyleNone:
             return emptyString();

         case wkCaptionTextEdgeStyleRaised:
             return cssPropertyWithTextEdgeColor(CSSPropertyTextShadow, edgeStyleRaised, color);
         case wkCaptionTextEdgeStyleDepressed:
             return cssPropertyWithTextEdgeColor(CSSPropertyTextShadow, edgeStyleDepressed, color);
         case wkCaptionTextEdgeStyleDropShadow:
             return cssPropertyWithTextEdgeColor(CSSPropertyTextShadow, edgeStyleDropShadow, color);
         case wkCaptionTextEdgeStyleUniform:
             return cssPropertyWithTextEdgeColor(CSSPropertyWebkitTextStroke, edgeStyleUniform, color);

         case wkCaptionTextEdgeStyleMax:
             ASSERT_NOT_REACHED();
         default:
             ASSERT_NOT_REACHED();
             break;
     }

     return emptyString();
 }

 String CaptionUserPreferencesMac::captionsDefaultFont() const
 {
     RetainPtr<CGFontRef> font(AdoptCF, wkCaptionAppearanceCopyFontForStyle(wkCaptionFontStyleDefault));
     if (!font)
         return emptyString();

     RetainPtr<CFStringRef> name(AdoptCF, CGFontCopyPostScriptName(font.get()));
     if (!name)
         return emptyString();

     StringBuilder builder;

     builder.append(getPropertyNameString(CSSPropertyFontFamily));
     builder.append(": \"");
     builder.append(name.get());
     builder.append("\";");

     return builder.toString();
 }

 String CaptionUserPreferencesMac::captionsStyleSheetOverride() const
 {
     StringBuilder captionsOverrideStyleSheet;

     Color color = captionsBackgroundColor();
     if (color.isValid()) {
         captionsOverrideStyleSheet.append(" video::");
         captionsOverrideStyleSheet.append(TextTrackCue::pastNodesShadowPseudoId());
         captionsOverrideStyleSheet.append('{');
         captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyBackgroundColor, color));
         captionsOverrideStyleSheet.append('}');

         captionsOverrideStyleSheet.append(" video::");
         captionsOverrideStyleSheet.append(TextTrackCue::futureNodesShadowPseudoId());
         captionsOverrideStyleSheet.append('{');
         captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyBackgroundColor, color));
         captionsOverrideStyleSheet.append('}');
     }

     color = captionsWindowColor();
     if (color.isValid()) {
         captionsOverrideStyleSheet.append(" video::");
         captionsOverrideStyleSheet.append(TextTrackCueBox::textTrackCueBoxShadowPseudoId());
         captionsOverrideStyleSheet.append('{');
         captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyBackgroundColor, color));
         captionsOverrideStyleSheet.append('}');
     }

     color = captionsTextColor();
     String edgeStyle = captionsTextEdgeStyle();
     String fontName = captionsDefaultFont();
     if (color.isValid() || !edgeStyle.isEmpty() || !fontName.isEmpty()) {
         captionsOverrideStyleSheet.append(" video::");
         captionsOverrideStyleSheet.append(TextTrackCueBox::textTrackCueBoxShadowPseudoId());
         captionsOverrideStyleSheet.append('{');

         if (color.isValid())
             captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyColor, color));
         if (!edgeStyle.isEmpty())
             captionsOverrideStyleSheet.append(edgeStyle);
         if (!fontName.isEmpty())
             captionsOverrideStyleSheet.append(fontName);

         captionsOverrideStyleSheet.append('}');
     }

     return captionsOverrideStyleSheet.toString();
 }

 float CaptionUserPreferencesMac::captionFontSizeScale() const
 {
     CGFloat characterScale = CaptionUserPreferences::captionFontSizeScale();
     CGFloat scaleAdjustment;

     if (!wkCaptionAppearanceGetRelativeCharacterSize(&scaleAdjustment))
         return characterScale;

 #if defined(__LP64__) && __LP64__
     return narrowPrecisionToFloat(scaleAdjustment * characterScale);
 #else
     return scaleAdjustment * characterScale;
 #endif
 }

 void CaptionUserPreferencesMac::captionPreferencesChanged()
 {
     if (m_captionPreferenceChangeListeners.isEmpty())
         return;

     updateCaptionStyleSheetOveride();

     for (HashSet<CaptionPreferencesChangedListener*>::iterator i = m_captionPreferenceChangeListeners.begin(); i != m_captionPreferenceChangeListeners.end(); ++i)
         (*i)->captionPreferencesChanged();
 }

 void CaptionUserPreferencesMac::updateCaptionStyleSheetOveride()
 {
     // Identify our override style sheet with a unique URL - a new scheme and a UUID.
     DEFINE_STATIC_LOCAL(KURL, captionsStyleSheetURL, (ParsedURLString, "user-captions-override:01F6AF12-C3B0-4F70-AF5E-A3E00234DC23"));

     pageGroup()->removeUserStyleSheetFromWorld(mainThreadNormalWorld(), captionsStyleSheetURL);

     if (!userHasCaptionPreferences())
         return;

     String captionsOverrideStyleSheet = captionsStyleSheetOverride();
     if (captionsOverrideStyleSheet.isEmpty())
         return;

     pageGroup()->addUserStyleSheetToWorld(mainThreadNormalWorld(), captionsOverrideStyleSheet, captionsStyleSheetURL, Vector<String>(),
              Vector<String>(), InjectInAllFrames, UserStyleAuthorLevel, InjectInExistingDocuments);
 }

 }

 #endif // ENABLE(VIDEO_TRACK)
	/*
	* Copyright (C) 2012 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
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import "config.h"

	#if ENABLE(VIDEO_TRACK)

	#import "CaptionUserPreferencesMac.h"

	#import "ColorMac.h"
	#import "DOMWrapperWorld.h"
	#import "FloatConversion.h"
	#import "KURL.h"
	#import "PageGroup.h"
	#import "TextTrackCue.h"
	#import "UserStyleSheetTypes.h"
	#import "WebCoreSystemInterface.h"
	#import <wtf/RetainPtr.h>
	#import <wtf/text/StringBuilder.h>

	using namespace std;

	namespace WebCore {

	static void userCaptionPreferencesChangedNotificationCallback(CFNotificationCenterRef, void* observer, CFStringRef, const void *, CFDictionaryRef)
	{
	static_cast<CaptionUserPreferencesMac*>(observer)->captionPreferencesChanged();
	}


	CaptionUserPreferencesMac::CaptionUserPreferencesMac(PageGroup* group)
	: CaptionUserPreferences(group)
	, m_listeningForPreferenceChanges(false)
	{
	}

	CaptionUserPreferencesMac::~CaptionUserPreferencesMac()
	{
	if (wkCaptionAppearanceGetSettingsChangedNotification())
	CFNotificationCenterRemoveObserver(CFNotificationCenterGetLocalCenter(), this, wkCaptionAppearanceGetSettingsChangedNotification(), NULL);
	}

	bool CaptionUserPreferencesMac::userHasCaptionPreferences() const
	{
	return wkCaptionAppearanceHasUserPreferences();
	}

	bool CaptionUserPreferencesMac::userPrefersCaptions() const
	{
	return wkCaptionAppearanceShowCaptionsWhenAvailable();
	}

	void CaptionUserPreferencesMac::registerForCaptionPreferencesChangedCallbacks(CaptionPreferencesChangedListener* listener)
	{
	ASSERT(!m_captionPreferenceChangeListeners.contains(listener));

	if (!wkCaptionAppearanceGetSettingsChangedNotification())
	return;

	if (!m_listeningForPreferenceChanges) {
	m_listeningForPreferenceChanges = true;
	CFNotificationCenterAddObserver (CFNotificationCenterGetLocalCenter(), this, userCaptionPreferencesChangedNotificationCallback, wkCaptionAppearanceGetSettingsChangedNotification(), NULL, CFNotificationSuspensionBehaviorCoalesce);
	updateCaptionStyleSheetOveride();
	}

	m_captionPreferenceChangeListeners.add(listener);
	}

	void CaptionUserPreferencesMac::unregisterForCaptionPreferencesChangedCallbacks(CaptionPreferencesChangedListener* listener)
	{
	if (wkCaptionAppearanceGetSettingsChangedNotification())
	m_captionPreferenceChangeListeners.remove(listener);
	}

	Color CaptionUserPreferencesMac::captionsWindowColor() const
	{
	RetainPtr<CGColorRef> color(AdoptCF, wkCaptionAppearanceCopyWindowColor());
	Color windowColor(color.get());
	if (!windowColor.isValid())
	windowColor = Color::transparent;

	CGFloat opacity;
	if (wkCaptionAppearanceGetWindowOpacity(&opacity))
	return Color(windowColor.red(), windowColor.green(), windowColor.blue(), static_cast<int>(opacity * 255));

	if (!color)
	return Color();

	return windowColor;
	}

	Color CaptionUserPreferencesMac::captionsBackgroundColor() const
	{
	// This default value must be the same as the one specified in mediaControls.css for -webkit-media-text-track-past-nodes
	// and webkit-media-text-track-future-nodes.
	DEFINE_STATIC_LOCAL(Color, defaultBackgroundColor, (Color(0, 0, 0, 0.8 * 255)));

	RetainPtr<CGColorRef> color(AdoptCF, wkCaptionAppearanceCopyBackgroundColor());
	Color backgroundColor(color.get());
	if (!backgroundColor.isValid()) {
	backgroundColor = defaultBackgroundColor;
	}

	CGFloat opacity;
	if (wkCaptionAppearanceGetBackgroundOpacity(&opacity))
	return Color(backgroundColor.red(), backgroundColor.green(), backgroundColor.blue(), static_cast<int>(opacity * 255));

	if (!color)
	return Color();

	return backgroundColor;
	}

	Color CaptionUserPreferencesMac::captionsTextColor() const
	{
	RetainPtr<CGColorRef> color(AdoptCF, wkCaptionAppearanceCopyForegroundColor());
	Color textColor(color.get());
	if (!textColor.isValid()) {
	// This default value must be the same as the one specified in mediaControls.css for -webkit-media-text-track-container.
	textColor = Color::white;
	}

	CGFloat opacity;
	if (wkCaptionAppearanceGetForegroundOpacity(&opacity))
	return Color(textColor.red(), textColor.green(), textColor.blue(), static_cast<int>(opacity * 255));

	if (!color)
	return Color();

	return textColor;
	}

	Color CaptionUserPreferencesMac::captionsEdgeColorForTextColor(const Color& textColor) const
	{
	int distanceFromWhite = differenceSquared(textColor, Color::white);
	int distanceFromBlack = differenceSquared(textColor, Color::black);

	if (distanceFromWhite < distanceFromBlack)
	return textColor.dark();

	return textColor.light();
	}

	String CaptionUserPreferencesMac::cssPropertyWithTextEdgeColor(CSSPropertyID id, const String& value, const Color& textColor) const
	{
	StringBuilder builder;

	builder.append(getPropertyNameString(id));
	builder.append(':');
	builder.append(value);
	builder.append(' ');
	builder.append(captionsEdgeColorForTextColor(textColor).serialized());
	builder.append(';');

	return builder.toString();
	}

	String CaptionUserPreferencesMac::cssColorProperty(CSSPropertyID id, const Color& color) const
	{
	StringBuilder builder;

	builder.append(getPropertyNameString(id));
	builder.append(':');
	builder.append(color.serialized());
	builder.append(';');

	return builder.toString();
	}

	String CaptionUserPreferencesMac::captionsTextEdgeStyle() const
	{
	DEFINE_STATIC_LOCAL(const String, edgeStyleRaised, (" -.05em -.05em 0 ", String::ConstructFromLiteral));
	DEFINE_STATIC_LOCAL(const String, edgeStyleDepressed, (" .05em .05em 0 ", String::ConstructFromLiteral));
	DEFINE_STATIC_LOCAL(const String, edgeStyleDropShadow, (" .075em .075em 0 ", String::ConstructFromLiteral));
	DEFINE_STATIC_LOCAL(const String, edgeStyleUniform, (" .03em ", String::ConstructFromLiteral));

	Color color = captionsTextColor();
	if (!color.isValid())
	color.setNamedColor("black");
	color = captionsEdgeColorForTextColor(color);

	wkCaptionTextEdgeStyle textEdgeStyle = static_cast<wkCaptionTextEdgeStyle>(wkCaptionAppearanceGetTextEdgeStyle());
	switch (textEdgeStyle) {
	case wkCaptionTextEdgeStyleUndefined:
	case wkCaptionTextEdgeStyleNone:
	return emptyString();

	case wkCaptionTextEdgeStyleRaised:
	return cssPropertyWithTextEdgeColor(CSSPropertyTextShadow, edgeStyleRaised, color);
	case wkCaptionTextEdgeStyleDepressed:
	return cssPropertyWithTextEdgeColor(CSSPropertyTextShadow, edgeStyleDepressed, color);
	case wkCaptionTextEdgeStyleDropShadow:
	return cssPropertyWithTextEdgeColor(CSSPropertyTextShadow, edgeStyleDropShadow, color);
	case wkCaptionTextEdgeStyleUniform:
	return cssPropertyWithTextEdgeColor(CSSPropertyWebkitTextStroke, edgeStyleUniform, color);

	case wkCaptionTextEdgeStyleMax:
	ASSERT_NOT_REACHED();
	default:
	ASSERT_NOT_REACHED();
	break;
	}

	return emptyString();
	}

	String CaptionUserPreferencesMac::captionsDefaultFont() const
	{
	RetainPtr<CGFontRef> font(AdoptCF, wkCaptionAppearanceCopyFontForStyle(wkCaptionFontStyleDefault));
	if (!font)
	return emptyString();

	RetainPtr<CFStringRef> name(AdoptCF, CGFontCopyPostScriptName(font.get()));
	if (!name)
	return emptyString();

	StringBuilder builder;

	builder.append(getPropertyNameString(CSSPropertyFontFamily));
	builder.append(": \"");
	builder.append(name.get());
	builder.append("\";");

	return builder.toString();
	}

	String CaptionUserPreferencesMac::captionsStyleSheetOverride() const
	{
	StringBuilder captionsOverrideStyleSheet;

	Color color = captionsBackgroundColor();
	if (color.isValid()) {
	captionsOverrideStyleSheet.append(" video::");
	captionsOverrideStyleSheet.append(TextTrackCue::pastNodesShadowPseudoId());
	captionsOverrideStyleSheet.append('{');
	captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyBackgroundColor, color));
	captionsOverrideStyleSheet.append('}');

	captionsOverrideStyleSheet.append(" video::");
	captionsOverrideStyleSheet.append(TextTrackCue::futureNodesShadowPseudoId());
	captionsOverrideStyleSheet.append('{');
	captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyBackgroundColor, color));
	captionsOverrideStyleSheet.append('}');
	}

	color = captionsWindowColor();
	if (color.isValid()) {
	captionsOverrideStyleSheet.append(" video::");
	captionsOverrideStyleSheet.append(TextTrackCueBox::textTrackCueBoxShadowPseudoId());
	captionsOverrideStyleSheet.append('{');
	captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyBackgroundColor, color));
	captionsOverrideStyleSheet.append('}');
	}

	color = captionsTextColor();
	String edgeStyle = captionsTextEdgeStyle();
	String fontName = captionsDefaultFont();
	if (color.isValid() \|\| !edgeStyle.isEmpty() \|\| !fontName.isEmpty()) {
	captionsOverrideStyleSheet.append(" video::");
	captionsOverrideStyleSheet.append(TextTrackCueBox::textTrackCueBoxShadowPseudoId());
	captionsOverrideStyleSheet.append('{');

	if (color.isValid())
	captionsOverrideStyleSheet.append(cssColorProperty(CSSPropertyColor, color));
	if (!edgeStyle.isEmpty())
	captionsOverrideStyleSheet.append(edgeStyle);
	if (!fontName.isEmpty())
	captionsOverrideStyleSheet.append(fontName);

	captionsOverrideStyleSheet.append('}');
	}

	return captionsOverrideStyleSheet.toString();
	}

	float CaptionUserPreferencesMac::captionFontSizeScale() const
	{
	CGFloat characterScale = CaptionUserPreferences::captionFontSizeScale();
	CGFloat scaleAdjustment;

	if (!wkCaptionAppearanceGetRelativeCharacterSize(&scaleAdjustment))
	return characterScale;

	#if defined(__LP64__) && __LP64__
	return narrowPrecisionToFloat(scaleAdjustment * characterScale);
	#else
	return scaleAdjustment * characterScale;
	#endif
	}

	void CaptionUserPreferencesMac::captionPreferencesChanged()
	{
	if (m_captionPreferenceChangeListeners.isEmpty())
	return;

	updateCaptionStyleSheetOveride();

	for (HashSet<CaptionPreferencesChangedListener*>::iterator i = m_captionPreferenceChangeListeners.begin(); i != m_captionPreferenceChangeListeners.end(); ++i)
	(*i)->captionPreferencesChanged();
	}

	void CaptionUserPreferencesMac::updateCaptionStyleSheetOveride()
	{
	// Identify our override style sheet with a unique URL - a new scheme and a UUID.
	DEFINE_STATIC_LOCAL(KURL, captionsStyleSheetURL, (ParsedURLString, "user-captions-override:01F6AF12-C3B0-4F70-AF5E-A3E00234DC23"));

	pageGroup()->removeUserStyleSheetFromWorld(mainThreadNormalWorld(), captionsStyleSheetURL);

	if (!userHasCaptionPreferences())
	return;

	String captionsOverrideStyleSheet = captionsStyleSheetOverride();
	if (captionsOverrideStyleSheet.isEmpty())
	return;

	pageGroup()->addUserStyleSheetToWorld(mainThreadNormalWorld(), captionsOverrideStyleSheet, captionsStyleSheetURL, Vector<String>(),
	Vector<String>(), InjectInAllFrames, UserStyleAuthorLevel, InjectInExistingDocuments);
	}

	}

	#endif // ENABLE(VIDEO_TRACK)