WebCore/platform/mac/ScrollbarThemeMac.mm - WebKit - Git at Google

 /*
  * Copyright (C) 2008 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.
  */

 #include "config.h"
 #include "ScrollbarThemeMac.h"

 #include "ImageBuffer.h"
 #include "PlatformMouseEvent.h"
 #include "ScrollView.h"
 #include <Carbon/Carbon.h>
 #include <wtf/StdLibExtras.h>
 #include <wtf/UnusedParam.h>

 // FIXME: There are repainting problems due to Aqua scroll bar buttons' visual overflow.

 using namespace std;
 using namespace WebCore;

 static HashSet<Scrollbar*>* gScrollbars;

 @interface ScrollbarPrefsObserver : NSObject
 {

 }

 + (void)registerAsObserver;
 + (void)appearancePrefsChanged:(NSNotification*)theNotification;
 + (void)behaviorPrefsChanged:(NSNotification*)theNotification;

 @end

 @implementation ScrollbarPrefsObserver

 + (void)appearancePrefsChanged:(NSNotification*)unusedNotification
 {
     UNUSED_PARAM(unusedNotification);

     static_cast<ScrollbarThemeMac*>(ScrollbarTheme::nativeTheme())->preferencesChanged();
     if (!gScrollbars)
         return;
     HashSet<Scrollbar*>::iterator end = gScrollbars->end();
     for (HashSet<Scrollbar*>::iterator it = gScrollbars->begin(); it != end; ++it) {
         (*it)->styleChanged();
         (*it)->invalidate();
     }
 }

 + (void)behaviorPrefsChanged:(NSNotification*)unusedNotification
 {
     UNUSED_PARAM(unusedNotification);

     static_cast<ScrollbarThemeMac*>(ScrollbarTheme::nativeTheme())->preferencesChanged();
 }

 + (void)registerAsObserver
 {
     [[NSDistributedNotificationCenter defaultCenter] addObserver:self selector:@selector(appearancePrefsChanged:) name:@"AppleAquaScrollBarVariantChanged" object:nil suspensionBehavior:NSNotificationSuspensionBehaviorDeliverImmediately];
     [[NSDistributedNotificationCenter defaultCenter] addObserver:self selector:@selector(behaviorPrefsChanged:) name:@"AppleNoRedisplayAppearancePreferenceChanged" object:nil suspensionBehavior:NSNotificationSuspensionBehaviorCoalesce];
 }

 @end

 namespace WebCore {

 ScrollbarTheme* ScrollbarTheme::nativeTheme()
 {
     DEFINE_STATIC_LOCAL(ScrollbarThemeMac, theme, ());
     return &theme;
 }

 // FIXME: Get these numbers from CoreUI.
 static int cScrollbarThickness[] = { 15, 11 };
 static int cRealButtonLength[] = { 28, 21 };
 static int cButtonInset[] = { 14, 11 };
 static int cButtonHitInset[] = { 3, 2 };
 // cRealButtonLength - cButtonInset
 static int cButtonLength[] = { 14, 10 };
 static int cThumbMinLength[] = { 26, 20 };

 static int cOuterButtonLength[] = { 16, 14 }; // The outer button in a double button pair is a bit bigger.
 static int cOuterButtonOverlap = 2;

 static float gInitialButtonDelay = 0.5f;
 static float gAutoscrollButtonDelay = 0.05f;
 static bool gJumpOnTrackClick = false;
 static ScrollbarButtonsPlacement gButtonPlacement = ScrollbarButtonsDoubleEnd;

 static void updateArrowPlacement()
 {
     NSString *buttonPlacement = [[NSUserDefaults standardUserDefaults] objectForKey:@"AppleScrollBarVariant"];
     if ([buttonPlacement isEqualToString:@"Single"])
         gButtonPlacement = ScrollbarButtonsSingle;
     else if ([buttonPlacement isEqualToString:@"DoubleMin"])
         gButtonPlacement = ScrollbarButtonsDoubleStart;
     else if ([buttonPlacement isEqualToString:@"DoubleBoth"])
         gButtonPlacement = ScrollbarButtonsDoubleBoth;
     else
         gButtonPlacement = ScrollbarButtonsDoubleEnd; // The default is ScrollbarButtonsDoubleEnd.
 }

 void ScrollbarThemeMac::registerScrollbar(Scrollbar* scrollbar)
 {
     if (!gScrollbars)
         gScrollbars = new HashSet<Scrollbar*>;
     gScrollbars->add(scrollbar);
 }

 void ScrollbarThemeMac::unregisterScrollbar(Scrollbar* scrollbar)
 {
     gScrollbars->remove(scrollbar);
     if (gScrollbars->isEmpty()) {
         delete gScrollbars;
         gScrollbars = 0;
     }
 }

 ScrollbarThemeMac::ScrollbarThemeMac()
 {
     static bool initialized;
     if (!initialized) {
         initialized = true;
         [ScrollbarPrefsObserver registerAsObserver];
         preferencesChanged();
     }
 }

 ScrollbarThemeMac::~ScrollbarThemeMac()
 {
 }

 void ScrollbarThemeMac::preferencesChanged()
 {
     NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
     [defaults synchronize];
     updateArrowPlacement();
     gInitialButtonDelay = [defaults floatForKey:@"NSScrollerButtonDelay"];
     gAutoscrollButtonDelay = [defaults floatForKey:@"NSScrollerButtonPeriod"];
     gJumpOnTrackClick = [defaults boolForKey:@"AppleScrollerPagingBehavior"];
 }

 int ScrollbarThemeMac::scrollbarThickness(ScrollbarControlSize controlSize)
 {
     return cScrollbarThickness[controlSize];
 }

 double ScrollbarThemeMac::initialAutoscrollTimerDelay()
 {
     return gInitialButtonDelay;
 }

 double ScrollbarThemeMac::autoscrollTimerDelay()
 {
     return gAutoscrollButtonDelay;
 }

 ScrollbarButtonsPlacement ScrollbarThemeMac::buttonsPlacement() const
 {
     return gButtonPlacement;
 }

 bool ScrollbarThemeMac::hasButtons(Scrollbar* scrollbar)
 {
     return scrollbar->enabled() && (scrollbar->orientation() == HorizontalScrollbar ?
              scrollbar->width() :
              scrollbar->height()) >= 2 * (cRealButtonLength[scrollbar->controlSize()] - cButtonHitInset[scrollbar->controlSize()]);
 }

 bool ScrollbarThemeMac::hasThumb(Scrollbar* scrollbar)
 {
     return scrollbar->enabled() && (scrollbar->orientation() == HorizontalScrollbar ?
              scrollbar->width() :
              scrollbar->height()) >= 2 * cButtonInset[scrollbar->controlSize()] + cThumbMinLength[scrollbar->controlSize()] + 1;
 }

 static IntRect buttonRepaintRect(const IntRect& buttonRect, ScrollbarOrientation orientation, ScrollbarControlSize controlSize, bool start)
 {
     IntRect paintRect(buttonRect);
     if (orientation == HorizontalScrollbar) {
         paintRect.setWidth(cRealButtonLength[controlSize]);
         if (!start)
             paintRect.setX(buttonRect.x() - (cRealButtonLength[controlSize] - buttonRect.width()));
     } else {
         paintRect.setHeight(cRealButtonLength[controlSize]);
         if (!start)
             paintRect.setY(buttonRect.y() - (cRealButtonLength[controlSize] - buttonRect.height()));
     }

     return paintRect;
 }

 IntRect ScrollbarThemeMac::backButtonRect(Scrollbar* scrollbar, ScrollbarPart part, bool painting)
 {
     IntRect result;

     if (part == BackButtonStartPart && (buttonsPlacement() == ScrollbarButtonsNone || buttonsPlacement() == ScrollbarButtonsDoubleEnd))
         return result;

     if (part == BackButtonEndPart && (buttonsPlacement() == ScrollbarButtonsNone || buttonsPlacement() == ScrollbarButtonsDoubleStart || buttonsPlacement() == ScrollbarButtonsSingle))
         return result;

     int thickness = scrollbarThickness(scrollbar->controlSize());
     bool outerButton = part == BackButtonStartPart && (buttonsPlacement() == ScrollbarButtonsDoubleStart || buttonsPlacement() == ScrollbarButtonsDoubleBoth);
     if (outerButton) {
         if (scrollbar->orientation() == HorizontalScrollbar)
             result = IntRect(scrollbar->x(), scrollbar->y(), cOuterButtonLength[scrollbar->controlSize()] + painting ? cOuterButtonOverlap : 0, thickness);
         else
             result = IntRect(scrollbar->x(), scrollbar->y(), thickness, cOuterButtonLength[scrollbar->controlSize()] + painting ? cOuterButtonOverlap : 0);
         return result;
     }

     // Our repaint rect is slightly larger, since we are a button that is adjacent to the track.
     if (scrollbar->orientation() == HorizontalScrollbar) {
         int start = part == BackButtonStartPart ? scrollbar->x() : scrollbar->x() + scrollbar->width() - cOuterButtonLength[scrollbar->controlSize()] - cButtonLength[scrollbar->controlSize()];
         result = IntRect(start, scrollbar->y(), cButtonLength[scrollbar->controlSize()], thickness);
     } else {
         int start = part == BackButtonStartPart ? scrollbar->y() : scrollbar->y() + scrollbar->height() - cOuterButtonLength[scrollbar->controlSize()] - cButtonLength[scrollbar->controlSize()];
         result = IntRect(scrollbar->x(), start, thickness, cButtonLength[scrollbar->controlSize()]);
     }

     if (painting)
         return buttonRepaintRect(result, scrollbar->orientation(), scrollbar->controlSize(), part == BackButtonStartPart);
     return result;
 }

 IntRect ScrollbarThemeMac::forwardButtonRect(Scrollbar* scrollbar, ScrollbarPart part, bool painting)
 {
     IntRect result;

     if (part == ForwardButtonEndPart && (buttonsPlacement() == ScrollbarButtonsNone || buttonsPlacement() == ScrollbarButtonsDoubleStart))
         return result;

     if (part == ForwardButtonStartPart && (buttonsPlacement() == ScrollbarButtonsNone || buttonsPlacement() == ScrollbarButtonsDoubleEnd || buttonsPlacement() == ScrollbarButtonsSingle))
         return result;

     int thickness = scrollbarThickness(scrollbar->controlSize());
     int outerButtonLength = cOuterButtonLength[scrollbar->controlSize()];
     int buttonLength = cButtonLength[scrollbar->controlSize()];

     bool outerButton = part == ForwardButtonEndPart && (buttonsPlacement() == ScrollbarButtonsDoubleEnd || buttonsPlacement() == ScrollbarButtonsDoubleBoth);
     if (outerButton) {
         if (scrollbar->orientation() == HorizontalScrollbar) {
             result = IntRect(scrollbar->x() + scrollbar->width() - outerButtonLength, scrollbar->y(), outerButtonLength, thickness);
             if (painting)
                 result.inflateX(cOuterButtonOverlap);
         } else {
             result = IntRect(scrollbar->x(), scrollbar->y() + scrollbar->height() - outerButtonLength, thickness, outerButtonLength);
             if (painting)
                 result.inflateY(cOuterButtonOverlap);
         }
         return result;
     }

     if (scrollbar->orientation() == HorizontalScrollbar) {
         int start = part == ForwardButtonEndPart ? scrollbar->x() + scrollbar->width() - buttonLength : scrollbar->x() + outerButtonLength;
         result = IntRect(start, scrollbar->y(), buttonLength, thickness);
     } else {
         int start = part == ForwardButtonEndPart ? scrollbar->y() + scrollbar->height() - buttonLength : scrollbar->y() + outerButtonLength;
         result = IntRect(scrollbar->x(), start, thickness, buttonLength);
     }
     if (painting)
         return buttonRepaintRect(result, scrollbar->orientation(), scrollbar->controlSize(), part == ForwardButtonStartPart);
     return result;
 }

 IntRect ScrollbarThemeMac::trackRect(Scrollbar* scrollbar, bool painting)
 {
     if (painting || !hasButtons(scrollbar))
         return scrollbar->frameRect();

     IntRect result;
     int thickness = scrollbarThickness(scrollbar->controlSize());
     int startWidth = 0;
     int endWidth = 0;
     int outerButtonLength = cOuterButtonLength[scrollbar->controlSize()];
     int buttonLength = cButtonLength[scrollbar->controlSize()];
     int doubleButtonLength = outerButtonLength + buttonLength;
     switch (buttonsPlacement()) {
         case ScrollbarButtonsSingle:
             startWidth = buttonLength;
             endWidth = buttonLength;
             break;
         case ScrollbarButtonsDoubleStart:
             startWidth = doubleButtonLength;
             break;
         case ScrollbarButtonsDoubleEnd:
             endWidth = doubleButtonLength;
             break;
         case ScrollbarButtonsDoubleBoth:
             startWidth = doubleButtonLength;
             endWidth = doubleButtonLength;
             break;
         default:
             break;
     }

     int totalWidth = startWidth + endWidth;
     if (scrollbar->orientation() == HorizontalScrollbar)
         return IntRect(scrollbar->x() + startWidth, scrollbar->y(), scrollbar->width() - totalWidth, thickness);
     return IntRect(scrollbar->x(), scrollbar->y() + startWidth, thickness, scrollbar->height() - totalWidth);
 }

 int ScrollbarThemeMac::minimumThumbLength(Scrollbar* scrollbar)
 {
     return cThumbMinLength[scrollbar->controlSize()];
 }

 bool ScrollbarThemeMac::shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent& evt)
 {
     if (evt.button() != LeftButton)
         return false;
     if (gJumpOnTrackClick)
         return !evt.altKey();
     return evt.altKey();
 }

 static int scrollbarPartToHIPressedState(ScrollbarPart part)
 {
     switch (part) {
         case BackButtonStartPart:
             return kThemeTopOutsideArrowPressed;
         case BackButtonEndPart:
             return kThemeTopOutsideArrowPressed; // This does not make much sense.  For some reason the outside constant is required.
         case ForwardButtonStartPart:
             return kThemeTopInsideArrowPressed;
         case ForwardButtonEndPart:
             return kThemeBottomOutsideArrowPressed;
         case ThumbPart:
             return kThemeThumbPressed;
         default:
             return 0;
     }
 }

 bool ScrollbarThemeMac::paint(Scrollbar* scrollbar, GraphicsContext* context, const IntRect& damageRect)
 {
     HIThemeTrackDrawInfo trackInfo;
     trackInfo.version = 0;
     trackInfo.kind = scrollbar->controlSize() == RegularScrollbar ? kThemeMediumScrollBar : kThemeSmallScrollBar;
     trackInfo.bounds = scrollbar->frameRect();
     trackInfo.min = 0;
     trackInfo.max = scrollbar->maximum();
     trackInfo.value = scrollbar->currentPos();
     trackInfo.trackInfo.scrollbar.viewsize = scrollbar->pageStep();
     trackInfo.attributes = 0;
     if (scrollbar->orientation() == HorizontalScrollbar)
         trackInfo.attributes |= kThemeTrackHorizontal;

     if (!scrollbar->enabled())
         trackInfo.enableState = kThemeTrackDisabled;
     else
         trackInfo.enableState = scrollbar->client()->isActive() ? kThemeTrackActive : kThemeTrackInactive;

     if (hasThumb(scrollbar))
         trackInfo.attributes |= kThemeTrackShowThumb;
     else if (!hasButtons(scrollbar))
         trackInfo.enableState = kThemeTrackNothingToScroll;
     trackInfo.trackInfo.scrollbar.pressState = scrollbarPartToHIPressedState(scrollbar->pressedPart());

     CGAffineTransform currentCTM = CGContextGetCTM(context->platformContext());

     // The Aqua scrollbar is buggy when rotated and scaled.  We will just draw into a bitmap if we detect a scale or rotation.
     bool canDrawDirectly = currentCTM.a == 1.0f && currentCTM.b == 0.0f && currentCTM.c == 0.0f && (currentCTM.d == 1.0f || currentCTM.d == -1.0f);
     if (canDrawDirectly)
         HIThemeDrawTrack(&trackInfo, 0, context->platformContext(), kHIThemeOrientationNormal);
     else {
         trackInfo.bounds = IntRect(IntPoint(), scrollbar->frameRect().size());

         IntRect bufferRect(scrollbar->frameRect());
         bufferRect.intersect(damageRect);
         bufferRect.move(-scrollbar->frameRect().x(), -scrollbar->frameRect().y());

         OwnPtr<ImageBuffer> imageBuffer = ImageBuffer::create(bufferRect.size());
         if (!imageBuffer)
             return true;

         HIThemeDrawTrack(&trackInfo, 0, imageBuffer->context()->platformContext(), kHIThemeOrientationNormal);
         context->drawImage(imageBuffer->image(), DeviceColorSpace, scrollbar->frameRect().location());
     }

     return true;
 }

 }
	/*
	* Copyright (C) 2008 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.
	*/

	#include "config.h"
	#include "ScrollbarThemeMac.h"

	#include "ImageBuffer.h"
	#include "PlatformMouseEvent.h"
	#include "ScrollView.h"
	#include <Carbon/Carbon.h>
	#include <wtf/StdLibExtras.h>
	#include <wtf/UnusedParam.h>

	// FIXME: There are repainting problems due to Aqua scroll bar buttons' visual overflow.

	using namespace std;
	using namespace WebCore;

	static HashSet<Scrollbar> gScrollbars;

	@interface ScrollbarPrefsObserver : NSObject
	{

	}

	+ (void)registerAsObserver;
	+ (void)appearancePrefsChanged:(NSNotification*)theNotification;
	+ (void)behaviorPrefsChanged:(NSNotification*)theNotification;

	@end

	@implementation ScrollbarPrefsObserver

	+ (void)appearancePrefsChanged:(NSNotification*)unusedNotification
	{
	UNUSED_PARAM(unusedNotification);

	static_cast<ScrollbarThemeMac*>(ScrollbarTheme::nativeTheme())->preferencesChanged();
	if (!gScrollbars)
	return;
	HashSet<Scrollbar*>::iterator end = gScrollbars->end();
	for (HashSet<Scrollbar*>::iterator it = gScrollbars->begin(); it != end; ++it) {
	(*it)->styleChanged();
	(*it)->invalidate();
	}
	}

	+ (void)behaviorPrefsChanged:(NSNotification*)unusedNotification
	{
	UNUSED_PARAM(unusedNotification);

	static_cast<ScrollbarThemeMac*>(ScrollbarTheme::nativeTheme())->preferencesChanged();
	}

	+ (void)registerAsObserver
	{
	[[NSDistributedNotificationCenter defaultCenter] addObserver:self selector:@selector(appearancePrefsChanged:) name:@"AppleAquaScrollBarVariantChanged" object:nil suspensionBehavior:NSNotificationSuspensionBehaviorDeliverImmediately];
	[[NSDistributedNotificationCenter defaultCenter] addObserver:self selector:@selector(behaviorPrefsChanged:) name:@"AppleNoRedisplayAppearancePreferenceChanged" object:nil suspensionBehavior:NSNotificationSuspensionBehaviorCoalesce];
	}

	@end

	namespace WebCore {

	ScrollbarTheme* ScrollbarTheme::nativeTheme()
	{
	DEFINE_STATIC_LOCAL(ScrollbarThemeMac, theme, ());
	return &theme;
	}

	// FIXME: Get these numbers from CoreUI.
	static int cScrollbarThickness[] = { 15, 11 };
	static int cRealButtonLength[] = { 28, 21 };
	static int cButtonInset[] = { 14, 11 };
	static int cButtonHitInset[] = { 3, 2 };
	// cRealButtonLength - cButtonInset
	static int cButtonLength[] = { 14, 10 };
	static int cThumbMinLength[] = { 26, 20 };

	static int cOuterButtonLength[] = { 16, 14 }; // The outer button in a double button pair is a bit bigger.
	static int cOuterButtonOverlap = 2;

	static float gInitialButtonDelay = 0.5f;
	static float gAutoscrollButtonDelay = 0.05f;
	static bool gJumpOnTrackClick = false;
	static ScrollbarButtonsPlacement gButtonPlacement = ScrollbarButtonsDoubleEnd;

	static void updateArrowPlacement()
	{
	NSString *buttonPlacement = [[NSUserDefaults standardUserDefaults] objectForKey:@"AppleScrollBarVariant"];
	if ([buttonPlacement isEqualToString:@"Single"])
	gButtonPlacement = ScrollbarButtonsSingle;
	else if ([buttonPlacement isEqualToString:@"DoubleMin"])
	gButtonPlacement = ScrollbarButtonsDoubleStart;
	else if ([buttonPlacement isEqualToString:@"DoubleBoth"])
	gButtonPlacement = ScrollbarButtonsDoubleBoth;
	else
	gButtonPlacement = ScrollbarButtonsDoubleEnd; // The default is ScrollbarButtonsDoubleEnd.
	}

	void ScrollbarThemeMac::registerScrollbar(Scrollbar* scrollbar)
	{
	if (!gScrollbars)
	gScrollbars = new HashSet<Scrollbar*>;
	gScrollbars->add(scrollbar);
	}

	void ScrollbarThemeMac::unregisterScrollbar(Scrollbar* scrollbar)
	{
	gScrollbars->remove(scrollbar);
	if (gScrollbars->isEmpty()) {
	delete gScrollbars;
	gScrollbars = 0;
	}
	}

	ScrollbarThemeMac::ScrollbarThemeMac()
	{
	static bool initialized;
	if (!initialized) {
	initialized = true;
	[ScrollbarPrefsObserver registerAsObserver];
	preferencesChanged();
	}
	}

	ScrollbarThemeMac::~ScrollbarThemeMac()
	{
	}

	void ScrollbarThemeMac::preferencesChanged()
	{
	NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
	[defaults synchronize];
	updateArrowPlacement();
	gInitialButtonDelay = [defaults floatForKey:@"NSScrollerButtonDelay"];
	gAutoscrollButtonDelay = [defaults floatForKey:@"NSScrollerButtonPeriod"];
	gJumpOnTrackClick = [defaults boolForKey:@"AppleScrollerPagingBehavior"];
	}

	int ScrollbarThemeMac::scrollbarThickness(ScrollbarControlSize controlSize)
	{
	return cScrollbarThickness[controlSize];
	}

	double ScrollbarThemeMac::initialAutoscrollTimerDelay()
	{
	return gInitialButtonDelay;
	}

	double ScrollbarThemeMac::autoscrollTimerDelay()
	{
	return gAutoscrollButtonDelay;
	}

	ScrollbarButtonsPlacement ScrollbarThemeMac::buttonsPlacement() const
	{
	return gButtonPlacement;
	}

	bool ScrollbarThemeMac::hasButtons(Scrollbar* scrollbar)
	{
	return scrollbar->enabled() && (scrollbar->orientation() == HorizontalScrollbar ?
	scrollbar->width() :
	scrollbar->height()) >= 2 * (cRealButtonLength[scrollbar->controlSize()] - cButtonHitInset[scrollbar->controlSize()]);
	}

	bool ScrollbarThemeMac::hasThumb(Scrollbar* scrollbar)
	{
	return scrollbar->enabled() && (scrollbar->orientation() == HorizontalScrollbar ?
	scrollbar->width() :
	scrollbar->height()) >= 2 * cButtonInset[scrollbar->controlSize()] + cThumbMinLength[scrollbar->controlSize()] + 1;
	}

	static IntRect buttonRepaintRect(const IntRect& buttonRect, ScrollbarOrientation orientation, ScrollbarControlSize controlSize, bool start)
	{
	IntRect paintRect(buttonRect);
	if (orientation == HorizontalScrollbar) {
	paintRect.setWidth(cRealButtonLength[controlSize]);
	if (!start)
	paintRect.setX(buttonRect.x() - (cRealButtonLength[controlSize] - buttonRect.width()));
	} else {
	paintRect.setHeight(cRealButtonLength[controlSize]);
	if (!start)
	paintRect.setY(buttonRect.y() - (cRealButtonLength[controlSize] - buttonRect.height()));
	}

	return paintRect;
	}

	IntRect ScrollbarThemeMac::backButtonRect(Scrollbar* scrollbar, ScrollbarPart part, bool painting)
	{
	IntRect result;

	if (part == BackButtonStartPart && (buttonsPlacement() == ScrollbarButtonsNone \|\| buttonsPlacement() == ScrollbarButtonsDoubleEnd))
	return result;

	if (part == BackButtonEndPart && (buttonsPlacement() == ScrollbarButtonsNone \|\| buttonsPlacement() == ScrollbarButtonsDoubleStart \|\| buttonsPlacement() == ScrollbarButtonsSingle))
	return result;

	int thickness = scrollbarThickness(scrollbar->controlSize());
	bool outerButton = part == BackButtonStartPart && (buttonsPlacement() == ScrollbarButtonsDoubleStart \|\| buttonsPlacement() == ScrollbarButtonsDoubleBoth);
	if (outerButton) {
	if (scrollbar->orientation() == HorizontalScrollbar)
	result = IntRect(scrollbar->x(), scrollbar->y(), cOuterButtonLength[scrollbar->controlSize()] + painting ? cOuterButtonOverlap : 0, thickness);
	else
	result = IntRect(scrollbar->x(), scrollbar->y(), thickness, cOuterButtonLength[scrollbar->controlSize()] + painting ? cOuterButtonOverlap : 0);
	return result;
	}

	// Our repaint rect is slightly larger, since we are a button that is adjacent to the track.
	if (scrollbar->orientation() == HorizontalScrollbar) {
	int start = part == BackButtonStartPart ? scrollbar->x() : scrollbar->x() + scrollbar->width() - cOuterButtonLength[scrollbar->controlSize()] - cButtonLength[scrollbar->controlSize()];
	result = IntRect(start, scrollbar->y(), cButtonLength[scrollbar->controlSize()], thickness);
	} else {
	int start = part == BackButtonStartPart ? scrollbar->y() : scrollbar->y() + scrollbar->height() - cOuterButtonLength[scrollbar->controlSize()] - cButtonLength[scrollbar->controlSize()];
	result = IntRect(scrollbar->x(), start, thickness, cButtonLength[scrollbar->controlSize()]);
	}

	if (painting)
	return buttonRepaintRect(result, scrollbar->orientation(), scrollbar->controlSize(), part == BackButtonStartPart);
	return result;
	}

	IntRect ScrollbarThemeMac::forwardButtonRect(Scrollbar* scrollbar, ScrollbarPart part, bool painting)
	{
	IntRect result;

	if (part == ForwardButtonEndPart && (buttonsPlacement() == ScrollbarButtonsNone \|\| buttonsPlacement() == ScrollbarButtonsDoubleStart))
	return result;

	if (part == ForwardButtonStartPart && (buttonsPlacement() == ScrollbarButtonsNone \|\| buttonsPlacement() == ScrollbarButtonsDoubleEnd \|\| buttonsPlacement() == ScrollbarButtonsSingle))
	return result;

	int thickness = scrollbarThickness(scrollbar->controlSize());
	int outerButtonLength = cOuterButtonLength[scrollbar->controlSize()];
	int buttonLength = cButtonLength[scrollbar->controlSize()];

	bool outerButton = part == ForwardButtonEndPart && (buttonsPlacement() == ScrollbarButtonsDoubleEnd \|\| buttonsPlacement() == ScrollbarButtonsDoubleBoth);
	if (outerButton) {
	if (scrollbar->orientation() == HorizontalScrollbar) {
	result = IntRect(scrollbar->x() + scrollbar->width() - outerButtonLength, scrollbar->y(), outerButtonLength, thickness);
	if (painting)
	result.inflateX(cOuterButtonOverlap);
	} else {
	result = IntRect(scrollbar->x(), scrollbar->y() + scrollbar->height() - outerButtonLength, thickness, outerButtonLength);
	if (painting)
	result.inflateY(cOuterButtonOverlap);
	}
	return result;
	}

	if (scrollbar->orientation() == HorizontalScrollbar) {
	int start = part == ForwardButtonEndPart ? scrollbar->x() + scrollbar->width() - buttonLength : scrollbar->x() + outerButtonLength;
	result = IntRect(start, scrollbar->y(), buttonLength, thickness);
	} else {
	int start = part == ForwardButtonEndPart ? scrollbar->y() + scrollbar->height() - buttonLength : scrollbar->y() + outerButtonLength;
	result = IntRect(scrollbar->x(), start, thickness, buttonLength);
	}
	if (painting)
	return buttonRepaintRect(result, scrollbar->orientation(), scrollbar->controlSize(), part == ForwardButtonStartPart);
	return result;
	}

	IntRect ScrollbarThemeMac::trackRect(Scrollbar* scrollbar, bool painting)
	{
	if (painting \|\| !hasButtons(scrollbar))
	return scrollbar->frameRect();

	IntRect result;
	int thickness = scrollbarThickness(scrollbar->controlSize());
	int startWidth = 0;
	int endWidth = 0;
	int outerButtonLength = cOuterButtonLength[scrollbar->controlSize()];
	int buttonLength = cButtonLength[scrollbar->controlSize()];
	int doubleButtonLength = outerButtonLength + buttonLength;
	switch (buttonsPlacement()) {
	case ScrollbarButtonsSingle:
	startWidth = buttonLength;
	endWidth = buttonLength;
	break;
	case ScrollbarButtonsDoubleStart:
	startWidth = doubleButtonLength;
	break;
	case ScrollbarButtonsDoubleEnd:
	endWidth = doubleButtonLength;
	break;
	case ScrollbarButtonsDoubleBoth:
	startWidth = doubleButtonLength;
	endWidth = doubleButtonLength;
	break;
	default:
	break;
	}

	int totalWidth = startWidth + endWidth;
	if (scrollbar->orientation() == HorizontalScrollbar)
	return IntRect(scrollbar->x() + startWidth, scrollbar->y(), scrollbar->width() - totalWidth, thickness);
	return IntRect(scrollbar->x(), scrollbar->y() + startWidth, thickness, scrollbar->height() - totalWidth);
	}

	int ScrollbarThemeMac::minimumThumbLength(Scrollbar* scrollbar)
	{
	return cThumbMinLength[scrollbar->controlSize()];
	}

	bool ScrollbarThemeMac::shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent& evt)
	{
	if (evt.button() != LeftButton)
	return false;
	if (gJumpOnTrackClick)
	return !evt.altKey();
	return evt.altKey();
	}

	static int scrollbarPartToHIPressedState(ScrollbarPart part)
	{
	switch (part) {
	case BackButtonStartPart:
	return kThemeTopOutsideArrowPressed;
	case BackButtonEndPart:
	return kThemeTopOutsideArrowPressed; // This does not make much sense. For some reason the outside constant is required.
	case ForwardButtonStartPart:
	return kThemeTopInsideArrowPressed;
	case ForwardButtonEndPart:
	return kThemeBottomOutsideArrowPressed;
	case ThumbPart:
	return kThemeThumbPressed;
	default:
	return 0;
	}
	}

	bool ScrollbarThemeMac::paint(Scrollbar* scrollbar, GraphicsContext* context, const IntRect& damageRect)
	{
	HIThemeTrackDrawInfo trackInfo;
	trackInfo.version = 0;
	trackInfo.kind = scrollbar->controlSize() == RegularScrollbar ? kThemeMediumScrollBar : kThemeSmallScrollBar;
	trackInfo.bounds = scrollbar->frameRect();
	trackInfo.min = 0;
	trackInfo.max = scrollbar->maximum();
	trackInfo.value = scrollbar->currentPos();
	trackInfo.trackInfo.scrollbar.viewsize = scrollbar->pageStep();
	trackInfo.attributes = 0;
	if (scrollbar->orientation() == HorizontalScrollbar)
	trackInfo.attributes \|= kThemeTrackHorizontal;

	if (!scrollbar->enabled())
	trackInfo.enableState = kThemeTrackDisabled;
	else
	trackInfo.enableState = scrollbar->client()->isActive() ? kThemeTrackActive : kThemeTrackInactive;

	if (hasThumb(scrollbar))
	trackInfo.attributes \|= kThemeTrackShowThumb;
	else if (!hasButtons(scrollbar))
	trackInfo.enableState = kThemeTrackNothingToScroll;
	trackInfo.trackInfo.scrollbar.pressState = scrollbarPartToHIPressedState(scrollbar->pressedPart());

	CGAffineTransform currentCTM = CGContextGetCTM(context->platformContext());

	// The Aqua scrollbar is buggy when rotated and scaled. We will just draw into a bitmap if we detect a scale or rotation.
	bool canDrawDirectly = currentCTM.a == 1.0f && currentCTM.b == 0.0f && currentCTM.c == 0.0f && (currentCTM.d == 1.0f \|\| currentCTM.d == -1.0f);
	if (canDrawDirectly)
	HIThemeDrawTrack(&trackInfo, 0, context->platformContext(), kHIThemeOrientationNormal);
	else {
	trackInfo.bounds = IntRect(IntPoint(), scrollbar->frameRect().size());

	IntRect bufferRect(scrollbar->frameRect());
	bufferRect.intersect(damageRect);
	bufferRect.move(-scrollbar->frameRect().x(), -scrollbar->frameRect().y());

	OwnPtr<ImageBuffer> imageBuffer = ImageBuffer::create(bufferRect.size());
	if (!imageBuffer)
	return true;

	HIThemeDrawTrack(&trackInfo, 0, imageBuffer->context()->platformContext(), kHIThemeOrientationNormal);
	context->drawImage(imageBuffer->image(), DeviceColorSpace, scrollbar->frameRect().location());
	}

	return true;
	}

	}