third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.mm - chromium/src - Git at Google

 /*
  * Copyright (C) 2008, 2011 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 "platform/RuntimeEnabledFeatures.h"
 #include "platform/scroll/ScrollbarThemeMac.h"

 #include <Carbon/Carbon.h>
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/mac/ColorMac.h"
 #include "platform/mac/LocalCurrentGraphicsContext.h"
 #include "platform/mac/NSScrollerImpDetails.h"
 #include "platform/mac/ScrollAnimatorMac.h"
 #include "platform/scroll/ScrollbarThemeClient.h"
 #include "public/platform/WebMouseEvent.h"
 #include "public/platform/WebThemeEngine.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebRect.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "wtf/HashSet.h"
 #include "wtf/RetainPtr.h"
 #include "wtf/StdLibExtras.h"

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

 using namespace blink;

 @interface NSColor (WebNSColorDetails)
 + (NSImage*)_linenPatternImage;
 @end

 @interface BlinkScrollbarObserver : NSObject {
   blink::ScrollbarThemeClient* _scrollbar;
   RetainPtr<ScrollbarPainter> _scrollbarPainter;
 }
 - (id)initWithScrollbar:(blink::ScrollbarThemeClient*)scrollbar
                 painter:(const RetainPtr<ScrollbarPainter>&)painter;
 @end

 @implementation BlinkScrollbarObserver

 - (id)initWithScrollbar:(blink::ScrollbarThemeClient*)scrollbar
                 painter:(const RetainPtr<ScrollbarPainter>&)painter {
   if (!(self = [super init]))
     return nil;
   _scrollbar = scrollbar;
   _scrollbarPainter = painter;
   [_scrollbarPainter.get() addObserver:self
                             forKeyPath:@"knobAlpha"
                                options:0
                                context:nil];
   return self;
 }

 - (id)painter {
   return _scrollbarPainter.get();
 }

 - (void)dealloc {
   [_scrollbarPainter.get() removeObserver:self forKeyPath:@"knobAlpha"];
   [super dealloc];
 }

 - (void)observeValueForKeyPath:(NSString*)keyPath
                       ofObject:(id)object
                         change:(NSDictionary*)change
                        context:(void*)context {
   if ([keyPath isEqualToString:@"knobAlpha"]) {
     BOOL visible = [_scrollbarPainter.get() knobAlpha] > 0;
     _scrollbar->setScrollbarsHidden(!visible);
   }
 }

 @end

 namespace blink {

 typedef HashSet<ScrollbarThemeClient*> ScrollbarSet;

 static ScrollbarSet& scrollbarSet() {
   DEFINE_STATIC_LOCAL(ScrollbarSet, set, ());
   return set;
 }

 static float gInitialButtonDelay = 0.5f;
 static float gAutoscrollButtonDelay = 0.05f;
 static NSScrollerStyle gPreferredScrollerStyle = NSScrollerStyleLegacy;

 typedef HashMap<ScrollbarThemeClient*, RetainPtr<BlinkScrollbarObserver>>
     ScrollbarPainterMap;

 static ScrollbarPainterMap& scrollbarPainterMap() {
   static ScrollbarPainterMap* map = new ScrollbarPainterMap;
   return *map;
 }

 static bool supportsExpandedScrollbars() {
   // FIXME: This is temporary until all platforms that support ScrollbarPainter
   // support this part of the API.
   static bool globalSupportsExpandedScrollbars =
       [NSClassFromString(@"NSScrollerImp")
           instancesRespondToSelector:@selector(setExpanded:)];
   return globalSupportsExpandedScrollbars;
 }

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

 void ScrollbarThemeMac::paintTickmarks(GraphicsContext& context,
                                        const Scrollbar& scrollbar,
                                        const IntRect& rect) {
   IntRect tickmarkTrackRect = rect;
   tickmarkTrackRect.setX(tickmarkTrackRect.x() + 1);
   tickmarkTrackRect.setWidth(tickmarkTrackRect.width() - 1);
   ScrollbarTheme::paintTickmarks(context, scrollbar, tickmarkTrackRect);
 }

 ScrollbarThemeMac::~ScrollbarThemeMac() {}

 void ScrollbarThemeMac::preferencesChanged(
     float initialButtonDelay,
     float autoscrollButtonDelay,
     NSScrollerStyle preferredScrollerStyle,
     bool redraw,
     WebScrollbarButtonsPlacement buttonPlacement) {
   updateButtonPlacement(buttonPlacement);
   gInitialButtonDelay = initialButtonDelay;
   gAutoscrollButtonDelay = autoscrollButtonDelay;
   gPreferredScrollerStyle = preferredScrollerStyle;
   if (redraw && !scrollbarSet().isEmpty()) {
     ScrollbarSet::iterator end = scrollbarSet().end();
     for (ScrollbarSet::iterator it = scrollbarSet().begin(); it != end; ++it) {
       (*it)->styleChanged();
       (*it)->invalidate();
     }
   }
 }

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

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

 bool ScrollbarThemeMac::shouldDragDocumentInsteadOfThumb(
     const ScrollbarThemeClient&,
     const WebMouseEvent& event) {
   return (event.modifiers() & WebInputEvent::Modifiers::AltKey) != 0;
 }

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

 ScrollbarPart ScrollbarThemeMac::invalidateOnThumbPositionChange(
     const ScrollbarThemeClient& scrollbar,
     float oldPosition,
     float newPosition) const {
   // ScrollAnimatorMac will invalidate scrollbar parts if necessary.
   return NoPart;
 }

 void ScrollbarThemeMac::registerScrollbar(ScrollbarThemeClient& scrollbar) {
   scrollbarSet().insert(&scrollbar);

   bool isHorizontal = scrollbar.orientation() == HorizontalScrollbar;
   RetainPtr<ScrollbarPainter> scrollbarPainter(
       AdoptNS, [[NSClassFromString(@"NSScrollerImp")
                    scrollerImpWithStyle:recommendedScrollerStyle()
                             controlSize:(NSControlSize)scrollbar.controlSize()
                              horizontal:isHorizontal
                    replacingScrollerImp:nil] retain]);
   RetainPtr<BlinkScrollbarObserver> observer(
       AdoptNS,
       [[BlinkScrollbarObserver alloc] initWithScrollbar:&scrollbar
                                                 painter:scrollbarPainter]);

   scrollbarPainterMap().insert(&scrollbar, observer);
   updateEnabledState(scrollbar);
   updateScrollbarOverlayColorTheme(scrollbar);
 }

 void ScrollbarThemeMac::unregisterScrollbar(ScrollbarThemeClient& scrollbar) {
   scrollbarPainterMap().remove(&scrollbar);
   scrollbarSet().remove(&scrollbar);
 }

 void ScrollbarThemeMac::setNewPainterForScrollbar(
     ScrollbarThemeClient& scrollbar,
     ScrollbarPainter newPainter) {
   RetainPtr<ScrollbarPainter> scrollbarPainter(AdoptNS, [newPainter retain]);
   RetainPtr<BlinkScrollbarObserver> observer(
       AdoptNS,
       [[BlinkScrollbarObserver alloc] initWithScrollbar:&scrollbar
                                                 painter:scrollbarPainter]);
   scrollbarPainterMap().set(&scrollbar, observer);
   updateEnabledState(scrollbar);
   updateScrollbarOverlayColorTheme(scrollbar);
 }

 ScrollbarPainter ScrollbarThemeMac::painterForScrollbar(
     const ScrollbarThemeClient& scrollbar) const {
   return [scrollbarPainterMap()
               .get(const_cast<ScrollbarThemeClient*>(&scrollbar))
               .get() painter];
 }

 void ScrollbarThemeMac::paintTrackBackground(GraphicsContext& context,
                                              const Scrollbar& scrollbar,
                                              const IntRect& rect) {
   if (DrawingRecorder::useCachedDrawingIfPossible(
           context, scrollbar, DisplayItem::kScrollbarTrackBackground))
     return;

   DrawingRecorder recorder(context, scrollbar,
                            DisplayItem::kScrollbarTrackBackground, rect);

   GraphicsContextStateSaver stateSaver(context);
   context.translate(rect.x(), rect.y());
   LocalCurrentGraphicsContext localContext(context,
                                            IntRect(IntPoint(), rect.size()));

   CGRect frameRect = scrollbar.frameRect();
   ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
   [scrollbarPainter setEnabled:scrollbar.enabled()];
   [scrollbarPainter setBoundsSize:NSSizeFromCGSize(frameRect.size)];
   NSRect trackRect =
       NSMakeRect(0, 0, frameRect.size.width, frameRect.size.height);
   [scrollbarPainter drawKnobSlotInRect:trackRect highlight:NO];
 }

 void ScrollbarThemeMac::paintThumb(GraphicsContext& context,
                                    const Scrollbar& scrollbar,
                                    const IntRect& rect) {
   if (DrawingRecorder::useCachedDrawingIfPossible(context, scrollbar,
                                                   DisplayItem::kScrollbarThumb))
     return;

   // Expand dirty rect to allow for scroll thumb anti-aliasing in minimum thumb
   // size case.
   IntRect dirtyRect = IntRect(rect);
   dirtyRect.inflate(1);
   DrawingRecorder recorder(context, scrollbar, DisplayItem::kScrollbarThumb,
                            dirtyRect);

   GraphicsContextStateSaver stateSaver(context);
   context.translate(rect.x(), rect.y());
   LocalCurrentGraphicsContext localContext(context,
                                            IntRect(IntPoint(), rect.size()));

   ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
   [scrollbarPainter setEnabled:scrollbar.enabled()];
   // drawKnob aligns the thumb to right side of the draw rect.
   // If the vertical overlay scrollbar is on the left, use trackWidth instead
   // of scrollbar width, to avoid the gap on the left side of the thumb.
   IntRect drawRect = IntRect(rect);
   if (usesOverlayScrollbars() && scrollbar.isLeftSideVerticalScrollbar()) {
     int thumbWidth = [scrollbarPainter trackWidth];
     drawRect.setWidth(thumbWidth);
   }
   [scrollbarPainter setBoundsSize:NSSizeFromCGSize(drawRect.size())];

   [scrollbarPainter setDoubleValue:0];
   [scrollbarPainter setKnobProportion:1];

   CGFloat oldKnobAlpha = [scrollbarPainter knobAlpha];
   [scrollbarPainter setKnobAlpha:1];

   if (scrollbar.enabled())
     [scrollbarPainter drawKnob];

   // If this state is not set, then moving the cursor over the scrollbar area
   // will only cause the scrollbar to engorge when moved over the top of the
   // scrollbar area.
   [scrollbarPainter
       setBoundsSize:NSSizeFromCGSize(scrollbar.frameRect().size())];
   [scrollbarPainter setKnobAlpha:oldKnobAlpha];
 }

 int ScrollbarThemeMac::scrollbarThickness(ScrollbarControlSize controlSize) {
   NSControlSize nsControlSize = static_cast<NSControlSize>(controlSize);
   ScrollbarPainter scrollbarPainter = [NSClassFromString(@"NSScrollerImp")
       scrollerImpWithStyle:recommendedScrollerStyle()
                controlSize:nsControlSize
                 horizontal:NO
       replacingScrollerImp:nil];
   BOOL wasExpanded = NO;
   if (supportsExpandedScrollbars()) {
     wasExpanded = [scrollbarPainter isExpanded];
     [scrollbarPainter setExpanded:YES];
   }
   int thickness = [scrollbarPainter trackBoxWidth];
   if (supportsExpandedScrollbars())
     [scrollbarPainter setExpanded:wasExpanded];
   return thickness;
 }

 bool ScrollbarThemeMac::usesOverlayScrollbars() const {
   return recommendedScrollerStyle() == NSScrollerStyleOverlay;
 }

 void ScrollbarThemeMac::updateScrollbarOverlayColorTheme(
     const ScrollbarThemeClient& scrollbar) {
   ScrollbarPainter painter = painterForScrollbar(scrollbar);
   switch (scrollbar.getScrollbarOverlayColorTheme()) {
     case ScrollbarOverlayColorThemeDark:
       [painter setKnobStyle:NSScrollerKnobStyleDark];
       break;
     case ScrollbarOverlayColorThemeLight:
       [painter setKnobStyle:NSScrollerKnobStyleLight];
       break;
   }
 }

 WebScrollbarButtonsPlacement ScrollbarThemeMac::buttonsPlacement() const {
   return WebScrollbarButtonsPlacementNone;
 }

 bool ScrollbarThemeMac::hasThumb(const ScrollbarThemeClient& scrollbar) {
   ScrollbarPainter painter = painterForScrollbar(scrollbar);
   int minLengthForThumb =
       [painter knobMinLength] + [painter trackOverlapEndInset] +
       [painter knobOverlapEndInset] +
       2 * ([painter trackEndInset] + [painter knobEndInset]);
   return scrollbar.enabled() &&
          (scrollbar.orientation() == HorizontalScrollbar
               ? scrollbar.width()
               : scrollbar.height()) >= minLengthForThumb;
 }

 IntRect ScrollbarThemeMac::backButtonRect(const ScrollbarThemeClient& scrollbar,
                                           ScrollbarPart part,
                                           bool painting) {
   ASSERT(buttonsPlacement() == WebScrollbarButtonsPlacementNone);
   return IntRect();
 }

 IntRect ScrollbarThemeMac::forwardButtonRect(
     const ScrollbarThemeClient& scrollbar,
     ScrollbarPart part,
     bool painting) {
   ASSERT(buttonsPlacement() == WebScrollbarButtonsPlacementNone);
   return IntRect();
 }

 IntRect ScrollbarThemeMac::trackRect(const ScrollbarThemeClient& scrollbar,
                                      bool painting) {
   ASSERT(!hasButtons(scrollbar));
   return scrollbar.frameRect();
 }

 int ScrollbarThemeMac::minimumThumbLength(
     const ScrollbarThemeClient& scrollbar) {
   return [painterForScrollbar(scrollbar) knobMinLength];
 }

 void ScrollbarThemeMac::updateEnabledState(
     const ScrollbarThemeClient& scrollbar) {
   [painterForScrollbar(scrollbar) setEnabled:scrollbar.enabled()];
 }

 float ScrollbarThemeMac::thumbOpacity(
     const ScrollbarThemeClient& scrollbar) const {
   ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
   return [scrollbarPainter knobAlpha];
 }

 // static
 NSScrollerStyle ScrollbarThemeMac::recommendedScrollerStyle() {
   if (RuntimeEnabledFeatures::overlayScrollbarsEnabled())
     return NSScrollerStyleOverlay;
   return gPreferredScrollerStyle;
 }

 }  // namespace blink
	/*
	* Copyright (C) 2008, 2011 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 "platform/RuntimeEnabledFeatures.h"
	#include "platform/scroll/ScrollbarThemeMac.h"

	#include <Carbon/Carbon.h>
	#include "platform/graphics/GraphicsContext.h"
	#include "platform/graphics/GraphicsContextStateSaver.h"
	#include "platform/graphics/paint/DrawingRecorder.h"
	#include "platform/mac/ColorMac.h"
	#include "platform/mac/LocalCurrentGraphicsContext.h"
	#include "platform/mac/NSScrollerImpDetails.h"
	#include "platform/mac/ScrollAnimatorMac.h"
	#include "platform/scroll/ScrollbarThemeClient.h"
	#include "public/platform/WebMouseEvent.h"
	#include "public/platform/WebThemeEngine.h"
	#include "public/platform/Platform.h"
	#include "public/platform/WebRect.h"
	#include "skia/ext/skia_utils_mac.h"
	#include "wtf/HashSet.h"
	#include "wtf/RetainPtr.h"
	#include "wtf/StdLibExtras.h"

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

	using namespace blink;

	@interface NSColor (WebNSColorDetails)
	+ (NSImage*)_linenPatternImage;
	@end

	@interface BlinkScrollbarObserver : NSObject {
	blink::ScrollbarThemeClient* _scrollbar;
	RetainPtr<ScrollbarPainter> _scrollbarPainter;
	}
	- (id)initWithScrollbar:(blink::ScrollbarThemeClient*)scrollbar
	painter:(const RetainPtr<ScrollbarPainter>&)painter;
	@end

	@implementation BlinkScrollbarObserver

	- (id)initWithScrollbar:(blink::ScrollbarThemeClient*)scrollbar
	painter:(const RetainPtr<ScrollbarPainter>&)painter {
	if (!(self = [super init]))
	return nil;
	_scrollbar = scrollbar;
	_scrollbarPainter = painter;
	[_scrollbarPainter.get() addObserver:self
	forKeyPath:@"knobAlpha"
	options:0
	context:nil];
	return self;
	}

	- (id)painter {
	return _scrollbarPainter.get();
	}

	- (void)dealloc {
	[_scrollbarPainter.get() removeObserver:self forKeyPath:@"knobAlpha"];
	[super dealloc];
	}

	- (void)observeValueForKeyPath:(NSString*)keyPath
	ofObject:(id)object
	change:(NSDictionary*)change
	context:(void*)context {
	if ([keyPath isEqualToString:@"knobAlpha"]) {
	BOOL visible = [_scrollbarPainter.get() knobAlpha] > 0;
	_scrollbar->setScrollbarsHidden(!visible);
	}
	}

	@end

	namespace blink {

	typedef HashSet<ScrollbarThemeClient*> ScrollbarSet;

	static ScrollbarSet& scrollbarSet() {
	DEFINE_STATIC_LOCAL(ScrollbarSet, set, ());
	return set;
	}

	static float gInitialButtonDelay = 0.5f;
	static float gAutoscrollButtonDelay = 0.05f;
	static NSScrollerStyle gPreferredScrollerStyle = NSScrollerStyleLegacy;

	typedef HashMap<ScrollbarThemeClient*, RetainPtr<BlinkScrollbarObserver>>
	ScrollbarPainterMap;

	static ScrollbarPainterMap& scrollbarPainterMap() {
	static ScrollbarPainterMap* map = new ScrollbarPainterMap;
	return *map;
	}

	static bool supportsExpandedScrollbars() {
	// FIXME: This is temporary until all platforms that support ScrollbarPainter
	// support this part of the API.
	static bool globalSupportsExpandedScrollbars =
	[NSClassFromString(@"NSScrollerImp")
	instancesRespondToSelector:@selector(setExpanded:)];
	return globalSupportsExpandedScrollbars;
	}

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

	void ScrollbarThemeMac::paintTickmarks(GraphicsContext& context,
	const Scrollbar& scrollbar,
	const IntRect& rect) {
	IntRect tickmarkTrackRect = rect;
	tickmarkTrackRect.setX(tickmarkTrackRect.x() + 1);
	tickmarkTrackRect.setWidth(tickmarkTrackRect.width() - 1);
	ScrollbarTheme::paintTickmarks(context, scrollbar, tickmarkTrackRect);
	}

	ScrollbarThemeMac::~ScrollbarThemeMac() {}

	void ScrollbarThemeMac::preferencesChanged(
	float initialButtonDelay,
	float autoscrollButtonDelay,
	NSScrollerStyle preferredScrollerStyle,
	bool redraw,
	WebScrollbarButtonsPlacement buttonPlacement) {
	updateButtonPlacement(buttonPlacement);
	gInitialButtonDelay = initialButtonDelay;
	gAutoscrollButtonDelay = autoscrollButtonDelay;
	gPreferredScrollerStyle = preferredScrollerStyle;
	if (redraw && !scrollbarSet().isEmpty()) {
	ScrollbarSet::iterator end = scrollbarSet().end();
	for (ScrollbarSet::iterator it = scrollbarSet().begin(); it != end; ++it) {
	(*it)->styleChanged();
	(*it)->invalidate();
	}
	}
	}

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

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

	bool ScrollbarThemeMac::shouldDragDocumentInsteadOfThumb(
	const ScrollbarThemeClient&,
	const WebMouseEvent& event) {
	return (event.modifiers() & WebInputEvent::Modifiers::AltKey) != 0;
	}

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

	ScrollbarPart ScrollbarThemeMac::invalidateOnThumbPositionChange(
	const ScrollbarThemeClient& scrollbar,
	float oldPosition,
	float newPosition) const {
	// ScrollAnimatorMac will invalidate scrollbar parts if necessary.
	return NoPart;
	}

	void ScrollbarThemeMac::registerScrollbar(ScrollbarThemeClient& scrollbar) {
	scrollbarSet().insert(&scrollbar);

	bool isHorizontal = scrollbar.orientation() == HorizontalScrollbar;
	RetainPtr<ScrollbarPainter> scrollbarPainter(
	AdoptNS, [[NSClassFromString(@"NSScrollerImp")
	scrollerImpWithStyle:recommendedScrollerStyle()
	controlSize:(NSControlSize)scrollbar.controlSize()
	horizontal:isHorizontal
	replacingScrollerImp:nil] retain]);
	RetainPtr<BlinkScrollbarObserver> observer(
	AdoptNS,
	[[BlinkScrollbarObserver alloc] initWithScrollbar:&scrollbar
	painter:scrollbarPainter]);

	scrollbarPainterMap().insert(&scrollbar, observer);
	updateEnabledState(scrollbar);
	updateScrollbarOverlayColorTheme(scrollbar);
	}

	void ScrollbarThemeMac::unregisterScrollbar(ScrollbarThemeClient& scrollbar) {
	scrollbarPainterMap().remove(&scrollbar);
	scrollbarSet().remove(&scrollbar);
	}

	void ScrollbarThemeMac::setNewPainterForScrollbar(
	ScrollbarThemeClient& scrollbar,
	ScrollbarPainter newPainter) {
	RetainPtr<ScrollbarPainter> scrollbarPainter(AdoptNS, [newPainter retain]);
	RetainPtr<BlinkScrollbarObserver> observer(
	AdoptNS,
	[[BlinkScrollbarObserver alloc] initWithScrollbar:&scrollbar
	painter:scrollbarPainter]);
	scrollbarPainterMap().set(&scrollbar, observer);
	updateEnabledState(scrollbar);
	updateScrollbarOverlayColorTheme(scrollbar);
	}

	ScrollbarPainter ScrollbarThemeMac::painterForScrollbar(
	const ScrollbarThemeClient& scrollbar) const {
	return [scrollbarPainterMap()
	.get(const_cast<ScrollbarThemeClient*>(&scrollbar))
	.get() painter];
	}

	void ScrollbarThemeMac::paintTrackBackground(GraphicsContext& context,
	const Scrollbar& scrollbar,
	const IntRect& rect) {
	if (DrawingRecorder::useCachedDrawingIfPossible(
	context, scrollbar, DisplayItem::kScrollbarTrackBackground))
	return;

	DrawingRecorder recorder(context, scrollbar,
	DisplayItem::kScrollbarTrackBackground, rect);

	GraphicsContextStateSaver stateSaver(context);
	context.translate(rect.x(), rect.y());
	LocalCurrentGraphicsContext localContext(context,
	IntRect(IntPoint(), rect.size()));

	CGRect frameRect = scrollbar.frameRect();
	ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
	[scrollbarPainter setEnabled:scrollbar.enabled()];
	[scrollbarPainter setBoundsSize:NSSizeFromCGSize(frameRect.size)];
	NSRect trackRect =
	NSMakeRect(0, 0, frameRect.size.width, frameRect.size.height);
	[scrollbarPainter drawKnobSlotInRect:trackRect highlight:NO];
	}

	void ScrollbarThemeMac::paintThumb(GraphicsContext& context,
	const Scrollbar& scrollbar,
	const IntRect& rect) {
	if (DrawingRecorder::useCachedDrawingIfPossible(context, scrollbar,
	DisplayItem::kScrollbarThumb))
	return;

	// Expand dirty rect to allow for scroll thumb anti-aliasing in minimum thumb
	// size case.
	IntRect dirtyRect = IntRect(rect);
	dirtyRect.inflate(1);
	DrawingRecorder recorder(context, scrollbar, DisplayItem::kScrollbarThumb,
	dirtyRect);

	GraphicsContextStateSaver stateSaver(context);
	context.translate(rect.x(), rect.y());
	LocalCurrentGraphicsContext localContext(context,
	IntRect(IntPoint(), rect.size()));

	ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
	[scrollbarPainter setEnabled:scrollbar.enabled()];
	// drawKnob aligns the thumb to right side of the draw rect.
	// If the vertical overlay scrollbar is on the left, use trackWidth instead
	// of scrollbar width, to avoid the gap on the left side of the thumb.
	IntRect drawRect = IntRect(rect);
	if (usesOverlayScrollbars() && scrollbar.isLeftSideVerticalScrollbar()) {
	int thumbWidth = [scrollbarPainter trackWidth];
	drawRect.setWidth(thumbWidth);
	}
	[scrollbarPainter setBoundsSize:NSSizeFromCGSize(drawRect.size())];

	[scrollbarPainter setDoubleValue:0];
	[scrollbarPainter setKnobProportion:1];

	CGFloat oldKnobAlpha = [scrollbarPainter knobAlpha];
	[scrollbarPainter setKnobAlpha:1];

	if (scrollbar.enabled())
	[scrollbarPainter drawKnob];

	// If this state is not set, then moving the cursor over the scrollbar area
	// will only cause the scrollbar to engorge when moved over the top of the
	// scrollbar area.
	[scrollbarPainter
	setBoundsSize:NSSizeFromCGSize(scrollbar.frameRect().size())];
	[scrollbarPainter setKnobAlpha:oldKnobAlpha];
	}

	int ScrollbarThemeMac::scrollbarThickness(ScrollbarControlSize controlSize) {
	NSControlSize nsControlSize = static_cast<NSControlSize>(controlSize);
	ScrollbarPainter scrollbarPainter = [NSClassFromString(@"NSScrollerImp")
	scrollerImpWithStyle:recommendedScrollerStyle()
	controlSize:nsControlSize
	horizontal:NO
	replacingScrollerImp:nil];
	BOOL wasExpanded = NO;
	if (supportsExpandedScrollbars()) {
	wasExpanded = [scrollbarPainter isExpanded];
	[scrollbarPainter setExpanded:YES];
	}
	int thickness = [scrollbarPainter trackBoxWidth];
	if (supportsExpandedScrollbars())
	[scrollbarPainter setExpanded:wasExpanded];
	return thickness;
	}

	bool ScrollbarThemeMac::usesOverlayScrollbars() const {
	return recommendedScrollerStyle() == NSScrollerStyleOverlay;
	}

	void ScrollbarThemeMac::updateScrollbarOverlayColorTheme(
	const ScrollbarThemeClient& scrollbar) {
	ScrollbarPainter painter = painterForScrollbar(scrollbar);
	switch (scrollbar.getScrollbarOverlayColorTheme()) {
	case ScrollbarOverlayColorThemeDark:
	[painter setKnobStyle:NSScrollerKnobStyleDark];
	break;
	case ScrollbarOverlayColorThemeLight:
	[painter setKnobStyle:NSScrollerKnobStyleLight];
	break;
	}
	}

	WebScrollbarButtonsPlacement ScrollbarThemeMac::buttonsPlacement() const {
	return WebScrollbarButtonsPlacementNone;
	}

	bool ScrollbarThemeMac::hasThumb(const ScrollbarThemeClient& scrollbar) {
	ScrollbarPainter painter = painterForScrollbar(scrollbar);
	int minLengthForThumb =
	[painter knobMinLength] + [painter trackOverlapEndInset] +
	[painter knobOverlapEndInset] +
	2 * ([painter trackEndInset] + [painter knobEndInset]);
	return scrollbar.enabled() &&
	(scrollbar.orientation() == HorizontalScrollbar
	? scrollbar.width()
	: scrollbar.height()) >= minLengthForThumb;
	}

	IntRect ScrollbarThemeMac::backButtonRect(const ScrollbarThemeClient& scrollbar,
	ScrollbarPart part,
	bool painting) {
	ASSERT(buttonsPlacement() == WebScrollbarButtonsPlacementNone);
	return IntRect();
	}

	IntRect ScrollbarThemeMac::forwardButtonRect(
	const ScrollbarThemeClient& scrollbar,
	ScrollbarPart part,
	bool painting) {
	ASSERT(buttonsPlacement() == WebScrollbarButtonsPlacementNone);
	return IntRect();
	}

	IntRect ScrollbarThemeMac::trackRect(const ScrollbarThemeClient& scrollbar,
	bool painting) {
	ASSERT(!hasButtons(scrollbar));
	return scrollbar.frameRect();
	}

	int ScrollbarThemeMac::minimumThumbLength(
	const ScrollbarThemeClient& scrollbar) {
	return [painterForScrollbar(scrollbar) knobMinLength];
	}

	void ScrollbarThemeMac::updateEnabledState(
	const ScrollbarThemeClient& scrollbar) {
	[painterForScrollbar(scrollbar) setEnabled:scrollbar.enabled()];
	}

	float ScrollbarThemeMac::thumbOpacity(
	const ScrollbarThemeClient& scrollbar) const {
	ScrollbarPainter scrollbarPainter = painterForScrollbar(scrollbar);
	return [scrollbarPainter knobAlpha];
	}

	// static
	NSScrollerStyle ScrollbarThemeMac::recommendedScrollerStyle() {
	if (RuntimeEnabledFeatures::overlayScrollbarsEnabled())
	return NSScrollerStyleOverlay;
	return gPreferredScrollerStyle;
	}

	} // namespace blink