/*

 * Copyright (C) 2008 Apple Inc. All Rights Reserved.

 * Copyright (C) 2009 Google 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 "ScrollbarThemeChromiumMac.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;

// This file (and its associated .h file) is a clone of ScrollbarThemeMac.mm.

// Because we want to draw tickmarks in the scrollbar, we must maintain a fork.

// Please maintain this file by performing parallel changes to it.

//

// The only changes from ScrollbarThemeMac should be:

// - The classname change from ScrollbarThemeMac to ScrollbarThemeChromiumMac.

// - In paint() the code to paint the track, tickmarks, and thumb separately.

//

// For all other differences, if it was introduced in this file, then the

// maintainer forgot to include it in the list; otherwise it is an update that

// should have been applied to this file but was not.

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<ScrollbarThemeChromiumMac*>(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<ScrollbarThemeChromiumMac*>(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(ScrollbarThemeChromiumMac, 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 ScrollbarThemeChromiumMac::registerScrollbar(Scrollbar* scrollbar)

{

    if (!gScrollbars)

        gScrollbars = new HashSet<Scrollbar*>;

    gScrollbars->add(scrollbar);

}

void ScrollbarThemeChromiumMac::unregisterScrollbar(Scrollbar* scrollbar)

{

    gScrollbars->remove(scrollbar);

    if (gScrollbars->isEmpty()) {

        delete gScrollbars;

        gScrollbars = 0;

    }

}

ScrollbarThemeChromiumMac::ScrollbarThemeChromiumMac()

{

    static bool initialized;

    if (!initialized) {

        initialized = true;

        [ScrollbarPrefsObserver registerAsObserver];

        preferencesChanged();

    }

}

ScrollbarThemeChromiumMac::~ScrollbarThemeChromiumMac()

{

}

void ScrollbarThemeChromiumMac::preferencesChanged()

{

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    [defaults synchronize];

    updateArrowPlacement();

    gInitialButtonDelay = [defaults floatForKey:@"NSScrollerButtonDelay"];

    gAutoscrollButtonDelay = [defaults floatForKey:@"NSScrollerButtonPeriod"];

    gJumpOnTrackClick = [defaults boolForKey:@"AppleScrollerPagingBehavior"];

}

int ScrollbarThemeChromiumMac::scrollbarThickness(ScrollbarControlSize controlSize)

{

    return cScrollbarThickness[controlSize];

}

double ScrollbarThemeChromiumMac::initialAutoscrollTimerDelay()

{

    return gInitialButtonDelay;

}

double ScrollbarThemeChromiumMac::autoscrollTimerDelay()

{

    return gAutoscrollButtonDelay;

}

ScrollbarButtonsPlacement ScrollbarThemeChromiumMac::buttonsPlacement() const

{

    return gButtonPlacement;

}

bool ScrollbarThemeChromiumMac::hasButtons(Scrollbar* scrollbar)

{

    return scrollbar->enabled() && (scrollbar->orientation() == HorizontalScrollbar ?

             scrollbar->width() :

             scrollbar->height()) >= 2 * (cRealButtonLength[scrollbar->controlSize()] - cButtonHitInset[scrollbar->controlSize()]);

}

bool ScrollbarThemeChromiumMac::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 ScrollbarThemeChromiumMac::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 ScrollbarThemeChromiumMac::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 ScrollbarThemeChromiumMac::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 ScrollbarThemeChromiumMac::minimumThumbLength(Scrollbar* scrollbar)

{

    return cThumbMinLength[scrollbar->controlSize()];

}

bool ScrollbarThemeChromiumMac::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 ScrollbarThemeChromiumMac::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->visibleSize();

    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 (!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);

    GraphicsContext* drawingContext = context;

    OwnPtr<ImageBuffer> imageBuffer;

    if (!canDrawDirectly) {

        trackInfo.bounds = IntRect(IntPoint(), scrollbar->frameRect().size());

        IntRect bufferRect(scrollbar->frameRect());

        bufferRect.intersect(damageRect);

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

        imageBuffer = ImageBuffer::create(bufferRect.size());

        if (!imageBuffer)

            return true;

        drawingContext = imageBuffer->context();

    }

    // Draw thumbless.

    HIThemeDrawTrack(&trackInfo, 0, drawingContext->platformContext(), kHIThemeOrientationNormal);

    Vector<IntRect> tickmarks;

    scrollbar->client()->getTickmarks(tickmarks);

    if (scrollbar->orientation() == VerticalScrollbar && tickmarks.size()) {

        drawingContext->save();

        drawingContext->setShouldAntialias(false);

        drawingContext->setStrokeColor(Color(0xCC, 0xAA, 0x00, 0xFF), DeviceColorSpace);

        drawingContext->setFillColor(Color(0xFF, 0xDD, 0x00, 0xFF), DeviceColorSpace);

        IntRect thumbArea = trackRect(scrollbar, false);

        if (!canDrawDirectly) {

            thumbArea.setX(0);

            thumbArea.setY(0);

        }

        // The ends are rounded and the thumb doesn't go there.

        thumbArea.inflateY(-thumbArea.width());

        for (Vector<IntRect>::const_iterator i = tickmarks.begin(); i != tickmarks.end(); ++i) {

            // Calculate how far down (in %) the tick-mark should appear.

            const float percent = static_cast<float>(i->y()) / scrollbar->totalSize();

            if (percent < 0.0 || percent > 1.0)

              continue;

            // Calculate how far down (in pixels) the tick-mark should appear.

            const int yPos = static_cast<int>((thumbArea.topLeft().y() + (thumbArea.height() * percent))) & ~1;

            // Paint.

            const int indent = 2;

            FloatRect tickRect(thumbArea.topLeft().x() + indent, yPos, thumbArea.width() - 2 * indent - 1, 2);

            drawingContext->fillRect(tickRect);

            drawingContext->strokeRect(tickRect, 1);

        }

        drawingContext->restore();

    }

    if (hasThumb(scrollbar)) {

        trackInfo.attributes |= (kThemeTrackShowThumb | kThemeTrackHideTrack);

        HIThemeDrawTrack(&trackInfo, 0, drawingContext->platformContext(), kHIThemeOrientationNormal);

    }

    if (!canDrawDirectly) {

        context->drawImage(imageBuffer->image(), DeviceColorSpace, scrollbar->frameRect().location());

    }

    return true;

}

}