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#include "config.h"

#include "ScrollbarThemeChromiumLinux.h"

#include "PlatformContextSkia.h"

#include "PlatformMouseEvent.h"

#include "PlatformThemeChromiumGtk.h"

#include "Scrollbar.h"

#include "TransformationMatrix.h"

namespace WebCore {

static const int scrollbarThicknessValue = 15;

static const int buttonLength = 14;

ScrollbarTheme* ScrollbarTheme::nativeTheme()

{

    static ScrollbarThemeChromiumLinux theme;

    return &theme;

}

int ScrollbarThemeChromiumLinux::scrollbarThickness(ScrollbarControlSize controlSize)

{

    return scrollbarThicknessValue;

}

static void drawVertLine(SkCanvas* canvas, int x, int y1, int y2, const SkPaint& paint)

{

    SkIRect skrect;

    skrect.set(x, y1, x + 1, y2 + 1);

    canvas->drawIRect(skrect, paint);

}

static void drawHorizLine(SkCanvas* canvas, int x1, int x2, int y, const SkPaint& paint)

{

    SkIRect skrect;

    skrect.set(x1, y, x2 + 1, y + 1);

    canvas->drawIRect(skrect, paint);

}

static void drawBox(SkCanvas* canvas, const IntRect& rect, const SkPaint& paint)

{

    const int right = rect.x() + rect.width() - 1;

    const int bottom = rect.y() + rect.height() - 1;

    drawHorizLine(canvas, rect.x(), right, rect.y(), paint);

    drawVertLine(canvas, right, rect.y(), bottom, paint);

    drawHorizLine(canvas, rect.x(), right, bottom, paint);

    drawVertLine(canvas, rect.x(), rect.y(), bottom, paint);

}

void ScrollbarThemeChromiumLinux::paintTrackPiece(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart partType)

{

    SkCanvas* const canvas = gc->platformContext()->canvas();

    SkPaint paint;

    SkIRect skrect;

    skrect.set(rect.x(), rect.y(), rect.x() + rect.width(), rect.y() + rect.height());

    SkScalar trackHSV[3];

    SkColorToHSV(PlatformThemeChromiumGtk::trackColor(), trackHSV);

    paint.setColor(PlatformThemeChromiumGtk::saturateAndBrighten(trackHSV, 0, 0));

    canvas->drawIRect(skrect, paint);

    SkScalar thumbHSV[3];

    SkColorToHSV(PlatformThemeChromiumGtk::thumbInactiveColor(),

                 thumbHSV);

    paint.setColor(PlatformThemeChromiumGtk::outlineColor(trackHSV, thumbHSV));

    drawBox(canvas, rect, paint);

}

void ScrollbarThemeChromiumLinux::paintButton(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect, ScrollbarPart part)

{

    PlatformThemeChromiumGtk::ArrowDirection direction;

    if (scrollbar->orientation() == HorizontalScrollbar) {

        if (part == BackButtonStartPart)

            direction = PlatformThemeChromiumGtk::West;

        else

            direction = PlatformThemeChromiumGtk::East;

    } else {

        if (part == BackButtonStartPart)

            direction = PlatformThemeChromiumGtk::North;

        else

            direction = PlatformThemeChromiumGtk::South;

    }

    ControlStates states = 0;

    // Determine if the button can be pressed.

    if (((direction == PlatformThemeChromiumGtk::West || direction == PlatformThemeChromiumGtk::North) && scrollbar->currentPos())

        || (direction == PlatformThemeChromiumGtk::East || direction == PlatformThemeChromiumGtk::South) && scrollbar->currentPos() != scrollbar->maximum())

        states |= EnabledState;

    if (states & EnabledState) {

        if (part == scrollbar->pressedPart())

            states |= PressedState;

        else if (part == scrollbar->hoveredPart())

            states |= HoverState;

    }

    PlatformThemeChromiumGtk::paintArrowButton(gc, rect, direction, states);

}

void ScrollbarThemeChromiumLinux::paintThumb(GraphicsContext* gc, Scrollbar* scrollbar, const IntRect& rect)

{

    const bool hovered = scrollbar->hoveredPart() == ThumbPart;

    const int midx = rect.x() + rect.width() / 2;

    const int midy = rect.y() + rect.height() / 2;

    const bool vertical = scrollbar->orientation() == VerticalScrollbar;

    SkCanvas* const canvas = gc->platformContext()->canvas();

    SkScalar thumb[3];

    SkColorToHSV(hovered

                 ? PlatformThemeChromiumGtk::thumbActiveColor()

                 : PlatformThemeChromiumGtk::thumbInactiveColor(),

                 thumb);

    SkPaint paint;

    paint.setColor(PlatformThemeChromiumGtk::saturateAndBrighten(thumb, 0, 0.02));

    SkIRect skrect;

    if (vertical)

        skrect.set(rect.x(), rect.y(), midx + 1, rect.y() + rect.height());

    else

        skrect.set(rect.x(), rect.y(), rect.x() + rect.width(), midy + 1);

    canvas->drawIRect(skrect, paint);

    paint.setColor(PlatformThemeChromiumGtk::saturateAndBrighten(thumb, 0, -0.02));

    if (vertical)

        skrect.set(midx + 1, rect.y(), rect.x() + rect.width(), rect.y() + rect.height());

    else

        skrect.set(rect.x(), midy + 1, rect.x() + rect.width(), rect.y() + rect.height());

    canvas->drawIRect(skrect, paint);

    SkScalar track[3];

    SkColorToHSV(PlatformThemeChromiumGtk::trackColor(), track);

    paint.setColor(PlatformThemeChromiumGtk::outlineColor(track, thumb));

    drawBox(canvas, rect, paint);

    if (rect.height() > 10 && rect.width() > 10) {

        const int grippyHalfWidth = 2;

        const int interGrippyOffset = 3;

        if (vertical) {

            drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy - interGrippyOffset, paint);

            drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy,                     paint);

            drawHorizLine(canvas, midx - grippyHalfWidth, midx + grippyHalfWidth, midy + interGrippyOffset, paint);

        } else {

            drawVertLine(canvas, midx - interGrippyOffset, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);

            drawVertLine(canvas, midx,                     midy - grippyHalfWidth, midy + grippyHalfWidth, paint);

            drawVertLine(canvas, midx + interGrippyOffset, midy - grippyHalfWidth, midy + grippyHalfWidth, paint);

        }

    }

}

bool ScrollbarThemeChromiumLinux::shouldCenterOnThumb(Scrollbar*, const PlatformMouseEvent& evt)

{

    return (evt.shiftKey() && evt.button() == LeftButton) || (evt.button() == MiddleButton);

}

IntSize ScrollbarThemeChromiumLinux::buttonSize(Scrollbar* scrollbar)

{

    if (scrollbar->orientation() == VerticalScrollbar)

        return IntSize(scrollbarThicknessValue, buttonLength);

    // HorizontalScrollbar

    return IntSize(buttonLength, scrollbarThicknessValue);

}

int ScrollbarThemeChromiumLinux::minimumThumbLength(Scrollbar* scrollbar)

{

    // This matches Firefox on Linux.

    return 2 * scrollbarThickness(scrollbar->controlSize());

}

} // namespace WebCore