/*

 * 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 "RenderScrollbarPart.h"

#include "RenderScrollbar.h"

#include "RenderScrollbarTheme.h"

#include "RenderView.h"

using namespace std;

namespace WebCore {

RenderScrollbarPart::RenderScrollbarPart(Node* node, RenderScrollbar* scrollbar, ScrollbarPart part)

    : RenderBlock(node)

    , m_scrollbar(scrollbar)

    , m_part(part)

{

}

RenderScrollbarPart::~RenderScrollbarPart()

{

}

void RenderScrollbarPart::layout()

{

    setLocation(IntPoint()); // We don't worry about positioning ourselves.  We're just determining our minimum width/height.

    if (m_scrollbar->orientation() == HorizontalScrollbar)

        layoutHorizontalPart();

    else

        layoutVerticalPart();

    setNeedsLayout(false);

}

void RenderScrollbarPart::layoutHorizontalPart()

{

    if (m_part == ScrollbarBGPart) {

        setWidth(m_scrollbar->width());

        computeScrollbarHeight();

    } else {

        computeScrollbarWidth();

        setHeight(m_scrollbar->height());

    }

}

void RenderScrollbarPart::layoutVerticalPart()

{

    if (m_part == ScrollbarBGPart) {

        computeScrollbarWidth();

        setHeight(m_scrollbar->height());

    } else {

        setWidth(m_scrollbar->width());

        computeScrollbarHeight();

    } 

}

static int calcScrollbarThicknessUsing(const Length& l, int containingLength)

{

    if (l.isIntrinsicOrAuto())

        return ScrollbarTheme::nativeTheme()->scrollbarThickness();

    return l.calcMinValue(containingLength);

}

void RenderScrollbarPart::computeScrollbarWidth()

{

    int visibleSize = m_scrollbar->owningRenderer()->width() - m_scrollbar->owningRenderer()->borderLeft() - m_scrollbar->owningRenderer()->borderRight();

    int w = calcScrollbarThicknessUsing(style()->width(), visibleSize);

    int minWidth = calcScrollbarThicknessUsing(style()->minWidth(), visibleSize);

    int maxWidth = style()->maxWidth().isUndefined() ? w : calcScrollbarThicknessUsing(style()->maxWidth(), visibleSize);

    setWidth(max(minWidth, min(maxWidth, w)));

    // Buttons and track pieces can all have margins along the axis of the scrollbar. 

    m_marginLeft = style()->marginLeft().calcMinValue(visibleSize);

    m_marginRight = style()->marginRight().calcMinValue(visibleSize);

}

void RenderScrollbarPart::computeScrollbarHeight()

{

    int visibleSize = m_scrollbar->owningRenderer()->height() -  m_scrollbar->owningRenderer()->borderTop() - m_scrollbar->owningRenderer()->borderBottom();

    int h = calcScrollbarThicknessUsing(style()->height(), visibleSize);

    int minHeight = calcScrollbarThicknessUsing(style()->minHeight(), visibleSize);

    int maxHeight = style()->maxHeight().isUndefined() ? h : calcScrollbarThicknessUsing(style()->maxHeight(), visibleSize);

    setHeight(max(minHeight, min(maxHeight, h)));

    // Buttons and track pieces can all have margins along the axis of the scrollbar. 

    m_marginTop = style()->marginTop().calcMinValue(visibleSize);

    m_marginBottom = style()->marginBottom().calcMinValue(visibleSize);

}

void RenderScrollbarPart::calcPrefWidths()

{

    if (!prefWidthsDirty())

        return;

    m_minPrefWidth = m_maxPrefWidth = 0;

    setPrefWidthsDirty(false);

}

void RenderScrollbarPart::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)

{

    RenderBlock::styleWillChange(diff, newStyle);

    setInline(false);

}

void RenderScrollbarPart::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)

{

    RenderBlock::styleDidChange(diff, oldStyle);

    setInline(false);

    setPositioned(false);

    setFloating(false);

    setHasOverflowClip(false);

    if (oldStyle && m_scrollbar && m_part != NoPart && diff >= StyleDifferenceRepaint)

        m_scrollbar->theme()->invalidatePart(m_scrollbar, m_part);

}

void RenderScrollbarPart::imageChanged(WrappedImagePtr image, const IntRect* rect)

{

    if (m_scrollbar && m_part != NoPart)

        m_scrollbar->theme()->invalidatePart(m_scrollbar, m_part);

    else {

        if (FrameView* frameView = view()->frameView()) {

            if (frameView->isFrameViewScrollCorner(this)) {

                frameView->invalidateScrollCorner();

                return;

            }

        }

        RenderBlock::imageChanged(image, rect);

    }

}

void RenderScrollbarPart::paintIntoRect(GraphicsContext* graphicsContext, int tx, int ty, const IntRect& rect)

{

    // Make sure our dimensions match the rect.

    setLocation(rect.x() - tx, rect.y() - ty);

    setWidth(rect.width());

    setHeight(rect.height());

    if (graphicsContext->paintingDisabled())

        return;

    // Now do the paint.

    PaintInfo paintInfo(graphicsContext, rect, PaintPhaseBlockBackground, false, 0, 0);

    paint(paintInfo, tx, ty);

    paintInfo.phase = PaintPhaseChildBlockBackgrounds;

    paint(paintInfo, tx, ty);

    paintInfo.phase = PaintPhaseFloat;

    paint(paintInfo, tx, ty);

    paintInfo.phase = PaintPhaseForeground;

    paint(paintInfo, tx, ty);

    paintInfo.phase = PaintPhaseOutline;

    paint(paintInfo, tx, ty);

}

}