/*

 * Copyright (C) 2004, 2006 Apple Computer, 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 COMPUTER, 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 COMPUTER, 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 "ScrollBar.h"

#include <algorithm>

using std::max;

using std::min;

namespace WebCore {

Scrollbar::Scrollbar(ScrollbarClient* client, ScrollbarOrientation orientation, ScrollbarControlSize controlSize)

    : m_client(client)

    , m_orientation(orientation)

    , m_controlSize(controlSize)

    , m_visibleSize(0)

    , m_totalSize(0)

    , m_currentPos(0)

    , m_lineStep(0)

    , m_pageStep(0)

    , m_pixelStep(1)

{

}

bool Scrollbar::setValue(int v)

{

    v = max(min(v, m_totalSize - m_visibleSize), 0);

    if (value() == v)

        return false; // Our value stayed the same.

    m_currentPos = v;

    updateThumbPosition();

    if (client())

        client()->valueChanged(this);

    return true;

}

void Scrollbar::setProportion(int visibleSize, int totalSize)

{

    if (visibleSize == m_visibleSize && totalSize == m_totalSize)

        return;

    m_visibleSize = visibleSize;

    m_totalSize = totalSize;

    updateThumbProportion();

}

void Scrollbar::setSteps(int lineStep, int pageStep, int pixelsPerStep)

{

    m_lineStep = lineStep;

    m_pageStep = pageStep;

    m_pixelStep = 1.0f / pixelsPerStep;

}

bool Scrollbar::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier)

{

    float step = 0;

    if ((direction == ScrollUp && m_orientation == VerticalScrollbar) || (direction == ScrollLeft && m_orientation == HorizontalScrollbar))

        step = -1;

    else if ((direction == ScrollDown && m_orientation == VerticalScrollbar) || (direction == ScrollRight && m_orientation == HorizontalScrollbar)) 

        step = 1;

    if (granularity == ScrollByLine)

        step *= m_lineStep;

    else if (granularity == ScrollByPage)

        step *= m_pageStep;

    else if (granularity == ScrollByDocument)

        step *= m_totalSize;

    else if (granularity == ScrollByPixel)

        step *= m_pixelStep;

    float newPos = m_currentPos + step * multiplier;

    float maxPos = m_totalSize - m_visibleSize;

    newPos = max(min(newPos, maxPos), 0.0f);

    if (newPos == m_currentPos)

        return false;

    int oldValue = value();

    m_currentPos = newPos;

    updateThumbPosition();

    if (value() != oldValue && client())

        client()->valueChanged(this);

    // return true even if the integer value did not change so that scroll event gets eaten

    return true;

}

}