/*

 * This file is part of the select element renderer in WebCore.

 *

 * Copyright (C) 2006, 2007 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. 

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission. 

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "RenderListBox.h"

#include "Document.h"

#include "EventHandler.h"

#include "EventNames.h"

#include "Frame.h"

#include "FrameView.h"

#include "GraphicsContext.h"

#include "HTMLNames.h"

#include "HTMLOptGroupElement.h"

#include "HTMLOptionElement.h"

#include "HTMLSelectElement.h"

#include "HitTestResult.h"

#include "RenderTheme.h"

#include "RenderView.h"

#include "TextStyle.h"

#include <math.h>

using namespace std;

namespace WebCore {

using namespace EventNames;

using namespace HTMLNames;

const int rowSpacing = 1;

const int optionsSpacingHorizontal = 2;

const int minSize = 4;

const int maxDefaultSize = 10;

// FIXME: This hardcoded baselineAdjustment is what we used to do for the old

// widget, but I'm not sure this is right for the new control.

const int baselineAdjustment = 7;

RenderListBox::RenderListBox(HTMLSelectElement* element)

    : RenderBlock(element)

    , m_optionsChanged(true)

    , m_scrollToRevealSelectionAfterLayout(false)

    , m_inAutoscroll(false)

    , m_optionsWidth(0)

    , m_indexOffset(0)

{

}

RenderListBox::~RenderListBox()

{

    if (m_vBar && m_vBar->isWidget())

        if (FrameView* view = node()->document()->view())

            view->removeChild(static_cast<PlatformScrollbar*>(m_vBar.get()));

}

void RenderListBox::setStyle(RenderStyle* style)

{

    RenderBlock::setStyle(style);

    setReplaced(isInline());

}

void RenderListBox::updateFromElement()

{

    if (m_optionsChanged) {

        const Vector<HTMLElement*>& listItems = static_cast<HTMLSelectElement*>(node())->listItems();

        int size = numItems();

        float width = 0;

        TextStyle textStyle(0, 0, 0, false, false, false, false);

        for (int i = 0; i < size; ++i) {

            HTMLElement* element = listItems[i];

            String text;

            Font itemFont = style()->font();

            if (element->hasTagName(optionTag))

                text = static_cast<HTMLOptionElement*>(element)->optionText();

            else if (element->hasTagName(optgroupTag)) {

                text = static_cast<HTMLOptGroupElement*>(element)->groupLabelText();

                FontDescription d = itemFont.fontDescription();

                d.setBold(true);

                itemFont = Font(d, itemFont.letterSpacing(), itemFont.wordSpacing());

                itemFont.update();

            }

            if (!text.isEmpty()) {

                float textWidth = itemFont.floatWidth(TextRun(text.impl()), textStyle);

                width = max(width, textWidth);

            }

        }

        m_optionsWidth = static_cast<int>(ceilf(width));

        m_optionsChanged = false;

        if (!m_vBar && Scrollbar::hasPlatformScrollbars())

            if (FrameView* view = node()->document()->view()) {

                RefPtr<PlatformScrollbar> widget = new PlatformScrollbar(this, VerticalScrollbar, SmallScrollbar);

                view->addChild(widget.get());

                m_vBar = widget.release();

            }

        setNeedsLayoutAndPrefWidthsRecalc();

    }

}

void RenderListBox::selectionChanged()

{

    repaint();

    if (!m_inAutoscroll) {

        if (m_optionsChanged || needsLayout())

            m_scrollToRevealSelectionAfterLayout = true;

        else

            scrollToRevealSelection();

    }

}

void RenderListBox::layout()

{

    RenderBlock::layout();

    if (m_scrollToRevealSelectionAfterLayout)

        scrollToRevealSelection();

}

void RenderListBox::scrollToRevealSelection()

{    

    HTMLSelectElement* select = static_cast<HTMLSelectElement*>(node());

    m_scrollToRevealSelectionAfterLayout = false;

    int firstIndex = select->activeSelectionStartListIndex();

    if (firstIndex >= 0 && !listIndexIsVisible(select->activeSelectionEndListIndex()))

        scrollToRevealElementAtListIndex(firstIndex);

}

void RenderListBox::calcPrefWidths()

{

    ASSERT(!m_optionsChanged);

    m_minPrefWidth = 0;

    m_maxPrefWidth = 0;

    if (style()->width().isFixed() && style()->width().value() > 0)

        m_minPrefWidth = m_maxPrefWidth = calcContentBoxWidth(style()->width().value());

    else {

        m_maxPrefWidth = m_optionsWidth + 2 * optionsSpacingHorizontal;

        if (m_vBar)

            m_maxPrefWidth += m_vBar->width();

    }

    if (style()->minWidth().isFixed() && style()->minWidth().value() > 0) {

        m_maxPrefWidth = max(m_maxPrefWidth, calcContentBoxWidth(style()->minWidth().value()));

        m_minPrefWidth = max(m_minPrefWidth, calcContentBoxWidth(style()->minWidth().value()));

    } else if (style()->width().isPercent() || (style()->width().isAuto() && style()->height().isPercent()))

        m_minPrefWidth = 0;

    else

        m_minPrefWidth = m_maxPrefWidth;

    if (style()->maxWidth().isFixed() && style()->maxWidth().value() != undefinedLength) {

        m_maxPrefWidth = min(m_maxPrefWidth, calcContentBoxWidth(style()->maxWidth().value()));

        m_minPrefWidth = min(m_minPrefWidth, calcContentBoxWidth(style()->maxWidth().value()));

    }

    int toAdd = paddingLeft() + paddingRight() + borderLeft() + borderRight();

    m_minPrefWidth += toAdd;

    m_maxPrefWidth += toAdd;

    setPrefWidthsDirty(false);

}

int RenderListBox::size() const

{

    int specifiedSize = static_cast<HTMLSelectElement*>(node())->size();

    if (specifiedSize > 1)

        return max(minSize, specifiedSize);

    return min(max(minSize, numItems()), maxDefaultSize);

}

int RenderListBox::numVisibleItems() const

{

    // Only count fully visible rows. But don't return 0 even if only part of a row shows.

    return max(1, (contentHeight() + rowSpacing) / itemHeight());

}

int RenderListBox::numItems() const

{

    return static_cast<HTMLSelectElement*>(node())->listItems().size();

}

int RenderListBox::listHeight() const

{

    return itemHeight() * numItems() - rowSpacing;

}

void RenderListBox::calcHeight()

{

    int toAdd = paddingTop() + paddingBottom() + borderTop() + borderBottom();

    int itemHeight = RenderListBox::itemHeight();

    m_height = itemHeight * size() - rowSpacing + toAdd;

    RenderBlock::calcHeight();

    if (m_vBar) {

        m_vBar->setEnabled(numVisibleItems() < numItems());

        m_vBar->setSteps(1, min(1, numVisibleItems() - 1), itemHeight);

        m_vBar->setProportion(numVisibleItems(), numItems());

    }

}

short RenderListBox::baselinePosition(bool b, bool isRootLineBox) const

{

    return height() + marginTop() + marginBottom() - baselineAdjustment;

}

IntRect RenderListBox::itemBoundingBoxRect(int tx, int ty, int index)

{

    return IntRect(tx + borderLeft() + paddingLeft(),

                   ty + borderTop() + paddingTop() + itemHeight() * (index - m_indexOffset),

                   contentWidth(), itemHeight());

}

void RenderListBox::paintObject(PaintInfo& paintInfo, int tx, int ty)

{

    if (style()->visibility() != VISIBLE)

        return;

    int listItemsSize = numItems();

    if (paintInfo.phase == PaintPhaseForeground) {

        int index = m_indexOffset;

        while (index < listItemsSize && index <= m_indexOffset + numVisibleItems()) {

            paintItemForeground(paintInfo, tx, ty, index);

            index++;

        }

    }

    // Paint the children.

    RenderBlock::paintObject(paintInfo, tx, ty);

    if (paintInfo.phase == PaintPhaseBlockBackground)

        paintScrollbar(paintInfo);

    else if (paintInfo.phase == PaintPhaseChildBlockBackground || paintInfo.phase == PaintPhaseChildBlockBackgrounds) {

        int index = m_indexOffset;

        while (index < listItemsSize && index <= m_indexOffset + numVisibleItems()) {

            paintItemBackground(paintInfo, tx, ty, index);

            index++;

        }

    }

}

void RenderListBox::paintScrollbar(PaintInfo& paintInfo)

{

    if (m_vBar) {

        IntRect absBounds = absoluteBoundingBoxRect();

        IntRect scrollRect(absBounds.right() - borderRight() - m_vBar->width(),

                           absBounds.y() + borderTop(),

                           m_vBar->width(),

                           absBounds.height() - (borderTop() + borderBottom()));

        m_vBar->setRect(scrollRect);

        m_vBar->paint(paintInfo.context, scrollRect);

    }

}

void RenderListBox::paintItemForeground(PaintInfo& paintInfo, int tx, int ty, int listIndex)

{

    HTMLSelectElement* select = static_cast<HTMLSelectElement*>(node());

    const Vector<HTMLElement*>& listItems = select->listItems();

    HTMLElement* element = listItems[listIndex];

    String itemText;

    if (element->hasTagName(optionTag))

        itemText = static_cast<HTMLOptionElement*>(element)->optionText();

    else if (element->hasTagName(optgroupTag))

        itemText = static_cast<HTMLOptGroupElement*>(element)->groupLabelText();

    // Determine where the item text should be placed

    IntRect r = itemBoundingBoxRect(tx, ty, listIndex);

    r.move(optionsSpacingHorizontal, style()->font().ascent());

    RenderStyle* itemStyle = element->renderStyle();

    if (!itemStyle)

        itemStyle = style();

    Color textColor = element->renderStyle() ? element->renderStyle()->color() : style()->color();

    if (element->hasTagName(optionTag) && static_cast<HTMLOptionElement*>(element)->selected()) {

        if (document()->frame()->isActive() && document()->focusedNode() == node())

            textColor = theme()->activeListBoxSelectionForegroundColor();

        // Honor the foreground color for disabled items

        else if (!element->disabled())

            textColor = theme()->inactiveListBoxSelectionForegroundColor();

    }

    paintInfo.context->setFillColor(textColor);

    Font itemFont = style()->font();

    if (element->hasTagName(optgroupTag)) {

        FontDescription d = itemFont.fontDescription();

        d.setBold(true);

        itemFont = Font(d, itemFont.letterSpacing(), itemFont.wordSpacing());

        itemFont.update();

    }

    paintInfo.context->setFont(itemFont);

    unsigned length = itemText.length();

    const UChar* string = itemText.characters();

    TextStyle textStyle(0, 0, 0, itemStyle->direction() == RTL, itemStyle->unicodeBidi() == Override, false, false);

    TextRun textRun(string, length);

    // Draw the item text

    if (itemStyle->visibility() != HIDDEN)

        paintInfo.context->drawBidiText(textRun, r.location(), textStyle);

}

void RenderListBox::paintItemBackground(PaintInfo& paintInfo, int tx, int ty, int listIndex)

{

    HTMLSelectElement* select = static_cast<HTMLSelectElement*>(node());

    const Vector<HTMLElement*>& listItems = select->listItems();

    HTMLElement* element = listItems[listIndex];

    Color backColor;

    if (element->hasTagName(optionTag) && static_cast<HTMLOptionElement*>(element)->selected()) {

        if (document()->frame()->isActive() && document()->focusedNode() == node())

            backColor = theme()->activeListBoxSelectionBackgroundColor();

        else

            backColor = theme()->inactiveListBoxSelectionBackgroundColor();

    } else

        backColor = element->renderStyle() ? element->renderStyle()->backgroundColor() : style()->backgroundColor();

    // Draw the background for this list box item

    if (!element->renderStyle() || element->renderStyle()->visibility() != HIDDEN) {

        IntRect itemRect = itemBoundingBoxRect(tx, ty, listIndex);

        itemRect.intersect(controlClipRect(tx, ty));

        paintInfo.context->fillRect(itemRect, backColor);

    }

}

bool RenderListBox::isPointInOverflowControl(HitTestResult& result, int _x, int _y, int _tx, int _ty)

{

    if (!m_vBar)

        return false;

    IntRect vertRect(_tx + width() - borderRight() - m_vBar->width(),

                   _ty + borderTop() - borderTopExtra(),

                   m_vBar->width(),

                   height() + borderTopExtra() + borderBottomExtra() - borderTop() - borderBottom());

    if (vertRect.contains(_x, _y)) {

        result.setScrollbar(m_vBar->isWidget() ? static_cast<PlatformScrollbar*>(m_vBar.get()) : 0);

        return true;

    }

    return false;

}

int RenderListBox::listIndexAtOffset(int offsetX, int offsetY)

{

    if (!numItems())

        return -1;

    if (offsetY < borderTop() + paddingTop() || offsetY > height() - paddingBottom() - borderBottom())

        return -1;

    int scrollbarWidth = m_vBar ? m_vBar->width() : 0;

    if (offsetX < borderLeft() + paddingLeft() || offsetX > width() - borderRight() - paddingRight() - scrollbarWidth)

        return -1;

    int newOffset = (offsetY - borderTop() - paddingTop()) / itemHeight() + m_indexOffset;

    return newOffset < numItems() ? newOffset : -1;

}

void RenderListBox::autoscroll()

{

    IntPoint pos = document()->frame()->view()->windowToContents(document()->frame()->eventHandler()->currentMousePosition());

    int rx = 0;

    int ry = 0;

    absolutePosition(rx, ry);

    int offsetX = pos.x() - rx;

    int offsetY = pos.y() - ry;

    int endIndex = -1;

    int rows = numVisibleItems();

    int offset = m_indexOffset;

    if (offsetY < borderTop() + paddingTop() && scrollToRevealElementAtListIndex(offset - 1))

        endIndex = offset - 1;

    else if (offsetY > height() - paddingBottom() - borderBottom() && scrollToRevealElementAtListIndex(offset + rows))

        endIndex = offset + rows - 1;

    else

        endIndex = listIndexAtOffset(offsetX, offsetY);

    if (endIndex >= 0) {

        HTMLSelectElement* select = static_cast<HTMLSelectElement*>(node());

        m_inAutoscroll = true;

        if (!select->multiple())

            select->setActiveSelectionAnchorIndex(endIndex);

        select->setActiveSelectionEndIndex(endIndex);

        select->updateListBoxSelection(!select->multiple());

        m_inAutoscroll = false;

    }

}

void RenderListBox::stopAutoscroll()

{

    static_cast<HTMLSelectElement*>(node())->listBoxOnChange();

}

bool RenderListBox::scrollToRevealElementAtListIndex(int index)

{

    if (index < 0 || index >= numItems() || listIndexIsVisible(index))

        return false;

    int newOffset;

    if (index < m_indexOffset)

        newOffset = index;

    else

        newOffset = index - numVisibleItems() + 1;

    m_indexOffset = newOffset;

    if (m_vBar)

        m_vBar->setValue(m_indexOffset);

    return true;

}

bool RenderListBox::listIndexIsVisible(int index)

{    

    return index >= m_indexOffset && index < m_indexOffset + numVisibleItems();

}

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

{

    return m_vBar && m_vBar->scroll(direction, granularity, multiplier);

}

void RenderListBox::valueChanged(unsigned listIndex)

{

    HTMLSelectElement* select = static_cast<HTMLSelectElement*>(node());

    select->setSelectedIndex(select->listToOptionIndex(listIndex));

    select->onChange();

}

void RenderListBox::valueChanged(Scrollbar*)

{

    int newOffset = m_vBar->value();

    if (newOffset != m_indexOffset) {

        m_indexOffset = newOffset;

        repaint();

        // Fire the scroll DOM event.

        EventTargetNodeCast(node())->dispatchHTMLEvent(scrollEvent, true, false);

    }

}

int RenderListBox::itemHeight() const

{

    return style()->font().height() + rowSpacing;

}

int RenderListBox::verticalScrollbarWidth() const

{

    return m_vBar ? m_vBar->width() : 0;

}

// FIXME: We ignore padding in the vertical direction as far as these values are concerned, since that's

// how the control currently paints.

int RenderListBox::scrollWidth() const

{

    // There is no horizontal scrolling allowed.

    return clientWidth();

}

int RenderListBox::scrollHeight() const

{

    return max(clientHeight(), listHeight());

}

int RenderListBox::scrollLeft() const

{

    return 0;

}

void RenderListBox::setScrollLeft(int)

{

}

int RenderListBox::scrollTop() const

{

    return m_indexOffset * itemHeight();

}

void RenderListBox::setScrollTop(int newTop)

{

    // Determine an index and scroll to it.    

    int index = newTop / itemHeight();

    if (index < 0 || index >= numItems() || index == m_indexOffset)

        return;

    m_indexOffset = index;

    if (m_vBar)

        m_vBar->setValue(index);

}

IntRect RenderListBox::controlClipRect(int tx, int ty) const

{