rendertablecell.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 1997 Martin Jones ([e-mail])
 *           (C) 1997 Torben Weis ([e-mail])
 *           (C) 1998 Waldo Bastian ([e-mail])
 *           (C) 1999 Lars Knoll ([e-mail])
 *           (C) 1999 Antti Koivisto ([e-mail])
 * Copyright (C) 2003, 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "RenderTableCell.h"

#include "FloatQuad.h"
#include "GraphicsContext.h"
#include "HTMLNames.h"
#include "HTMLTableCellElement.h"
#include "RenderTableCol.h"
#include "RenderView.h"
#include "TransformState.h"

using namespace std;

namespace WebCore {

using namespace HTMLNames;

RenderTableCell::RenderTableCell(Node* node)
    : RenderBlock(node)
    , m_row(-1)
    , m_column(-1)
    , m_rowSpan(1)
    , m_columnSpan(1)
    , m_intrinsicPaddingTop(0)
    , m_intrinsicPaddingBottom(0)
    , m_percentageHeight(0)
{
    updateFromElement();
}

void RenderTableCell::destroy()
{
    RenderTableSection* recalcSection = parent() ? section() : 0;

    RenderBlock::destroy();

    if (recalcSection)
        recalcSection->setNeedsCellRecalc();
}

void RenderTableCell::updateFromElement()
{
    Node* n = node();
    if (n && (n->hasTagName(tdTag) || n->hasTagName(thTag))) {
        HTMLTableCellElement* tc = static_cast<HTMLTableCellElement*>(n);
        int oldRSpan = m_rowSpan;
        int oldCSpan = m_columnSpan;

        m_columnSpan = tc->colSpan();
        m_rowSpan = tc->rowSpan();
        if ((oldRSpan != m_rowSpan || oldCSpan != m_columnSpan) && style() && parent()) {
            setNeedsLayoutAndPrefWidthsRecalc();
            if (section())
                section()->setNeedsCellRecalc();
        }
    }
}

Length RenderTableCell::styleOrColWidth() const
{
    Length w = style()->width();
    if (colSpan() > 1 || !w.isAuto())
        return w;
    RenderTableCol* tableCol = table()->colElement(col());
    if (tableCol) {
        w = tableCol->style()->width();
        
        // Column widths specified on <col> apply to the border box of the cell.
        // Percentages don't need to be handled since they're always treated this way (even when specified on the cells).
        // See Bugzilla bug 8126 for details.
        if (w.isFixed() && w.value() > 0)
            w = Length(max(0, w.value() - borderLeft() - borderRight() - paddingLeft() - paddingRight()), Fixed);
    }
    return w;
}

void RenderTableCell::calcPrefWidths()
{
    // The child cells rely on the grids up in the sections to do their calcPrefWidths work.  Normally the sections are set up early, as table
    // cells are added, but relayout can cause the cells to be freed, leaving stale pointers in the sections'
    // grids.  We must refresh those grids before the child cells try to use them.
    table()->recalcSectionsIfNeeded();

    RenderBlock::calcPrefWidths();
    if (node() && style()->autoWrap()) {
        // See if nowrap was set.
        Length w = styleOrColWidth();
        String nowrap = static_cast<Element*>(node())->getAttribute(nowrapAttr);
        if (!nowrap.isNull() && w.isFixed())
            // Nowrap is set, but we didn't actually use it because of the
            // fixed width set on the cell.  Even so, it is a WinIE/Moz trait
            // to make the minwidth of the cell into the fixed width.  They do this
            // even in strict mode, so do not make this a quirk.  Affected the top
            // of hiptop.com.
            m_minPrefWidth = max(w.value(), m_minPrefWidth);
    }
}

void RenderTableCell::calcWidth()
{
}

void RenderTableCell::updateWidth(int w)
{
    if (w != width()) {
        setWidth(w);
        setCellWidthChanged(true);
    }
}

void RenderTableCell::layout()
{
    layoutBlock(cellWidthChanged());
    setCellWidthChanged(false);
}

int RenderTableCell::paddingTop(bool includeIntrinsicPadding) const
{
    return RenderBlock::paddingTop() + (includeIntrinsicPadding ? intrinsicPaddingTop() : 0);
}

int RenderTableCell::paddingBottom(bool includeIntrinsicPadding) const
{
    return RenderBlock::paddingBottom() + (includeIntrinsicPadding ? intrinsicPaddingBottom() : 0);
}

void RenderTableCell::setOverrideSize(int size)
{
    clearIntrinsicPadding();
    RenderBlock::setOverrideSize(size);
}

IntRect RenderTableCell::clippedOverflowRectForRepaint(RenderBoxModelObject* repaintContainer)
{
    // If the table grid is dirty, we cannot get reliable information about adjoining cells,
    // so we ignore outside borders. This should not be a problem because it means that
    // the table is going to recalculate the grid, relayout and repaint its current rect, which
    // includes any outside borders of this cell.
    if (!table()->collapseBorders() || table()->needsSectionRecalc())
        return RenderBlock::clippedOverflowRectForRepaint(repaintContainer);

    bool rtl = table()->style()->direction() == RTL;
    int outlineSize = style()->outlineSize();
    int left = max(borderHalfLeft(true), outlineSize);
    int right = max(borderHalfRight(true), outlineSize);
    int top = max(borderHalfTop(true), outlineSize);
    int bottom = max(borderHalfBottom(true), outlineSize);
    if (left && !rtl || right && rtl) {
        if (RenderTableCell* before = table()->cellBefore(this)) {
            top = max(top, before->borderHalfTop(true));
            bottom = max(bottom, before->borderHalfBottom(true));
        }
    }
    if (left && rtl || right && !rtl) {
        if (RenderTableCell* after = table()->cellAfter(this)) {
            top = max(top, after->borderHalfTop(true));
            bottom = max(bottom, after->borderHalfBottom(true));
        }
    }
    if (top) {
        if (RenderTableCell* above = table()->cellAbove(this)) {
            left = max(left, above->borderHalfLeft(true));
            right = max(right, above->borderHalfRight(true));
        }
    }
    if (bottom) {
        if (RenderTableCell* below = table()->cellBelow(this)) {
            left = max(left, below->borderHalfLeft(true));
            right = max(right, below->borderHalfRight(true));
        }
    }
    left = max(left, -overflowLeft(false));
    top = max(top, -overflowTop(false));
    IntRect r(-left, - top, left + max(width() + right, overflowWidth(false)), top + max(height() + bottom, overflowHeight(false)));

    if (RenderView* v = view()) {
        // FIXME: layoutDelta needs to be applied in parts before/after transforms and
        // repaint containers. https://bugs.webkit.org/show_bug.cgi?id=23308
        r.move(v->layoutDelta());
    }
    computeRectForRepaint(repaintContainer, r);
    return r;
}

void RenderTableCell::computeRectForRepaint(RenderBoxModelObject* repaintContainer, IntRect& r, bool fixed)
{
    if (repaintContainer == this)
        return;
    r.setY(r.y());
    RenderView* v = view();
    if ((!v || !v->layoutStateEnabled()) && parent())
        r.move(-parentBox()->x(), -parentBox()->y()); // Rows are in the same coordinate space, so don't add their offset in.
    RenderBlock::computeRectForRepaint(repaintContainer, r, fixed);
}

void RenderTableCell::mapLocalToContainer(RenderBoxModelObject* repaintContainer, bool fixed, bool useTransforms, TransformState& transformState) const
{
    if (repaintContainer == this)
        return;

    RenderView* v = view();
    if ((!v || !v->layoutStateEnabled()) && parent()) {
        // Rows are in the same coordinate space, so don't add their offset in.
        // FIXME: this is wrong with transforms
        transformState.move(-parentBox()->x(), -parentBox()->y());
    }
    RenderBlock::mapLocalToContainer(repaintContainer, fixed, useTransforms, transformState);
}

void RenderTableCell::mapAbsoluteToLocalPoint(bool fixed, bool useTransforms, TransformState& transformState) const
{
    RenderBlock::mapAbsoluteToLocalPoint(fixed, useTransforms, transformState);
    if (parent()) {
        // Rows are in the same coordinate space, so add their offset back in.
        // FIXME: this is wrong with transforms
        transformState.move(parentBox()->x(), parentBox()->y());
    }
}

int RenderTableCell::baselinePosition(bool firstLine, bool isRootLineBox) const
{
    if (isRootLineBox)
        return RenderBox::baselinePosition(firstLine, isRootLineBox);

    // <http://www.w3.org/TR/2007/CR-CSS21-20070719/tables.html#height-layout>: The baseline of a cell is the baseline of
    // the first in-flow line box in the cell, or the first in-flow table-row in the cell, whichever comes first. If there
    // is no such line box or table-row, the baseline is the bottom of content edge of the cell box.
    int firstLineBaseline = firstLineBoxBaseline();
    if (firstLineBaseline != -1)
        return firstLineBaseline;
    return paddingTop() + borderTop() + contentHeight();
}

void RenderTableCell::styleWillChange(StyleDifference diff, const RenderStyle* newStyle)
{
    if (parent() && section() && style() && style()->height() != newStyle->height())
        section()->setNeedsCellRecalc();

    ASSERT(newStyle->display() == TABLE_CELL);

    RenderBlock::styleWillChange(diff, newStyle);
}

void RenderTableCell::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
    RenderBlock::styleDidChange(diff, oldStyle);
    setHasBoxDecorations(true);
}

// The following rules apply for resolving conflicts and figuring out which border
// to use.
// (1) Borders with the 'border-style' of 'hidden' take precedence over all other conflicting 
// borders. Any border with this value suppresses all borders at this location.
// (2) Borders with a style of 'none' have the lowest priority. Only if the border properties of all 
// the elements meeting at this edge are 'none' will the border be omitted (but note that 'none' is 
// the default value for the border style.)
// (3) If none of the styles are 'hidden' and at least one of them is not 'none', then narrow borders 
// are discarded in favor of wider ones. If several have the same 'border-width' then styles are preferred 
// in this order: 'double', 'solid', 'dashed', 'dotted', 'ridge', 'outset', 'groove', and the lowest: 'inset'.
// (4) If border styles differ only in color, then a style set on a cell wins over one on a row, 
// which wins over a row group, column, column group and, lastly, table. It is undefined which color 
// is used when two elements of the same type disagree.
static CollapsedBorderValue compareBorders(const CollapsedBorderValue& border1, const CollapsedBorderValue& border2)
{
    // Sanity check the values passed in.  If either is null, return the other.
    if (!border2.exists())
        return border1;
    if (!border1.exists())
        return border2;

    // Rule #1 above.