RootInlineBox.cpp   [plain text]

/*
 * Copyright (C) 2003, 2006, 2008 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 "RootInlineBox.h"

#include "BidiResolver.h"
#include "Chrome.h"
#include "ChromeClient.h"
#include "Document.h"
#include "EllipsisBox.h"
#include "Frame.h"
#include "GraphicsContext.h"
#include "HitTestResult.h"
#include "Page.h"
#include "RenderArena.h"
#include "RenderBlock.h"

using namespace std;

namespace WebCore {
    
typedef WTF::HashMap<const RootInlineBox*, EllipsisBox*> EllipsisBoxMap;
static EllipsisBoxMap* gEllipsisBoxMap = 0;

void RootInlineBox::destroy(RenderArena* arena)
{
    detachEllipsisBox(arena);
    InlineFlowBox::destroy(arena);
}

void RootInlineBox::detachEllipsisBox(RenderArena* arena)
{
    if (m_hasEllipsisBox) {
        EllipsisBox* box = gEllipsisBoxMap->take(this);
        box->setParent(0);
        box->destroy(arena);
        m_hasEllipsisBox = false;
    }
}

RenderLineBoxList* RootInlineBox::rendererLineBoxes() const
{
    return block()->lineBoxes();
}

void RootInlineBox::clearTruncation()
{
    if (m_hasEllipsisBox) {
        detachEllipsisBox(renderer()->renderArena());
        InlineFlowBox::clearTruncation();
    }
}

bool RootInlineBox::canAccommodateEllipsis(bool ltr, int blockEdge, int lineBoxEdge, int ellipsisWidth)
{
    // First sanity-check the unoverflowed width of the whole line to see if there is sufficient room.
    int delta = ltr ? lineBoxEdge - blockEdge : blockEdge - lineBoxEdge;
    if (width() - delta < ellipsisWidth)
        return false;

    // Next iterate over all the line boxes on the line.  If we find a replaced element that intersects
    // then we refuse to accommodate the ellipsis.  Otherwise we're ok.
    return InlineFlowBox::canAccommodateEllipsis(ltr, blockEdge, ellipsisWidth);
}

void RootInlineBox::placeEllipsis(const AtomicString& ellipsisStr,  bool ltr, int blockLeftEdge, int blockRightEdge, int ellipsisWidth,
                                  InlineBox* markupBox)
{
    // Create an ellipsis box.
    EllipsisBox* ellipsisBox = new (renderer()->renderArena()) EllipsisBox(renderer(), ellipsisStr, this,
                                                              ellipsisWidth - (markupBox ? markupBox->width() : 0), height(),
                                                              y(), !prevRootBox(),
                                                              markupBox);
    
    if (!gEllipsisBoxMap)
        gEllipsisBoxMap = new EllipsisBoxMap();
    gEllipsisBoxMap->add(this, ellipsisBox);
    m_hasEllipsisBox = true;

    // FIXME: Do we need an RTL version of this?
    if (ltr && (x() + width() + ellipsisWidth) <= blockRightEdge) {
        ellipsisBox->m_x = x() + width();
        return;
    }

    // Now attempt to find the nearest glyph horizontally and place just to the right (or left in RTL)
    // of that glyph.  Mark all of the objects that intersect the ellipsis box as not painting (as being
    // truncated).
    bool foundBox = false;
    ellipsisBox->m_x = placeEllipsisBox(ltr, blockLeftEdge, blockRightEdge, ellipsisWidth, foundBox);
}

int RootInlineBox::placeEllipsisBox(bool ltr, int blockLeftEdge, int blockRightEdge, int ellipsisWidth, bool& foundBox)
{
    int result = InlineFlowBox::placeEllipsisBox(ltr, blockLeftEdge, blockRightEdge, ellipsisWidth, foundBox);
    if (result == -1)
        result = ltr ? blockRightEdge - ellipsisWidth : blockLeftEdge;
    return result;
}

void RootInlineBox::paintEllipsisBox(RenderObject::PaintInfo& paintInfo, int tx, int ty) const
{
    if (m_hasEllipsisBox && renderer()->shouldPaintWithinRoot(paintInfo) && renderer()->style()->visibility() == VISIBLE &&
            paintInfo.phase == PaintPhaseForeground)
        ellipsisBox()->paint(paintInfo, tx, ty);
}

#if PLATFORM(MAC)

void RootInlineBox::addHighlightOverflow()
{
    Frame* frame = renderer()->document()->frame();
    if (!frame)
        return;
    Page* page = frame->page();
    if (!page)
        return;

    // Highlight acts as a selection inflation.
    FloatRect rootRect(0, selectionTop(), width(), selectionHeight());
    IntRect inflatedRect = enclosingIntRect(page->chrome()->client()->customHighlightRect(renderer()->node(), renderer()->style()->highlight(), rootRect));
    setHorizontalOverflowPositions(leftLayoutOverflow(), rightLayoutOverflow(), min(leftVisualOverflow(), inflatedRect.x()), max(rightVisualOverflow(), inflatedRect.right()));
    setVerticalOverflowPositions(topLayoutOverflow(), bottomLayoutOverflow(), min(topVisualOverflow(), inflatedRect.y()), max(bottomVisualOverflow(), inflatedRect.bottom()), height());
}

void RootInlineBox::paintCustomHighlight(RenderObject::PaintInfo& paintInfo, int tx, int ty, const AtomicString& highlightType)
{
    if (!renderer()->shouldPaintWithinRoot(paintInfo) || renderer()->style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseForeground)
        return;

    Frame* frame = renderer()->document()->frame();
    if (!frame)
        return;
    Page* page = frame->page();
    if (!page)
        return;

    // Get the inflated rect so that we can properly hit test.
    FloatRect rootRect(tx + x(), ty + selectionTop(), width(), selectionHeight());
    FloatRect inflatedRect = page->chrome()->client()->customHighlightRect(renderer()->node(), highlightType, rootRect);
    if (inflatedRect.intersects(paintInfo.rect))
        page->chrome()->client()->paintCustomHighlight(renderer()->node(), highlightType, rootRect, rootRect, false, true);
}

#endif

void RootInlineBox::paint(RenderObject::PaintInfo& paintInfo, int tx, int ty)
{
    InlineFlowBox::paint(paintInfo, tx, ty);
    paintEllipsisBox(paintInfo, tx, ty);
#if PLATFORM(MAC)
    RenderStyle* styleToUse = renderer()->style(m_firstLine);
    if (styleToUse->highlight() != nullAtom && !paintInfo.context->paintingDisabled())
        paintCustomHighlight(paintInfo, tx, ty, styleToUse->highlight());
#endif
}

bool RootInlineBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int x, int y, int tx, int ty)
{
    if (m_hasEllipsisBox && visibleToHitTesting()) {
        if (ellipsisBox()->nodeAtPoint(request, result, x, y, tx, ty)) {
            renderer()->updateHitTestResult(result, IntPoint(x - tx, y - ty));
            return true;
        }
    }
    return InlineFlowBox::nodeAtPoint(request, result, x, y, tx, ty);
}

void RootInlineBox::adjustPosition(int dx, int dy)
{
    InlineFlowBox::adjustPosition(dx, dy);
    m_lineTop += dy;
    m_lineBottom += dy;
    m_blockHeight += dy;
}

void RootInlineBox::childRemoved(InlineBox* box)
{
    if (box->renderer() == m_lineBreakObj)
        setLineBreakInfo(0, 0, BidiStatus());

    for (RootInlineBox* prev = prevRootBox(); prev && prev->lineBreakObj() == box->renderer(); prev = prev->prevRootBox()) {
        prev->setLineBreakInfo(0, 0, BidiStatus());
        prev->markDirty();
    }
}

int RootInlineBox::verticallyAlignBoxes(int heightOfBlock)
{
    int maxPositionTop = 0;
    int maxPositionBottom = 0;
    int maxAscent = 0;
    int maxDescent = 0;

    // Figure out if we're in strict mode.  Note that we can't simply use !style()->htmlHacks(),
    // because that would match almost strict mode as well.
    RenderObject* curr = renderer();
    while (curr && !curr->node())
        curr = curr->container();
    bool strictMode = (curr && curr->document()->inStrictMode());

    computeLogicalBoxHeights(maxPositionTop, maxPositionBottom, maxAscent, maxDescent, strictMode);

    if (maxAscent + maxDescent < max(maxPositionTop, maxPositionBottom))
        adjustMaxAscentAndDescent(maxAscent, maxDescent, maxPositionTop, maxPositionBottom);

    int maxHeight = maxAscent + maxDescent;
    int lineTop = heightOfBlock;
    int lineBottom = heightOfBlock;
    placeBoxesVertically(heightOfBlock, maxHeight, maxAscent, strictMode, lineTop, lineBottom);
    computeVerticalOverflow(lineTop, lineBottom, strictMode);
    setLineTopBottomPositions(lineTop, lineBottom);

    // Detect integer overflow.
    if (heightOfBlock > numeric_limits<int>::max() - maxHeight)
        return numeric_limits<int>::max();

    heightOfBlock = heightOfBlock + maxHeight;
    
    return heightOfBlock;
}

GapRects RootInlineBox::fillLineSelectionGap(int selTop, int selHeight, RenderBlock* rootBlock, int blockX, int blockY, int tx, int ty,
                                             const RenderObject::PaintInfo* paintInfo)
{
    RenderObject::SelectionState lineState = selectionState();

    bool leftGap, rightGap;
    block()->getHorizontalSelectionGapInfo(lineState, leftGap, rightGap);

    GapRects result;

    InlineBox* firstBox = firstSelectedBox();
    InlineBox* lastBox = lastSelectedBox();
    if (leftGap)
        result.uniteLeft(block()->fillLeftSelectionGap(firstBox->parent()->renderer(),
                                                       firstBox->x(), selTop, selHeight,
                                                       rootBlock, blockX, blockY, tx, ty, paintInfo));
    if (rightGap)
        result.uniteRight(block()->fillRightSelectionGap(lastBox->parent()->renderer(),
                                                         lastBox->x() + lastBox->width(), selTop, selHeight,
                                                         rootBlock, blockX, blockY, tx, ty, paintInfo));

    // When dealing with bidi text, a non-contiguous selection region is possible.
    // e.g. The logical text aaaAAAbbb (capitals denote RTL text and non-capitals LTR) is layed out
    // visually as 3 text runs |aaa|bbb|AAA| if we select 4 characters from the start of the text the
    // selection will look like (underline denotes selection):
    // |aaa|bbb|AAA|
    //  ___       _
    // We can see that the |bbb| run is not part of the selection while the runs around it are.
    if (firstBox && firstBox != lastBox) {
        // Now fill in any gaps on the line that occurred between two selected elements.
        int lastX = firstBox->x() + firstBox->width();
        bool isPreviousBoxSelected = firstBox->selectionState() != RenderObject::SelectionNone;
        for (InlineBox* box = firstBox->nextLeafChild(); box; box = box->nextLeafChild()) {
            if (box->selectionState() != RenderObject::SelectionNone) {
                if (isPreviousBoxSelected)  // VisibleSelection may be non-contiguous, see comment above.
                    result.uniteCenter(block()->fillHorizontalSelectionGap(box->parent()->renderer(),
                                                                           lastX + tx, selTop + ty,
                                                                           box->x() - lastX, selHeight, paintInfo));
                lastX = box->x() + box->width();
            }
            if (box == lastBox)
                break;
            isPreviousBoxSelected = box->selectionState() != RenderObject::SelectionNone;
        }
    }

    return result;
}

void RootInlineBox::setHasSelectedChildren(bool b)
{
    if (m_hasSelectedChildren == b)
        return;
    m_hasSelectedChildren = b;
}

RenderObject::SelectionState RootInlineBox::selectionState()
{
    // Walk over all of the selected boxes.
    RenderObject::SelectionState state = RenderObject::SelectionNone;
    for (InlineBox* box = firstLeafChild(); box; box = box->nextLeafChild()) {
        RenderObject::SelectionState boxState = box->selectionState();
        if ((boxState == RenderObject::SelectionStart && state == RenderObject::SelectionEnd) ||
            (boxState == RenderObject::SelectionEnd && state == RenderObject::SelectionStart))
            state = RenderObject::SelectionBoth;
        else if (state == RenderObject::SelectionNone ||
                 ((boxState == RenderObject::SelectionStart || boxState == RenderObject::SelectionEnd) &&
                  (state == RenderObject::SelectionNone || state == RenderObject::SelectionInside)))
            state = boxState;
        if (state == RenderObject::SelectionBoth)
            break;
    }

    return state;
}

InlineBox* RootInlineBox::firstSelectedBox()
{
    for (InlineBox* box = firstLeafChild(); box; box = box->nextLeafChild()) {
        if (box->selectionState() != RenderObject::SelectionNone)
            return box;
    }

    return 0;
}

InlineBox* RootInlineBox::lastSelectedBox()
{
    for (InlineBox* box = lastLeafChild(); box; box = box->prevLeafChild()) {
        if (box->selectionState() != RenderObject::SelectionNone)
            return box;
    }

    return 0;
}

int RootInlineBox::selectionTop() const
{
    int selectionTop = m_lineTop;
    if (!prevRootBox())
        return selectionTop;

    int prevBottom = prevRootBox()->selectionBottom();
    if (prevBottom < selectionTop && block()->containsFloats()) {
        // This line has actually been moved further down, probably from a large line-height, but possibly because the
        // line was forced to clear floats.  If so, let's check the offsets, and only be willing to use the previous
        // line's bottom overflow if the offsets are greater on both sides.
        int prevLeft = block()->leftOffset(prevBottom, !prevRootBox());
        int prevRight = block()->rightOffset(prevBottom, !prevRootBox());
        int newLeft = block()->leftOffset(selectionTop, !prevRootBox());
        int newRight = block()->rightOffset(selectionTop, !prevRootBox());
        if (prevLeft > newLeft || prevRight < newRight)
            return selectionTop;
    }

    return prevBottom;
}

RenderBlock* RootInlineBox::block() const
{
    return toRenderBlock(renderer());
}

static bool isEditableLeaf(InlineBox* leaf)
{
    return leaf && leaf->renderer() && leaf->renderer()->node() && leaf->renderer()->node()->isContentEditable();
}

InlineBox* RootInlineBox::closestLeafChildForXPos(int x, bool onlyEditableLeaves)
{
    InlineBox* firstLeaf = firstLeafChild();
    InlineBox* lastLeaf = lastLeafChild();
    if (firstLeaf == lastLeaf && (!onlyEditableLeaves || isEditableLeaf(firstLeaf)))
        return firstLeaf;

    // Avoid returning a list marker when possible.
    if (x <= firstLeaf->m_x && !firstLeaf->renderer()->isListMarker() && (!onlyEditableLeaves || isEditableLeaf(firstLeaf)))
        // The x coordinate is less or equal to left edge of the firstLeaf.
        // Return it.
        return firstLeaf;

    if (x >= lastLeaf->m_x + lastLeaf->m_width && !lastLeaf->renderer()->isListMarker() && (!onlyEditableLeaves || isEditableLeaf(lastLeaf)))
        // The x coordinate is greater or equal to right edge of the lastLeaf.
        // Return it.
        return lastLeaf;

    InlineBox* closestLeaf = 0;
    for (InlineBox* leaf = firstLeaf; leaf; leaf = leaf->nextLeafChild()) {
        if (!leaf->renderer()->isListMarker() && (!onlyEditableLeaves || isEditableLeaf(leaf))) {
            closestLeaf = leaf;
            if (x < leaf->m_x + leaf->m_width)
                // The x coordinate is less than the right edge of the box.
                // Return it.
                return leaf;
        }
    }

    return closestLeaf ? closestLeaf : lastLeaf;
}

BidiStatus RootInlineBox::lineBreakBidiStatus() const
{ 
    return BidiStatus(m_lineBreakBidiStatusEor, m_lineBreakBidiStatusLastStrong, m_lineBreakBidiStatusLast, m_lineBreakContext);
}

void RootInlineBox::setLineBreakInfo(RenderObject* obj, unsigned breakPos, const BidiStatus& status)
{
    m_lineBreakObj = obj;
    m_lineBreakPos = breakPos;
    m_lineBreakBidiStatusEor = status.eor;
    m_lineBreakBidiStatusLastStrong = status.lastStrong;
    m_lineBreakBidiStatusLast = status.last;
    m_lineBreakContext = status.context;
}

EllipsisBox* RootInlineBox::ellipsisBox() const
{
    if (!m_hasEllipsisBox)
        return false;
    return gEllipsisBoxMap->get(this);
}

void RootInlineBox::removeLineBoxFromRenderObject()
{
    block()->lineBoxes()->removeLineBox(this);
}

void RootInlineBox::extractLineBoxFromRenderObject()
{
    block()->lineBoxes()->extractLineBox(this);
}

void RootInlineBox::attachLineBoxToRenderObject()
{
    block()->lineBoxes()->attachLineBox(this);
}

} // namespace WebCore