path: root/WebCore/rendering/RenderInline.cpp

/*
 * This file is part of the render object implementation for KHTML.
 *
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 * Copyright (C) 2003, 2004, 2005, 2006 Apple Computer, Inc.
 *
 * 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 "RenderInline.h"

#include "Document.h"
#include "RenderArena.h"
#include "RenderBlock.h"
#include "VisiblePosition.h"

namespace WebCore {

RenderInline::RenderInline(Node* node)
    : RenderFlow(node)
{
}

RenderInline::~RenderInline()
{
}

void RenderInline::styleDidChange(RenderStyle::Diff diff, const RenderStyle* oldStyle)
{
    RenderFlow::styleDidChange(diff, oldStyle);

    setInline(true);
    setHasReflection(false);

    // Ensure that all of the split inlines pick up the new style. We
    // only do this if we're an inline, since we don't want to propagate
    // a block's style to the other inlines.
    // e.g., <font>foo <h4>goo</h4> moo</font>.  The <font> inlines before
    // and after the block share the same style, but the block doesn't
    // need to pass its style on to anyone else.
    RenderFlow* currCont = continuation();
    while (currCont) {
        if (currCont->isInline()) {
            RenderFlow* nextCont = currCont->continuation();
            currCont->setContinuation(0);
            currCont->setStyle(style());
            currCont->setContinuation(nextCont);
        }
        currCont = currCont->continuation();
    }

    m_lineHeight = -1;

    // Update pseudos for :before and :after now.
    if (!isAnonymous()) {
        updateBeforeAfterContent(RenderStyle::BEFORE);
        updateBeforeAfterContent(RenderStyle::AFTER);
    }
}

bool RenderInline::isInlineContinuation() const
{
    return m_isContinuation;
}

static inline bool isAfterContent(RenderObject* child)
{
    if (!child)
        return false;
    if (child->style()->styleType() != RenderStyle::AFTER)
        return false;
    // Text nodes don't have their own styles, so ignore the style on a text node.
    if (child->isText() && !child->isBR())
        return false;
    return true;
}

void RenderInline::addChildToFlow(RenderObject* newChild, RenderObject* beforeChild)
{
    // Make sure we don't append things after :after-generated content if we have it.
    if (!beforeChild && isAfterContent(lastChild()))
        beforeChild = lastChild();

    if (!newChild->isInline() && !newChild->isFloatingOrPositioned()) {
        // We are placing a block inside an inline. We have to perform a split of this
        // inline into continuations.  This involves creating an anonymous block box to hold
        // |newChild|.  We then make that block box a continuation of this inline.  We take all of
        // the children after |beforeChild| and put them in a clone of this object.
        RefPtr<RenderStyle> newStyle = RenderStyle::create();
        newStyle->inheritFrom(style());
        newStyle->setDisplay(BLOCK);

        RenderBlock* newBox = new (renderArena()) RenderBlock(document() /* anonymous box */);
        newBox->setStyle(newStyle.release());
        RenderFlow* oldContinuation = continuation();
        setContinuation(newBox);

        // Someone may have put a <p> inside a <q>, causing a split.  When this happens, the :after content
        // has to move into the inline continuation.  Call updateBeforeAfterContent to ensure that our :after
        // content gets properly destroyed.
        bool isLastChild = (beforeChild == lastChild());
        updateBeforeAfterContent(RenderStyle::AFTER);
        if (isLastChild && beforeChild != lastChild())
            beforeChild = 0; // We destroyed the last child, so now we need to update our insertion
                             // point to be 0.  It's just a straight append now.

        splitFlow(beforeChild, newBox, newChild, oldContinuation);
        return;
    }

    RenderContainer::addChild(newChild, beforeChild);

    newChild->setNeedsLayoutAndPrefWidthsRecalc();
}

RenderInline* RenderInline::cloneInline(RenderFlow* src)
{
    RenderInline* o = new (src->renderArena()) RenderInline(src->element());
    o->m_isContinuation = true;
    o->setStyle(src->style());
    return o;
}

void RenderInline::splitInlines(RenderBlock* fromBlock, RenderBlock* toBlock,
                                RenderBlock* middleBlock,
                                RenderObject* beforeChild, RenderFlow* oldCont)
{
    // Create a clone of this inline.
    RenderInline* clone = cloneInline(this);
    clone->setContinuation(oldCont);

    // Now take all of the children from beforeChild to the end and remove
    // them from |this| and place them in the clone.
    RenderObject* o = beforeChild;
    while (o) {
        RenderObject* tmp = o;
        o = tmp->nextSibling();
        clone->addChildToFlow(removeChildNode(tmp), 0);
        tmp->setNeedsLayoutAndPrefWidthsRecalc();
    }

    // Hook |clone| up as the continuation of the middle block.
    middleBlock->setContinuation(clone);

    // We have been reparented and are now under the fromBlock.  We need
    // to walk up our inline parent chain until we hit the containing block.
    // Once we hit the containing block we're done.
    RenderFlow* curr = static_cast<RenderFlow*>(parent());
    RenderFlow* currChild = this;
    
    // FIXME: Because splitting is O(n^2) as tags nest pathologically, we cap the depth at which we're willing to clone.
    // There will eventually be a better approach to this problem that will let us nest to a much
    // greater depth (see bugzilla bug 13430) but for now we have a limit.  This *will* result in
    // incorrect rendering, but the alternative is to hang forever.
    unsigned splitDepth = 1;
    const unsigned cMaxSplitDepth = 200; 
    while (curr && curr != fromBlock) {
        if (splitDepth < cMaxSplitDepth) {
            // Create a new clone.
            RenderInline* cloneChild = clone;
            clone = cloneInline(curr);

            // Insert our child clone as the first child.
            clone->addChildToFlow(cloneChild, 0);

            // Hook the clone up as a continuation of |curr|.
            RenderFlow* oldCont = curr->continuation();
            curr->setContinuation(clone);
            clone->setContinuation(oldCont);

            // Someone may have indirectly caused a <q> to split.  When this happens, the :after content
            // has to move into the inline continuation.  Call updateBeforeAfterContent to ensure that the inline's :after
            // content gets properly destroyed.
            curr->updateBeforeAfterContent(RenderStyle::AFTER);

            // Now we need to take all of the children starting from the first child
            // *after* currChild and append them all to the clone.
            o = currChild->nextSibling();
            while (o) {
                RenderObject* tmp = o;
                o = tmp->nextSibling();
                clone->addChildToFlow(curr->removeChildNode(tmp), 0);
                tmp->setNeedsLayoutAndPrefWidthsRecalc();
            }
        }
        
        // Keep walking up the chain.
        currChild = curr;
        curr = static_cast<RenderFlow*>(curr->parent());
        splitDepth++;
    }

    // Now we are at the block level. We need to put the clone into the toBlock.
    toBlock->appendChildNode(clone);

    // Now take all the children after currChild and remove them from the fromBlock
    // and put them in the toBlock.
    o = currChild->nextSibling();
    while (o) {
        RenderObject* tmp = o;
        o = tmp->nextSibling();
        toBlock->appendChildNode(fromBlock->removeChildNode(tmp));
    }
}

void RenderInline::splitFlow(RenderObject* beforeChild, RenderBlock* newBlockBox,
                             RenderObject* newChild, RenderFlow* oldCont)
{
    RenderBlock* pre = 0;
    RenderBlock* block = containingBlock();
    
    // Delete our line boxes before we do the inline split into continuations.
    block->deleteLineBoxTree();
    
    bool madeNewBeforeBlock = false;
    if (block->isAnonymousBlock() && (!block->parent() || !block->parent()->createsAnonymousWrapper())) {
        // We can reuse this block and make it the preBlock of the next continuation.
        pre = block;
        block = block->containingBlock();
    } else {
        // No anonymous block available for use.  Make one.
        pre = block->createAnonymousBlock();
        madeNewBeforeBlock = true;
    }

    RenderBlock* post = block->createAnonymousBlock();

    RenderObject* boxFirst = madeNewBeforeBlock ? block->firstChild() : pre->nextSibling();
    if (madeNewBeforeBlock)
        block->insertChildNode(pre, boxFirst);
    block->insertChildNode(newBlockBox, boxFirst);
    block->insertChildNode(post, boxFirst);
    block->setChildrenInline(false);
    
    if (madeNewBeforeBlock) {
        RenderObject* o = boxFirst;
        while (o) {
            RenderObject* no = o;
            o = no->nextSibling();
            pre->appendChildNode(block->removeChildNode(no));
            no->setNeedsLayoutAndPrefWidthsRecalc();
        }
    }

    splitInlines(pre, post, newBlockBox, beforeChild, oldCont);

    // We already know the newBlockBox isn't going to contain inline kids, so avoid wasting
    // time in makeChildrenNonInline by just setting this explicitly up front.
    newBlockBox->setChildrenInline(false);

    // We don't just call addChild, since it would pass things off to the
    // continuation, so we call addChildToFlow explicitly instead.  We delayed
    // adding the newChild until now so that the |newBlockBox| would be fully
    // connected, thus allowing newChild access to a renderArena should it need
    // to wrap itself in additional boxes (e.g., table construction).
    newBlockBox->addChildToFlow(newChild, 0);

    // Always just do a full layout in order to ensure that line boxes (especially wrappers for images)
    // get deleted properly.  Because objects moves from the pre block into the post block, we want to
    // make new line boxes instead of leaving the old line boxes around.
    pre->setNeedsLayoutAndPrefWidthsRecalc();
    block->setNeedsLayoutAndPrefWidthsRecalc();
    post->setNeedsLayoutAndPrefWidthsRecalc();
}

void RenderInline::paint(PaintInfo& paintInfo, int tx, int ty)
{
    paintLines(paintInfo, tx, ty);
}

void RenderInline::absoluteRects(Vector<IntRect>& rects, int tx, int ty, bool topLevel)
{
    for (InlineRunBox* curr = firstLineBox(); curr; curr = curr->nextLineBox())
        rects.append(IntRect(tx + curr->xPos(), ty + curr->yPos(), curr->width(), curr->height()));

    for (RenderObject* curr = firstChild(); curr; curr = curr->nextSibling()) {
        if (!curr->isText())
            curr->absoluteRects(rects, tx + curr->xPos(), ty + curr->yPos(), false);
    }

    if (continuation() && topLevel)
        continuation()->absoluteRects(rects, 
                                      tx - containingBlock()->xPos() + continuation()->xPos(),
                                      ty - containingBlock()->yPos() + continuation()->yPos(),
                                      topLevel);
}

bool RenderInline::requiresLayer()
{
    return isRelPositioned() || isTransparent() || hasMask();
}

int RenderInline::width() const
{
    // Return the width of the minimal left side and the maximal right side.
    int leftSide = 0;
    int rightSide = 0;
    for (InlineRunBox* curr = firstLineBox(); curr; curr = curr->nextLineBox()) {
        if (curr == firstLineBox() || curr->xPos() < leftSide)
            leftSide = curr->xPos();
        if (curr == firstLineBox() || curr->xPos() + curr->width() > rightSide)
            rightSide = curr->xPos() + curr->width();
    }

    return rightSide - leftSide;
}

int RenderInline::height() const
{
    // See <rdar://problem/5289721>, for an unknown reason the linked list here is sometimes inconsistent, first is non-zero and last is zero.  We have been
    // unable to reproduce this at all (and consequently unable to figure ot why this is happening).  The assert will hopefully catch the problem in debug
    // builds and help us someday figure out why.  We also put in a redundant check of lastLineBox() to avoid the crash for now.
    ASSERT(!firstLineBox() == !lastLineBox());  // Either both are null or both exist.
    if (firstLineBox() && lastLineBox())
        return lastLineBox()->yPos() + lastLineBox()->height() - firstLineBox()->yPos();
    return 0;
}

int RenderInline::offsetLeft() const
{
    int x = RenderFlow::offsetLeft();
    if (firstLineBox())
        x += firstLineBox()->xPos();
    return x;
}

int RenderInline::offsetTop() const
{
    int y = RenderFlow::offsetTop();
    if (firstLineBox())
        y += firstLineBox()->yPos();
    return y;
}

const char* RenderInline::renderName() const
{
    if (isRelPositioned())
        return "RenderInline (relative positioned)";
    if (isAnonymous())
        return "RenderInline (generated)";
    return "RenderInline";
}

bool RenderInline::nodeAtPoint(const HitTestRequest& request, HitTestResult& result,
                                int x, int y, int tx, int ty, HitTestAction hitTestAction)
{
    return hitTestLines(request, result, x, y, tx, ty, hitTestAction);
}

VisiblePosition RenderInline::positionForCoordinates(int x, int y)
{
    // Translate the coords from the pre-anonymous block to the post-anonymous block.
    RenderBlock* cb = containingBlock();
    int parentBlockX = cb->xPos() + x;
    int parentBlockY = cb->yPos() + y;
    for (RenderObject* c = continuation(); c; c = c->continuation()) {
        RenderObject* contBlock = c;
        if (c->isInline())
            contBlock = c->containingBlock();
        if (c->isInline() || c->firstChild())
            return c->positionForCoordinates(parentBlockX - contBlock->xPos(), parentBlockY - contBlock->yPos());
    }

    return RenderFlow::positionForCoordinates(x, y);
}

} // namespace WebCore