C++ RenderFlow类代码示例

InlineTextBox * RenderText::findInlineTextBox( int offset, int &pos, bool checkFirstLetter )
{
    // The text boxes point to parts of the rendertext's str string
    // (they don't include '\n')
    // Find the text box that includes the character at @p offset
    // and return pos, which is the position of the char in the run.

    // FIXME: make this use binary search? Dirk says it won't work :-( (LS)
    (void)checkFirstLetter;
#if 0
    if (checkFirstLetter && forcedMinOffset()) {
//        kdDebug(6040) << "checkFirstLetter: forcedMinOffset: " << forcedMinOffset() << endl;
        RenderFlow *firstLetter = static_cast<RenderFlow *>(previousSibling());
        if (firstLetter && firstLetter->isFlow() && firstLetter->isFirstLetter()) {
            RenderText *letterText = static_cast<RenderText *>(firstLetter->firstChild());
            //kdDebug(6040) << "lettertext: " << letterText << " minOfs: " << letterText->minOffset() << " maxOfs: " << letterText->maxOffset() << endl;
	    if (offset >= letterText->minOffset() && offset <= letterText->maxOffset()) {
	        InlineTextBox *result = letterText->findInlineTextBox(offset, pos, false);
            //kdDebug(6040) << "result: " << result << endl;
		if (result) return result;
	    }
        }
    }
#endif

    if ( m_lines.isEmpty() )
        return 0L;

    // The text boxes don't resemble a contiguous coverage of the text, there
    // may be holes. Therefore, we snap to the nearest previous text box if
    // the given offset happens to point to such a hole.

    InlineTextBox* s = m_lines[0];
    uint count = m_lines.count();
    uint si = 0;
    uint nearest_idx = 0;		// index of nearest text box
    int nearest = INT_MAX;		// nearest distance
//kdDebug(6040) << "s[" << si << "] m_start " << s->m_start << " m_end " << (s->m_start + s->m_len) << endl;
    while(!(offset >= s->m_start && offset <= s->m_start + s->m_len)
    		&& ++si < count)
    {
        int dist = offset - (s->m_start + s->m_len);
//kdDebug(6040) << "dist " << dist << " nearest " << nearest << endl;
	if (dist >= 0 && dist <= nearest) {
	    nearest = dist;
	    nearest_idx = si - 1;
	}/*end if*/
        s = m_lines[si];
//kdDebug(6040) << "s[" << si << "] m_start " << s->m_start << " m_end " << (s->m_start + s->m_len) << endl;
    }
//kdDebug(6040) << "nearest_idx " << nearest_idx << " count " << count << endl;
    if (si >= count) s = m_lines[nearest_idx];
    // we are now in the correct text box
    pos = kMin(offset - s->m_start, int( s->m_len ));
    //kdDebug(6040) << "offset=" << offset << " s->m_start=" << s->m_start << endl;
    return s;
}

RenderFlow* RenderFlow::createAnonymousFlow(DOM::DocumentImpl* doc, RenderStyle* style)
{
    RenderFlow* result;
    if (style->display() == INLINE)
        result = new (doc->renderArena()) RenderInline(doc);
    else
        result = new (doc->renderArena()) RenderBlock(doc);
    result->setStyle(style);
    return result;
}

RenderFlow* RenderFlow::createFlow(DOM::NodeImpl* node, RenderStyle* style, RenderArena* arena)
{
    RenderFlow* result;
    if (style->display() == INLINE)
        result = new (arena) RenderInline(node);
    else
        result = new (arena) RenderBlock(node);
    result->setStyle(style);
    return result;
}

void RenderInline::setStyle(RenderStyle* newStyle)
{
    RenderFlow::setStyle(newStyle);
    setInline(true);

    // 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);
    }
}

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

    setInline(true);
    //Nicki Vankoughnett:  this change is indicated in webkit changest 37637, 
    //but not obviously relevant to changes to the RenderStyle class.
    //  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);
    }
}

void RenderInline::setStyle(RenderStyle *_style)
{
    RenderFlow::setStyle(_style);
    setInline(true);

    // 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();
    }

    if(attached())
    {
        // Update replaced content
        updateReplacedContent();
        // Update pseudos for ::before and ::after
        updatePseudoChildren();
    }
}

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->x() + x;
    int parentBlockY = cb->y() + y;
    for (RenderFlow* c = continuation(); c; c = c->continuation()) {
        RenderFlow* contBlock = c;
        if (c->isInline())
            contBlock = c->containingBlock();
        if (c->isInline() || c->firstChild())
            return c->positionForCoordinates(parentBlockX - contBlock->x(), parentBlockY - contBlock->y());
    }

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

void InlineFlowBox::determineSpacingForFlowBoxes(bool lastLine, RenderObject* endObject)
{
    // All boxes start off open.  They will not apply any margins/border/padding on
    // any side.
    bool includeLeftEdge = false;
    bool includeRightEdge = false;

    RenderFlow* flow = static_cast<RenderFlow*>(object());

    if (!flow->firstChild())
        includeLeftEdge = includeRightEdge = true; // Empty inlines never split across lines.
    else if (parent()) { // The root inline box never has borders/margins/padding.
        bool ltr = flow->style()->direction() == LTR;

        // Check to see if all initial lines are unconstructed.  If so, then
        // we know the inline began on this line.
        if (!flow->firstLineBox()->isConstructed()) {
            if (ltr && flow->firstLineBox() == this)
                includeLeftEdge = true;
            else if (!ltr && flow->lastLineBox() == this)
                includeRightEdge = true;
        }

        // In order to determine if the inline ends on this line, we check three things:
        // (1) If we are the last line and we don't have a continuation(), then we can
        // close up.
        // (2) If the last line box for the flow has an object following it on the line (ltr,
        // reverse for rtl), then the inline has closed.
        // (3) The line may end on the inline.  If we are the last child (climbing up
        // the end object's chain), then we just closed as well.
        if (!flow->lastLineBox()->isConstructed()) {
            if (ltr) {
                if (!nextLineBox() &&
                    ((lastLine && !object()->continuation()) || nextOnLineExists()
                     || onEndChain(endObject)))
                    includeRightEdge = true;
            }
            else {
                if ((!prevLineBox() || !prevLineBox()->isConstructed()) &&
                    ((lastLine && !object()->continuation()) ||
                     prevOnLineExists() || onEndChain(endObject)))
                    includeLeftEdge = true;
            }

        }
    }

    setEdges(includeLeftEdge, includeRightEdge);

    // Recur into our children.
    for (InlineBox* currChild = firstChild(); currChild; currChild = currChild->nextOnLine()) {
        if (currChild->isInlineFlowBox()) {
            InlineFlowBox* currFlow = static_cast<InlineFlowBox*>(currChild);
            currFlow->determineSpacingForFlowBoxes(lastLine, endObject);
        }
    }
}

long CharacterDataImpl::minOffset() const
{
  RenderText *r = static_cast<RenderText *>(renderer());
  if (!r || !r->isText()) return 0;

  // take :first-letter into consideration
#ifdef __GNUC__
#warning FIXME
#endif
#if 0
  if (r->forcedMinOffset()) {
    RenderFlow *firstLetter = static_cast<RenderFlow *>(r->previousSibling());
    if (firstLetter && firstLetter->isFlow() && firstLetter->isFirstLetter()) {
      RenderText *letterText = static_cast<RenderText *>(firstLetter->firstChild());
      return letterText->minOffset();
    }
  }
#endif

  return r->minOffset();
}

RenderFlow* RenderFlow::continuationBefore(RenderObject* beforeChild)
{
    if (beforeChild && beforeChild->parent() == this)
        return this;
    
    RenderFlow* curr = continuation();
    RenderFlow* nextToLast = this;
    RenderFlow* last = this;
    while (curr) {
        if (beforeChild && beforeChild->parent() == curr) {
            if (curr->firstChild() == beforeChild)
                return last;
            return curr;
        }
        
        nextToLast = last;
        last = curr;
        curr = curr->continuation();
    }
    
    if (!beforeChild && !last->firstChild())
        return nextToLast;
    return last;
}

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 RenderFlow::addChildWithContinuation(RenderObject* newChild, RenderObject* beforeChild)
{
    RenderFlow* flow = continuationBefore(beforeChild);
    KHTMLAssert(!beforeChild || beforeChild->parent()->isRenderBlock() ||
                beforeChild->parent()->isRenderInline());
    RenderFlow* beforeChildParent = beforeChild ? static_cast<RenderFlow*>(beforeChild->parent()) : 
                                    (flow->continuation() ? flow->continuation() : flow);
    
    if (newChild->isFloatingOrPositioned())
        return beforeChildParent->addChildToFlow(newChild, beforeChild);
    
    // A continuation always consists of two potential candidates: an inline or an anonymous
    // block box holding block children.
    bool childInline = newChild->isInline();
    bool bcpInline = beforeChildParent->isInline();
    bool flowInline = flow->isInline();
    
    if (flow == beforeChildParent)
        return flow->addChildToFlow(newChild, beforeChild);
    else {
        // The goal here is to match up if we can, so that we can coalesce and create the
        // minimal # of continuations needed for the inline.
        if (childInline == bcpInline)
            return beforeChildParent->addChildToFlow(newChild, beforeChild);
        else if (flowInline == childInline)
            return flow->addChildToFlow(newChild, 0); // Just treat like an append.
        else 
            return beforeChildParent->addChildToFlow(newChild, beforeChild);
    }
}

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
    // then 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->setNeedsLayoutAndMinMaxRecalc();
    }

    // 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;
    while(curr && curr != fromBlock)
    {
        // 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);

        // 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->appendChildNode(curr->removeChildNode(tmp));
            tmp->setNeedsLayoutAndMinMaxRecalc();
        }

        // Keep walking up the chain.
        currChild = curr;
        curr = static_cast< RenderFlow * >(curr->parent());
    }

    // 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));
    }
}