visible_units.cpp

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static unsigned previousSentencePositionBoundary(const UChar* characters, unsigned length)
{
    // FIXME: This is identical to startSentenceBoundary. I'm pretty sure that's not right.
    TextBreakIterator* iterator = sentenceBreakIterator(characters, length);
    // FIXME: The following function can return -1; we don't handle that.
    return textBreakPreceding(iterator, length);
}

VisiblePosition previousSentencePosition(const VisiblePosition &c)
{
    VisiblePosition prev = previousBoundary(c, previousSentencePositionBoundary);
    return c.honorEditableBoundaryAtOrAfter(prev);
}

static unsigned nextSentencePositionBoundary(const UChar* characters, unsigned length)
{
    // FIXME: This is identical to endSentenceBoundary.  This isn't right, it needs to 
    // move to the equivlant position in the following sentence.
    TextBreakIterator* iterator = sentenceBreakIterator(characters, length);
    return textBreakFollowing(iterator, 0);
}

VisiblePosition nextSentencePosition(const VisiblePosition &c)
{
    VisiblePosition next = nextBoundary(c, nextSentencePositionBoundary);    
    return c.honorEditableBoundaryAtOrBefore(next);
}

// FIXME: Broken for positions before/after images that aren't inline (5027702)
VisiblePosition startOfParagraph(const VisiblePosition &c)
{
    Position p = c.deepEquivalent();
    Node *startNode = p.node();

    if (!startNode)
        return VisiblePosition();
    
    if (startNode->renderer()
        && ((startNode->renderer()->isTable() && !startNode->renderer()->isInline())
            || startNode->renderer()->isHR())
        && p.offset() == maxDeepOffset(startNode))
        return VisiblePosition(Position(startNode, 0));

    Node* startBlock = enclosingBlock(startNode);

    Node *node = startNode;
    int offset = p.offset();

    Node *n = startNode;
    while (n) {
        if (n->isContentEditable() != startNode->isContentEditable())
            break;
        RenderObject *r = n->renderer();
        if (!r) {
            n = n->traversePreviousNodePostOrder(startBlock);
            continue;
        }
        RenderStyle *style = r->style();
        if (style->visibility() != VISIBLE) {
            n = n->traversePreviousNodePostOrder(startBlock);
            continue;
        }
        
        if (r->isBR() || isBlock(n))
            break;
            
        if (r->isText()) {
            if (style->preserveNewline()) {
                const UChar* chars = toRenderText(r)->characters();
                int i = toRenderText(r)->textLength();
                int o = offset;
                if (n == startNode && o < i)
                    i = max(0, o);
                while (--i >= 0)
                    if (chars[i] == '\n')
                        return VisiblePosition(n, i + 1, DOWNSTREAM);
            }
            node = n;
            offset = 0;
            n = n->traversePreviousNodePostOrder(startBlock);
        } else if (editingIgnoresContent(n) || isTableElement(n)) {
            node = n;
            offset = 0;
            n = n->previousSibling() ? n->previousSibling() : n->traversePreviousNodePostOrder(startBlock);
        } else
            n = n->traversePreviousNodePostOrder(startBlock);
    }

    return VisiblePosition(node, offset, DOWNSTREAM);
}

// FIXME: Broken for positions before/after images that aren't inline (5027702)
VisiblePosition endOfParagraph(const VisiblePosition &c)
{    
    if (c.isNull())
        return VisiblePosition();

    Position p = c.deepEquivalent();
    Node* startNode = p.node();

    if (startNode->renderer()
        && ((startNode->renderer()->isTable() && !startNode->renderer()->isInline())
            || startNode->renderer()->isHR())
        && p.offset() == 0)
        return VisiblePosition(Position(startNode, maxDeepOffset(startNode)));
    
    Node* startBlock = enclosingBlock(startNode);
    Node *stayInsideBlock = startBlock;
    
    Node *node = startNode;
    int offset = p.offset();

    Node *n = startNode;
    while (n) {
        if (n->isContentEditable() != startNode->isContentEditable())
            break;
        RenderObject *r = n->renderer();
        if (!r) {
            n = n->traverseNextNode(stayInsideBlock);
            continue;
        }
        RenderStyle *style = r->style();
        if (style->visibility() != VISIBLE) {
            n = n->traverseNextNode(stayInsideBlock);
            continue;
        }
        
        if (r->isBR() || isBlock(n))
            break;
            
        // FIXME: We avoid returning a position where the renderer can't accept the caret.
        // We should probably do this in other cases such as startOfParagraph.
        if (r->isText() && r->caretMaxRenderedOffset() > 0) {
            int length = toRenderText(r)->textLength();
            if (style->preserveNewline()) {
                const UChar* chars = toRenderText(r)->characters();
                int o = n == startNode ? offset : 0;
                for (int i = o; i < length; ++i)
                    if (chars[i] == '\n')
                        return VisiblePosition(n, i, DOWNSTREAM);
            }
            node = n;
            offset = r->caretMaxOffset();
            n = n->traverseNextNode(stayInsideBlock);
        } else if (editingIgnoresContent(n) || isTableElement(n)) {
            node = n;
            offset = maxDeepOffset(n);
            n = n->traverseNextSibling(stayInsideBlock);
        } else
            n = n->traverseNextNode(stayInsideBlock);
    }

    return VisiblePosition(node, offset, DOWNSTREAM);
}

VisiblePosition startOfNextParagraph(const VisiblePosition& visiblePosition)
{
    VisiblePosition paragraphEnd(endOfParagraph(visiblePosition));
    VisiblePosition afterParagraphEnd(paragraphEnd.next(true));
    // The position after the last position in the last cell of a table
    // is not the start of the next paragraph.
    if (isFirstPositionAfterTable(afterParagraphEnd))
        return afterParagraphEnd.next(true);
    return afterParagraphEnd;
}

bool inSameParagraph(const VisiblePosition &a, const VisiblePosition &b)
{
    return a.isNotNull() && startOfParagraph(a) == startOfParagraph(b);
}

bool isStartOfParagraph(const VisiblePosition &pos)
{
    return pos.isNotNull() && pos == startOfParagraph(pos);
}

bool isEndOfParagraph(const VisiblePosition &pos)
{
    return pos.isNotNull() && pos == endOfParagraph(pos);
}

VisiblePosition previousParagraphPosition(const VisiblePosition &p, int x)
{
    VisiblePosition pos = p;
    do {
        VisiblePosition n = previousLinePosition(pos, x);
        if (n.isNull() || n == pos)
            return p;
        pos = n;
    } while (inSameParagraph(p, pos));
    return pos;
}

VisiblePosition nextParagraphPosition(const VisiblePosition &p, int x)
{
    VisiblePosition pos = p;
    do {
        VisiblePosition n = nextLinePosition(pos, x);
        if (n.isNull() || n == pos)
            return p;
        pos = n;
    } while (inSameParagraph(p, pos));
    return pos;
}

// ---------

VisiblePosition startOfBlock(const VisiblePosition &c)
{
    Position p = c.deepEquivalent();
    Node *startNode = p.node();
    if (!startNode)
        return VisiblePosition();
    return VisiblePosition(Position(startNode->enclosingBlockFlowElement(), 0), DOWNSTREAM);
}

VisiblePosition endOfBlock(const VisiblePosition &c)
{
    Position p = c.deepEquivalent();

    Node *startNode = p.node();
    if (!startNode)
        return VisiblePosition();

    Node *startBlock = startNode->enclosingBlockFlowElement();
    
    return VisiblePosition(startBlock, startBlock->childNodeCount(), VP_DEFAULT_AFFINITY);   
}

bool inSameBlock(const VisiblePosition &a, const VisiblePosition &b)
{
    return !a.isNull() && enclosingBlockFlowElement(a) == enclosingBlockFlowElement(b);
}

bool isStartOfBlock(const VisiblePosition &pos)
{
    return pos.isNotNull() && pos == startOfBlock(pos);
}

bool isEndOfBlock(const VisiblePosition &pos)
{
    return pos.isNotNull() && pos == endOfBlock(pos);
}

// ---------

VisiblePosition startOfDocument(const Node* node)
{
    if (!node)
        return VisiblePosition();
    
    return VisiblePosition(node->document()->documentElement(), 0, DOWNSTREAM);
}

VisiblePosition startOfDocument(const VisiblePosition &c)
{
    return startOfDocument(c.deepEquivalent().node());
}

VisiblePosition endOfDocument(const Node* node)
{
    if (!node || !node->document())
        return VisiblePosition();
    
    Element* doc = node->document()->documentElement();
    return VisiblePosition(doc, doc->childNodeCount(), DOWNSTREAM);
}

VisiblePosition endOfDocument(const VisiblePosition &c)
{
    return endOfDocument(c.deepEquivalent().node());
}

bool inSameDocument(const VisiblePosition &a, const VisiblePosition &b)
{
    Position ap = a.deepEquivalent();
    Node *an = ap.node();
    if (!an)
        return false;
    Position bp = b.deepEquivalent();
    Node *bn = bp.node();
    if (an == bn)
        return true;

    return an->document() == bn->document();
}

bool isStartOfDocument(const VisiblePosition &p)
{
    return p.isNotNull() && p.previous().isNull();
}

bool isEndOfDocument(const VisiblePosition &p)
{
    return p.isNotNull() && p.next().isNull();
}

// ---------

VisiblePosition startOfEditableContent(const VisiblePosition& visiblePosition)
{
    Node* highestRoot = highestEditableRoot(visiblePosition.deepEquivalent());
    if (!highestRoot)
        return VisiblePosition();

    return VisiblePosition(highestRoot, 0, DOWNSTREAM);
}

VisiblePosition endOfEditableContent(const VisiblePosition& visiblePosition)
{
    Node* highestRoot = highestEditableRoot(visiblePosition.deepEquivalent());
    if (!highestRoot)
        return VisiblePosition();

    return VisiblePosition(highestRoot, maxDeepOffset(highestRoot), DOWNSTREAM);
}

}