range.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

/*
 * (C) 1999 Lars Knoll ([e-mail])
 * (C) 2000 Gunnstein Lye ([e-mail])
 * (C) 2000 Frederik Holljen ([e-mail])
 * (C) 2001 Peter Kelly ([e-mail])
 * Copyright (C) 2004, 2005, 2006, 2007, 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 "Range.h"
#include "RangeException.h"

#include "CString.h"
#include "DocumentFragment.h"
#include "NodeWithIndex.h"
#include "ProcessingInstruction.h"
#include "Text.h"
#include "TextIterator.h"
#include "VisiblePosition.h"
#include "markup.h"
#include "visible_units.h"
#include <stdio.h>
#include <wtf/RefCountedLeakCounter.h>

namespace WebCore {

using namespace std;

#ifndef NDEBUG
static WTF::RefCountedLeakCounter rangeCounter("Range");
#endif

inline Range::Range(PassRefPtr<Document> ownerDocument)
    : m_ownerDocument(ownerDocument)
    , m_start(m_ownerDocument)
    , m_end(m_ownerDocument)
{
#ifndef NDEBUG
    rangeCounter.increment();
#endif

    m_ownerDocument->attachRange(this);
}

PassRefPtr<Range> Range::create(PassRefPtr<Document> ownerDocument)
{
    return adoptRef(new Range(ownerDocument));
}

inline Range::Range(PassRefPtr<Document> ownerDocument, PassRefPtr<Node> startContainer, int startOffset, PassRefPtr<Node> endContainer, int endOffset)
    : m_ownerDocument(ownerDocument)
    , m_start(m_ownerDocument)
    , m_end(m_ownerDocument)
{
#ifndef NDEBUG
    rangeCounter.increment();
#endif

    m_ownerDocument->attachRange(this);

    // Simply setting the containers and offsets directly would not do any of the checking
    // that setStart and setEnd do, so we call those functions.
    ExceptionCode ec = 0;
    setStart(startContainer, startOffset, ec);
    ASSERT(!ec);
    setEnd(endContainer, endOffset, ec);
    ASSERT(!ec);
}

PassRefPtr<Range> Range::create(PassRefPtr<Document> ownerDocument, PassRefPtr<Node> startContainer, int startOffset, PassRefPtr<Node> endContainer, int endOffset)
{
    return adoptRef(new Range(ownerDocument, startContainer, startOffset, endContainer, endOffset));
}

PassRefPtr<Range> Range::create(PassRefPtr<Document> ownerDocument, const Position& start, const Position& end)
{
    return adoptRef(new Range(ownerDocument, start.container.get(), start.posOffset, end.container.get(), end.posOffset));
}

Range::~Range()
{
    if (m_start.container())
        m_ownerDocument->detachRange(this);

#ifndef NDEBUG
    rangeCounter.decrement();
#endif
}

Node* Range::startContainer(ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    return m_start.container();
}

int Range::startOffset(ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    return m_start.offset();
}

Node* Range::endContainer(ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    return m_end.container();
}

int Range::endOffset(ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    return m_end.offset();
}

Node* Range::commonAncestorContainer(ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    return commonAncestorContainer(m_start.container(), m_end.container());
}

Node* Range::commonAncestorContainer(Node* containerA, Node* containerB)
{
    for (Node* parentA = containerA; parentA; parentA = parentA->parentNode()) {
        for (Node* parentB = containerB; parentB; parentB = parentB->parentNode()) {
            if (parentA == parentB)
                return parentA;
        }
    }
    return 0;
}

bool Range::collapsed(ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    return m_start == m_end;
}

void Range::setStart(PassRefPtr<Node> refNode, int offset, ExceptionCode& ec)
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return;
    }

    if (!refNode) {
        ec = NOT_FOUND_ERR;
        return;
    }

    if (refNode->document() != m_ownerDocument) {
        ec = WRONG_DOCUMENT_ERR;
        return;
    }

    ec = 0;
    Node* childNode = checkNodeWOffset(refNode.get(), offset, ec);
    if (ec)
        return;

    m_start.set(refNode, offset, childNode);

    // check if different root container
    Node* endRootContainer = m_end.container();
    while (endRootContainer->parentNode())
        endRootContainer = endRootContainer->parentNode();
    Node* startRootContainer = m_start.container();
    while (startRootContainer->parentNode())
        startRootContainer = startRootContainer->parentNode();
    if (startRootContainer != endRootContainer)
        collapse(true, ec);
    // check if new start after end
    else if (compareBoundaryPoints(m_start.container(), m_start.offset(), m_end.container(), m_end.offset()) > 0)
        collapse(true, ec);
}

void Range::setEnd(PassRefPtr<Node> refNode, int offset, ExceptionCode& ec)
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return;
    }

    if (!refNode) {
        ec = NOT_FOUND_ERR;
        return;
    }

    if (refNode->document() != m_ownerDocument) {
        ec = WRONG_DOCUMENT_ERR;
        return;
    }

    ec = 0;
    Node* childNode = checkNodeWOffset(refNode.get(), offset, ec);
    if (ec)
        return;

    m_end.set(refNode, offset, childNode);

    // check if different root container
    Node* endRootContainer = m_end.container();
    while (endRootContainer->parentNode())
        endRootContainer = endRootContainer->parentNode();
    Node* startRootContainer = m_start.container();
    while (startRootContainer->parentNode())
        startRootContainer = startRootContainer->parentNode();
    if (startRootContainer != endRootContainer)
        collapse(false, ec);
    // check if new end before start
    if (compareBoundaryPoints(m_start.container(), m_start.offset(), m_end.container(), m_end.offset()) > 0)
        collapse(false, ec);
}

void Range::collapse(bool toStart, ExceptionCode& ec)
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return;
    }

    if (toStart)
        m_end = m_start;
    else
        m_start = m_end;
}

bool Range::isPointInRange(Node* refNode, int offset, ExceptionCode& ec)
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return false;
    }

    if (!refNode) {
        ec = HIERARCHY_REQUEST_ERR;
        return false;
    }

    if (!refNode->attached()) {
        // Firefox doesn't throw an exception for this case; it returns false.
        return false;
    }

    if (refNode->document() != m_ownerDocument) {
        ec = WRONG_DOCUMENT_ERR;
        return false;
    }

    ec = 0;
    checkNodeWOffset(refNode, offset, ec);
    if (ec)
        return false;

    return compareBoundaryPoints(refNode, offset, m_start.container(), m_start.offset()) >= 0
        && compareBoundaryPoints(refNode, offset, m_end.container(), m_end.offset()) <= 0;
}

short Range::comparePoint(Node* refNode, int offset, ExceptionCode& ec)
{
    // http://developer.mozilla.org/en/docs/DOM:range.comparePoint
    // This method returns -1, 0 or 1 depending on if the point described by the 
    // refNode node and an offset within the node is before, same as, or after the range respectively.

    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    if (!refNode) {
        ec = HIERARCHY_REQUEST_ERR;
        return 0;
    }

    if (!refNode->attached() || refNode->document() != m_ownerDocument) {
        ec = WRONG_DOCUMENT_ERR;
        return 0;
    }

    ec = 0;
    checkNodeWOffset(refNode, offset, ec);
    if (ec)
        return 0;

    // compare to start, and point comes before
    if (compareBoundaryPoints(refNode, offset, m_start.container(), m_start.offset()) < 0)
        return -1;

    // compare to end, and point comes after
    if (compareBoundaryPoints(refNode, offset, m_end.container(), m_end.offset()) > 0)
        return 1;

    // point is in the middle of this range, or on the boundary points
    return 0;
}

Range::CompareResults Range::compareNode(Node* refNode, ExceptionCode& ec)
{
    // http://developer.mozilla.org/en/docs/DOM:range.compareNode
    // This method returns 0, 1, 2, or 3 based on if the node is before, after,
    // before and after(surrounds), or inside the range, respectively

    if (!refNode) {
        ec = NOT_FOUND_ERR;
        return NODE_BEFORE;
    }
    
    if (!m_start.container() && refNode->attached()) {
        ec = INVALID_STATE_ERR;
        return NODE_BEFORE;
    }

    if (m_start.container() && !refNode->attached()) {
        // Firefox doesn't throw an exception for this case; it returns 0.
        return NODE_BEFORE;
    }

    if (refNode->document() != m_ownerDocument) {
        // Firefox doesn't throw an exception for this case; it returns 0.
        return NODE_BEFORE;
    }

    Node* parentNode = refNode->parentNode();
    int nodeIndex = refNode->nodeIndex();
    
    if (!parentNode) {
        // if the node is the top document we should return NODE_BEFORE_AND_AFTER
        // but we throw to match firefox behavior
        ec = NOT_FOUND_ERR;
        return NODE_BEFORE;
    }

    if (comparePoint(parentNode, nodeIndex, ec) < 0) { // starts before
        if (comparePoint(parentNode, nodeIndex + 1, ec) > 0) // ends after the range
            return NODE_BEFORE_AND_AFTER;
        return NODE_BEFORE; // ends before or in the range
    } else { // starts at or after the range start
        if (comparePoint(parentNode, nodeIndex + 1, ec) > 0) // ends after the range
            return NODE_AFTER;
        return NODE_INSIDE; // ends inside the range
    }
}


short Range::compareBoundaryPoints(CompareHow how, const Range* sourceRange, ExceptionCode& ec) const
{
    if (!m_start.container()) {
        ec = INVALID_STATE_ERR;
        return 0;
    }

    if (!sourceRange) {
        ec = NOT_FOUND_ERR;
        return 0;
    }

    ec = 0;
    Node* thisCont = commonAncestorContainer(ec);
    if (ec)
        return 0;
    Node* sourceCont = sourceRange->commonAncestorContainer(ec);
    if (ec)
        return 0;

    if (thisCont->document() != sourceCont->document()) {
        ec = WRONG_DOCUMENT_ERR;
        return 0;
    }

    Node* thisTop = thisCont;
    Node* sourceTop = sourceCont;
    while (thisTop->parentNode())
        thisTop = thisTop->parentNode();
    while (sourceTop->parentNode())
        sourceTop = sourceTop->parentNode();
    if (thisTop != sourceTop) { // in different DocumentFragments
        ec = WRONG_DOCUMENT_ERR;
        return 0;
    }

    switch (how) {
        case START_TO_START:
            return compareBoundaryPoints(m_start.container(), m_start.offset(),
                sourceRange->m_start.container(), sourceRange->m_start.offset());
        case START_TO_END:
            return compareBoundaryPoints(m_end.container(), m_end.offset(),
                sourceRange->m_start.container(), sourceRange->m_start.offset());
        case END_TO_END:
            return compareBoundaryPoints(m_end.container(), m_end.offset(),
                sourceRange->m_end.container(), sourceRange->m_end.offset());
        case END_TO_START:
            return compareBoundaryPoints(m_start.container(), m_start.offset(),
                sourceRange->m_end.container(), sourceRange->m_end.offset());
    }

    ec = SYNTAX_ERR;
    return 0;
}

short Range::compareBoundaryPoints(Node* containerA, int offsetA, Node* containerB, int offsetB)
{
    ASSERT(containerA && containerB);
    if (!containerA)
        return -1;
    if (!containerB)
        return 1;
    // see DOM2 traversal & range section 2.5

    // case 1: both points have the same container
    if (containerA == containerB) {
        if (offsetA == offsetB)