/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtDeclarative module of the Qt Toolkit.

**

** $QT_BEGIN_LICENSE:LGPL$

** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

**

**

**

**

**

**

**

**

** $QT_END_LICENSE$

**

****************************************************************************/

#include "private/textwriter_p.h"

QT_QML_BEGIN_NAMESPACE

using namespace QDeclarativeJS;

TextWriter::TextWriter()

        :string(0), cursor(0)

{

}

static bool overlaps(int posA, int lengthA, int posB, int lengthB) {

    return (posA < posB + lengthB && posA + lengthA > posB + lengthB)

            || (posA < posB && posA + lengthA > posB);

}

bool TextWriter::hasOverlap(int pos, int length)

{

    {

        QListIterator<Replace> i(replaceList);

        while (i.hasNext()) {

            const Replace &cmd = i.next();

            if (overlaps(pos, length, cmd.pos, cmd.length))

                return true;

        }

    }

    {

        QListIterator<Move> i(moveList);

        while (i.hasNext()) {

            const Move &cmd = i.next();

            if (overlaps(pos, length, cmd.pos, cmd.length))

                return true;

        }

        return false;

    }

}

bool TextWriter::hasMoveInto(int pos, int length)

{

    QListIterator<Move> i(moveList);

    while (i.hasNext()) {

        const Move &cmd = i.next();

        if (cmd.to >= pos && cmd.to < pos + length)

            return true;

    }

    return false;

}

void TextWriter::replace(int pos, int length, const QString &replacement)

{

    Q_ASSERT(!hasOverlap(pos, length));

    Q_ASSERT(!hasMoveInto(pos, length));

    Replace cmd;

    cmd.pos = pos;

    cmd.length = length;

    cmd.replacement = replacement;

    replaceList += cmd;

}

void TextWriter::move(int pos, int length, int to)

{

    Q_ASSERT(!hasOverlap(pos, length));

    Move cmd;

    cmd.pos = pos;

    cmd.length = length;

    cmd.to = to;

    moveList += cmd;

}

void TextWriter::doReplace(const Replace &replace)

{

    int diff = replace.replacement.size() - replace.length;

    {

        QMutableListIterator<Replace> i(replaceList);

        while (i.hasNext()) {

            Replace &c = i.next();

            if (replace.pos < c.pos)

                c.pos += diff;

            else if (replace.pos + replace.length < c.pos + c.length)

                c.length += diff;

        }

    }

    {

        QMutableListIterator<Move> i(moveList);

        while (i.hasNext()) {

            Move &c = i.next();

            if (replace.pos < c.pos)

                c.pos += diff;

            else if (replace.pos + replace.length < c.pos + c.length)

                c.length += diff;

            if (replace.pos < c.to)

                c.to += diff;

        }

    }

    if (string) {

        string->replace(replace.pos, replace.length, replace.replacement);

    } else if (cursor) {

        cursor->setPosition(replace.pos);

        cursor->setPosition(replace.pos + replace.length, QTextCursor::KeepAnchor);

        cursor->insertText(replace.replacement);

    }

}

void TextWriter::doMove(const Move &move)

{

    QString text;

    if (string) {

        text = string->mid(move.pos, move.length);

    } else if (cursor) {

        cursor->setPosition(move.pos);

        cursor->setPosition(move.pos + move.length, QTextCursor::KeepAnchor);

        text = cursor->selectedText();

    }

    Replace cut;

    cut.pos = move.pos;

    cut.length = move.length;

    Replace paste;

    paste.pos = move.to;

    paste.length = 0;

    paste.replacement = text;

    replaceList.append(cut);

    replaceList.append(paste);

    Replace cmd;

    while (!replaceList.isEmpty()) {

        cmd = replaceList.first();

        replaceList.removeFirst();

        doReplace(cmd);

    }

}

void TextWriter::write(QString *s)

{

    string = s;

    write_helper();

    string = 0;

}

void TextWriter::write(QTextCursor *textCursor)

{

    cursor = textCursor;

    write_helper();

    cursor = 0;

}

void TextWriter::write_helper()

{

    if (cursor)

        cursor->beginEditBlock();

    {

        Replace cmd;

        while (!replaceList.isEmpty()) {

            cmd = replaceList.first();

            replaceList.removeFirst();

            doReplace(cmd);

        }

    }

    {

        Move cmd;

        while (!moveList.isEmpty()) {

            cmd = moveList.first();

            moveList.removeFirst();

            doMove(cmd);

        }

    }

    if (cursor)

        cursor->endEditBlock();

}

QT_QML_END_NAMESPACE