qt-creator/src/libs/utils/changeset.cpp

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#include "changeset.h"

namespace Utils {

ChangeSet::ChangeSet()
    : m_string(0), m_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 ChangeSet::hasOverlap(int pos, int length)
{
    {
        QListIterator<Replace> i(m_replaceList);
        while (i.hasNext()) {
            const Replace &cmd = i.next();
            if (overlaps(pos, length, cmd.pos, cmd.length))
                return true;
        }
    }
    {
        QListIterator<Move> i(m_moveList);
        while (i.hasNext()) {
            const Move &cmd = i.next();
            if (overlaps(pos, length, cmd.pos, cmd.length))
                return true;
        }
        return false;
    }
}

bool ChangeSet::hasMoveInto(int pos, int length)
{
    QListIterator<Move> i(m_moveList);
    while (i.hasNext()) {
        const Move &cmd = i.next();
        if (cmd.to >= pos && cmd.to < pos + length)
            return true;
    }
    return false;
}

bool ChangeSet::isEmpty() const
{
    if (m_replaceList.isEmpty() && m_moveList.isEmpty())
        return true;

    return false;
}

QList<ChangeSet::Replace> ChangeSet::replaceList() const
{
    return m_replaceList;
}

QList<ChangeSet::Move> ChangeSet::moveList() const
{
    return m_moveList;
}

void ChangeSet::clear()
{
    m_string = 0;
    m_cursor = 0;
    m_replaceList.clear();
    m_moveList.clear();
}

void ChangeSet::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;
    m_replaceList += cmd;
}

void ChangeSet::move(int pos, int length, int to)
{
    Q_ASSERT(!hasOverlap(pos, length));

    Move cmd;
    cmd.pos = pos;
    cmd.length = length;
    cmd.to = to;
    m_moveList += cmd;
}

void ChangeSet::doReplace(const Replace &replace)
{
    int diff = replace.replacement.size() - replace.length;
    {
        QMutableListIterator<Replace> i(m_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(m_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 (m_string) {
        m_string->replace(replace.pos, replace.length, replace.replacement);
    } else if (m_cursor) {
        m_cursor->setPosition(replace.pos);
        m_cursor->setPosition(replace.pos + replace.length, QTextCursor::KeepAnchor);
        m_cursor->insertText(replace.replacement);
    }
}

void ChangeSet::doMove(const Move &move)
{
    QString text;
    if (m_string) {
        text = m_string->mid(move.pos, move.length);
    } else if (m_cursor) {
        m_cursor->setPosition(move.pos);
        m_cursor->setPosition(move.pos + move.length, QTextCursor::KeepAnchor);
        text = m_cursor->selectedText();
    }

    Replace cut;
    cut.pos = move.pos;
    cut.length = move.length;
    Replace paste;
    paste.pos = move.to;
    paste.length = 0;
    paste.replacement = text;

    m_replaceList.append(cut);
    m_replaceList.append(paste);

    Replace cmd;
    while (!m_replaceList.isEmpty()) {
        cmd = m_replaceList.first();
        m_replaceList.removeFirst();
        doReplace(cmd);
    }
}

void ChangeSet::write(QString *s)
{
    m_string = s;
    write_helper();
    m_string = 0;
}

void ChangeSet::write(QTextCursor *textCursor)
{
    m_cursor = textCursor;
    write_helper();
    m_cursor = 0;
}

void ChangeSet::write_helper()
{
    if (m_cursor)
        m_cursor->beginEditBlock();
    {
        Replace cmd;
        while (!m_replaceList.isEmpty()) {
            cmd = m_replaceList.first();
            m_replaceList.removeFirst();
            doReplace(cmd);
        }
    }
    {
        Move cmd;
        while (!m_moveList.isEmpty()) {
            cmd = m_moveList.first();
            m_moveList.removeFirst();
            doMove(cmd);
        }
    }
    if (m_cursor)
        m_cursor->endEditBlock();
}

} // end namespace Utils