qtextcursor.cpp

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#include "qtextcursor.h"
#include "qtextcursor_p.h"
#include "qglobal.h"
#include "qtextdocumentfragment.h"
#include "qtextdocumentfragment_p.h"
#include "qtextlist.h"
#include "qtexttable.h"
#include "qtexttable_p.h"
#include "qtextengine_p.h"
#include "qabstracttextdocumentlayout.h"

#include <qtextlayout.h>
#include <qdebug.h>

QT_BEGIN_NAMESPACE

enum {
    AdjustPrev = 0x1,
    AdjustUp = 0x3,
    AdjustNext = 0x4,
    AdjustDown = 0x12
};

QTextCursorPrivate::QTextCursorPrivate(QTextDocumentPrivate *p)
    : priv(p), x(0), position(0), anchor(0), adjusted_anchor(0),
      currentCharFormat(-1), visualNavigation(false), keepPositionOnInsert(false),
      changed(false)
{
    priv->addCursor(this);
}

QTextCursorPrivate::QTextCursorPrivate(const QTextCursorPrivate &rhs)
    : QSharedData(rhs)
{
    position = rhs.position;
    anchor = rhs.anchor;
    adjusted_anchor = rhs.adjusted_anchor;
    priv = rhs.priv;
    x = rhs.x;
    currentCharFormat = rhs.currentCharFormat;
    visualNavigation = rhs.visualNavigation;
    keepPositionOnInsert = rhs.keepPositionOnInsert;
    changed = rhs.changed;
    priv->addCursor(this);
}

QTextCursorPrivate::~QTextCursorPrivate()
{
    if (priv)
        priv->removeCursor(this);
}

QTextCursorPrivate::AdjustResult QTextCursorPrivate::adjustPosition(int positionOfChange, int charsAddedOrRemoved, QTextUndoCommand::Operation op)
{
    QTextCursorPrivate::AdjustResult result = QTextCursorPrivate::CursorMoved;
    // not(!) <= , so that inserting text adjusts the cursor correctly
    if (position < positionOfChange
        || (position == positionOfChange
            && (op == QTextUndoCommand::KeepCursor
                || keepPositionOnInsert)
            )
         ) {
        result = CursorUnchanged;
    } else {
        if (charsAddedOrRemoved < 0 && position < positionOfChange - charsAddedOrRemoved)
            position = positionOfChange;
        else
            position += charsAddedOrRemoved;

        currentCharFormat = -1;
    }

    if (anchor >= positionOfChange
        && (anchor != positionOfChange || op != QTextUndoCommand::KeepCursor)) {
        if (charsAddedOrRemoved < 0 && anchor < positionOfChange - charsAddedOrRemoved)
            anchor = positionOfChange;
        else
            anchor += charsAddedOrRemoved;
    }

    if (adjusted_anchor >= positionOfChange
        && (adjusted_anchor != positionOfChange || op != QTextUndoCommand::KeepCursor)) {
        if (charsAddedOrRemoved < 0 && adjusted_anchor < positionOfChange - charsAddedOrRemoved)
            adjusted_anchor = positionOfChange;
        else
            adjusted_anchor += charsAddedOrRemoved;
    }

    return result;
}

void QTextCursorPrivate::setX()
{
    if (priv->isInEditBlock()) {
        x = -1; // mark dirty
        return;
    }

    QTextBlock block = this->block();
    const QTextLayout *layout = blockLayout(block);
    int pos = position - block.position();

    QTextLine line = layout->lineForTextPosition(pos);
    if (line.isValid())
        x = line.cursorToX(pos);
    else
        x = -1; // delayed init.  Makes movePosition() call setX later on again.
}

void QTextCursorPrivate::remove()
{
    if (anchor == position)
        return;
    currentCharFormat = -1;
    int pos1 = position;
    int pos2 = adjusted_anchor;
    QTextUndoCommand::Operation op = QTextUndoCommand::KeepCursor;
    if (pos1 > pos2) {
        pos1 = adjusted_anchor;
        pos2 = position;
        op = QTextUndoCommand::MoveCursor;
    }

    // deleting inside table? -> delete only content
    QTextTable *table = complexSelectionTable();
    if (table) {
        priv->beginEditBlock();
        int startRow, startCol, numRows, numCols;
        selectedTableCells(&startRow, &numRows, &startCol, &numCols);
        clearCells(table, startRow, startCol, numRows, numCols, op);
        adjusted_anchor = anchor = position;
        priv->endEditBlock();
    } else {
        priv->remove(pos1, pos2-pos1, op);
        adjusted_anchor = anchor = position;
        priv->finishEdit();
    }

}

void QTextCursorPrivate::clearCells(QTextTable *table, int startRow, int startCol, int numRows, int numCols, QTextUndoCommand::Operation op)
{
    priv->beginEditBlock();

    for (int row = startRow; row < startRow + numRows; ++row)
        for (int col = startCol; col < startCol + numCols; ++col) {
            QTextTableCell cell = table->cellAt(row, col);
            const int startPos = cell.firstPosition();
            const int endPos = cell.lastPosition();
            Q_ASSERT(startPos <= endPos);
            priv->remove(startPos, endPos - startPos, op);
        }

    priv->endEditBlock();
}

bool QTextCursorPrivate::canDelete(int pos) const
{
    QTextDocumentPrivate::FragmentIterator fit = priv->find(pos);
    QTextCharFormat fmt = priv->formatCollection()->charFormat((*fit)->format);
    return (fmt.objectIndex() == -1 || fmt.objectType() == QTextFormat::ImageObject);
}

void QTextCursorPrivate::insertBlock(const QTextBlockFormat &format, const QTextCharFormat &charFormat)
{
    QTextFormatCollection *formats = priv->formatCollection();
    int idx = formats->indexForFormat(format);
    Q_ASSERT(formats->format(idx).isBlockFormat());

    priv->insertBlock(position, idx, formats->indexForFormat(charFormat));
    currentCharFormat = -1;
}

void QTextCursorPrivate::adjustCursor(QTextCursor::MoveOperation m)
{
    adjusted_anchor = anchor;
    if (position == anchor)
        return;

    QTextFrame *f_position = priv->frameAt(position);
    QTextFrame *f_anchor = priv->frameAt(adjusted_anchor);

    if (f_position != f_anchor) {
        // find common parent frame
        QList<QTextFrame *> positionChain;
        QList<QTextFrame *> anchorChain;
        QTextFrame *f = f_position;
        while (f) {
            positionChain.prepend(f);
            f = f->parentFrame();
        }
        f = f_anchor;
        while (f) {
            anchorChain.prepend(f);
            f = f->parentFrame();
        }
        Q_ASSERT(positionChain.at(0) == anchorChain.at(0));
        int i = 1;
        int l = qMin(positionChain.size(), anchorChain.size());
        for (; i < l; ++i) {
            if (positionChain.at(i) != anchorChain.at(i))
                break;
        }

        if (m <= QTextCursor::WordLeft) {
            if (i < positionChain.size())
                position = positionChain.at(i)->firstPosition() - 1;
        } else {
            if (i < positionChain.size())
                position = positionChain.at(i)->lastPosition() + 1;
        }
        if (position < adjusted_anchor) {
            if (i < anchorChain.size())
                adjusted_anchor = anchorChain.at(i)->lastPosition() + 1;
        } else {
            if (i < anchorChain.size())
                adjusted_anchor = anchorChain.at(i)->firstPosition() - 1;
        }

        f_position = positionChain.at(i-1);
    }

    // same frame, either need to adjust to cell boundaries or return
    QTextTable *table = qobject_cast<QTextTable *>(f_position);
    if (!table)
        return;

    QTextTableCell c_position = table->cellAt(position);
    QTextTableCell c_anchor = table->cellAt(adjusted_anchor);
    if (c_position != c_anchor) {
        bool before;
        int col_position = c_position.column();
        int col_anchor = c_anchor.column();
        if (col_position == col_anchor) {
            before = c_position.row() < c_anchor.row();
        } else {
            before = col_position < col_anchor;
        }

        // adjust to cell boundaries
        if (m <= QTextCursor::WordLeft) {
            position = c_position.firstPosition();
            if (!before)
                --position;
        } else {
            position = c_position.lastPosition();
            if (before)
                ++position;
        }
        if (position < adjusted_anchor)
            adjusted_anchor = c_anchor.lastPosition();
        else
            adjusted_anchor = c_anchor.firstPosition();
    }
    currentCharFormat = -1;
}

void QTextCursorPrivate::aboutToRemoveCell(int from, int to)
{
    Q_ASSERT(from <= to);
    if (position == anchor)
        return;

    QTextTable *t = qobject_cast<QTextTable *>(priv->frameAt(position));
    if (!t)
        return;
    QTextTableCell removedCellFrom = t->cellAt(from);
    QTextTableCell removedCellEnd = t->cellAt(to);
    if (! removedCellFrom.isValid() || !removedCellEnd.isValid())
        return;

    int curFrom = position;
    int curTo = adjusted_anchor;
    if (curTo < curFrom)
        qSwap(curFrom, curTo);

    QTextTableCell cellStart = t->cellAt(curFrom);
    QTextTableCell cellEnd = t->cellAt(curTo);

    if (cellStart.row() >= removedCellFrom.row() && cellEnd.row() <= removedCellEnd.row()
            && cellStart.column() >= removedCellFrom.column()
              && cellEnd.column() <= removedCellEnd.column()) { // selection is completely removed
        // find a new position, as close as possible to where we were.
        QTextTableCell cell;
        if (removedCellFrom.row() == 0 && removedCellEnd.row() == t->rows()-1) // removed n columns
            cell = t->cellAt(cellStart.row(), removedCellEnd.column()+1);
        else if (removedCellFrom.column() == 0 && removedCellEnd.column() == t->columns()-1) // removed n rows
            cell = t->cellAt(removedCellEnd.row() + 1, cellStart.column());

        int newPosition;
        if (cell.isValid())
            newPosition = cell.firstPosition();
        else
            newPosition = t->lastPosition()+1;

        setPosition(newPosition);
        anchor = newPosition;
        adjusted_anchor = newPosition;
        x = 0;
    }
    else if (cellStart.row() >= removedCellFrom.row() && cellStart.row() <= removedCellEnd.row()
        && cellEnd.row() > removedCellEnd.row()) {
        int newPosition = t->cellAt(removedCellEnd.row() + 1, cellStart.column()).firstPosition();
        if (position < anchor)
            position = newPosition;
        else
            anchor = adjusted_anchor = newPosition;
    }
    else if (cellStart.column() >= removedCellFrom.column() && cellStart.column() <= removedCellEnd.column()
        && cellEnd.column() > removedCellEnd.column()) {
        int newPosition = t->cellAt(cellStart.row(), removedCellEnd.column()+1).firstPosition();
        if (position < anchor)
            position = newPosition;
        else
            anchor = adjusted_anchor = newPosition;
    }
}

bool QTextCursorPrivate::movePosition(QTextCursor::MoveOperation op, QTextCursor::MoveMode mode)
{
    currentCharFormat = -1;
    bool adjustX = true;
    QTextBlock blockIt = block();
    bool visualMovement = priv->defaultCursorMoveStyle == Qt::VisualMoveStyle;

    if (!blockIt.isValid())
        return false;

    if (blockIt.textDirection() == Qt::RightToLeft) {
        if (op == QTextCursor::WordLeft)
            op = QTextCursor::NextWord;
        else if (op == QTextCursor::WordRight)
            op = QTextCursor::PreviousWord;

        if (!visualMovement) {
            if (op == QTextCursor::Left)
                op = QTextCursor::NextCharacter;
            else if (op == QTextCursor::Right)
                op = QTextCursor::PreviousCharacter;
        }
    }

    const QTextLayout *layout = blockLayout(blockIt);
    int relativePos = position - blockIt.position();
    QTextLine line;
    if (!priv->isInEditBlock())
        line = layout->lineForTextPosition(relativePos);

    Q_ASSERT(priv->frameAt(position) == priv->frameAt(adjusted_anchor));

    int newPosition = position;

    if (x == -1 && !priv->isInEditBlock() && (op == QTextCursor::Up || op == QTextCursor::Down))
        setX();

    switch(op) {
    case QTextCursor::NoMove:
        return true;

    case QTextCursor::Start:
        newPosition = 0;
        break;
    case QTextCursor::StartOfLine: {
        newPosition = blockIt.position();
        if (line.isValid())
            newPosition += line.textStart();

        break;
    }
    case QTextCursor::StartOfBlock: {
        newPosition = blockIt.position();
        break;
    }
    case QTextCursor::PreviousBlock: {
        if (blockIt == priv->blocksBegin())
            return false;
        blockIt = blockIt.previous();

        newPosition = blockIt.position();
        break;
    }
    case QTextCursor::PreviousCharacter:
#ifdef Q_WS_MAC
        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)
            newPosition = qMin(position, adjusted_anchor);
        else
#endif
            newPosition = priv->previousCursorPosition(position, QTextLayout::SkipCharacters);
        break;
    case QTextCursor::Left:
#ifdef Q_WS_MAC
        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)
            newPosition = visualMovement ? qMax(position, adjusted_anchor)
                                         : qMin(position, adjusted_anchor);
        else
#endif
            newPosition = visualMovement ? priv->leftCursorPosition(position)
                                         : priv->previousCursorPosition(position, QTextLayout::SkipCharacters);
        break;
    case QTextCursor::StartOfWord: {
        if (relativePos == 0)
            break;

        // skip if already at word start
        QTextEngine *engine = layout->engine();
        engine->attributes();
        if ((relativePos == blockIt.length() - 1)
            && (engine->atSpace(relativePos - 1) || engine->atWordSeparator(relativePos - 1)))
            return false;

        if (relativePos < blockIt.length()-1)
            ++position;

        // FALL THROUGH!
    }
    case QTextCursor::PreviousWord:
    case QTextCursor::WordLeft:
        newPosition = priv->previousCursorPosition(position, QTextLayout::SkipWords);
        break;
    case QTextCursor::Up: {
        int i = line.lineNumber() - 1;
        if (i == -1) {
            if (blockIt == priv->blocksBegin())
                return false;
            int blockPosition = blockIt.position();
            QTextTable *table = qobject_cast<QTextTable *>(priv->frameAt(blockPosition));
            if (table) {
                QTextTableCell cell = table->cellAt(blockPosition);
                if (cell.firstPosition() == blockPosition) {
                    int row = cell.row() - 1;
                    if (row >= 0) {
                        blockPosition = table->cellAt(row, cell.column()).lastPosition();
                    } else {
                        // move to line above the table
                        blockPosition = table->firstPosition() - 1;
                    }
                    blockIt = priv->blocksFind(blockPosition);
                } else {
                    blockIt = blockIt.previous();
                }
            } else {
                blockIt = blockIt.previous();
            }
            layout = blockLayout(blockIt);
            i = layout->lineCount()-1;
        }
        if (layout->lineCount()) {
            QTextLine line = layout->lineAt(i);
            newPosition = line.xToCursor(x) + blockIt.position();
        } else {
            newPosition = blockIt.position();
        }
        adjustX = false;
        break;
    }

    case QTextCursor::End:
        newPosition = priv->length() - 1;
        break;
    case QTextCursor::EndOfLine: {
        if (!line.isValid() || line.textLength() == 0) {
            if (blockIt.length() >= 1)
                // position right before the block separator
                newPosition = blockIt.position() + blockIt.length() - 1;
            break;
        }
        newPosition = blockIt.position() + line.textStart() + line.textLength();
        if (line.lineNumber() < layout->lineCount() - 1) {
            const QString text = blockIt.text();
            // ###### this relies on spaces being the cause for linebreaks.
            // this doesn't work with japanese
            if (text.at(line.textStart() + line.textLength() - 1).isSpace())
                --newPosition;
        }
        break;
    }
    case QTextCursor::EndOfWord: {
        QTextEngine *engine = layout->engine();
        engine->attributes();
        const int len = blockIt.length() - 1;
        if (relativePos >= len)
            return false;
        if (engine->atWordSeparator(relativePos)) {
            ++relativePos;
            while (relativePos < len && engine->atWordSeparator(relativePos))
                ++relativePos;
        } else {
            while (relativePos < len && !engine->atSpace(relativePos) && !engine->atWordSeparator(relativePos))
                ++relativePos;
        }
        newPosition = blockIt.position() + relativePos;
        break;
    }
    case QTextCursor::EndOfBlock:
        if (blockIt.length() >= 1)
            // position right before the block separator
            newPosition = blockIt.position() + blockIt.length() - 1;
        break;
    case QTextCursor::NextBlock: {
        blockIt = blockIt.next();
        if (!blockIt.isValid())
            return false;

        newPosition = blockIt.position();
        break;
    }
    case QTextCursor::NextCharacter:
#ifdef Q_WS_MAC
        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)
            newPosition = qMax(position, adjusted_anchor);
        else
#endif
            newPosition = priv->nextCursorPosition(position, QTextLayout::SkipCharacters);
        break;
    case QTextCursor::Right:
#ifdef Q_WS_MAC
        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)
            newPosition = visualMovement ? qMin(position, adjusted_anchor)
                                         : qMax(position, adjusted_anchor);
        else
#endif
            newPosition = visualMovement ? priv->rightCursorPosition(position)
                                         : priv->nextCursorPosition(position, QTextLayout::SkipCharacters);
        break;
    case QTextCursor::NextWord:
    case QTextCursor::WordRight:
        newPosition = priv->nextCursorPosition(position, QTextLayout::SkipWords);
        break;

    case QTextCursor::Down: {
        int i = line.lineNumber() + 1;

        if (i >= layout->lineCount()) {
            int blockPosition = blockIt.position() + blockIt.length() - 1;
            QTextTable *table = qobject_cast<QTextTable *>(priv->frameAt(blockPosition));
            if (table) {
                QTextTableCell cell = table->cellAt(blockPosition);
                if (cell.lastPosition() == blockPosition) {
                    int row = cell.row() + cell.rowSpan();
                    if (row < table->rows()) {
                        blockPosition = table->cellAt(row, cell.column()).firstPosition();
                    } else {
                        // move to line below the table
                        blockPosition = table->lastPosition() + 1;
                    }
                    blockIt = priv->blocksFind(blockPosition);
                } else {
                    blockIt = blockIt.next();
                }
            } else {
                blockIt = blockIt.next();
            }

            if (blockIt == priv->blocksEnd())
                return false;
            layout = blockLayout(blockIt);
            i = 0;
        }
        if (layout->lineCount()) {
            QTextLine line = layout->lineAt(i);
            newPosition = line.xToCursor(x) + blockIt.position();
        } else {
            newPosition = blockIt.position();
        }
        adjustX = false;
        break;
    }
    case QTextCursor::NextCell: // fall through
    case QTextCursor::PreviousCell: // fall through
    case QTextCursor::NextRow: // fall through
    case QTextCursor::PreviousRow: {
        QTextTable *table = qobject_cast<QTextTable *>(priv->frameAt(position));
        if (!table)
            return false;

        QTextTableCell cell = table->cellAt(position);
        Q_ASSERT(cell.isValid());
        int column = cell.column();
        int row = cell.row();
        const int currentRow = row;
        if (op == QTextCursor::NextCell || op == QTextCursor::NextRow) {
            do {
                column += cell.columnSpan();
                if (column >= table->columns()) {
                    column = 0;
                    ++row;
                }
                cell = table->cellAt(row, column);
                // note we also continue while we have not reached a cell thats not merged with one above us
            } while (cell.isValid()
                    && ((op == QTextCursor::NextRow && currentRow == cell.row())
                        || cell.row() < row));
        }
        else if (op == QTextCursor::PreviousCell || op == QTextCursor::PreviousRow) {
            do {
                --column;
                if (column < 0) {
                    column = table->columns()-1;
                    --row;
                }
                cell = table->cellAt(row, column);
                // note we also continue while we have not reached a cell thats not merged with one above us
            } while (cell.isValid()
                    && ((op == QTextCursor::PreviousRow && currentRow == cell.row())
                        || cell.row() < row));
        }
        if (cell.isValid())
            newPosition = cell.firstPosition();
        break;
    }
    }

    if (mode == QTextCursor::KeepAnchor) {
        QTextTable *table = qobject_cast<QTextTable *>(priv->frameAt(position));
        if (table && ((op >= QTextCursor::PreviousBlock && op <= QTextCursor::WordLeft)
                      || (op >= QTextCursor::NextBlock && op <= QTextCursor::WordRight))) {
            int oldColumn = table->cellAt(position).column();

            const QTextTableCell otherCell = table->cellAt(newPosition);
            if (!otherCell.isValid())
                return false;

            int newColumn = otherCell.column();
            if ((oldColumn > newColumn && op >= QTextCursor::End)
                || (oldColumn < newColumn && op <= QTextCursor::WordLeft))
                return false;
        }
    }

    const bool moved = setPosition(newPosition);

    if (mode == QTextCursor::MoveAnchor) {
        anchor = position;
        adjusted_anchor = position;
    } else {
        adjustCursor(op);
    }

    if (adjustX)
        setX();

    return moved;
}

QTextTable *QTextCursorPrivate::complexSelectionTable() const
{
    if (position == anchor)
        return 0;

    QTextTable *t = qobject_cast<QTextTable *>(priv->frameAt(position));
    if (t) {
        QTextTableCell cell_pos = t->cellAt(position);
        QTextTableCell cell_anchor = t->cellAt(adjusted_anchor);

        Q_ASSERT(cell_anchor.isValid());

        if (cell_pos == cell_anchor)
            t = 0;
    }
    return t;
}

void QTextCursorPrivate::selectedTableCells(int *firstRow, int *numRows, int *firstColumn, int *numColumns) const
{
    *firstRow = -1;
    *firstColumn = -1;
    *numRows = -1;
    *numColumns = -1;

    if (position == anchor)
        return;

    QTextTable *t = qobject_cast<QTextTable *>(priv->frameAt(position));
    if (!t)
        return;

    QTextTableCell cell_pos = t->cellAt(position);
    QTextTableCell cell_anchor = t->cellAt(adjusted_anchor);

    Q_ASSERT(cell_anchor.isValid());

    if (cell_pos == cell_anchor)
        return;

    *firstRow = qMin(cell_pos.row(), cell_anchor.row());
    *firstColumn = qMin(cell_pos.column(), cell_anchor.column());
    *numRows = qMax(cell_pos.row() + cell_pos.rowSpan(), cell_anchor.row() + cell_anchor.rowSpan()) - *firstRow;
    *numColumns = qMax(cell_pos.column() + cell_pos.columnSpan(), cell_anchor.column() + cell_anchor.columnSpan()) - *firstColumn;
}

static void setBlockCharFormatHelper(QTextDocumentPrivate *priv, int pos1, int pos2,
                               const QTextCharFormat &format, QTextDocumentPrivate::FormatChangeMode changeMode)
{
    QTextBlock it = priv->blocksFind(pos1);
    QTextBlock end = priv->blocksFind(pos2);
    if (end.isValid())
        end = end.next();

    for (; it != end; it = it.next()) {
        priv->setCharFormat(it.position() - 1, 1, format, changeMode);
    }
}

void QTextCursorPrivate::setBlockCharFormat(const QTextCharFormat &_format,
    QTextDocumentPrivate::FormatChangeMode changeMode)
{
    priv->beginEditBlock();

    QTextCharFormat format = _format;
    format.clearProperty(QTextFormat::ObjectIndex);

    QTextTable *table = complexSelectionTable();
    if (table) {
        int row_start, col_start, num_rows, num_cols;
        selectedTableCells(&row_start, &num_rows, &col_start, &num_cols);

        Q_ASSERT(row_start != -1);
        for (int r = row_start; r < row_start + num_rows; ++r) {
            for (int c = col_start; c < col_start + num_cols; ++c) {
                QTextTableCell cell = table->cellAt(r, c);
                int rspan = cell.rowSpan();
                int cspan = cell.columnSpan();
                if (rspan != 1) {
                    int cr = cell.row();
                    if (cr != r)
                        continue;
                }
                if (cspan != 1) {
                    int cc = cell.column();
                    if (cc != c)
                        continue;
                }

                int pos1 = cell.firstPosition();
                int pos2 = cell.lastPosition();
                setBlockCharFormatHelper(priv, pos1, pos2, format, changeMode);
            }
        }
    } else {
        int pos1 = position;
        int pos2 = adjusted_anchor;
        if (pos1 > pos2) {
            pos1 = adjusted_anchor;
            pos2 = position;
        }

        setBlockCharFormatHelper(priv, pos1, pos2, format, changeMode);
    }
    priv->endEditBlock();
}


void QTextCursorPrivate::setBlockFormat(const QTextBlockFormat &format, QTextDocumentPrivate::FormatChangeMode changeMode)
{
    QTextTable *table = complexSelectionTable();
    if (table) {
        priv->beginEditBlock();
        int row_start, col_start, num_rows, num_cols;
        selectedTableCells(&row_start, &num_rows, &col_start, &num_cols);

        Q_ASSERT(row_start != -1);
        for (int r = row_start; r < row_start + num_rows; ++r) {
            for (int c = col_start; c < col_start + num_cols; ++c) {
                QTextTableCell cell = table->cellAt(r, c);
                int rspan = cell.rowSpan();
                int cspan = cell.columnSpan();
                if (rspan != 1) {
                    int cr = cell.row();
                    if (cr != r)
                        continue;
                }
                if (cspan != 1) {
                    int cc = cell.column();
                    if (cc != c)
                        continue;
                }

                int pos1 = cell.firstPosition();
                int pos2 = cell.lastPosition();
                priv->setBlockFormat(priv->blocksFind(pos1), priv->blocksFind(pos2), format, changeMode);
            }
        }
        priv->endEditBlock();
    } else {
        int pos1 = position;
        int pos2 = adjusted_anchor;
        if (pos1 > pos2) {
            pos1 = adjusted_anchor;
            pos2 = position;
        }

        priv->setBlockFormat(priv->blocksFind(pos1), priv->blocksFind(pos2), format, changeMode);
    }
}

void QTextCursorPrivate::setCharFormat(const QTextCharFormat &_format, QTextDocumentPrivate::FormatChangeMode changeMode)
{
    Q_ASSERT(position != anchor);

    QTextCharFormat format = _format;
    format.clearProperty(QTextFormat::ObjectIndex);

    QTextTable *table = complexSelectionTable();
    if (table) {
        priv->beginEditBlock();
        int row_start, col_start, num_rows, num_cols;
        selectedTableCells(&row_start, &num_rows, &col_start, &num_cols);

        Q_ASSERT(row_start != -1);
        for (int r = row_start; r < row_start + num_rows; ++r) {
            for (int c = col_start; c < col_start + num_cols; ++c) {
                QTextTableCell cell = table->cellAt(r, c);
                int rspan = cell.rowSpan();
                int cspan = cell.columnSpan();
                if (rspan != 1) {
                    int cr = cell.row();
                    if (cr != r)
                        continue;
                }
                if (cspan != 1) {
                    int cc = cell.column();
                    if (cc != c)
                        continue;
                }

                int pos1 = cell.firstPosition();
                int pos2 = cell.lastPosition();
                priv->setCharFormat(pos1, pos2-pos1, format, changeMode);
            }
        }
        priv->endEditBlock();
    } else {
        int pos1 = position;
        int pos2 = adjusted_anchor;
        if (pos1 > pos2) {
            pos1 = adjusted_anchor;
            pos2 = position;
        }

        priv->setCharFormat(pos1, pos2-pos1, format, changeMode);
    }
}


QTextLayout *QTextCursorPrivate::blockLayout(QTextBlock &block) const{
    QTextLayout *tl = block.layout();
    if (!tl->lineCount() && priv->layout())
        priv->layout()->blockBoundingRect(block);
    return tl;
}

QTextCursor::QTextCursor()
    : d(0)
{
}

QTextCursor::QTextCursor(QTextDocument *document)
    : d(new QTextCursorPrivate(document->docHandle()))
{
}

QTextCursor::QTextCursor(QTextFrame *frame)
    : d(new QTextCursorPrivate(frame->document()->docHandle()))
{
    d->adjusted_anchor = d->anchor = d->position = frame->firstPosition();
}


QTextCursor::QTextCursor(const QTextBlock &block)
    : d(new QTextCursorPrivate(block.docHandle()))
{
    d->adjusted_anchor = d->anchor = d->position = block.position();
}


QTextCursor::QTextCursor(QTextDocumentPrivate *p, int pos)
    : d(new QTextCursorPrivate(p))
{
    d->adjusted_anchor = d->anchor = d->position = pos;

    d->setX();
}

QTextCursor::QTextCursor(QTextCursorPrivate *d)
{
    Q_ASSERT(d);
    this->d = d;
}

QTextCursor::QTextCursor(const QTextCursor &cursor)
{
    d = cursor.d;
}

QTextCursor &QTextCursor::operator=(const QTextCursor &cursor)
{
    d = cursor.d;
    return *this;
}

QTextCursor::~QTextCursor()
{
}

bool QTextCursor::isNull() const
{
    return !d || !d->priv;
}

void QTextCursor::setPosition(int pos, MoveMode m)
{
    if (!d || !d->priv)
        return;

    if (pos < 0 || pos >= d->priv->length()) {
        qWarning("QTextCursor::setPosition: Position '%d' out of range", pos);
        return;
    }

    d->setPosition(pos);
    if (m == MoveAnchor) {
        d->anchor = pos;
        d->adjusted_anchor = pos;
    } else { // keep anchor
        QTextCursor::MoveOperation op;
        if (pos < d->anchor)
            op = QTextCursor::Left;
        else
            op = QTextCursor::Right;
        d->adjustCursor(op);
    }
    d->setX();
}

int QTextCursor::position() const
{
    if (!d || !d->priv)
        return -1;
    return d->position;
}

int QTextCursor::positionInBlock() const
{
    if (!d || !d->priv)
        return 0;
    return d->position - d->block().position();
}

int QTextCursor::anchor() const
{
    if (!d || !d->priv)
        return -1;
    return d->anchor;
}

bool QTextCursor::movePosition(MoveOperation op, MoveMode mode, int n)
{
    if (!d || !d->priv)
        return false;
    switch (op) {
    case Start:
    case StartOfLine:
    case End:
    case EndOfLine:
        n = 1;
        break;
    default: break;
    }

    int previousPosition = d->position;
    for (; n > 0; --n) {
        if (!d->movePosition(op, mode))
            return false;
    }

    if (d->visualNavigation && !d->block().isVisible()) {
        QTextBlock b = d->block();
        if (previousPosition < d->position) {
            while (!b.next().isVisible())
                b = b.next();
            d->setPosition(b.position() + b.length() - 1);
        } else {
            while (!b.previous().isVisible())
                b = b.previous();
            d->setPosition(b.position());
        }
        if (mode == QTextCursor::MoveAnchor)
            d->anchor = d->position;
        while (d->movePosition(op, mode)
               && !d->block().isVisible())
            ;

    }
    return true;
}

bool QTextCursor::visualNavigation() const
{
    return d ? d->visualNavigation : false;
}

void QTextCursor::setVisualNavigation(bool b)
{
    if (d)
        d->visualNavigation = b;
}


void QTextCursor::setVerticalMovementX(int x)
{
    if (d)
        d->x = x;
}

int QTextCursor::verticalMovementX() const
{
    return d ? d->x : -1;
}

bool QTextCursor::keepPositionOnInsert() const
{
    return d ? d->keepPositionOnInsert : false;
}

void QTextCursor::setKeepPositionOnInsert(bool b)
{
    if (d)
        d->keepPositionOnInsert = b;
}



void QTextCursor::insertText(const QString &text)
{
    QTextCharFormat fmt = charFormat();
    fmt.clearProperty(QTextFormat::ObjectType);
    insertText(text, fmt);
}

void QTextCursor::insertText(const QString &text, const QTextCharFormat &_format)
{
    if (!d || !d->priv)
        return;

    Q_ASSERT(_format.isValid());

    QTextCharFormat format = _format;
    format.clearProperty(QTextFormat::ObjectIndex);

    bool hasEditBlock = false;

    if (d->anchor != d->position) {
        hasEditBlock = true;
        d->priv->beginEditBlock();
        d->remove();
    }

    if (!text.isEmpty()) {
        QTextFormatCollection *formats = d->priv->formatCollection();
        int formatIdx = formats->indexForFormat(format);
        Q_ASSERT(formats->format(formatIdx).isCharFormat());

        QTextBlockFormat blockFmt = blockFormat();


        int textStart = d->priv->text.length();
        int blockStart = 0;
        d->priv->text += text;
        int textEnd = d->priv->text.length();

        for (int i = 0; i < text.length(); ++i) {
            QChar ch = text.at(i);

            const int blockEnd = i;

            if (ch == QLatin1Char('\r')
                && (i + 1) < text.length()
                && text.at(i + 1) == QLatin1Char('\n')) {
                ++i;
                ch = text.at(i);
            }

            if (ch == QLatin1Char('\n')
                || ch == QChar::ParagraphSeparator
                || ch == QTextBeginningOfFrame
                || ch == QTextEndOfFrame
                || ch == QLatin1Char('\r')) {

                if (!hasEditBlock) {
                    hasEditBlock = true;
                    d->priv->beginEditBlock();
                }

                if (blockEnd > blockStart)
                    d->priv->insert(d->position, textStart + blockStart, blockEnd - blockStart, formatIdx);

                d->insertBlock(blockFmt, format);
                blockStart = i + 1;
            }
        }
        if (textStart + blockStart < textEnd)
            d->priv->insert(d->position, textStart + blockStart, textEnd - textStart - blockStart, formatIdx);
    }
    if (hasEditBlock)
        d->priv->endEditBlock();
    d->setX();
}

void QTextCursor::deleteChar()
{
    if (!d || !d->priv)
        return;

    if (d->position != d->anchor) {
        removeSelectedText();
        return;
    }

    if (!d->canDelete(d->position))
        return;
    d->adjusted_anchor = d->anchor =
                         d->priv->nextCursorPosition(d->anchor, QTextLayout::SkipCharacters);
    d->remove();
    d->setX();
}

void QTextCursor::deletePreviousChar()
{
    if (!d || !d->priv)
        return;

    if (d->position != d->anchor) {
        removeSelectedText();
        return;
    }

    if (d->anchor < 1 || !d->canDelete(d->anchor-1))
        return;
    d->anchor--;

    QTextDocumentPrivate::FragmentIterator fragIt = d->priv->find(d->anchor);
    const QTextFragmentData * const frag = fragIt.value();
    int fpos = fragIt.position();
    QChar uc = d->priv->buffer().at(d->anchor - fpos + frag->stringPosition);
    if (d->anchor > fpos && uc.isLowSurrogate()) {
        // second half of a surrogate, check if we have the first half as well,
        // if yes delete both at once
        uc = d->priv->buffer().at(d->anchor - 1 - fpos + frag->stringPosition);
        if (uc.isHighSurrogate())
            --d->anchor;
    }

    d->adjusted_anchor = d->anchor;
    d->remove();
    d->setX();
}

void QTextCursor::select(SelectionType selection)
{
    if (!d || !d->priv)
        return;

    clearSelection();

    const QTextBlock block = d->block();

    switch (selection) {
        case LineUnderCursor:
            movePosition(StartOfLine);
            movePosition(EndOfLine, KeepAnchor);
            break;
        case WordUnderCursor:
            movePosition(StartOfWord);
            movePosition(EndOfWord, KeepAnchor);
            break;
        case BlockUnderCursor:
            if (block.length() == 1) // no content
                break;
            movePosition(StartOfBlock);
            // also select the paragraph separator
            if (movePosition(PreviousBlock)) {
                movePosition(EndOfBlock);
                movePosition(NextBlock, KeepAnchor);
            }
            movePosition(EndOfBlock, KeepAnchor);
            break;
        case Document:
            movePosition(Start);
            movePosition(End, KeepAnchor);
            break;
    }
}

bool QTextCursor::hasSelection() const
{
    return !!d && d->position != d->anchor;
}


bool QTextCursor::hasComplexSelection() const
{
    if (!d)
        return false;

    return d->complexSelectionTable() != 0;
}

void QTextCursor::selectedTableCells(int *firstRow, int *numRows, int *firstColumn, int *numColumns) const
{
    *firstRow = -1;
    *firstColumn = -1;
    *numRows = -1;
    *numColumns = -1;

    if (!d || d->position == d->anchor)
        return;

    d->selectedTableCells(firstRow, numRows, firstColumn, numColumns);
}


void QTextCursor::clearSelection()
{
    if (!d)
        return;
    d->adjusted_anchor = d->anchor = d->position;
    d->currentCharFormat = -1;
}

void QTextCursor::removeSelectedText()
{
    if (!d || !d->priv || d->position == d->anchor)
        return;

    d->priv->beginEditBlock();
    d->remove();
    d->priv->endEditBlock();
    d->setX();
}

int QTextCursor::selectionStart() const
{
    if (!d || !d->priv)
        return -1;
    return qMin(d->position, d->adjusted_anchor);
}

int QTextCursor::selectionEnd() const
{
    if (!d || !d->priv)
        return -1;
    return qMax(d->position, d->adjusted_anchor);
}

static void getText(QString &text, QTextDocumentPrivate *priv, const QString &docText, int pos, int end)
{
    while (pos < end) {
        QTextDocumentPrivate::FragmentIterator fragIt = priv->find(pos);
        const QTextFragmentData * const frag = fragIt.value();

        const int offsetInFragment = qMax(0, pos - fragIt.position());
        const int len = qMin(int(frag->size_array[0] - offsetInFragment), end - pos);

        text += QString(docText.constData() + frag->stringPosition + offsetInFragment, len);
        pos += len;
    }
}

QString QTextCursor::selectedText() const
{
    if (!d || !d->priv || d->position == d->anchor)
        return QString();

    const QString docText = d->priv->buffer();
    QString text;

    QTextTable *table = d->complexSelectionTable();
    if (table) {
        int row_start, col_start, num_rows, num_cols;
        selectedTableCells(&row_start, &num_rows, &col_start, &num_cols);

        Q_ASSERT(row_start != -1);
        for (int r = row_start; r < row_start + num_rows; ++r) {
            for (int c = col_start; c < col_start + num_cols; ++c) {
                QTextTableCell cell = table->cellAt(r, c);
                int rspan = cell.rowSpan();
                int cspan = cell.columnSpan();
                if (rspan != 1) {
                    int cr = cell.row();
                    if (cr != r)
                        continue;
                }
                if (cspan != 1) {
                    int cc = cell.column();
                    if (cc != c)
                        continue;
                }

                getText(text, d->priv, docText, cell.firstPosition(), cell.lastPosition());
            }
        }
    } else {
        getText(text, d->priv, docText, selectionStart(), selectionEnd());
    }

    return text;
}

QTextDocumentFragment QTextCursor::selection() const
{
    return QTextDocumentFragment(*this);
}

QTextBlock QTextCursor::block() const
{
    if (!d || !d->priv)
        return QTextBlock();
    return d->block();
}

QTextBlockFormat QTextCursor::blockFormat() const
{
    if (!d || !d->priv)
        return QTextBlockFormat();

    return d->block().blockFormat();
}

void QTextCursor::setBlockFormat(const QTextBlockFormat &format)
{
    if (!d || !d->priv)
        return;

    d->setBlockFormat(format, QTextDocumentPrivate::SetFormat);
}

void QTextCursor::mergeBlockFormat(const QTextBlockFormat &modifier)
{
    if (!d || !d->priv)
        return;

    d->setBlockFormat(modifier, QTextDocumentPrivate::MergeFormat);
}

QTextCharFormat QTextCursor::blockCharFormat() const
{
    if (!d || !d->priv)
        return QTextCharFormat();

    return d->block().charFormat();
}

void QTextCursor::setBlockCharFormat(const QTextCharFormat &format)
{
    if (!d || !d->priv)
        return;

    d->setBlockCharFormat(format, QTextDocumentPrivate::SetFormatAndPreserveObjectIndices);
}

void QTextCursor::mergeBlockCharFormat(const QTextCharFormat &modifier)
{
    if (!d || !d->priv)
        return;

    d->setBlockCharFormat(modifier, QTextDocumentPrivate::MergeFormat);
}

QTextCharFormat QTextCursor::charFormat() const
{
    if (!d || !d->priv)
        return QTextCharFormat();

    int idx = d->currentCharFormat;
    if (idx == -1) {
        QTextBlock block = d->block();

        int pos;
        if (d->position == block.position()
            && block.length() > 1)
            pos = d->position;
        else
            pos = d->position - 1;

        if (pos == -1) {
            idx = d->priv->blockCharFormatIndex(d->priv->blockMap().firstNode());
        } else {
            Q_ASSERT(pos >= 0 && pos < d->priv->length());

            QTextDocumentPrivate::FragmentIterator it = d->priv->find(pos);
            Q_ASSERT(!it.atEnd());
            idx = it.value()->format;
        }
    }

    QTextCharFormat cfmt = d->priv->formatCollection()->charFormat(idx);
    cfmt.clearProperty(QTextFormat::ObjectIndex);

    Q_ASSERT(cfmt.isValid());
    return cfmt;
}

void QTextCursor::setCharFormat(const QTextCharFormat &format)
{
    if (!d || !d->priv)
        return;
    if (d->position == d->anchor) {
        d->currentCharFormat = d->priv->formatCollection()->indexForFormat(format);
        return;
    }
    d->setCharFormat(format, QTextDocumentPrivate::SetFormatAndPreserveObjectIndices);
}

void QTextCursor::mergeCharFormat(const QTextCharFormat &modifier)
{
    if (!d || !d->priv)
        return;
    if (d->position == d->anchor) {
        QTextCharFormat format = charFormat();
        format.merge(modifier);
        d->currentCharFormat = d->priv->formatCollection()->indexForFormat(format);
        return;
    }

    d->setCharFormat(modifier, QTextDocumentPrivate::MergeFormat);
}

bool QTextCursor::atBlockStart() const
{
    if (!d || !d->priv)
        return false;

    return d->position == d->block().position();
}

bool QTextCursor::atBlockEnd() const
{
    if (!d || !d->priv)
        return false;

    return d->position == d->block().position() + d->block().length() - 1;
}

bool QTextCursor::atStart() const
{
    if (!d || !d->priv)
        return false;

    return d->position == 0;
}

bool QTextCursor::atEnd() const
{
    if (!d || !d->priv)
        return false;

    return d->position == d->priv->length() - 1;
}

void QTextCursor::insertBlock()
{
    insertBlock(blockFormat());
}

void QTextCursor::insertBlock(const QTextBlockFormat &format)
{
    QTextCharFormat charFmt = charFormat();
    charFmt.clearProperty(QTextFormat::ObjectType);
    insertBlock(format, charFmt);
}

void QTextCursor::insertBlock(const QTextBlockFormat &format, const QTextCharFormat &_charFormat)
{
    if (!d || !d->priv)
        return;

    QTextCharFormat charFormat = _charFormat;
    charFormat.clearProperty(QTextFormat::ObjectIndex);

    d->priv->beginEditBlock();
    d->remove();
    d->insertBlock(format, charFormat);
    d->priv->endEditBlock();
    d->setX();
}

QTextList *QTextCursor::insertList(const QTextListFormat &format)
{
    insertBlock();
    return createList(format);
}

QTextList *QTextCursor::insertList(QTextListFormat::Style style)
{
    insertBlock();
    return createList(style);
}

QTextList *QTextCursor::createList(const QTextListFormat &format)
{
    if (!d || !d->priv)
        return 0;

    QTextList *list = static_cast<QTextList *>(d->priv->createObject(format));
    QTextBlockFormat modifier;
    modifier.setObjectIndex(list->objectIndex());
    mergeBlockFormat(modifier);
    return list;
}

QTextList *QTextCursor::createList(QTextListFormat::Style style)
{
    QTextListFormat fmt;
    fmt.setStyle(style);
    return createList(fmt);
}

QTextList *QTextCursor::currentList() const
{
    if (!d || !d->priv)
        return 0;

    QTextBlockFormat b = blockFormat();
    QTextObject *o = d->priv->objectForFormat(b);
    return qobject_cast<QTextList *>(o);
}

QTextTable *QTextCursor::insertTable(int rows, int cols)
{
    return insertTable(rows, cols, QTextTableFormat());
}

QTextTable *QTextCursor::insertTable(int rows, int cols, const QTextTableFormat &format)
{
    if(!d || !d->priv || rows == 0 || cols == 0)
        return 0;

    int pos = d->position;
    QTextTable *t = QTextTablePrivate::createTable(d->priv, d->position, rows, cols, format);
    d->setPosition(pos+1);
    // ##### what should we do if we have a selection?
    d->anchor = d->position;
    d->adjusted_anchor = d->anchor;
    return t;
}

QTextTable *QTextCursor::currentTable() const
{
    if(!d || !d->priv)
        return 0;

    QTextFrame *frame = d->priv->frameAt(d->position);
    while (frame) {
        QTextTable *table = qobject_cast<QTextTable *>(frame);
        if (table)
            return table;
        frame = frame->parentFrame();
    }
    return 0;
}

QTextFrame *QTextCursor::insertFrame(const QTextFrameFormat &format)
{
    if (!d || !d->priv)
        return 0;

    return d->priv->insertFrame(selectionStart(), selectionEnd(), format);
}

QTextFrame *QTextCursor::currentFrame() const
{
    if(!d || !d->priv)
        return 0;

    return d->priv->frameAt(d->position);
}


void QTextCursor::insertFragment(const QTextDocumentFragment &fragment)
{
    if (!d || !d->priv || fragment.isEmpty())
        return;

    d->priv->beginEditBlock();
    d->remove();
    fragment.d->insert(*this);
    d->priv->endEditBlock();

    if (fragment.d && fragment.d->doc)
        d->priv->mergeCachedResources(fragment.d->doc->docHandle());
}

#ifndef QT_NO_TEXTHTMLPARSER

void QTextCursor::insertHtml(const QString &html)
{
    if (!d || !d->priv)
        return;
    QTextDocumentFragment fragment = QTextDocumentFragment::fromHtml(html, d->priv->document());
    insertFragment(fragment);
}

#endif // QT_NO_TEXTHTMLPARSER

void QTextCursor::insertImage(const QTextImageFormat &format, QTextFrameFormat::Position alignment)
{
    if (!d || !d->priv)
        return;

    QTextFrameFormat ffmt;
    ffmt.setPosition(alignment);
    QTextObject *obj = d->priv->createObject(ffmt);

    QTextImageFormat fmt = format;
    fmt.setObjectIndex(obj->objectIndex());

    d->priv->beginEditBlock();
    d->remove();
    const int idx = d->priv->formatCollection()->indexForFormat(fmt);
    d->priv->insert(d->position, QString(QChar(QChar::ObjectReplacementCharacter)), idx);
    d->priv->endEditBlock();
}

void QTextCursor::insertImage(const QTextImageFormat &format)
{
    insertText(QString(QChar::ObjectReplacementCharacter), format);
}

void QTextCursor::insertImage(const QString &name)
{
    QTextImageFormat format;
    format.setName(name);
    insertImage(format);
}

void QTextCursor::insertImage(const QImage &image, const QString &name)
{
    if (image.isNull()) {
        qWarning("QTextCursor::insertImage: attempt to add an invalid image");
        return;
    }
    QString imageName = name;
    if (name.isEmpty())
        imageName = QString::number(image.serialNumber());
    d->priv->document()->addResource(QTextDocument::ImageResource, QUrl(imageName), image);
    QTextImageFormat format;
    format.setName(imageName);
    insertImage(format);
}

bool QTextCursor::operator!=(const QTextCursor &rhs) const
{
    return !operator==(rhs);
}

bool QTextCursor::operator<(const QTextCursor &rhs) const
{
    if (!d)
        return !!rhs.d;

    if (!rhs.d)
        return false;

    Q_ASSERT_X(d->priv == rhs.d->priv, "QTextCursor::operator<", "cannot compare cursors attached to different documents");

    return d->position < rhs.d->position;
}

bool QTextCursor::operator<=(const QTextCursor &rhs) const
{
    if (!d)
        return true;

    if (!rhs.d)
        return false;

    Q_ASSERT_X(d->priv == rhs.d->priv, "QTextCursor::operator<=", "cannot compare cursors attached to different documents");

    return d->position <= rhs.d->position;
}

bool QTextCursor::operator==(const QTextCursor &rhs) const
{
    if (!d)
        return !rhs.d;

    if (!rhs.d)
        return false;

    return d->position == rhs.d->position && d->priv == rhs.d->priv;
}

bool QTextCursor::operator>=(const QTextCursor &rhs) const
{
    if (!d)
        return false;

    if (!rhs.d)
        return true;

    Q_ASSERT_X(d->priv == rhs.d->priv, "QTextCursor::operator>=", "cannot compare cursors attached to different documents");

    return d->position >= rhs.d->position;
}

bool QTextCursor::operator>(const QTextCursor &rhs) const
{
    if (!d)
        return false;

    if (!rhs.d)
        return true;

    Q_ASSERT_X(d->priv == rhs.d->priv, "QTextCursor::operator>", "cannot compare cursors attached to different documents");

    return d->position > rhs.d->position;
}

void QTextCursor::beginEditBlock()
{
    if (!d || !d->priv)
        return;

    if (d->priv->editBlock == 0) // we are the initial edit block, store current cursor position for undo
        d->priv->editBlockCursorPosition = d->position;

    d->priv->beginEditBlock();
}

void QTextCursor::joinPreviousEditBlock()
{
    if (!d || !d->priv)
        return;

    d->priv->joinPreviousEditBlock();
}

void QTextCursor::endEditBlock()
{
    if (!d || !d->priv)
        return;

    d->priv->endEditBlock();
}

bool QTextCursor::isCopyOf(const QTextCursor &other) const
{
    return d == other.d;
}

int QTextCursor::blockNumber() const
{
    if (!d || !d->priv)
        return 0;

    return d->block().blockNumber();
}


int QTextCursor::columnNumber() const
{
    if (!d || !d->priv)
        return 0;

    QTextBlock block = d->block();
    if (!block.isValid())
        return 0;

    const QTextLayout *layout = d->blockLayout(block);

    const int relativePos = d->position - block.position();

    if (layout->lineCount() == 0)
        return relativePos;

    QTextLine line = layout->lineForTextPosition(relativePos);
    if (!line.isValid())
        return 0;
    return relativePos - line.textStart();
}

QTextDocument *QTextCursor::document() const
{
    if (d->priv)
        return d->priv->document();
    return 0; // document went away
}

QT_END_NAMESPACE