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** Public License version 3.0 as published by the Free Software Foundation

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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:

        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)

            newPosition = qMin(position, adjusted_anchor);

        else

            newPosition = priv->previousCursorPosition(position, QTextLayout::SkipCharacters);

        break;

    case QTextCursor::Left:

        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)

            newPosition = visualMovement ? qMax(position, adjusted_anchor)

                                         : qMin(position, adjusted_anchor);

        else

            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:

        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)

            newPosition = qMax(position, adjusted_anchor);

        else

            newPosition = priv->nextCursorPosition(position, QTextLayout::SkipCharacters);

        break;

    case QTextCursor::Right:

        if (mode == QTextCursor::MoveAnchor && position != adjusted_anchor)

            newPosition = visualMovement ? qMin(position, adjusted_anchor)

                                         : qMax(position, adjusted_anchor);

        else

            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;

}

/*!

    \class QTextCursor

    \reentrant

    \brief The QTextCursor class offers an API to access and modify QTextDocuments.

    \ingroup richtext-processing

    \ingroup shared

    Text cursors are objects that are used to access and modify the

    contents and underlying structure of text documents via a

    programming interface that mimics the behavior of a cursor in a

    text editor. QTextCursor contains information about both the

    cursor's position within a QTextDocument and any selection that it

    has made.

    QTextCursor is modeled on the way a text cursor behaves in a text

    editor, providing a programmatic means of performing standard

    actions through the user interface. A document can be thought of

    as a single string of characters. The cursor's current position()

    then is always either \e between two consecutive characters in the

    string, or else \e before the very first character or \e after the

    very last character in the string.  Documents can also contain

    tables, lists, images, and other objects in addition to text but,

    from the developer's point of view, the document can be treated as

    one long string.  Some portions of that string can be considered

    to lie within particular blocks (e.g. paragraphs), or within a

    table's cell, or a list's item, or other structural elements. When

    we refer to "current character" we mean the character immediately

    \e before the cursor position() in the document. Similarly, the

    "current block" is the block that contains the cursor position().

    A QTextCursor also has an anchor() position. The text that is

    between the anchor() and the position() is the selection. If

    anchor() == position() there is no selection.

    The cursor position can be changed programmatically using

    setPosition() and movePosition(); the latter can also be used to

    select text. For selections see selectionStart(), selectionEnd(),

    hasSelection(), clearSelection(), and removeSelectedText().

    If the position() is at the start of a block atBlockStart()

    returns true; and if it is at the end of a block atBlockEnd() returns

    true. The format of the current character is returned by

    charFormat(), and the format of the current block is returned by

    blockFormat().

    Formatting can be applied to the current text document using the

    setCharFormat(), mergeCharFormat(), setBlockFormat() and

    mergeBlockFormat() functions. The 'set' functions will replace the

    cursor's current character or block format, while the 'merge'

    functions add the given format properties to the cursor's current

    format. If the cursor has a selection the given format is applied

    to the current selection. Note that when only parts of a block is

    selected the block format is applied to the entire block. The text

    at the current character position can be turned into a list using

    createList().

    Deletions can be achieved using deleteChar(),

    deletePreviousChar(), and removeSelectedText().

    Text strings can be inserted into the document with the insertText()

    function, blocks (representing new paragraphs) can be inserted with

    insertBlock().

    Existing fragments of text can be inserted with insertFragment() but,

    if you want to insert pieces of text in various formats, it is usually

    still easier to use insertText() and supply a character format.

    Various types of higher-level structure can also be inserted into the

    document with the cursor:

    \list

    \i Lists are ordered sequences of block elements that are decorated with

       bullet points or symbols. These are inserted in a specified format

       with insertList().

    \i Tables are inserted with the insertTable() function, and can be

       given an optional format. These contain an array of cells that can

       be traversed using the cursor.

    \i Inline images are inserted with insertImage(). The image to be

       used can be specified in an image format, or by name.

    \i Frames are inserted by calling insertFrame() with a specified format.

    \endlist

    Actions can be grouped (i.e. treated as a single action for

    undo/redo) using beginEditBlock() and endEditBlock().

    Cursor movements are limited to valid cursor positions. In Latin

    writing this is between any two consecutive characters in the

    text, before the first character, or after the last character. In

    some other writing systems cursor movements are limited to

    "clusters" (e.g. a syllable in Devanagari, or a base letter plus

    diacritics).  Functions such as movePosition() and deleteChar()

    limit cursor movement to these valid positions.

    \sa \link richtext.html Rich Text Processing\endlink

*/

/*!

    \enum QTextCursor::MoveOperation

    \value NoMove Keep the cursor where it is

    \value Start Move to the start of the document.

    \value StartOfLine Move to the start of the current line.

    \value StartOfBlock Move to the start of the current block.

    \value StartOfWord Move to the start of the current word.

    \value PreviousBlock Move to the start of the previous block.

    \value PreviousCharacter Move to the previous character.

    \value PreviousWord Move to the beginning of the previous word.

    \value Up Move up one line.

    \value Left Move left one character.

    \value WordLeft Move left one word.

    \value End Move to the end of the document.

    \value EndOfLine Move to the end of the current line.

    \value EndOfWord Move to the end of the current word.

    \value EndOfBlock Move to the end of the current block.

    \value NextBlock Move to the beginning of the next block.

    \value NextCharacter Move to the next character.

    \value NextWord Move to the next word.

    \value Down Move down one line.

    \value Right Move right one character.

    \value WordRight Move right one word.

    \value NextCell  Move to the beginning of the next table cell inside the

           current table. If the current cell is the last cell in the row, the

           cursor will move to the first cell in the next row.

    \value PreviousCell  Move to the beginning of the previous table cell

           inside the current table. If the current cell is the first cell in

           the row, the cursor will move to the last cell in the previous row.

    \value NextRow  Move to the first new cell of the next row in the current

           table.

    \value PreviousRow  Move to the last cell of the previous row in the

           current table.

    \sa movePosition()

*/

/*!

    \enum QTextCursor::MoveMode

    \value MoveAnchor Moves the anchor to the same position as the cursor itself.

    \value KeepAnchor Keeps the anchor where it is.

    If the anchor() is kept where it is and the position() is moved,

    the text in between will be selected.

*/

/*!

    \enum QTextCursor::SelectionType

    This enum describes the types of selection that can be applied with the

    select() function.

    \value Document         Selects the entire document.

    \value BlockUnderCursor Selects the block of text under the cursor.

    \value LineUnderCursor  Selects the line of text under the cursor.

    \value WordUnderCursor  Selects the word under the cursor. If the cursor

           is not positioned within a string of selectable characters, no

           text is selected.

*/

/*!

    Constructs a null cursor.

 */

QTextCursor::QTextCursor()

    : d(0)

{

}

/*!

    Constructs a cursor pointing to the beginning of the \a document.

 */

QTextCursor::QTextCursor(QTextDocument *document)

    : d(new QTextCursorPrivate(document->docHandle()))

{

}

/*!

    Constructs a cursor pointing to the beginning of the \a frame.

*/

QTextCursor::QTextCursor(QTextFrame *frame)

    : d(new QTextCursorPrivate(frame->document()->docHandle()))

{

    d->adjusted_anchor = d->anchor = d->position = frame->firstPosition();

}

/*!

    Constructs a cursor pointing to the beginning of the \a block.

*/

QTextCursor::QTextCursor(const QTextBlock &block)

    : d(new QTextCursorPrivate(block.docHandle()))

{

    d->adjusted_anchor = d->anchor = d->position = block.position();

}

/*!

  \internal

 */

QTextCursor::QTextCursor(QTextDocumentPrivate *p, int pos)

    : d(new QTextCursorPrivate(p))

{

    d->adjusted_anchor = d->anchor = d->position = pos;

    d->setX();

}

/*!

    \internal

*/

QTextCursor::QTextCursor(QTextCursorPrivate *d)

{

    Q_ASSERT(d);

    this->d = d;

}

/*!

    Constructs a new cursor that is a copy of \a cursor.

 */

QTextCursor::QTextCursor(const QTextCursor &cursor)

{

    d = cursor.d;

}

/*!

    Makes a copy of \a cursor and assigns it to this QTextCursor. Note

    that QTextCursor is an \l{Implicitly Shared Classes}{implicitly

    shared} class.

 */

QTextCursor &QTextCursor::operator=(const QTextCursor &cursor)

{

    d = cursor.d;

    return *this;

}

/*!

    Destroys the QTextCursor.

 */

QTextCursor::~QTextCursor()

{

}

/*!

    Returns true if the cursor is null; otherwise returns false. A null

    cursor is created by the default constructor.

 */

bool QTextCursor::isNull() const

{

    return !d || !d->priv;

}

/*!

    Moves the cursor to the absolute position in the document specified by

    \a pos using a \c MoveMode specified by \a m. The cursor is positioned

    between characters.

    \sa position() movePosition() anchor()

*/

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();

}

/*!

    Returns the absolute position of the cursor within the document.

    The cursor is positioned between characters.

    \sa setPosition() movePosition() anchor() positionInBlock()

*/

int QTextCursor::position() const

{

    if (!d || !d->priv)

        return -1;

    return d->position;

}

/*!

    \since 4.7

    Returns the relative position of the cursor within the block.

    The cursor is positioned between characters.

    This is equivalent to \c{ position() - block().position()}.

    \sa position()

*/

int QTextCursor::positionInBlock() const

{

    if (!d || !d->priv)

        return 0;

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

}

/*!

    Returns the anchor position; this is the same as position() unless

    there is a selection in which case position() marks one end of the

    selection and anchor() marks the other end. Just like the cursor

    position, the anchor position is between characters.

    \sa position() setPosition() movePosition() selectionStart() selectionEnd()

*/

int QTextCursor::anchor() const

{

    if (!d || !d->priv)

        return -1;

    return d->anchor;

}

/*!

    \fn bool QTextCursor::movePosition(MoveOperation operation, MoveMode mode, int n)

    Moves the cursor by performing the given \a operation \a n times, using the specified

    \a mode, and returns true if all operations were completed successfully; otherwise

    returns false.

    For example, if this function is repeatedly used to seek to the end of the next

    word, it will eventually fail when the end of the document is reached.

    By default, the move operation is performed once (\a n = 1).

    If \a mode is \c KeepAnchor, the cursor selects the text it moves

    over. This is the same effect that the user achieves when they

    hold down the Shift key and move the cursor with the cursor keys.

    \sa setVisualNavigation()

*/

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;

}

/*!

  \since 4.4

  Returns true if the cursor does visual navigation; otherwise

  returns false.

  Visual navigation means skipping over hidden text pragraphs. The

  default is false.

  \sa setVisualNavigation(), movePosition()

 */

bool QTextCursor::visualNavigation() const

{

    return d ? d->visualNavigation : false;

}

/*!

  \since 4.4

  Sets visual navigation to \a b.

  Visual navigation means skipping over hidden text pragraphs. The

  default is false.

  \sa visualNavigation(), movePosition()

 */

void QTextCursor::setVisualNavigation(bool b)

{

    if (d)

        d->visualNavigation = b;

}

/*!

  \since 4.7

  Sets the visual x position for vertical cursor movements to \a x.

  The vertical movement x position is cleared automatically when the cursor moves horizontally, and kept

  unchanged when the cursor moves vertically. The mechanism allows the cursor to move up and down on a

  visually straight line with proportional fonts, and to gently "jump" over short lines.

  A value of -1 indicates no predefined x position. It will then be set automatically the next time the

  cursor moves up or down.

  \sa verticalMovementX()

  */

void QTextCursor::setVerticalMovementX(int x)

{

    if (d)

        d->x = x;

}

/*! \since 4.7

  Returns the visual x position for vertical cursor movements.

  A value of -1 indicates no predefined x position. It will then be set automatically the next time the

  cursor moves up or down.

  \sa setVerticalMovementX()

  */

int QTextCursor::verticalMovementX() const

{

    return d ? d->x : -1;

}

/*!

  \since 4.7

  Returns whether the cursor should keep its current position when text gets inserted at the position of the

  cursor.

  The default is false;

  \sa setKeepPositionOnInsert()

 */

bool QTextCursor::keepPositionOnInsert() const

{

    return d ? d->keepPositionOnInsert : false;

}

/*!

  \since 4.7

  Defines whether the cursor should keep its current position when text gets inserted at the current position of the

  cursor.

  If \a b is true, the cursor keeps its current position when text gets inserted at the positing of the cursor.

  If \a b is false, the cursor moves along with the inserted text.

  The default is false.

  Note that a cursor always moves when text is inserted before the current position of the cursor, and it

  always keeps its position when text is inserted after the current position of the cursor.

  \sa keepPositionOnInsert()

 */

void QTextCursor::setKeepPositionOnInsert(bool b)

{

    if (d)

        d->keepPositionOnInsert = b;

}

/*!

    Inserts \a text at the current position, using the current

    character format.

    If there is a selection, the selection is deleted and replaced by

    \a text, for example:

    \snippet doc/src/snippets/code/src_gui_text_qtextcursor.cpp 0

    This clears any existing selection, selects the word at the cursor

    (i.e. from position() forward), and replaces the selection with

    the phrase "Hello World".

    Any ASCII linefeed characters (\\n) in the inserted text are transformed

    into unicode block separators, corresponding to insertBlock() calls.

    \sa charFormat() hasSelection()

*/

void QTextCursor::insertText(const QString &text)

{

    QTextCharFormat fmt = charFormat();

    fmt.clearProperty(QTextFormat::ObjectType);

    insertText(text, fmt);

}

/*!

    \fn void QTextCursor::insertText(const QString &text, const QTextCharFormat &format)

    \overload

    Inserts \a text at the current position with the given \a format.

*/

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();

}

/*!

    If there is no selected text, deletes the character \e at the

    current cursor position; otherwise deletes the selected text.

    \sa deletePreviousChar() hasSelection() clearSelection()

*/

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();

}

/*!

    If there is no selected text, deletes the character \e before the

    current cursor position; otherwise deletes the selected text.

    \sa deleteChar() hasSelection() clearSelection()

*/

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();

}

/*!

    Selects text in the document according to the given \a selection.

*/

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;

    }

}

/*!

    Returns true if the cursor contains a selection; otherwise returns false.

*/

bool QTextCursor::hasSelection() const

{

    return !!d && d->position != d->anchor;

}