C++ QTextTableCell::isValid方法代码示例

/*!
    \since 4.1

    Merges the cell at the specified \a row and \a column with the adjacent cells
    into one cell. The new cell will span \a numRows rows and \a numCols columns.
    If \a numRows or \a numCols is less than the current number of rows or columns
    the cell spans then this method does nothing.

    \sa splitCell()
*/
void QTextTable::mergeCells(int row, int column, int numRows, int numCols)
{
    Q_D(QTextTable);

    if (d->dirty)
        d->update();

    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *fc = p->formatCollection();

    const QTextTableCell cell = cellAt(row, column);
    if (!cell.isValid() || row != cell.row() || column != cell.column())
        return;

    QTextCharFormat fmt = cell.format();
    const int rowSpan = fmt.tableCellRowSpan();
    const int colSpan = fmt.tableCellColumnSpan();

    numRows = qMin(numRows, rows() - cell.row());
    numCols = qMin(numCols, columns() - cell.column());

    // nothing to merge?
    if (numRows < rowSpan || numCols < colSpan)
        return;

    // check the edges of the merge rect to make sure no cell spans the edge
    for (int r = row; r < row + numRows; ++r) {
        if (cellAt(r, column) == cellAt(r, column - 1))
            return;
        if (cellAt(r, column + numCols) == cellAt(r, column + numCols - 1))
            return;
    }

    for (int c = column; c < column + numCols; ++c) {
        if (cellAt(row, c) == cellAt(row - 1, c))
            return;
        if (cellAt(row + numRows, c) == cellAt(row + numRows - 1, c))
            return;
    }

    p->beginEditBlock();

    const int origCellPosition = cell.firstPosition() - 1;

    const int cellFragment = d->grid[row * d->nCols + column];

    // find the position at which to insert the contents of the merged cells
    QFragmentFindHelper helper(origCellPosition, p->fragmentMap());
    QList<int>::Iterator it = std::lower_bound(d->cells.begin(), d->cells.end(), helper);
    Q_ASSERT(it != d->cells.end());
    Q_ASSERT(!(helper < *it));
    Q_ASSERT(*it == cellFragment);
    const int insertCellIndex = it - d->cells.begin();
    int insertFragment = d->cells.value(insertCellIndex + 1, d->fragment_end);
    uint insertPos = p->fragmentMap().position(insertFragment);

    d->blockFragmentUpdates = true;

    bool rowHasText = cell.firstCursorPosition().block().length();
    bool needsParagraph = rowHasText && colSpan == numCols;

    // find all cells that will be erased by the merge
    for (int r = row; r < row + numRows; ++r) {
        int firstColumn = r < row + rowSpan ? column + colSpan : column;

        // don't recompute the cell index for the first row
        int firstCellIndex = r == row ? insertCellIndex + 1 : -1;
        int cellIndex = firstCellIndex;

        for (int c = firstColumn; c < column + numCols; ++c) {
            const int fragment = d->grid[r * d->nCols + c];

            // already handled?
            if (fragment == cellFragment)
                continue;

            QTextDocumentPrivate::FragmentIterator it(&p->fragmentMap(), fragment);
            uint pos = it.position();

            if (firstCellIndex == -1) {
                QFragmentFindHelper helper(pos, p->fragmentMap());
                QList<int>::Iterator it = std::lower_bound(d->cells.begin(), d->cells.end(), helper);
                Q_ASSERT(it != d->cells.end());
                Q_ASSERT(!(helper < *it));
                Q_ASSERT(*it == fragment);
                firstCellIndex = cellIndex = it - d->cells.begin();
            }

            ++cellIndex;

//.........这里部分代码省略.........

/*!
    \since 4.1

    Splits the specified cell at \a row and \a column into an array of multiple
    cells with dimensions specified by \a numRows and \a numCols.

    \note It is only possible to split cells that span multiple rows or columns, such as rows
    that have been merged using mergeCells().

    \sa mergeCells()
*/
void QTextTable::splitCell(int row, int column, int numRows, int numCols)
{
    Q_D(QTextTable);

    if (d->dirty)
        d->update();

    QTextDocumentPrivate *p = d->pieceTable;
    QTextFormatCollection *c = p->formatCollection();

    const QTextTableCell cell = cellAt(row, column);
    if (!cell.isValid())
        return;
    row = cell.row();
    column = cell.column();

    QTextCharFormat fmt = cell.format();
    const int rowSpan = fmt.tableCellRowSpan();
    const int colSpan = fmt.tableCellColumnSpan();

    // nothing to split?
    if (numRows > rowSpan || numCols > colSpan)
        return;

    p->beginEditBlock();

    const int origCellPosition = cell.firstPosition() - 1;

    QVarLengthArray<int> rowPositions(rowSpan);

    rowPositions[0] = cell.lastPosition();

    for (int r = row + 1; r < row + rowSpan; ++r) {
        // find the cell before which to insert the new cell markers
        int gridIndex = r * d->nCols + column;
        QVector<int>::iterator it = std::upper_bound(d->cellIndices.begin(), d->cellIndices.end(), gridIndex);
        int cellIndex = it - d->cellIndices.begin();
        int fragment = d->cells.value(cellIndex, d->fragment_end);
        rowPositions[r - row] = p->fragmentMap().position(fragment);
    }

    fmt.setTableCellColumnSpan(1);
    fmt.setTableCellRowSpan(1);
    const int fmtIndex = c->indexForFormat(fmt);
    const int blockIndex = p->blockMap().find(cell.lastPosition())->format;

    int insertAdjustement = 0;
    for (int i = 0; i < numRows; ++i) {
        for (int c = 0; c < colSpan - numCols; ++c)
            p->insertBlock(QTextBeginningOfFrame, rowPositions[i] + insertAdjustement + c, blockIndex, fmtIndex);
        insertAdjustement += colSpan - numCols;
    }

    for (int i = numRows; i < rowSpan; ++i) {
        for (int c = 0; c < colSpan; ++c)
            p->insertBlock(QTextBeginningOfFrame, rowPositions[i] + insertAdjustement + c, blockIndex, fmtIndex);
        insertAdjustement += colSpan;
    }

    fmt.setTableCellRowSpan(numRows);
    fmt.setTableCellColumnSpan(numCols);
    p->setCharFormat(origCellPosition, 1, fmt);

    p->endEditBlock();
}