qtextcursor.cpp

奇趣公司比较新的qt/emd版本

    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 = blockIt.layout();
            i = 0;
        }
        if (layout->lineCount()) {
            QTextLine line = layout->lineAt(i);
            newPosition = line.xToCursor(x) + blockIt.position();
        } else {
            newPosition = blockIt.position();
        }
        adjustX = false;
        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 setBlockCharFormat(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();
                ::setBlockCharFormat(priv, pos1, pos2, format, changeMode);
            }
        }
    } else {
        int pos1 = position;
        int pos2 = adjusted_anchor;
        if (pos1 > pos2) {
            pos1 = adjusted_anchor;
            pos2 = position;
        }

        ::setBlockCharFormat(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);
    }
}

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

    \ingroup text
    \ingroup shared
    \mainclass

    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 with the cursor's position() being \e
    between any two characters (or at the very beginning or very end
    of the document). 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 after 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 usually after every character in the text. 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.

    \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()))