qtextcursor.cpp

奇趣公司比较新的qt/emd版本

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

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)
{
    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;
    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)) {
        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()
{
    QTextBlock block = priv->blocksFind(position);
    const QTextLayout *layout = block.layout();
    int pos = position - block.position();

    QTextLine line = layout->lineForTextPosition(pos);
    if (line.isValid())
        x = line.cursorToX(pos);
}

void QTextCursorPrivate::remove()
{
    if (anchor == position)
        return;
    priv->beginEditBlock();
    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) {
        int startRow, startCol, numRows, numCols;
        selectedTableCells(&startRow, &numRows, &startCol, &numCols);
        clearCells(table, startRow, startCol, numRows, numCols, op);
    } else {
        priv->remove(pos1, pos2-pos1, op);
    }

    adjusted_anchor = anchor = position;
    priv->endEditBlock();
}

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;
}

bool QTextCursorPrivate::movePosition(QTextCursor::MoveOperation op, QTextCursor::MoveMode mode)
{
    currentCharFormat = -1;
    bool adjustX = true;
    QTextBlock blockIt = block();

    if (op >= QTextCursor::Left && op <= QTextCursor::WordRight
        && blockIt.blockFormat().layoutDirection() == Qt::RightToLeft) {
        if (op == QTextCursor::Left)
            op = QTextCursor::NextCharacter;
        else if (op == QTextCursor::Right)
            op = QTextCursor::PreviousCharacter;
        else if (op == QTextCursor::WordLeft)
            op = QTextCursor::NextWord;
        else if (op == QTextCursor::WordRight)
            op = QTextCursor::PreviousWord;
    }

    const QTextLayout *layout = blockIt.layout();
    int relativePos = position - blockIt.position();
    QTextLine line = layout->lineForTextPosition(relativePos);

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

    int newPosition = position;

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

    case QTextCursor::Start:
        newPosition = 0;
        break;
    case QTextCursor::StartOfLine: {

        if (!line.isValid())
            break;
        newPosition = blockIt.position() + 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:
    case QTextCursor::Left:
        newPosition = priv->previousCursorPosition(position, QTextLayout::SkipCharacters);
        break;
    case QTextCursor::StartOfWord: {
        QTextEngine *engine = layout->engine();
        const QCharAttributes *attributes = engine->attributes();

        if (relativePos == 0)
            return false;

        // skip if already at word start
        if (attributes[relativePos - 1].whiteSpace
            && !attributes[relativePos].whiteSpace)
            return false;

        // 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 = blockIt.layout();
            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)
            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();
        const QCharAttributes *attributes = engine->attributes();
        const QString string = engine->layoutData->string;

        const int len = layout->engine()->layoutData->string.length();
        if (relativePos >= len)
            return false;
        relativePos++;
        while (relativePos < len
               && !attributes[relativePos].whiteSpace
               && !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:
    case QTextCursor::Right:
        newPosition = priv->nextCursorPosition(position, QTextLayout::SkipCharacters);
        break;
    case QTextCursor::NextWord:
    case QTextCursor::WordRight:
        newPosition = priv->nextCursorPosition(position, QTextLayout::SkipWords);
        break;