C++ QTextLayout::preeditAreaText方法代码示例

/*!
    \fn QString QAbstractTextDocumentLayout::anchorAt(const QPointF &position) const

    Returns the reference of the anchor the given \a position, or an empty
    string if no anchor exists at that point.
*/
QString QAbstractTextDocumentLayout::anchorAt(const QPointF& pos) const
{
    int cursorPos = hitTest(pos, Qt::ExactHit);
    if (cursorPos == -1)
        return QString();

    // compensate for preedit in the hit text block
    QTextBlock block = document()->firstBlock();
    while (block.isValid()) {
        QRectF blockBr = blockBoundingRect(block);
        if (blockBr.contains(pos)) {
            QTextLayout *layout = block.layout();
            int relativeCursorPos = cursorPos - block.position();
            const int preeditLength = layout ? layout->preeditAreaText().length() : 0;
            if (preeditLength > 0 && relativeCursorPos > layout->preeditAreaPosition())
                cursorPos -= qMin(cursorPos - layout->preeditAreaPosition(), preeditLength);
            break;
        }
        block = block.next();
    }

    QTextDocumentPrivate *pieceTable = qobject_cast<const QTextDocument *>(parent())->docHandle();
    QTextDocumentPrivate::FragmentIterator it = pieceTable->find(cursorPos);
    QTextCharFormat fmt = pieceTable->formatCollection()->charFormat(it->format);
    return fmt.anchorHref();
}

/*!
 *  Returns the rectangle for the cursor including the predictive text area.
 *  HbAbstractEditPrivate::ensurePositionVisible() uses the same algorithm.
 */
QRectF NmEditorTextEdit::rectForCursorPosition() const
{
    NM_FUNCTION;
    
    int cursorPos = cursorPosition();
    QRectF rect = rectForPosition(cursorPos);
    QTextDocument *doc = document();
    if (doc) {
        rect.adjust(0, -doc->documentMargin(), 0, doc->documentMargin());
        const QTextBlock block = doc->findBlock(cursorPos);
        QTextLayout *blockLayout = block.layout();
        if (block.isValid() && blockLayout) {
            if (blockLayout->preeditAreaText().length()) {
                // Adjust cursor rect so that predictive text will be also visible
                rect.adjust(0, 0, boundingRect().width() / 2, 0);
            }
        }
    }

    return rect;
}

void QSyntaxHighlighterPrivate::applyFormatChanges()
{
    QTextLayout *layout = currentBlock.layout();

    QList<QTextLayout::FormatRange> ranges = layout->additionalFormats();

    const int preeditAreaStart = layout->preeditAreaPosition();
    const int preeditAreaLength = layout->preeditAreaText().length();

    QList<QTextLayout::FormatRange>::Iterator it = ranges.begin();
    while (it != ranges.end()) {
        if (it->start >= preeditAreaStart
            && it->start + it->length <= preeditAreaStart + preeditAreaLength)
            ++it;
        else
            it = ranges.erase(it);
    }

    QTextCharFormat emptyFormat;

    QTextLayout::FormatRange r;
    r.start = r.length = -1;

    int i = 0;
    while (i < formatChanges.count()) {

        while (i < formatChanges.count() && formatChanges.at(i) == emptyFormat)
            ++i;

        if (i >= formatChanges.count())
            break;

        r.start = i;
        r.format = formatChanges.at(i);

        while (i < formatChanges.count() && formatChanges.at(i) == r.format)
            ++i;

        if (i >= formatChanges.count())
            break;

        r.length = i - r.start;

        if (r.start >= preeditAreaStart) {
            r.start += preeditAreaLength;
        } else if (r.start + r.length >= preeditAreaStart) {
            r.length += preeditAreaLength;
        }

        ranges << r;
        r.start = r.length = -1;
    }

    if (r.start != -1) {
        r.length = formatChanges.count() - r.start;

        if (r.start >= preeditAreaStart) {
            r.start += preeditAreaLength;
        } else if (r.start + r.length >= preeditAreaStart) {
            r.length += preeditAreaLength;
        }

        ranges << r;
    }

    layout->setAdditionalFormats(ranges);
}

//.........这里部分代码省略.........


    QAbstractTextDocumentLayout::PaintContext context = getPaintContext();

    while (block.isValid()) {

        QRectF r = blockBoundingRect(block).translated(offset);
        QTextLayout *layout = block.layout();

        if (!block.isVisible()) {
            offset.ry() += r.height();
            block = block.next();
            continue;
        }

        if (r.bottom() >= er.top() && r.top() <= er.bottom()) {

            QTextBlockFormat blockFormat = block.blockFormat();

            QBrush bg = blockFormat.background();
            if (bg != Qt::NoBrush) {
                QRectF contentsRect = r;
                contentsRect.setWidth(qMax(r.width(), maximumWidth));
                fillBackground(&painter, contentsRect, bg);
            }


            QVector<QTextLayout::FormatRange> selections;
            int blpos = block.position();
            int bllen = block.length();
            for (int i = 0; i < context.selections.size(); ++i) {
                const QAbstractTextDocumentLayout::Selection &range = context.selections.at(i);
                const int selStart = range.cursor.selectionStart() - blpos;
                const int selEnd = range.cursor.selectionEnd() - blpos;
                if (selStart < bllen && selEnd > 0
                    && selEnd > selStart) {
                    QTextLayout::FormatRange o;
                    o.start = selStart;
                    o.length = selEnd - selStart;
                    o.format = range.format;
                    selections.append(o);
                } else if (!range.cursor.hasSelection() && range.format.hasProperty(QTextFormat::FullWidthSelection)
                           && block.contains(range.cursor.position())) {
                    // for full width selections we don't require an actual selection, just
                    // a position to specify the line. that's more convenience in usage.
                    QTextLayout::FormatRange o;
                    QTextLine l = layout->lineForTextPosition(range.cursor.position() - blpos);
                    o.start = l.textStart();
                    o.length = l.textLength();
                    if (o.start + o.length == bllen - 1)
                        ++o.length; // include newline
                    o.format = range.format;
                    selections.append(o);
                }
            }

            bool drawCursor = ((editable || (textInteractionFlags() & Qt::TextSelectableByKeyboard))
                               && context.cursorPosition >= blpos
                               && context.cursorPosition < blpos + bllen);

            bool drawCursorAsBlock = drawCursor && overwriteMode() ;

            if (drawCursorAsBlock) {
                if (context.cursorPosition == blpos + bllen - 1) {
                    drawCursorAsBlock = false;
                } else {
                    QTextLayout::FormatRange o;
                    o.start = context.cursorPosition - blpos;
                    o.length = 1;
                    o.format.setForeground(palette().base());
                    o.format.setBackground(palette().text());
                    selections.append(o);
                }
            }


            layout->draw(&painter, offset, selections, er);
            if ((drawCursor && !drawCursorAsBlock)
                || (editable && context.cursorPosition < -1
                    && !layout->preeditAreaText().isEmpty())) {
                int cpos = context.cursorPosition;
                if (cpos < -1)
                    cpos = layout->preeditAreaPosition() - (cpos + 2);
                else
                    cpos -= blpos;
                layout->drawCursor(&painter, offset, cpos, cursorWidth());
            }
        }

        offset.ry() += r.height();
        if (offset.y() > viewportRect.height())
            break;
        block = block.next();
    }

    if (backgroundVisible() && !block.isValid() && offset.y() <= er.bottom()
        && (centerOnScroll() || verticalScrollBar()->maximum() == verticalScrollBar()->minimum())) {
        painter.fillRect(QRect(QPoint((int)er.left(), (int)offset.y()), er.bottomRight()), palette().background());
    }
}