C++ QTextLine::naturalTextWidth方法代码示例

void TextLabel::drawTextLayout(QPainter *painter, const QTextLayout &layout, const QRect &rect)
{
    if (rect.width() < 1 || rect.height() < 1) {
        return;
    }

    QPixmap pixmap(rect.size());
    pixmap.fill(Qt::transparent);

    QPainter p(&pixmap);
    p.setPen(painter->pen());

    // Create the alpha gradient for the fade out effect
    QLinearGradient alphaGradient(0, 0, 1, 0);
    alphaGradient.setCoordinateMode(QGradient::ObjectBoundingMode);
    if (layout.textOption().textDirection() == Qt::LeftToRight) {
        alphaGradient.setColorAt(0, QColor(0, 0, 0, 255));
        alphaGradient.setColorAt(1, QColor(0, 0, 0, 0));
    } else {
        alphaGradient.setColorAt(0, QColor(0, 0, 0, 0));
        alphaGradient.setColorAt(1, QColor(0, 0, 0, 255));
    }

    QFontMetrics fm(layout.font());
    int textHeight = layout.lineCount() * fm.lineSpacing();

    QPointF position(0, (rect.height() - textHeight) / 2);
    QList<QRect> fadeRects;
    int fadeWidth = 30;

    // Draw each line in the layout
    for (int i = 0; i < layout.lineCount(); i++) {
        QTextLine line = layout.lineAt(i);
        line.draw(&p, position);

        // Add a fade out rect to the list if the line is too long
        if (line.naturalTextWidth() > rect.width())
        {
            int x = int(qMin(line.naturalTextWidth(), (qreal)pixmap.width())) - fadeWidth;
            int y = int(line.position().y() + position.y());
            QRect r = QStyle::visualRect(layout.textOption().textDirection(), pixmap.rect(),
                                         QRect(x, y, fadeWidth, int(line.height())));
            fadeRects.append(r);
        }
    }

    // Reduce the alpha in each fade out rect using the alpha gradient
    if (!fadeRects.isEmpty()) {
        p.setCompositionMode(QPainter::CompositionMode_DestinationIn);
        foreach (const QRect &rect, fadeRects) {
            p.fillRect(rect, alphaGradient);
        }

void TextLabel::layoutText(QTextLayout &layout, const QString &text, const QSize &constraints)
{
    QFontMetrics metrics(layout.font());
    int leading = metrics.leading();
    int height = 0;
    int maxWidth = constraints.width();
    int widthUsed = 0;
    int lineSpacing = metrics.lineSpacing();
    QTextLine line;

    layout.setText(text);

    layout.beginLayout();
    while ((line = layout.createLine()).isValid()) {
        height += leading;

        // Make the last line that will fit infinitely long.
        // drawTextLayout() will handle this by fading the line out
        // if it won't fit in the constraints.
        if (height + 2 * lineSpacing > constraints.height()) {
            line.setPosition(QPoint(0, height));
            break;
        }

        line.setLineWidth(maxWidth);
        line.setPosition(QPoint(0, height));

        height += int(line.height());
        widthUsed = int(qMax(qreal(widthUsed), line.naturalTextWidth()));
    }
    layout.endLayout();
}

    void setContent(const ToolTipContent &data)
    {
        QString html;
        if (!data.mainText().isEmpty()) {
            html.append("<div><b>" + data.mainText() + "</b></div>");
        }
        html.append(data.subText());

        m_anchor.clear();
        m_document->clear();
        data.registerResources(m_document);
        if (!html.isEmpty()) {
            m_document->setHtml("<p>" + html + "</p>");
        }
        m_document->adjustSize();

        m_haloRects.clear();
        QTextLayout *layout = m_document->begin().layout();
        //layout->setPosition(QPointF(textRect.x(), textBoundingRect->y()));
        QTextLine line;
        for (int i = 0; i < layout->lineCount(); ++i) {
            line = layout->lineAt(i);

            // Add halo rect only when a non empty line is found
            if (line.naturalTextWidth()) {
                m_haloRects.append(line.naturalTextRect().translated(layout->position().toPoint()).toRect().translated(m_margin, m_margin));
            }
        }

        update();
    }

void KTextDocumentLayout::Private::adjustSize()
{
    if (parent->resizeMethod() == KTextDocument::NoResize)
        return;

    if (parent->shapes().isEmpty())
        return;
    // Limit auto-resizing to the first shape only (there won't be more
    // with auto-resizing turned on, unless specifically set)
    KShape *shape = parent->shapes().first();

    // Determine the maximum width of all text lines
    qreal width = 0;
    for (QTextBlock block = parent->document()->begin(); block.isValid(); block = block.next()) {
        // The block layout's wrap mode must be QTextOption::NoWrap, thus the line count
        // of a valid block must be 1 (otherwise this resizing scheme wouldn't work)
        Q_ASSERT(block.layout()->lineCount() == 1);
        QTextLine line = block.layout()->lineAt(0);
        width = qMax(width, line.naturalTextWidth());
    }

    // Use position and height of last text line to calculate height
    QTextLine line = parent->document()->lastBlock().layout()->lineAt(0);
    qreal height = line.position().y() + line.height();

    shape->setSize(QSizeF(width, height));
}

int JobItem::descriptionHeight(const QStyleOptionViewItem & option)
{
    int textTotalWidth = 0;
    int lineWidth = option.rect.width() - 2 * m_itemPadding;
    QString description = m_job->description().simplified();
    QTextLayout descriptionLayout(description, m_descriptionFont, m_paintDevice);
    descriptionLayout.beginLayout();
    for (int i = 0; i < m_descriptionLineCount - 1; ++i)
    {
        QTextLine line = descriptionLayout.createLine();
        if (!line.isValid())
        {
            // There is no text left to be inserted into the layout.
            break;
        }
        line.setLineWidth(lineWidth);
        textTotalWidth += line.naturalTextWidth();
    }
    descriptionLayout.endLayout();

    // Add space for last visible line.
    textTotalWidth += lineWidth;

    m_descriptionText = m_descriptionFontMetrics.elidedText(description,
                                                            Qt::ElideRight,
                                                            textTotalWidth);
    m_descriptionRect =
        m_descriptionFontMetrics.boundingRect(0,
                                              0,
                                              option.rect.width() - 2 * m_itemPadding,
                                              0,
                                              descriptionFlags(),
                                              m_descriptionText);
    return m_descriptionRect.height();
}

void paint_QTextLayout(QPainter &p, bool useCache)
{
    static bool first = true;
    static QTextLayout *textLayout[lines];
    if (first) {
        for (int i = 0; i < lines; ++i) {
            textLayout[i] = new QTextLayout(strings[i]);
            int leading = p.fontMetrics().leading();
            qreal height = 0;
            qreal widthUsed = 0;
            textLayout[i]->setCacheEnabled(useCache);
            textLayout[i]->beginLayout();
            while (1) {
                QTextLine line = textLayout[i]->createLine();
                if (!line.isValid())
                    break;

                line.setLineWidth(lineWidth);
                height += leading;
                line.setPosition(QPointF(0, height));
                height += line.height();
                widthUsed = qMax(widthUsed, line.naturalTextWidth());
            }
            textLayout[i]->endLayout();
        }
        first = false;
    }
    for (int i = 0; i < count; ++i) {
        for (int j = 0; j < lines; ++j) {
            textLayout[j]->draw(&p, QPoint(0, j*spacing));
        }
    }
}

qreal TextDocumentLayout::blockWidth(const QTextBlock &block)
{
    QTextLayout *layout = block.layout();
    if (!layout->lineCount())
        return 0; // only for layouted blocks
    qreal blockWidth = 0;
    for (int i = 0; i < layout->lineCount(); ++i) {
        QTextLine line = layout->lineAt(i);
        blockWidth = qMax(line.naturalTextWidth() + 8, blockWidth);
    }
    return blockWidth;
}

float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>*) const
{
    if (!run.length())
        return 0;
    const QString string = fixSpacing(qstring(run));
    QTextLayout layout(string, font());
    QTextLine line = setupLayout(&layout, run);
    int w = int(line.naturalTextWidth());
    // WebKit expects us to ignore word spacing on the first character (as opposed to what Qt does)
    if (treatAsSpace(run[0]))
        w -= m_wordSpacing;

    return w + run.padding();
}

static QTextLine setupLayout(QTextLayout* layout, const TextRun& style)
{
    int flags = style.rtl() ? Qt::TextForceRightToLeft : Qt::TextForceLeftToRight;
    if (style.padding())
        flags |= Qt::TextJustificationForced;
    layout->setFlags(flags);
    layout->beginLayout();
    QTextLine line = layout->createLine();
    line.setLineWidth(INT_MAX/256);
    if (style.padding())
        line.setLineWidth(line.naturalTextWidth() + style.padding());
    layout->endLayout();
    return line;
}

// Origin: Qt
static void viewItemTextLayout ( QTextLayout &textLayout, int lineWidth, qreal &height, qreal &widthUsed )
{
	height = 0;
	widthUsed = 0;
	textLayout.beginLayout();
	while ( true )
	{
		QTextLine line = textLayout.createLine();
		if ( !line.isValid() )
			break;
		line.setLineWidth ( lineWidth );
		line.setPosition ( QPointF ( 0, height ) );
		height += line.height();
		widthUsed = qMax ( widthUsed, line.naturalTextWidth() );
	}
	textLayout.endLayout();
}

// copied from QItemDelegate for drawDisplay
QSizeF doTextLayout(QTextLayout *textLayout, int lineWidth)
{
    qreal height = 0;
    qreal widthUsed = 0;
    textLayout->beginLayout();
    while (true) {
        QTextLine line = textLayout->createLine();
        if (!line.isValid())
            break;
        line.setLineWidth(lineWidth);
        line.setPosition(QPointF(0, height));
        height += line.height();
        widthUsed = qMax(widthUsed, line.naturalTextWidth());
    }
    textLayout->endLayout();
    return QSizeF(widthUsed, height);
}

void CodeEditor::paintEvent(QPaintEvent* event)
{
    QPlainTextEdit::paintEvent(event);

    QPainter painter(viewport());
    painter.setPen(Qt::darkGray);

    QTextBlock block = firstVisibleBlock();

    QRectF rect;

    do {

        if (!block.isVisible())
            continue;

        rect = blockBoundingGeometry(block).translated(contentOffset());

        QTextLine line = block.layout()->lineAt(0);

        if (config->whitespaces) {
            QString txt = block.text();

            for (int i = 0; i < txt.length(); i++) {
                // rect.x() <- учитывая горизонтальный скролинг
                QPoint point(rect.x() + line.cursorToX(i), rect.y() + line.ascent());

                if (txt[i] == ' ')
                    painter.drawText(point, QChar(0x00b7));
                else if (txt[i] == '\t')
                    painter.drawText(point, QChar(0x21b9));
            }
        }

        int state = block.userState();

        if (!(state & Error) && state & Folded) {
            QRect collapseRect(rect.x() + line.rect().x() + line.naturalTextWidth() + FONTWIDTH * 2,
                               rect.y() + 2, FONTWIDTH * 6, line.height() - 4);

            painter.drawText(collapseRect, Qt::AlignCenter, state & Comment ? "...;" : "...)");
            painter.drawRoundedRect(collapseRect, 4, 6);
        }

    } while ((block = block.next()).isValid() && rect.y() < viewport()->height());
}

static int layoutText(QTextLayout *layout, int maxWidth) {
    qreal height = 0;
    int textWidth = 0;
    layout->beginLayout();
    while (true) {
        QTextLine line = layout->createLine();
        if (!line.isValid()) {
            break;
        }
        line.setLineWidth(maxWidth);
        line.setPosition(QPointF(0, height));
        height += line.height();
        textWidth = qMax(textWidth, qRound(line.naturalTextWidth() + 0.5));
    }
    layout->endLayout();
    return textWidth;
}

QSizeF QItemDelegatePrivate::doTextLayout(int lineWidth) const
{
    qreal height = 0;
    qreal widthUsed = 0;
    textLayout.beginLayout();
    while (true) {
        QTextLine line = textLayout.createLine();
        if (!line.isValid())
            break;
        line.setLineWidth(lineWidth);
        line.setPosition(QPointF(0, height));
        height += line.height();
        widthUsed = qMax(widthUsed, line.naturalTextWidth());
    }
    textLayout.endLayout();
    return QSizeF(widthUsed, height);
}

void CodeEditor::mouseMoveEvent(QMouseEvent* event)
{
    QTextBlock block = findBlockByY(event->pos().y());

    QRect collapseRect;

    if (block.isValid()) {
        QRectF    rect = blockBoundingGeometry(block).translated(contentOffset());
        QTextLine line = block.layout()->lineAt(0);

        collapseRect = QRect(rect.x() + line.rect().x() + line.naturalTextWidth() + FONTWIDTH * 2,
                             rect.y() + 2, FONTWIDTH * 6, line.height() - 4);
    }

    int state = block.userState();

    if (!(state & Error) && state & Folded && collapseRect.contains(event->pos())) {
        pointedBlock = block;

        viewport()->setCursor(Qt::PointingHandCursor);

        QString str;

        while ((block = block.next()).isValid() && !block.isVisible()) {

            if (str.count() > 1)
                str += "\n";

            if (block.blockNumber() - pointedBlock.blockNumber() > 50) {
                str += "..."; // "\n...";
                break;
            }

            str += block.text();
        }

        QToolTip::showText(event->globalPos(), str, this);
    } else {
        pointedBlock = QTextBlock();
        viewport()->setCursor(Qt::IBeamCursor);
    }

    QPlainTextEdit::mouseMoveEvent(event);
}