qitemdelegate.cpp

奇趣公司比较新的qt/emd版本

        painter->setPen(option.palette.color(cg, QPalette::Text));
    }

    if (option.state & QStyle::State_Editing) {
        painter->save();
        painter->setPen(option.palette.color(cg, QPalette::Text));
        painter->drawRect(rect.adjusted(0, 0, -1, -1));
        painter->restore();
    }

    const QStyleOptionViewItemV3 opt = option;

    const QWidget *widget = d->widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
    const int textMargin = style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, widget) + 1;
    QRect textRect = rect.adjusted(textMargin, 0, -textMargin, 0); // remove width padding
    const bool wrapText = opt.features & QStyleOptionViewItemV2::WrapText;
    d->textOption.setWrapMode(wrapText ? QTextOption::WordWrap : QTextOption::ManualWrap);
    d->textOption.setTextDirection(option.direction);
    d->textOption.setAlignment(QStyle::visualAlignment(option.direction, option.displayAlignment));
    d->textLayout.setTextOption(d->textOption);
    d->textLayout.setFont(option.font);
    d->textLayout.setText(QItemDelegatePrivate::replaceNewLine(text));

    QSizeF textLayoutSize = d->doTextLayout(textRect.width());

    if (textRect.width() < textLayoutSize.width()
        || textRect.height() < textLayoutSize.height()) {
        QString elided;
        int start = 0;
        int end = text.indexOf(QChar::LineSeparator, start);
        if (end == -1) {
            elided += option.fontMetrics.elidedText(text, option.textElideMode, textRect.width());
        } else {
            while (end != -1) {
                elided += option.fontMetrics.elidedText(text.mid(start, end - start),
                                                        option.textElideMode, textRect.width());
                elided += QChar::LineSeparator;
                start = end + 1;
                end = text.indexOf(QChar::LineSeparator, start);
            }
            //let's add the last line (after the last QChar::LineSeparator)
            elided += option.fontMetrics.elidedText(text.mid(start),
                                                    option.textElideMode, textRect.width());
            if (end != -1)
                elided += QChar::LineSeparator;
        }
        d->textLayout.setText(elided);
        textLayoutSize = d->doTextLayout(textRect.width());
    }

    const QSize layoutSize(textRect.width(), int(textLayoutSize.height()));
    const QRect layoutRect = QStyle::alignedRect(option.direction, option.displayAlignment,
                                                  layoutSize, textRect);
    // if we still overflow even after eliding the text, enable clipping
    if (!hasClipping() && (textRect.width() < textLayoutSize.width()
                           || textRect.height() < textLayoutSize.height())) {
        painter->save();
        painter->setClipRect(layoutRect);
        d->textLayout.draw(painter, layoutRect.topLeft(), QVector<QTextLayout::FormatRange>(), layoutRect);
        painter->restore();
    } else {
        d->textLayout.draw(painter, layoutRect.topLeft(), QVector<QTextLayout::FormatRange>(), layoutRect);
    }
}

/*!
    Renders the decoration \a pixmap within the rectangle specified by
    \a rect using the given \a painter and style \a option.
*/
void QItemDelegate::drawDecoration(QPainter *painter, const QStyleOptionViewItem &option,
                                   const QRect &rect, const QPixmap &pixmap) const
{
    Q_D(const QItemDelegate);
    // if we have an icon, we ignore the pixmap
    if (!d->tmp.icon.isNull()) {
        d->tmp.icon.paint(painter, rect, option.decorationAlignment,
                          d->tmp.mode, d->tmp.state);
        return;
    }

    if (pixmap.isNull() || !rect.isValid())
        return;
    QPoint p = QStyle::alignedRect(option.direction, option.decorationAlignment,
                                   pixmap.size(), rect).topLeft();
    if (option.state & QStyle::State_Selected) {
        QPixmap *pm = selected(pixmap, option.palette, option.state & QStyle::State_Enabled);
        painter->drawPixmap(p, *pm);
    } else {
        painter->drawPixmap(p, pixmap);
    }
}

/*!
    Renders the region within the rectangle specified by \a rect, indicating
    that it has the focus, using the given \a painter and style \a option.
*/

void QItemDelegate::drawFocus(QPainter *painter,
                              const QStyleOptionViewItem &option,
                              const QRect &rect) const
{
    Q_D(const QItemDelegate);
    if ((option.state & QStyle::State_HasFocus) == 0 || !rect.isValid())
        return;
    QStyleOptionFocusRect o;
    o.QStyleOption::operator=(option);
    o.rect = rect;
    o.state |= QStyle::State_KeyboardFocusChange;
    o.state |= QStyle::State_Item;
    QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled)
                              ? QPalette::Normal : QPalette::Disabled;
    o.backgroundColor = option.palette.color(cg, (option.state & QStyle::State_Selected)
                                             ? QPalette::Highlight : QPalette::Window);
    const QWidget *widget = d->widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
    style->drawPrimitive(QStyle::PE_FrameFocusRect, &o, painter, widget);
}

/*!
    Renders a check indicator within the rectangle specified by \a
    rect, using the given \a painter and style \a option, using the
    given \a state.
*/

void QItemDelegate::drawCheck(QPainter *painter,
                              const QStyleOptionViewItem &option,
                              const QRect &rect, Qt::CheckState state) const
{
    Q_D(const QItemDelegate);
    if (!rect.isValid())
        return;

    QStyleOptionViewItem opt(option);
    opt.rect = rect;
    opt.state = opt.state & ~QStyle::State_HasFocus;

    switch (state) {
    case Qt::Unchecked:
        opt.state |= QStyle::State_Off;
        break;
    case Qt::PartiallyChecked:
        opt.state |= QStyle::State_NoChange;
        break;
    case Qt::Checked:
        opt.state |= QStyle::State_On;
        break;
    }

    const QWidget *widget = d->widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
    style->drawPrimitive(QStyle::PE_IndicatorViewItemCheck, &opt, painter, widget);
}

/*!
    \since 4.2

    Renders the item background for the given \a index,
    using the given \a painter and style \a option.
*/

void QItemDelegate::drawBackground(QPainter *painter,
                                   const QStyleOptionViewItem &option,
                                   const QModelIndex &index) const
{
    if (option.showDecorationSelected && (option.state & QStyle::State_Selected)) {
        QPalette::ColorGroup cg = option.state & QStyle::State_Enabled
                                  ? QPalette::Normal : QPalette::Disabled;
        if (cg == QPalette::Normal && !(option.state & QStyle::State_Active))
            cg = QPalette::Inactive;

        painter->fillRect(option.rect, option.palette.brush(cg, QPalette::Highlight));
    } else {
        QVariant value = index.data(Qt::BackgroundRole);
        if (qVariantCanConvert<QBrush>(value)) {
            QPointF oldBO = painter->brushOrigin();
            painter->setBrushOrigin(option.rect.topLeft());
            painter->fillRect(option.rect, qvariant_cast<QBrush>(value));
            painter->setBrushOrigin(oldBO);
        }
    }
}


/*!
    \internal
*/

void QItemDelegate::doLayout(const QStyleOptionViewItem &option,
                             QRect *checkRect, QRect *pixmapRect, QRect *textRect,
                             bool hint) const
{
    Q_ASSERT(checkRect && pixmapRect && textRect);
    Q_D(const QItemDelegate);
    const QWidget *widget = d->widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
    const bool hasCheck = checkRect->isValid();
    const bool hasPixmap = pixmapRect->isValid();
    const bool hasText = textRect->isValid();
    const int textMargin = hasText ? style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, widget) + 1 : 0;
    const int pixmapMargin = hasPixmap ? style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, widget) + 1 : 0;
    const int checkMargin = hasCheck ? style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, widget) + 1 : 0;
    int x = option.rect.left();
    int y = option.rect.top();
    int w, h;

    textRect->adjust(-textMargin, 0, textMargin, 0); // add width padding
    if (textRect->height() == 0 && !hasPixmap)
        textRect->setHeight(option.fontMetrics.height());

    QSize pm(0, 0);
    if (hasPixmap) {
        pm = pixmapRect->size();
        pm.rwidth() += 2 * pixmapMargin;
    }
    if (hint) {
        h = qMax(checkRect->height(), qMax(textRect->height(), pm.height()));
        if (option.decorationPosition == QStyleOptionViewItem::Left
            || option.decorationPosition == QStyleOptionViewItem::Right) {
            w = textRect->width() + pm.width();
        } else {
            w = qMax(textRect->width(), pm.width());
        }
    } else {
        w = option.rect.width();
        h = option.rect.height();
    }

    int cw = 0;
    QRect check;
    if (hasCheck) {
        cw = checkRect->width() + 2 * checkMargin;
        if (hint) w += cw;
        if (option.direction == Qt::RightToLeft) {
            check.setRect(x + w - cw, y, cw, h);
        } else {
            check.setRect(x + checkMargin, y, cw, h);
        }
    }

    // at this point w should be the *total* width

    QRect display;
    QRect decoration;
    switch (option.decorationPosition) {
    case QStyleOptionViewItem::Top: {
        if (hasPixmap)
            pm.setHeight(pm.height() + pixmapMargin); // add space
        h = hint ? textRect->height() : h - pm.height();

        if (option.direction == Qt::RightToLeft) {
            decoration.setRect(x, y, w - cw, pm.height());
            display.setRect(x, y + pm.height(), w - cw, h);
        } else {
            decoration.setRect(x + cw, y, w - cw, pm.height());
            display.setRect(x + cw, y + pm.height(), w - cw, h);
        }
        break; }
    case QStyleOptionViewItem::Bottom: {
        if (hasText)
            textRect->setHeight(textRect->height() + textMargin); // add space
        h = hint ? textRect->height() + pm.height() : h;

        if (option.direction == Qt::RightToLeft) {
            display.setRect(x, y, w - cw, textRect->height());
            decoration.setRect(x, y + textRect->height(), w - cw, h - textRect->height());
        } else {
            display.setRect(x + cw, y, w - cw, textRect->height());
            decoration.setRect(x + cw, y + textRect->height(), w - cw, h - textRect->height());
        }
        break; }
    case QStyleOptionViewItem::Left: {
        if (option.direction == Qt::LeftToRight) {
            decoration.setRect(x + cw, y, pm.width(), h);
            display.setRect(decoration.right() + 1, y, w - pm.width() - cw, h);
        } else {
            display.setRect(x, y, w - pm.width() - cw, h);
            decoration.setRect(display.right() + 1, y, pm.width(), h);
        }
        break; }
    case QStyleOptionViewItem::Right: {
        if (option.direction == Qt::LeftToRight) {
            display.setRect(x + cw, y, w - pm.width() - cw, h);
            decoration.setRect(display.right() + 1, y, pm.width(), h);
        } else {
            decoration.setRect(x, y, pm.width(), h);
            display.setRect(decoration.right() + 1, y, w - pm.width() - cw, h);
        }
        break; }
    default:
        qWarning("doLayout: decoration position is invalid");
        decoration = *pixmapRect;
        break;
    }

    if (!hint) { // we only need to do the internal layout if we are going to paint
        *checkRect = QStyle::alignedRect(option.direction, Qt::AlignCenter,
                                         checkRect->size(), check);
        *pixmapRect = QStyle::alignedRect(option.direction, option.decorationAlignment,
                                          pixmapRect->size(), decoration);
        // the text takes up all available space, unless the decoration is not shown as selected
        if (option.showDecorationSelected)
            *textRect = display;
        else
            *textRect = QStyle::alignedRect(option.direction, option.displayAlignment,
                                            textRect->size().boundedTo(display.size()), display);
    } else {
        *checkRect = check;
        *pixmapRect = decoration;
        *textRect = display;
    }
}

/*!
    \internal

    Returns the pixmap used to decorate the root of the item view.
    The style \a option controls the appearance of the root; the \a variant
    refers to the data associated with an item.
*/