qt5base-lts/examples/widgets/graphicsview/basicgraphicslayouts/layoutitem.cpp

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#include "layoutitem.h"

#include <QGradient>
#include <QPainter>

//! [0]
LayoutItem::LayoutItem(QGraphicsItem *parent)
    : QGraphicsLayoutItem(), QGraphicsItem(parent),
      m_pix(QPixmap(QLatin1String(":/images/block.png")))
{
    setGraphicsItem(this);
}
//! [0]

//! [1]
void LayoutItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
                       QWidget *widget)
{
    Q_UNUSED(widget);
    Q_UNUSED(option);

    QRectF frame(QPointF(0, 0), geometry().size());
    const QSize pmSize = m_pix.size();
    QGradientStops stops;
//! [1]

//! [2]
    // paint a background rect (with gradient)
    QLinearGradient gradient(frame.topLeft(), frame.topLeft() + QPointF(200,200));
    stops << QGradientStop(0.0, QColor(60, 60,  60));
    stops << QGradientStop(frame.height() / 2 / frame.height(), QColor(102, 176, 54));

    //stops << QGradientStop(((frame.height() + h)/2 )/frame.height(), QColor(157, 195,  55));
    stops << QGradientStop(1.0, QColor(215, 215, 215));
    gradient.setStops(stops);
    painter->setBrush(QBrush(gradient));
    painter->drawRoundedRect(frame, 10.0, 10.0);

    // paint a rect around the pixmap (with gradient)
    QPointF pixpos = frame.center() - (QPointF(pmSize.width(), pmSize.height()) / 2);
    QRectF innerFrame(pixpos, pmSize);
    innerFrame.adjust(-4, -4, 4, 4);
    gradient.setStart(innerFrame.topLeft());
    gradient.setFinalStop(innerFrame.bottomRight());
    stops.clear();
    stops << QGradientStop(0.0, QColor(215, 255, 200));
    stops << QGradientStop(0.5, QColor(102, 176, 54));
    stops << QGradientStop(1.0, QColor(0, 0,  0));
    gradient.setStops(stops);
    painter->setBrush(QBrush(gradient));
    painter->drawRoundedRect(innerFrame, 10.0, 10.0);
    painter->drawPixmap(pixpos, m_pix);
}
//! [2]

//! [3]
QRectF LayoutItem::boundingRect() const
{
    return QRectF(QPointF(0, 0), geometry().size());
}
//! [3]

//! [4]
void LayoutItem::setGeometry(const QRectF &geom)
{
    prepareGeometryChange();
    QGraphicsLayoutItem::setGeometry(geom);
    setPos(geom.topLeft());
}
//! [4]

//! [5]
QSizeF LayoutItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const
{
    switch (which) {
    case Qt::MinimumSize:
    case Qt::PreferredSize:
        // Do not allow a size smaller than the pixmap with two frames around it.
        return m_pix.size() + QSize(12, 12);
    case Qt::MaximumSize:
        return QSizeF(1000,1000);
    default:
        break;
    }
    return constraint;
}
//! [5]