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| |
| #include "helper.h" |
| |
| #include <QPainter> |
| #include <QPaintEvent> |
| #include <QWidget> |
| |
| //! [0] |
| Helper::Helper() |
| { |
| QLinearGradient gradient(QPointF(50, -20), QPointF(80, 20)); |
| gradient.setColorAt(0.0, Qt::white); |
| gradient.setColorAt(1.0, QColor(0xa6, 0xce, 0x39)); |
| |
| background = QBrush(QColor(64, 32, 64)); |
| circleBrush = QBrush(gradient); |
| circlePen = QPen(Qt::black); |
| circlePen.setWidth(1); |
| textPen = QPen(Qt::white); |
| textFont.setPixelSize(50); |
| } |
| //! [0] |
| |
| //! [1] |
| void Helper::paint(QPainter *painter, QPaintEvent *event, int elapsed) |
| { |
| painter->fillRect(event->rect(), background); |
| painter->translate(100, 100); |
| //! [1] |
| |
| //! [2] |
| painter->save(); |
| painter->setBrush(circleBrush); |
| painter->setPen(circlePen); |
| painter->rotate(elapsed * 0.030); |
| |
| qreal r = elapsed / 1000.0; |
| int n = 30; |
| for (int i = 0; i < n; ++i) { |
| painter->rotate(30); |
| qreal factor = (i + r) / n; |
| qreal radius = 0 + 120.0 * factor; |
| qreal circleRadius = 1 + factor * 20; |
| painter->drawEllipse(QRectF(radius, -circleRadius, |
| circleRadius * 2, circleRadius * 2)); |
| } |
| painter->restore(); |
| //! [2] |
| |
| //! [3] |
| painter->setPen(textPen); |
| painter->setFont(textFont); |
| painter->drawText(QRect(-50, -50, 100, 100), Qt::AlignCenter, QStringLiteral("Qt")); |
| } |
| //! [3] |