File indexing completed on 2024-05-12 04:06:27

 /*
     SPDX-FileCopyrightText: 2009 Stefan Majewsky <majewsky@gmx.net>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "loadingwidget.h"
 
 #include <cmath>
 #include <QPainter>
 #include <QRadialGradient>
 #include <QTimer>
 
 Palapeli::LoadingWidget::LoadingWidget(QWidget* parent)
     : QWidget(parent)
     , m_updateTimer(new QTimer(this))
     , m_angleDegrees(0)
 {
     setMinimumSize(QSize(64, 64));
     m_updateTimer->setInterval(30);
         connect(m_updateTimer, &QTimer::timeout, this,
                 qOverload<>(&QWidget::update));
 }
 
 void Palapeli::LoadingWidget::showEvent(QShowEvent* event)
 {
     Q_UNUSED(event)
     m_updateTimer->start();
 }
 
 void Palapeli::LoadingWidget::hideEvent(QHideEvent* event)
 {
     Q_UNUSED(event)
     m_updateTimer->stop();
 }
 
 void Palapeli::LoadingWidget::paintEvent(QPaintEvent* event)
 {
     Q_UNUSED(event)
     m_angleDegrees = (m_angleDegrees + 14) % 360;
     const qreal pointerAngle = 2 * M_PI * m_angleDegrees / 360.0;
     const QPointF pointerDirection(cos(pointerAngle), sin(pointerAngle));
 
     QPainter painter(this);
     painter.setRenderHint(QPainter::Antialiasing);
     const QColor baseColor = painter.pen().color();
     const QColor baseColorTransparent(baseColor.red(), baseColor.green(), baseColor.blue(), 0);
     painter.setPen(Qt::NoPen);
 
     //metrics
     const QPoint center = rect().center();
     const qreal distance = 32;
     for (int i = 0; i < 8; ++i)
     {
         //determine position of circle
         const qreal angle = 0.25 * M_PI * i;
         const QPointF thisDirection(cos(angle), sin(angle));
         const QPointF thisCenter = center + distance * thisDirection;
         //determine size of circle
         const qreal scalarProd = thisDirection.x() * pointerDirection.x() + thisDirection.y() * pointerDirection.y();
         const qreal thisRadius = 10 + 5 * scalarProd;
         QSizeF thisSize(2 * thisRadius, 2 * thisRadius);
         //create gradient for circle
         QRadialGradient gradient(thisCenter, thisRadius);
         gradient.setColorAt(0, baseColor);
         gradient.setColorAt(0.4, baseColor);
         gradient.setColorAt(0.6, baseColorTransparent);
         painter.setBrush(gradient);
         //draw circle
         QRectF thisRect(QPointF(), thisSize);
         thisRect.moveCenter(thisCenter);
         painter.drawEllipse(thisRect);
     }
 }