spinner.cpp

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/*
    Copyright © 2014-2019 by The qTox Project Contributors
 
    This file is part of qTox, a Qt-based graphical interface for Tox.
 
    qTox is libre software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    qTox is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with qTox.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#include "spinner.h"
#include "../pixmapcache.h"
 
#include <QDebug>
#include <QGraphicsScene>
#include <QPainter>
#include <QTime>
#include <QVariantAnimation>
 
#include <math.h>
 
Spinner::Spinner(const QString& img, QSize Size, qreal speed)
    : size(Size)
    , rotSpeed(speed)
{
    pmap = PixmapCache::getInstance().get(img, size);
 
    // Timer for the animation, if the Widget is not redrawn, no paint events will
    // arrive and the timer will not be restarted, so this stops automatically
    timer.setInterval(1000 / framerate);
    timer.setSingleShot(true);
 
    blendAnimation = new QVariantAnimation(this);
    blendAnimation->setStartValue(0.0);
    blendAnimation->setEndValue(1.0);
    blendAnimation->setDuration(350);
    blendAnimation->setEasingCurve(QEasingCurve::InCubic);
    blendAnimation->start(QAbstractAnimation::DeleteWhenStopped);
    connect(blendAnimation, &QVariantAnimation::valueChanged, this,
            [this](const QVariant& val) { alpha = val.toDouble(); });
 
    QObject::connect(&timer, &QTimer::timeout, this, &Spinner::timeout);
}
 
QRectF Spinner::boundingRect() const
{
    return QRectF(QPointF(-size.width() / 2.0, -size.height() / 2.0), size);
}
 
void Spinner::paint(QPainter* painter, const QStyleOptionGraphicsItem* option, QWidget* widget)
{
    painter->setClipRect(boundingRect());
 
    QTransform trans = QTransform().rotate(curRot)
                           .translate(-size.width() / 2.0, -size.height() / 2.0);
    painter->setOpacity(alpha);
    painter->setTransform(trans, true);
    painter->setRenderHint(QPainter::SmoothPixmapTransform);
    painter->drawPixmap(0, 0, pmap);
 
    if (!timer.isActive()) {
        timer.start(); // update bounding rectangle for next frame
    }
 
    Q_UNUSED(option)
    Q_UNUSED(widget)
}
 
void Spinner::setWidth(qreal width)
{
    Q_UNUSED(width)
}
 
qreal Spinner::getAscent() const
{
    return 0.0;
}
 
void Spinner::timeout()
{
    // Use global time, so the animations are synced
    float angle = QTime::currentTime().msecsSinceStartOfDay() / 1000.0f * rotSpeed;
    // limit to the range [0.0 - 360.0]
    curRot = remainderf(angle, 360.0f);
 
    if (scene()) {
        scene()->invalidate(sceneBoundingRect());
    }
}