window.cpp Example File | Qt Widgets 5.12.8

- Qt 5.12
- Qt Widgets
- Easing Curves Example
- window.cpp Example File
- Qt 5.12.8 Reference Documentation

# window.cpp Example File

animation/easing/window.cpp

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     #include "window.h"

     Window::Window(QWidget *parent)
         : QWidget(parent),
         m_iconSize(64, 64)
     {
         m_ui.setupUi(this);
         QButtonGroup *buttonGroup = findChild<QButtonGroup *>();     // ### workaround for uic in 4.4
         m_ui.easingCurvePicker->setIconSize(m_iconSize);
         m_ui.easingCurvePicker->setMinimumHeight(m_iconSize.height() + 50);
         buttonGroup->setId(m_ui.lineRadio, 0);
         buttonGroup->setId(m_ui.circleRadio, 1);

         QEasingCurve dummy;
         m_ui.periodSpinBox->setValue(dummy.period());
         m_ui.amplitudeSpinBox->setValue(dummy.amplitude());
         m_ui.overshootSpinBox->setValue(dummy.overshoot());

         connect(m_ui.easingCurvePicker, SIGNAL(currentRowChanged(int)), this, SLOT(curveChanged(int)));
         connect(buttonGroup, SIGNAL(buttonClicked(int)), this, SLOT(pathChanged(int)));
         connect(m_ui.periodSpinBox, SIGNAL(valueChanged(double)), this, SLOT(periodChanged(double)));
         connect(m_ui.amplitudeSpinBox, SIGNAL(valueChanged(double)), this, SLOT(amplitudeChanged(double)));
         connect(m_ui.overshootSpinBox, SIGNAL(valueChanged(double)), this, SLOT(overshootChanged(double)));
         createCurveIcons();

         QPixmap pix(QLatin1String(":/images/qt-logo.png"));
         m_item = new PixmapItem(pix);
         m_scene.addItem(m_item);
         m_ui.graphicsView->setScene(&m_scene);

         m_anim = new Animation(m_item, "pos");
         m_anim->setEasingCurve(QEasingCurve::OutBounce);
         m_ui.easingCurvePicker->setCurrentRow(int(QEasingCurve::OutBounce));

         startAnimation();
     }

     QEasingCurve createEasingCurve(QEasingCurve::Type curveType)
     {
         QEasingCurve curve(curveType);

         if (curveType == QEasingCurve::BezierSpline) {
             curve.addCubicBezierSegment(QPointF(0.4, 0.1), QPointF(0.6, 0.9), QPointF(1.0, 1.0));

         } else if (curveType == QEasingCurve::TCBSpline) {
             curve.addTCBSegment(QPointF(0.0, 0.0), 0, 0, 0);
             curve.addTCBSegment(QPointF(0.3, 0.4), 0.2, 1, -0.2);
             curve.addTCBSegment(QPointF(0.7, 0.6), -0.2, 1, 0.2);
             curve.addTCBSegment(QPointF(1.0, 1.0), 0, 0, 0);
         }

         return curve;
     }

     void Window::createCurveIcons()
     {
         QPixmap pix(m_iconSize);
         QPainter painter(&pix);
         QLinearGradient gradient(0,0, 0, m_iconSize.height());
         gradient.setColorAt(0.0, QColor(240, 240, 240));
         gradient.setColorAt(1.0, QColor(224, 224, 224));
         QBrush brush(gradient);
         const QMetaObject &mo = QEasingCurve::staticMetaObject;
         QMetaEnum metaEnum = mo.enumerator(mo.indexOfEnumerator("Type"));
         // Skip QEasingCurve::Custom
         for (int i = 0; i < QEasingCurve::NCurveTypes - 1; ++i) {
             painter.fillRect(QRect(QPoint(0, 0), m_iconSize), brush);
             QEasingCurve curve = createEasingCurve((QEasingCurve::Type) i);
             painter.setPen(QColor(0, 0, 255, 64));
             qreal xAxis = m_iconSize.height()/1.5;
             qreal yAxis = m_iconSize.width()/3;
             painter.drawLine(0, xAxis, m_iconSize.width(),  xAxis);
             painter.drawLine(yAxis, 0, yAxis, m_iconSize.height());

             qreal curveScale = m_iconSize.height()/2;

             painter.setPen(Qt::NoPen);

             // start point
             painter.setBrush(Qt::red);
             QPoint start(yAxis, xAxis - curveScale * curve.valueForProgress(0));
             painter.drawRect(start.x() - 1, start.y() - 1, 3, 3);

             // end point
             painter.setBrush(Qt::blue);
             QPoint end(yAxis + curveScale, xAxis - curveScale * curve.valueForProgress(1));
             painter.drawRect(end.x() - 1, end.y() - 1, 3, 3);

             QPainterPath curvePath;
             curvePath.moveTo(start);
             for (qreal t = 0; t <= 1.0; t+=1.0/curveScale) {
                 QPoint to;
                 to.setX(yAxis + curveScale * t);
                 to.setY(xAxis - curveScale * curve.valueForProgress(t));
                 curvePath.lineTo(to);
             }
             painter.setRenderHint(QPainter::Antialiasing, true);
             painter.strokePath(curvePath, QColor(32, 32, 32));
             painter.setRenderHint(QPainter::Antialiasing, false);
             QListWidgetItem *item = new QListWidgetItem;
             item->setIcon(QIcon(pix));
             item->setText(metaEnum.key(i));
             m_ui.easingCurvePicker->addItem(item);
         }
     }

     void Window::startAnimation()
     {
         m_anim->setStartValue(QPointF(0, 0));
         m_anim->setEndValue(QPointF(100, 100));
         m_anim->setDuration(2000);
         m_anim->setLoopCount(-1); // forever
         m_anim->start();
     }

     void Window::curveChanged(int row)
     {
         QEasingCurve::Type curveType = (QEasingCurve::Type)row;
         m_anim->setEasingCurve(createEasingCurve(curveType));
         m_anim->setCurrentTime(0);

         bool isElastic = curveType >= QEasingCurve::InElastic && curveType <= QEasingCurve::OutInElastic;
         bool isBounce = curveType >= QEasingCurve::InBounce && curveType <= QEasingCurve::OutInBounce;
         m_ui.periodSpinBox->setEnabled(isElastic);
         m_ui.amplitudeSpinBox->setEnabled(isElastic || isBounce);
         m_ui.overshootSpinBox->setEnabled(curveType >= QEasingCurve::InBack && curveType <= QEasingCurve::OutInBack);
     }

     void Window::pathChanged(int index)
     {
         m_anim->setPathType((Animation::PathType)index);
     }

     void Window::periodChanged(double value)
     {
         QEasingCurve curve = m_anim->easingCurve();
         curve.setPeriod(value);
         m_anim->setEasingCurve(curve);
     }

     void Window::amplitudeChanged(double value)
     {
         QEasingCurve curve = m_anim->easingCurve();
         curve.setAmplitude(value);
         m_anim->setEasingCurve(curve);
     }

     void Window::overshootChanged(double value)
     {
         QEasingCurve curve = m_anim->easingCurve();
         curve.setOvershoot(value);
         m_anim->setEasingCurve(curve);
     }