Qt Reference Documentation

# blurpicker.cpp Example File

effects/blurpicker/blurpicker.cpp

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     #include "blurpicker.h"

     #include <QtGui>

     #include "blureffect.h"

     #ifndef M_PI
     #define M_PI 3.14159265358979323846
     #endif

     BlurPicker::BlurPicker(QWidget *parent): QGraphicsView(parent), m_index(0.0), m_animation(this, "index")
     {
         setBackgroundBrush(QPixmap(":/images/background.jpg"));
         setScene(new QGraphicsScene(this));

         setupScene();
         setIndex(0);

         m_animation.setDuration(400);
         m_animation.setEasingCurve(QEasingCurve::InOutSine);

         setRenderHint(QPainter::Antialiasing, true);
         setFrameStyle(QFrame::NoFrame);
     }

     qreal BlurPicker::index() const
     {
         return m_index;
     }

     void BlurPicker::setIndex(qreal index)
     {
         m_index = index;

         qreal baseline = 0;
         for (int i = 0; i < m_icons.count(); ++i) {
             QGraphicsItem *icon = m_icons[i];
             qreal a = ((i + m_index) * 2 * M_PI) / m_icons.count();
             qreal xs = 170 * sin(a);
             qreal ys = 100 * cos(a);
             QPointF pos(xs, ys);
             pos = QTransform().rotate(-20).map(pos);
             pos -= QPointF(40, 40);
             icon->setPos(pos);
             baseline = qMax(baseline, ys);
             static_cast<BlurEffect *>(icon->graphicsEffect())->setBaseLine(baseline);
         }

         scene()->update();
     }

     void BlurPicker::setupScene()
     {
         scene()->setSceneRect(-200, -120, 400, 240);

         QStringList names;
         names << ":/images/accessories-calculator.png";
         names << ":/images/accessories-text-editor.png";
         names << ":/images/help-browser.png";
         names << ":/images/internet-group-chat.png";
         names << ":/images/internet-mail.png";
         names << ":/images/internet-web-browser.png";
         names << ":/images/office-calendar.png";
         names << ":/images/system-users.png";

         for (int i = 0; i < names.count(); i++) {
             QPixmap pixmap(names[i]);
             QGraphicsPixmapItem *icon = scene()->addPixmap(pixmap);
             icon->setZValue(1);
             icon->setGraphicsEffect(new BlurEffect(icon));
             m_icons << icon;
         }

         QGraphicsPixmapItem *bg = scene()->addPixmap(QPixmap(":/images/background.jpg"));
         bg->setZValue(0);
         bg->setPos(-200, -150);
     }

     void BlurPicker::keyPressEvent(QKeyEvent *event)
     {
         int delta = 0;
         switch (event->key())
         {
         case Qt::Key_Left:
             delta = -1;
             break;
         case  Qt::Key_Right:
             delta = 1;
             break;
         default:
             break;
         }
         if (m_animation.state() == QAbstractAnimation::Stopped && delta) {
                 m_animation.setEndValue(m_index + delta);
                 m_animation.start();
                 event->accept();
         }
     }