Qt 5.9 | Qt Widgets | Blur Picker Effect Example | blurpicker.cpp Example File

Qt 5.9.9 Reference Documentation

# blurpicker.cpp Example File

effects/blurpicker/blurpicker.cpp

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      #include "blurpicker.h"

      #include <QtWidgets>
      #include <QtCore/qmath.h>

      #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 * qSin(a);
              qreal ys = 100 * qCos(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();
          }
      }

      void BlurPicker::resizeEvent(QResizeEvent * /* event */)
      {
      }

      void BlurPicker::mousePressEvent(QMouseEvent *event)
      {
          int delta = 0;
          if(event->x() > (width() / 2))
          {
              delta = 1;
          }
          else
          {
              delta = -1;
          }

          if (m_animation.state() == QAbstractAnimation::Stopped && delta) {
              m_animation.setEndValue(m_index + delta);
              m_animation.start();
              event->accept();
          }
      }