blurpicker.cpp Example File

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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();
      }
  }