fademessage.cpp Example File

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 #include "fademessage.h"

 #include <QtWidgets>

 FadeMessage::FadeMessage(QWidget *parent): QGraphicsView(parent)
 {
     setScene(&m_scene);
     setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
     setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

     setupScene();

     m_animation = new QPropertyAnimation(m_effect, "strength", this);
     m_animation->setDuration(500);
     m_animation->setEasingCurve(QEasingCurve::InOutSine);
     m_animation->setStartValue(0);
     m_animation->setEndValue(1);

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

 void FadeMessage::togglePopup()
 {
     if (m_message->isVisible()) {
         m_message->setVisible(false);
         m_animation->setDirection(QAbstractAnimation::Backward);
     } else {
         m_message->setVisible(true);
         m_animation->setDirection(QAbstractAnimation::Forward);
     }
     m_animation->start();
 }

 void FadeMessage::setupScene()
 {
     QGraphicsRectItem *parent = m_scene.addRect(0, 0, 800, 600);
     parent->setPen(Qt::NoPen);
     parent->setZValue(0);

     QGraphicsPixmapItem *bg = m_scene.addPixmap(QPixmap(":/background.jpg"));
     bg->setParentItem(parent);
     bg->setZValue(-1);

     for (int i = 1; i < 5; ++i)
         for (int j = 2; j < 5; ++j) {
             QGraphicsRectItem *item = m_scene.addRect(i * 50, (j - 1) * 50, 38, 38);
             item->setParentItem(parent);
             item->setZValue(1);
             int hue = 12 * (i * 5 + j);
             item->setBrush(QColor::fromHsv(hue, 128, 128));
         }

     QFont font;
     font.setPointSize(font.pointSize() * 2);
     font.setBold(true);
     QFontMetrics fontMetrics(font);
     int fh = fontMetrics.height();

     QString sceneText = "Qt Everywhere!";
     int sceneTextWidth = fontMetrics.width(sceneText);

     QGraphicsRectItem *block = m_scene.addRect(50, 300, sceneTextWidth, fh + 3);
     block->setPen(Qt::NoPen);
     block->setBrush(QColor(102, 153, 51));

     QGraphicsTextItem *text = m_scene.addText(sceneText, font);
     text->setDefaultTextColor(Qt::white);
     text->setPos(50, 300);
     block->setZValue(2);
     block->hide();

     text->setParentItem(block);
     m_message = block;

     m_effect = new QGraphicsColorizeEffect;
     m_effect->setColor(QColor(122, 193, 66));
     m_effect->setStrength(0);
     m_effect->setEnabled(true);
     parent->setGraphicsEffect(m_effect);

     QPushButton *press = new QPushButton;
     press->setText(tr("Press me"));
     connect(press, SIGNAL(clicked()), SLOT(togglePopup()));
     m_scene.addWidget(press);

     press->move(300, 500);
 }