fademessage.cpp Example File | Qt Widgets 5.12.9

- Qt 5.12
- Qt Widgets
- Fade Message Effect Example
- fademessage.cpp Example File
- Qt 5.12.9 Reference Documentation

# fademessage.cpp Example File

effects/fademessage/fademessage.cpp

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     ** This file is part of the examples of the Qt Toolkit.
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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.horizontalAdvance(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);
     }