wigglywidget.cpp Example File

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 #include <QtWidgets>

 #include "wigglywidget.h"

 WigglyWidget::WigglyWidget(QWidget *parent)
     : QWidget(parent)
 {
     setBackgroundRole(QPalette::Midlight);
     setAutoFillBackground(true);

     QFont newFont = font();
     newFont.setPointSize(newFont.pointSize() + 20);
     setFont(newFont);

     step = 0;
     timer.start(60, this);
 }

 void WigglyWidget::paintEvent(QPaintEvent * /* event */)
 {
     static const int sineTable[16] = {
         0, 38, 71, 92, 100, 92, 71, 38, 0, -38, -71, -92, -100, -92, -71, -38
     };

     QFontMetrics metrics(font());
     int x = (width() - metrics.width(text)) / 2;
     int y = (height() + metrics.ascent() - metrics.descent()) / 2;
     QColor color;

     QPainter painter(this);
     for (int i = 0; i < text.size(); ++i) {
         int index = (step + i) % 16;
         color.setHsv((15 - index) * 16, 255, 191);
         painter.setPen(color);
         painter.drawText(x, y - ((sineTable[index] * metrics.height()) / 400),
                          QString(text[i]));
         x += metrics.width(text[i]);
     }
 }

 void WigglyWidget::timerEvent(QTimerEvent *event)
 {
     if (event->timerId() == timer.timerId()) {
         ++step;
         update();
     } else {
         QWidget::timerEvent(event);
     }
 }