Qt 4.8: wigglywidget.cpp Example File (widgets/wiggly/wigglywidget.cpp)

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# wigglywidget.cpp Example File

widgets/wiggly/wigglywidget.cpp

     /****************************************************************************
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     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
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     #include <QtGui>

     #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);
         }
     }