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

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# wigglywidget.cpp Example File

widgets/wiggly/wigglywidget.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** You may use this file under the terms of the BSD license as follows:
     **
     ** "Redistribution and use in source and binary forms, with or without
     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
     **     of its contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
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     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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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);
         }
     }