wigglywidget.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** 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 Nokia Corporation 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.
 **
 ** 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
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #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);
     }
 }