demos/browser/chasewidget.cpp

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  41
  42 #include "chasewidget.h"
  43
  44 #include <QtCore/QPoint>
  45
  46 #include <QtGui/QApplication>
  47 #include <QtGui/QHideEvent>
  48 #include <QtGui/QPainter>
  49 #include <QtGui/QPaintEvent>
  50 #include <QtGui/QShowEvent>
  51
  52 ChaseWidget::ChaseWidget(QWidget *parent, QPixmap pixmap, bool pixmapEnabled)
  53     : QWidget(parent)
  54     , m_segment(0)
  55     , m_delay(100)
  56     , m_step(40)
  57     , m_timerId(-1)
  58     , m_animated(false)
  59     , m_pixmap(pixmap)
  60     , m_pixmapEnabled(pixmapEnabled)
  61 {
  62 }
  63
  64 void ChaseWidget::setAnimated(bool value)
  65 {
  66     if (m_animated == value)
  67         return;
  68     m_animated = value;
  69     if (m_timerId != -1) {
  70         killTimer(m_timerId);
  71         m_timerId = -1;
  72     }
  73     if (m_animated) {
  74         m_segment = 0;
  75         m_timerId = startTimer(m_delay);
  76     }
  77     update();
  78 }
  79
  80 void ChaseWidget::paintEvent(QPaintEvent *event)
  81 {
  82     Q_UNUSED(event);
  83     QPainter p(this);
  84     if (m_pixmapEnabled && !m_pixmap.isNull()) {
  85         p.drawPixmap(0, 0, m_pixmap);
  86         return;
  87     }
  88
  89     const int extent = qMin(width() - 8, height() - 8);
  90     const int displ = extent / 4;
  91     const int ext = extent / 4 - 1;
  92
  93     p.setRenderHint(QPainter::Antialiasing, true);
  94
  95     if(m_animated)
  96         p.setPen(Qt::gray);
  97     else
  98         p.setPen(QPen(palette().dark().color()));
  99
 100     p.translate(width() / 2, height() / 2); // center
 101
 102     for (int segment = 0; segment < segmentCount(); ++segment) {
 103         p.rotate(QApplication::isRightToLeft() ? m_step : -m_step);
 104         if(m_animated)
 105             p.setBrush(colorForSegment(segment));
 106         else
 107             p.setBrush(palette().background());
 108         p.drawEllipse(QRect(displ, -ext / 2, ext, ext));
 109     }
 110 }
 111
 112 QSize ChaseWidget::sizeHint() const
 113 {
 114     return QSize(32, 32);
 115 }
 116
 117 void ChaseWidget::timerEvent(QTimerEvent *event)
 118 {
 119     if (event->timerId() == m_timerId) {
 120         ++m_segment;
 121         update();
 122     }
 123     QWidget::timerEvent(event);
 124 }
 125
 126 QColor ChaseWidget::colorForSegment(int seg) const
 127 {
 128     int index = ((seg + m_segment) % segmentCount());
 129     int comp = qMax(0, 255 - (index * (255 / segmentCount())));
 130     return QColor(comp, comp, comp, 255);
 131 }
 132
 133 int ChaseWidget::segmentCount() const
 134 {
 135     return 360 / m_step;
 136 }
 137
 138 void ChaseWidget::setPixmapEnabled(bool enable)
 139 {
 140     m_pixmapEnabled = enable;
 141 }
 142