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50
51#include "wigglywidget.h"
52
53#include <QFontMetrics>
54#include <QPainter>
55#include <QTimerEvent>
56
57//! [0]
58WigglyWidget::WigglyWidget(QWidget *parent)
59 : QWidget(parent), step(0)
60{
61 setBackgroundRole(QPalette::Midlight);
62 setAutoFillBackground(true);
63
64 QFont newFont = font();
65 newFont.setPointSize(newFont.pointSize() + 20);
66 setFont(newFont);
67
68 timer.start(msec: 60, obj: this);
69}
70//! [0]
71
72//! [1]
73void WigglyWidget::paintEvent(QPaintEvent * /* event */)
74//! [1] //! [2]
75{
76 static constexpr int sineTable[16] = {
77 0, 38, 71, 92, 100, 92, 71, 38, 0, -38, -71, -92, -100, -92, -71, -38
78 };
79
80 QFontMetrics metrics(font());
81 int x = (width() - metrics.horizontalAdvance(text)) / 2;
82 int y = (height() + metrics.ascent() - metrics.descent()) / 2;
83 QColor color;
84//! [2]
85
86//! [3]
87 QPainter painter(this);
88//! [3] //! [4]
89 for (int i = 0; i < text.size(); ++i) {
90 int index = (step + i) % 16;
91 color.setHsv(h: (15 - index) * 16, s: 255, v: 191);
92 painter.setPen(color);
93 painter.drawText(x, y: y - ((sineTable[index] * metrics.height()) / 400),
94 s: QString(text[i]));
95 x += metrics.horizontalAdvance(text[i]);
96 }
97}
98//! [4]
99
100//! [5]
101void WigglyWidget::timerEvent(QTimerEvent *event)
102//! [5] //! [6]
103{
104 if (event->timerId() == timer.timerId()) {
105 ++step;
106 update();
107 } else {
108 QWidget::timerEvent(event);
109 }
110//! [6]
111}
112

source code of qtbase/examples/widgets/widgets/wiggly/wigglywidget.cpp