1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
#include <QApplication>
#include <QFinalState>
#include <QPainter>
#include <QStateMachine>
#include <QTimer>
#include <QVBoxLayout>
#include <QWidget>
//! [0]
class LightWidget : public QWidget
{
Q_OBJECT
Q_PROPERTY(bool on READ isOn WRITE setOn)
public:
LightWidget(const QColor &color, QWidget *parent = nullptr)
: QWidget(parent), m_color(color), m_on(false) {}
bool isOn() const
{ return m_on; }
void setOn(bool on)
{
if (on == m_on)
return;
m_on = on;
update();
}
public slots:
void turnOff() { setOn(false); }
void turnOn() { setOn(true); }
protected:
void paintEvent(QPaintEvent *) override
{
if (!m_on)
return;
QPainter painter(this);
painter.setRenderHint(QPainter::Antialiasing);
painter.setBrush(m_color);
painter.drawEllipse(0, 0, width(), height());
}
private:
QColor m_color;
bool m_on;
};
//! [0]
//! [1]
class TrafficLightWidget : public QWidget
{
public:
TrafficLightWidget(QWidget *parent = nullptr)
: QWidget(parent)
{
QVBoxLayout *vbox = new QVBoxLayout(this);
m_red = new LightWidget(Qt::red);
vbox->addWidget(m_red);
m_yellow = new LightWidget(Qt::yellow);
vbox->addWidget(m_yellow);
m_green = new LightWidget(Qt::green);
vbox->addWidget(m_green);
QPalette pal = palette();
pal.setColor(QPalette::Window, Qt::black);
setPalette(pal);
setAutoFillBackground(true);
}
LightWidget *redLight() const
{ return m_red; }
LightWidget *yellowLight() const
{ return m_yellow; }
LightWidget *greenLight() const
{ return m_green; }
private:
LightWidget *m_red;
LightWidget *m_yellow;
LightWidget *m_green;
};
//! [1]
//! [2]
QState *createLightState(LightWidget *light, int duration, QState *parent = nullptr)
{
QState *lightState = new QState(parent);
QTimer *timer = new QTimer(lightState);
timer->setInterval(duration);
timer->setSingleShot(true);
QState *timing = new QState(lightState);
QObject::connect(timing, &QAbstractState::entered, light, &LightWidget::turnOn);
QObject::connect(timing, &QAbstractState::entered, timer, QOverload<>::of(&QTimer::start));
QObject::connect(timing, &QAbstractState::exited, light, &LightWidget::turnOff);
QFinalState *done = new QFinalState(lightState);
timing->addTransition(timer, &QTimer::timeout, done);
lightState->setInitialState(timing);
return lightState;
}
//! [2]
//! [3]
class TrafficLight : public QWidget
{
public:
TrafficLight(QWidget *parent = nullptr)
: QWidget(parent)
{
QVBoxLayout *vbox = new QVBoxLayout(this);
TrafficLightWidget *widget = new TrafficLightWidget;
vbox->addWidget(widget);
vbox->setContentsMargins(QMargins());
QStateMachine *machine = new QStateMachine(this);
QState *redGoingYellow = createLightState(widget->redLight(), 3000);
redGoingYellow->setObjectName("redGoingYellow");
QState *yellowGoingGreen = createLightState(widget->yellowLight(), 1000);
yellowGoingGreen->setObjectName("yellowGoingGreen");
redGoingYellow->addTransition(redGoingYellow, &QState::finished, yellowGoingGreen);
QState *greenGoingYellow = createLightState(widget->greenLight(), 3000);
greenGoingYellow->setObjectName("greenGoingYellow");
yellowGoingGreen->addTransition(yellowGoingGreen, &QState::finished, greenGoingYellow);
QState *yellowGoingRed = createLightState(widget->yellowLight(), 1000);
yellowGoingRed->setObjectName("yellowGoingRed");
greenGoingYellow->addTransition(greenGoingYellow, &QState::finished, yellowGoingRed);
yellowGoingRed->addTransition(yellowGoingRed, &QState::finished, redGoingYellow);
machine->addState(redGoingYellow);
machine->addState(yellowGoingGreen);
machine->addState(greenGoingYellow);
machine->addState(yellowGoingRed);
machine->setInitialState(redGoingYellow);
machine->start();
}
};
//! [3]
//! [4]
int main(int argc, char **argv)
{
QApplication app(argc, argv);
TrafficLight widget;
widget.resize(110, 300);
widget.show();
return app.exec();
}
//! [4]
#include "main.moc"
|
