trafficlight example modernization

Add 'explicit' to some constructors.

Use inline class member initialization where possible.

Reformat some code using clang-format.

Add Q_OBJECT macros to QObjects.

Pass entire rectangle to QPainter::drawEllipse().

Use 'auto' where appropriate.

Add module prefix to Qt includes and sort them.

Task-number: QTBUG-111448
Change-Id: Ibfb49608b5f3710684b2b07d29b14ad03a8dfb24
Reviewed-by: Juha Vuolle <juha.vuolle@qt.io>
(cherry picked from commit 9c1a5a12fe8f49c7b1881f924e0b946bf8dc8232)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 35 insertions, 36 deletions

diff --git a/examples/statemachine/trafficlight/main.cpp b/examples/statemachine/trafficlight/main.cpp
index a2478dc..5c85921 100644
--- a/examples/statemachine/trafficlight/main.cpp
+++ b/examples/statemachine/trafficlight/main.cpp
@@ -1,13 +1,13 @@
 // 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>
+#include <QtCore/QTimer>
+#include <QtGui/QPainter>
+#include <QtStateMachine/QFinalState>
+#include <QtStateMachine/QStateMachine>
+#include <QtWidgets/QApplication>
+#include <QtWidgets/QVBoxLayout>
+#include <QtWidgets/QWidget>
 
 //! [0]
 class LightWidget : public QWidget
@@ -15,11 +15,13 @@ 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) {}
+    explicit LightWidget(const QColor &color, QWidget *parent = nullptr)
+        : QWidget(parent), m_color(color)
+    {
+    }
+
+    bool isOn() const { return m_on; }
 
-    bool isOn() const
-        { return m_on; }
     void setOn(bool on)
     {
         if (on == m_on)
@@ -40,41 +42,38 @@ protected:
         QPainter painter(this);
         painter.setRenderHint(QPainter::Antialiasing);
         painter.setBrush(m_color);
-        painter.drawEllipse(0, 0, width(), height());
+        painter.drawEllipse(rect());
     }
 
 private:
     QColor m_color;
-    bool m_on;
+    bool m_on = false;
 };
 //! [0]
 
 //! [1]
 class TrafficLightWidget : public QWidget
 {
+    Q_OBJECT
 public:
-    TrafficLightWidget(QWidget *parent = nullptr)
-        : QWidget(parent)
+    explicit TrafficLightWidget(QWidget *parent = nullptr) : QWidget(parent)
     {
-        QVBoxLayout *vbox = new QVBoxLayout(this);
+        auto 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();
+        auto 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; }
+    LightWidget *redLight() const { return m_red; }
+    LightWidget *yellowLight() const { return m_yellow; }
+    LightWidget *greenLight() const { return m_green; }
 
 private:
     LightWidget *m_red;
@@ -86,15 +85,15 @@ private:
 //! [2]
 QState *createLightState(LightWidget *light, int duration, QState *parent = nullptr)
 {
-    QState *lightState = new QState(parent);
-    QTimer *timer = new QTimer(lightState);
+    auto lightState = new QState(parent);
+    auto timer = new QTimer(lightState);
     timer->setInterval(duration);
     timer->setSingleShot(true);
-    QState *timing = new QState(lightState);
+    auto 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);
+    auto done = new QFinalState(lightState);
     timing->addTransition(timer, &QTimer::timeout, done);
     lightState->setInitialState(timing);
     return lightState;
@@ -104,25 +103,25 @@ QState *createLightState(LightWidget *light, int duration, QState *parent = null
 //! [3]
 class TrafficLight : public QWidget
 {
+    Q_OBJECT
 public:
-    TrafficLight(QWidget *parent = nullptr)
-        : QWidget(parent)
+    explicit TrafficLight(QWidget *parent = nullptr) : QWidget(parent)
     {
-        QVBoxLayout *vbox = new QVBoxLayout(this);
-        TrafficLightWidget *widget = new TrafficLightWidget;
+        auto vbox = new QVBoxLayout(this);
+        auto widget = new TrafficLightWidget;
         vbox->addWidget(widget);
         vbox->setContentsMargins(QMargins());
 
-        QStateMachine *machine = new QStateMachine(this);
-        QState *redGoingYellow = createLightState(widget->redLight(), 3000);
+        auto machine = new QStateMachine(this);
+        auto redGoingYellow = createLightState(widget->redLight(), 3000);
         redGoingYellow->setObjectName("redGoingYellow");
-        QState *yellowGoingGreen = createLightState(widget->yellowLight(), 1000);
+        auto yellowGoingGreen = createLightState(widget->yellowLight(), 1000);
         yellowGoingGreen->setObjectName("yellowGoingGreen");
         redGoingYellow->addTransition(redGoingYellow, &QState::finished, yellowGoingGreen);
-        QState *greenGoingYellow = createLightState(widget->greenLight(), 3000);
+        auto greenGoingYellow = createLightState(widget->greenLight(), 3000);
         greenGoingYellow->setObjectName("greenGoingYellow");
         yellowGoingGreen->addTransition(yellowGoingGreen, &QState::finished, greenGoingYellow);
-        QState *yellowGoingRed = createLightState(widget->yellowLight(), 1000);
+        auto yellowGoingRed = createLightState(widget->yellowLight(), 1000);
         yellowGoingRed->setObjectName("yellowGoingRed");
         greenGoingYellow->addTransition(greenGoingYellow, &QState::finished, yellowGoingRed);
         yellowGoingRed->addTransition(yellowGoingRed, &QState::finished, redGoingYellow);