demo.pro

#-------------------------------------------------
#
# Project created by QtCreator 2020-05-22T09:28:09
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = demo
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

SOURCES += \
        main.cpp \
        mainwindow.cpp \
    worker.cpp

HEADERS += \
        mainwindow.h \
    worker.h

FORMS += \
        mainwindow.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

main.cpp

#include "mainwindow.h"

#include <QApplication>

int main(int argc, char* argv[]) {
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include <QDebug>

MainWindow::MainWindow(QWidget* parent):
    QMainWindow(parent),
    ui(new Ui::MainWindow),
    workerThread(this),
    worker(new Worker),
    workerTimer(new QTimer(this)) {

    ui->setupUi(this);
    worker->moveToThread(&workerThread);
    workerThread.start();

    connect(workerTimer, &QTimer::timeout, worker, &Worker::makeResult);
}

MainWindow::~MainWindow() {
    stopWorker();

    workerThread.quit();
    workerThread.wait();

    delete worker;

    delete ui;
}

void MainWindow::startWorker() {
    workerTimer->start(10000);
    qDebug() << "Worker timer started";
}

void MainWindow::stopWorker() {
    workerTimer->stop();
    qDebug() << "Worker timer stopped";
}

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include "worker.h"

#include <QMainWindow>
#include <QThread>
#include <QTimer>

namespace Ui {
    class MainWindow;
}

class MainWindow: public QMainWindow {
    Q_OBJECT

public:
    explicit MainWindow(QWidget* parent = nullptr);
    ~MainWindow() override;

private slots:
    void startWorker(void);
    void stopWorker(void);

private:
    Ui::MainWindow* ui;
    QThread workerThread;
    Worker* worker;
    QTimer* workerTimer;
};

#endif // MAINWINDOW_H

mainwindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>400</width>
    <height>300</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralWidget">
   <widget class="QPushButton" name="pushButton">
    <property name="geometry">
     <rect>
      <x>50</x>
      <y>20</y>
      <width>88</width>
      <height>34</height>
     </rect>
    </property>
    <property name="text">
     <string>start</string>
    </property>
   </widget>
   <widget class="QPushButton" name="pushButton_2">
    <property name="geometry">
     <rect>
      <x>180</x>
      <y>20</y>
      <width>88</width>
      <height>34</height>
     </rect>
    </property>
    <property name="text">
     <string>stop</string>
    </property>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menuBar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>400</width>
     <height>30</height>
    </rect>
   </property>
  </widget>
  <widget class="QToolBar" name="mainToolBar">
   <attribute name="toolBarArea">
    <enum>TopToolBarArea</enum>
   </attribute>
   <attribute name="toolBarBreak">
    <bool>false</bool>
   </attribute>
  </widget>
  <widget class="QStatusBar" name="statusBar"/>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections>
  <connection>
   <sender>pushButton</sender>
   <signal>clicked()</signal>
   <receiver>MainWindow</receiver>
   <slot>startWorker()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>98</x>
     <y>80</y>
    </hint>
    <hint type="destinationlabel">
     <x>128</x>
     <y>154</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>pushButton_2</sender>
   <signal>clicked()</signal>
   <receiver>MainWindow</receiver>
   <slot>stopWorker()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>232</x>
     <y>81</y>
    </hint>
    <hint type="destinationlabel">
     <x>270</x>
     <y>159</y>
    </hint>
   </hints>
  </connection>
 </connections>
 <slots>
  <slot>startWorker()</slot>
  <slot>stopWorker()</slot>
 </slots>
</ui>

worker.cpp

#include "worker.h"

#include <QDebug>

#include <unistd.h>

Worker::Worker(QObject* parent): QObject(parent) {
}

void Worker::makeResult() {
    qDebug() << "starting long run" << taskNum;
    sleep(3);
    taskNum++;
    qDebug() << "task completed";
    emit resultReady(taskNum);
}

worker.h

#ifndef WORKER_H
#define WORKER_H

#include <QObject>

class Worker: public QObject {
    Q_OBJECT
public:
    explicit Worker(QObject* parent = nullptr);
    bool isWorking();

signals:
    void resultReady(int);

public slots:
    void makeResult();

private:
    bool isWorking_ { false };
    int taskNum { 0 };
};
#endif // WORKER_H