rospylib qt app

ros_qt_app.py

import sys
from time import sleep

from PySide2.QtCore import Qt, QObject, QThread, Signal, Slot
from PySide2.QtWidgets import (
    QApplication,
    QLabel,
    QMainWindow,
    QPushButton,
    QVBoxLayout,
    QWidget,
)

import roslibpy


class Robot:
    def __init__(self):
        self.client = roslibpy.Ros(host='192.168.0.78', port=9090)
        self.client.run()
        print('Is ROS connected?', self.client.is_connected)


class Listener(QObject):
    finished = Signal()
    progress = Signal(str)

    def __init__(self, client):
        super().__init__()

        listener = roslibpy.Topic(client, '/sensors', 'std_msgs/String')
        listener.subscribe(self.run)

    def run(self, message):
        print(message['data'])
        self.progress.emit(message['data'])
        # for i in range(5):
        #     sleep(1)
        #     self.progress.emit(i + 1)
        # self.finished.emit()

class Publisher(QObject):
    # finished = Signal()
    # progress = Signal(str)

    def __init__(self, client):
        super().__init__()

        self.count = 0
        self.publisher = roslibpy.Topic(client, '/cmd_vel', 'geometry_msgs/Twist')

    @Slot()
    def run(self):
        print("sending message")
        self.count += 1
        self.publisher.publish(roslibpy.Message({'linear': {'x': self.count, 'y': 0.0, 'z': 0.0}, 'angular': {'x': 0.0,'y': 0.0,'z': 0.0}}))
        # self.progress.emit(message['data'])


class Window(QMainWindow):
    closed = Signal()
    forward = Signal()

    def __init__(self, parent=None):
        super().__init__(parent)

        self.robot = Robot()

        self.clicksCount = 0
        self.setupUi()

        self.pub_thread = QThread()
        self.publisher = Publisher(self.robot.client)
        self.publisher.moveToThread(self.pub_thread)
        self.pub_thread.start()

        self.forward.connect(self.publisher.run)


    def setupUi(self):
        self.setWindowTitle("Freezing GUI")
        self.resize(300, 150)
        self.centralWidget = QWidget()
        self.setCentralWidget(self.centralWidget)

        # Create and connect widgets
        self.clicksLabel = QLabel("Counting: 0 clicks", self)
        self.clicksLabel.setAlignment(Qt.AlignHCenter | Qt.AlignVCenter)
        self.stepLabel = QLabel("Long-Running Step: 0")
        self.stepLabel.setAlignment(Qt.AlignHCenter | Qt.AlignVCenter)

        self.countBtn = QPushButton("Publisher!", self)
        self.countBtn.clicked.connect(self.countClicks)

        self.longRunningBtn = QPushButton("Listener!", self)
        self.longRunningBtn.clicked.connect(self.runLongTask)
        # Set the layout
        layout = QVBoxLayout()
        layout.addWidget(self.clicksLabel)
        layout.addWidget(self.countBtn)
        layout.addStretch()
        layout.addWidget(self.stepLabel)
        layout.addWidget(self.longRunningBtn)
        self.centralWidget.setLayout(layout)

    def countClicks(self):
        self.forward.emit()
        # self.clicksCount += 1
        # self.clicksLabel.setText(f"Counting: {self.clicksCount} clicks")

    def reportProgress(self, n):
        self.stepLabel.setText(n)

    def runLongTask(self):
        self.thread = QThread()
        self.listener = Listener(self.robot.client)
        self.listener.moveToThread(self.thread)

        self.thread.started.connect(self.listener.run)
        self.listener.finished.connect(self.thread.quit)
        self.listener.finished.connect(self.listener.deleteLater)
        self.thread.finished.connect(self.thread.deleteLater)
        self.listener.progress.connect(self.reportProgress)
        self.closed.connect(self.thread.quit)

        self.thread.start()

        self.longRunningBtn.setEnabled(False)
        self.thread.finished.connect(
            lambda: self.longRunningBtn.setEnabled(True)
        )
        self.thread.finished.connect(
            lambda: self.stepLabel.setText("Long-Running Step: 0")
        )

    def closeEvent(self, event):
        self.closed.emit()
        event.accept()




app = QApplication(sys.argv)
win = Window()
win.show()
sys.exit(app.exec_())