Need Advice To Keep Gui Responsive

Basically, what I have is a GUI with some QLineEdits, a 'search button' and a table. You hit the button and a class called DataGrabber searches a database for data, processes them,

Solution 1:

This can be handled with signals. You can use signals to send the results to the GUI and to update the GUI of the progress.

Here is a quick example of the implementation with a progress bar and status label. These can be included in a status bar if you would like:

classGUITest(QtWidgets.QWidget):

    def__init__(self):
        QtWidgets.QWidget.__init__(self)

        layout = QtWidgets.QGridLayout()

        self.button = QtWidgets.QPushButton('Run')
        self.button.clicked.connect(self.run)

        self.result_box = QtWidgets.QTextBrowser()

        self.label = QtWidgets.QLabel()

        self.progress_bar = QtWidgets.QProgressBar()
        self.progress_bar.setVisible(False)
        self.progress_bar.setMinimum(0)
        self.progress_bar.setMaximum(100)
        self.progress_bar.setValue(0)

        layout.addWidget(self.button)
        layout.addWidget(self.result_box)
        layout.addWidget(self.label)
        layout.addWidget(self.progress_bar)

        self.setLayout(layout)

    defrun(self):
        self.progress_bar.setVisible(True)
        self.label.setText('Searching...')
        self.thread = QtCore.QThread()
        self.data_grabber = DataGrabber()
        self.data_grabber.moveToThread(self.thread)
        self.data_grabber.update_progress.connect(self.update_progress_bar)
        self.data_grabber.results.connect(self.display_results)
        self.data_grabber.finished.connect(self.complete)
        self.data_grabber.finished.connect(self.thread.quit)
        self.data_grabber.finished.connect(self.data_grabber.deleteLater)
        self.thread.finished.connect(self.thread.deleteLater)
        self.thread.started.connect(self.data_grabber.run)
        self.thread.start()

    defupdate_progress_bar(self):
        self.progress_bar.setValue(self.progress_bar.value() + 1)

    defcomplete(self):
        self.label.setText('Complete')
        self.progress_bar.setVisible(False)

    defdisplay_results(self, results):
        for key, value in results.items():
            self.result_box.append('%s: %s' % (key, value))


classDataGrabber(QtCore.QObject):

    finished = QtCore.pyqtSignal()
    update_progress = QtCore.pyqtSignal()
    results = QtCore.pyqtSignal(dict)  # set the type of object you are sendingdef__init__(self):
        super().__init__()
        self.count = 0defrun(self):
        # search database here and emit update_progress when appropriatewhile self.count <= 100:
            self.update_progress.emit()
            self.count += 1
            time.sleep(0.02)
        self.send_results()  # when done, send the results
        self.finished.emit()

    defsend_results(self):
        results = {'one': 'Result One', 'two': 'Result Two', 'three': 'Result Three'}
        self.results.emit(results)