Slow Blink LED

blinker.py

#!/usr/local/bin/python
# Inspired by https://news.ycombinator.com/item?id=38274782#38276107
# Blinks a green circle on top of all windows at 60 BPM because it seems to help people focus?
# Requires `pip install pyqt5`

import sys
from PyQt5.QtWidgets import QApplication, QWidget, QLabel
from PyQt5.QtGui import QPixmap, QPainter, QColor, QBrush
from PyQt5.QtCore import QTimer, Qt

class BlinkingCircleApp(QWidget):
    def __init__(self):
        super().__init__()
        self.initUI()
        
    def initUI(self):
        self.setWindowTitle('Blinking Circle')
        self.setGeometry(300, 300, 250, 250)
        self.setWindowFlags(Qt.WindowStaysOnTopHint)
        self.label = QLabel(self)
        self.pixmap = QPixmap(250, 250)
        self.pixmap.fill(Qt.white)
        self.label.setPixmap(self.pixmap)
        self.visible = False
        self.timer = QTimer(self)
        self.timer.timeout.connect(self.blink_circle)
        self.timer.start(500)  # 500 ms interval for 60 bpm
        self.show()

    def blink_circle(self):
        painter = QPainter(self.pixmap)
        if self.visible:
            painter.setBrush(QBrush(Qt.white, Qt.SolidPattern))
            painter.drawEllipse(50, 50, 150, 150)
        else:
            painter.setBrush(QBrush(QColor('green'), Qt.SolidPattern))
            painter.drawEllipse(50, 50, 150, 150)
        self.label.setPixmap(self.pixmap)
        self.visible = not self.visible

if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = BlinkingCircleApp()
    sys.exit(app.exec_())