app.py

from PyQt4 import QtGui, QtCore, uic
import os, sys, ping, time, rrd, signal

host = "www.google.com"
rrdfile = "temp/ping.rrd"
rrdpng = "temp/ping.png"

default_graph_width = 400
default_graph_height = 100



class HelloworldApp(QtGui.QMainWindow):
	def __init__(self):
		QtGui.QMainWindow.__init__(self)
		
		f = open('resources/darkorange.stylesheet', 'r')
		self.styleData = f.read()
		f.close()
		
		self.ui = uic.loadUi('app.ui')
		self.ui.ms_label.setText("Initializing...")
		self.ui.setStyleSheet(self.styleData)
		self.ui.show()
		self.ui.showFullScreen() #seems to be troublesome for raspberry pis
		
		rrd_thread.set_graph_size(self.ui.graph.size().width(), self.ui.graph.size().height())
		
		self.connect(ping_thread, ping_thread.signal, self.updateUI)
		self.connect(self.ui.exitButton, QtCore.SIGNAL("clicked()"), exit)
		
	def updateUI(self, value):
		win.ui.ms_label.setText(str(value) + " ms")
		win.ui.graph.setPixmap(QtGui.QPixmap(os.getcwd() + "/" + rrdpng))


class PingThread(QtCore.QThread):
	def __init__(self):
		QtCore.QThread.__init__(self, parent=app)
		self.signal = QtCore.SIGNAL("ping_signal")
	
	def run(self):
		
		while True:
			try:
				pingval = ping.ping(host)
			except:
				pingval = {'minping': -1, 'avgping': -1, 'timeout': True}
			
			rrd.update_rrd(rrdfile, pingval)
			
			self.emit( rrd_thread.signal, pingval )
			self.emit( self.signal, str( round( float(pingval['minping']), 2 ) ) )
			
			time.sleep(1)


class RRDThread(QtCore.QThread):
	def __init__(self):
		QtCore.QThread.__init__(self, parent=app)
		self.signal = QtCore.SIGNAL("rrd_png_update_signal")
		self.graph_width = default_graph_width
		self.graph_height = default_graph_height
	
	def run(self):
		self.connect(ping_thread, rrd_thread.signal, self.update_png)
		
	def update_png(self, pingval):
		rrd.update_png(rrdpng, rrdfile, self.graph_width, self.graph_height)
	
	def set_graph_size(self, width, height):
		self.graph_width = int(width)
		self.graph_height = int(height)


def exit():
	sys.exit(0)

def signal_handler(signal, frame):
	sys.exit(0)

if __name__ == "__main__":
	signal.signal(signal.SIGINT, signal_handler)
	
	rrd.remove_png(rrdpng)
	rrd.create_rrd(rrdfile)
	
	app = QtGui.QApplication(sys.argv)
	app.setStyle('plastique')
	
	ping_thread = PingThread()
	rrd_thread = RRDThread()
	
	win = HelloworldApp()
	
	ping_thread.start()
	rrd_thread.start()
	
	sys.exit(app.exec_())