Fixed QtWindow closing event and restarting plot. Works with Py3 too.

SocketPlot-Test.py

@@ -1,6 +1,8 @@
 import asyncore, socket, time
 import numpy as np 
 from collections import deque
+from SoftOscilloscope import SocketClientPlot
+from multiprocessing import Process
 
 data = np.linspace(-np.pi, np.pi, 50)
 
@@ -14,31 +16,31 @@ def __init__(self, address):
 
     def handle_accept(self):
         global data
-        client,addr = self.accept()
-        print "Connected to " + str(addr)
+        client, addr = self.accept()
+        print("Connected to " + str(addr))
         while(1):
             try:
-                a = round(50 * np.sin(data[0]), 3)
-                b = round(20*data[0], 3)
-                client.send(str(a) + "," + str(b) + '\n')
+                a = str(round(50 * np.sin(data[0]), 3))
+                b = str(round(20*data[0], 3))
+                client.send((a + "," + b + '\n').encode())
                 data = np.roll(data, 1)
                 time.sleep(0.05)
-            except Exception, message:
-                print message
-                self.close() 
-                break
+            except Exception as e:
+                print(e)
+                return
 
     def handle_close(self):
         self.close()
-        print "Closing server."
+        print("Closing server.")
+
 
 if __name__ == '__main__':
     address = ('0.0.0.0',5000)
     server = Server(address)
     try:
-        print "Server listening on " + str(address) 
-        asyncore.loop(0.2,use_poll = True)
+        print("Server listening on " + str(address))
+        asyncore.loop(0.2, use_poll=True)
     except KeyboardInterrupt:
-        print "Closing server."
+        print("Closing server.")
         server.close()
 

SoftOscilloscope.py

@@ -2,20 +2,27 @@
 from pyqtgraph.Qt import QtGui, QtCore
 import pyqtgraph as pg
 import numpy as np
+import signal 
 
 class BasePlot(object):
     def __init__(self, stream, **kwargs):
         self.stream = stream
-        self.app = QtGui.QApplication([])
+        try:
+            self.app = QtGui.QApplication([])
+        except RuntimeError:
+            self.app = QtGui.QApplication.instance()
         self.view = pg.GraphicsView()
         self.layout = pg.GraphicsLayout(border=(100,100,100))
+        self.view.closeEvent = self.handle_close_event
+        self.layout.closeEvent = self.handle_close_event
         self.view.setCentralItem(self.layout)
         self.view.show()
-        self.view.setWindowTitle('pyqtgraph example: GraphicsLayout')
+        self.view.setWindowTitle('Software Oscilloscope')
         self.view.resize(800,600)
         self.plot_list = []
 
     def open_stream(self):
+        print("Opening Stream")
         self.stream.open()
 
     def close_stream(self):
@@ -24,10 +31,13 @@ def close_stream(self):
         if hasattr(self.stream, 'flushOutput'):
             self.stream.flushOutput()
         self.stream.close()
-        print "Stream closed"
+        print("Stream closed")
 
     def handle_close_event(self, event):
+        print("Here")
         self.close_stream()
+        self.app.exit()
+        print("App exited")
 
     def plot_init(self):
         for i in xrange(20):
@@ -58,7 +68,7 @@ def start(self):
         timer.timeout.connect(self.update)
         timer.start(0)   
         if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
-            QtGui.QApplication.instance().exec_()   
+            self.app.exec_()   
 
 class SerialPlot(BasePlot):
     def __init__(self, com_port, baud_rate, **kwargs):
@@ -70,7 +80,6 @@ def __init__(self, com_port, baud_rate, **kwargs):
 class SocketClientPlot(BasePlot):
     def __init__(self, address, port, **kwargs):
         self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        self.socket.settimeout(5)
         self.socket_params = (address, port)
         self.socket.connect((address, port))
         self.stream = self.socket.makefile()  

readme.md

@@ -1,9 +1,9 @@
 # Software Oscilloscope
-An ongoing python project which takes in data from any stream(Serial port, TCP socket or any generic stream) and plot it in real time using PyQtGraph. The stream must implement open(), close() and readline() methods 
+A python project which takes in data from any stream(Serial port, TCP socket or any generic stream) and plots it in real time using PyQtGraph. The stream must implement open(), close() and readline() methods 
 to work with the package.
 
 ## Installation
-* Requires Python 2
+* Works with Python 2/3
 * Clone the repo or download the zip
 * Install VC++ for Python from [here](https://www.microsoft.com/en-in/download/details.aspx?id=44266)
 * `cd` to the folder