Refactoring of USBPrinting plugin

USBPrinterManager.py

@@ -0,0 +1,81 @@
+from UM.Signal import Signal, SignalEmitter
+from UM.PluginObject import PluginObject
+
+import threading
+import platform
+import glob
+import time
+
+class USBPrinterManager(SignalEmitter,PluginObject):
+    def __init__(self):
+        super().__init__()
+        self._serial_port_list = []
+        self._printer_connections = []
+        
+        self._check_ports_thread = threading.Thread(target=self._updateConnectionList)
+        self._check_ports_thread.daemon = True
+        self._check_ports_thread.start()
+    
+    ##  Check all serial ports and create a PrinterConnection object for them.
+    #   Note that this does not validate if the serial ports are actually usable!
+    #   This is only done when the connect function is called.
+    def _updateConnectionList(self):  
+        while True: 
+            temp_serial_port_list = self.getSerialPortList(only_list_usb = True)
+            if temp_serial_port_list != self._serial_port_list: # Something changed about the list since we last changed something.
+                disconnected_ports = [port for port in self._serial_port_list if port not in temp_serial_port_list ]
+                self._serial_port_list = temp_serial.port_list
+                
+                for serial_port in self._serial_port_list:
+                    if self.getConnectionByPort(serial_port) is None: #If it doesn't already exist, add it
+                        self._printer_connections.append(PrinterConnection(serial_port))
+                
+                for serial_port in disconnected_ports: # Close connections and remove them from list.
+                    connection = self.getConnectionByPort(serial_port)
+                    connection.close()
+                    self._printer_connections.remove(connection)
+            
+            time.sleep(5) #Throttle, as we don't need this information to be updated every single second.        
+    
+    def connectAllConnections(self):
+        for connection in self._printer_connections:
+            connection.connect()
+            
+    def getActiveConnections(self):
+        return [connection for connection in self._printer_connections if connection.isConnected()]
+    
+    ##  
+    def getConnectionByPort(self, serial_port):
+        for printer_connection in self._printer_connections:
+            if serial_port == printer_connection.getSerialPort():
+                return printer_connection
+        return None
+
+    ##  Create a list of serial ports on the system.
+    #   \param only_list_usb If true, only usb ports are listed
+    def getSerialPortList(self,only_list_usb=False):
+        base_list=[]
+        if platform.system() == "Windows":
+            try:
+                key=_winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE,"HARDWARE\\DEVICEMAP\\SERIALCOMM")
+                i=0
+                while True:
+                    values = _winreg.EnumValue(key, i)
+                    if not base_list or 'USBSER' in values[0]:
+                        base_list+=[values[1]]
+                    i+=1
+            except:
+                pass
+        
+        if base_list:
+            base_list = base_list + glob.glob('/dev/ttyUSB*') + glob.glob('/dev/ttyACM*') + glob.glob("/dev/cu.usb*")
+            base_list = filter(lambda s: not 'Bluetooth' in s, base_list) #Filter because mac sometimes puts them in the list
+            #prev = profile.getMachineSetting('serial_port_auto')
+            #if prev in base_list:
+            #    base_list.remove(prev)
+            #    base_list.insert(0, prev)
+        else:
+            base_list = base_list + glob.glob('/dev/ttyUSB*') + glob.glob('/dev/ttyACM*') + glob.glob("/dev/cu.*") + glob.glob("/dev/tty.usb*") + glob.glob("/dev/rfcomm*") + glob.glob('/dev/serial/by-id/*')
+        #if version.isDevVersion() and not base_list:
+            #base_list.append('VIRTUAL')
+        return base_list