Refactoring of USBPrinting plugin

PrinterConnection.py

@@ -0,0 +1,150 @@
+from UM.Logger import Logger
+from .avr_isp import stk500v2
+
+class PrinterConnection():
+    def __init__(self, serial_port):
+        super().__init__()
+        
+        self._serial = None
+        self._serial_port = serial_port
+        self._error_state = None
+        
+        self._connect_thread = threading.Thread(target = self._connect)
+        self._connect_thread.daemon = True
+        
+        self._is_connected = False
+        self._is_connecting = False
+        self._required_responses_auto_baud = 10
+        
+        self._listen_thread = threading.Thread(target=self._listen)
+        self._listen_thread.daemon = True
+        #self._listen_thread.start()
+    
+    ##  Try to connect the serial. This simply starts the thread.
+    def connect(self):
+        self._connect_thread.start()
+    
+    def _connect(self):
+        self._is_connecting = True
+        programmer.connect(serial_port) #Connect with the serial, if this succeeds, it's an arduino based usb device.
+        try:
+            self._serial = programmer.leaveISP() 
+            # Create new printer connection
+            self.active_printer_connection = PrinterConnection(temp_serial)
+            Logger.log('i', "Established connection on port %s" % serial_port)
+            break
+        except ispBase.IspError as (e):
+            Logger.log('i', "Could not establish connection on %s: %s. Device is not arduino based." %(serial_port,str(e)))
+        except:
+            Logger.log('i', "Could not establish connection on %s, unknown reasons.  Device is not arduino based." % serial_port)
+        
+        if self._serial is None:
+            #Device is not arduino based, so we need to cycle the baud rates.
+            for baud_rate in self._getBaudrateList():
+                timeout_time = time.time() + 5
+                if self._serial = None:
+                    self._serial = serial.Serial(str(self._port), baud_rate, timeout=5, writeTimeout=10000)
+                else:
+                    if not self.setBaudRate(baud_rate):
+                        continue #Could not set the baud rate, go to the next
+                sucesfull_responses = 0
+                while timeout_time > time.time():
+                    line = self._readline():
+                    if "T:" in line:
+                        self._serial.timeout = 0.5
+                        self._sendCommand("M105") # Request temperature, as this should (if baudrate is correct) result in a command with 'T:' in it
+                        sucesfull_responses += 1
+                        if sucesfull_responses >= self._required_responses_auto_baud:
+                            self.setIsConnected(True)
+                            return 
+            self.setIsConnected(False)
+        else: 
+            self.setIsConnected(True)
+            return #Stop trying to connect, we are connected.
+    
+    def _listen(self):
+        time.sleep(5)
+        pass
+    
+    def setBaudRate(self, baud_rate):
+        try:
+            self._serial.baudrate = baud_rate
+        except:
+            return False
+    
+    def setIsConnected(self, state):
+        self._is_connecting = False
+        if state != state:
+            self._is_connected = state
+        else:
+            Logger.log('w', "Printer connection state was not changed")
+            
+        if self._is_connected:
+             self._listen_thread.start() #Start listening
+        
+    
+    def isConnected(self):
+        return self._is_connected = True
+            
+    def _listen(self):
+        while True:
+            line = self._readline()
+            if line is None: 
+                break #None is only returned when something went wrong. Stop listening
+            
+            if line.startswith('Error:'):
+                #Oh YEAH, consistency.
+                # Marlin reports an MIN/MAX temp error as "Error:x\n: Extruder switched off. MAXTEMP triggered !\n"
+                #       But a bed temp error is reported as "Error: Temperature heated bed switched off. MAXTEMP triggered !!"
+                #       So we can have an extra newline in the most common case. Awesome work people.
+                if re.match('Error:[0-9]\n', line):
+                        line = line.rstrip() + self._readline()
+                #Skip the communication errors, as those get corrected.
+                if 'Extruder switched off' in line or 'Temperature heated bed switched off' in line or 'Something is wrong, please turn off the printer.' in line:
+                    if not self.hasError():
+                        self._error_state = line[6:]
+            if ' T:' in line or line.startswith('T:'): #Temperature message
+                try:
+                    print("TEMPERATURE", float(re.search("T: *([0-9\.]*)", line).group(1)))
+                except:
+                    pass
+                if 'B:' in line: #Check if it's a bed temperature
+                    try:
+                        print("BED TEMPERATURE" ,float(re.search("B: *([0-9\.]*)", line).group(1)))
+                    except:
+                        pass
+                #TODO: temperature changed callback
+                
+                
+                
+    def hasError(self):
+        return self._error_state == None ? False : True
+        
+        
+    def _readline(self):
+        if self._serial is None:
+            return None
+        try:
+            ret = self._serial.readline()
+        except:
+            self._log("Unexpected error while reading serial port."))
+            self._errorValue = getExceptionString()
+            self.close(True)
+            return None
+        if ret == '':
+            return ''
+        #self._log("Recv: %s" % (unicode(ret, 'ascii', 'replace').encode('ascii', 'replace').rstrip()))
+        return ret
+    
+    
+    ##  Create a list of baud rates at which we can communicate.
+    #   \return list of int
+    def _getBaudrateList():
+        ret = [250000, 230400, 115200, 57600, 38400, 19200, 9600]
+        #if profile.getMachineSetting('serial_baud_auto') != '':
+            #prev = int(profile.getMachineSetting('serial_baud_auto'))
+            #if prev in ret:
+                #ret.remove(prev)
+                #ret.insert(0, prev)
+        return ret
+