Fixed the printing, added init and small API

src/printer.py

@@ -24,32 +24,46 @@ class Printer(object):
     # Is the printer ready to accept a new print ?
     ready = False
 
-    def __init__(self, app):
+    def __init__(self, app, device_id, vendor_id):
         super(Printer, self).__init__()
         self.app = app
         self.ready = False
         self.printer = None
+        self.device_id = device_id
+        self.vendor_id = vendor_id
+        self.usb_args = {}
+        self.usb_args['idVendor'] = self.device_id
+        self.usb_args['idProduct'] = self.vendor_id
 
-    def init_printer(self, device_id,vendor_id):
-
-        try:
-            p = Usb(0x04b8, 0x0e28, 0)
-        except USBNotFoundError as e:
-            self.app.logger.error("The USB device is not plugged in, aborting..." + str(e))
-            return False
-        waiting_elapsed = 10
-
-        # p.open()
+    def init_printer(self):
 
         # Is the printer online ? Is the communication with the printer successfull ?
-        while not p.is_online():
-            self.app.logger.debug('Waiting for printer to get online...')
+        waiting_elapsed = 30
+        self.app.logger.debug('Waiting for printer to get online...')
+
+        while not self.ready:
+            try:
+                # This also calls open(), which we need to close()
+                # or else the device will appear as busy.
+                p = Usb(self.device_id, self.vendor_id, 0, profile="TM-P80")
+            except USBNotFoundError as e:
+                self.app.logger.error("The USB device is not plugged in, trying again : " + str(e))
+                pass
+
+            try:
+                if p.is_online():
+                    self.ready = True
+            except Exception as e:
+                pass
+
             sleep(1)
             waiting_elapsed -= 1
             if waiting_elapsed < 1:
-                self.app.logger.error('Printer took more than 10 seconds to get online, aborting...')
+                self.app.logger.error('Printer took more than 30 seconds to get online, aborting...')
+                waiting_elapsed = 30 # Reset the waiting time for the next print.
                 return False
 
+
         # Let's check paper status.
         ps = p.paper_status()
         if ps == 0:
@@ -58,30 +72,32 @@ class Printer(object):
         elif ps == 1:
             self.app.logger.warning('Printer needs paper to be changed very soon ! ')
             sleep(5)
-        elif ps == 0:
+        elif ps == 2:
             self.app.logger.debug('Printer has paper, good to go')
 
-        # We're going to print a little text to let know that we're good, as a final check.
-        # p.textln("Hello world ! \nStarting up at " + strftime("%Y-%m-%d %H:%M:%S", gmtime()))
-        # p.set(align='center', font='a', bold=False, underline=0, width=1, height=1, density=9, invert=False, smooth=False, flip=False, double_width=False, double_height=False, custom_size=False)
-        # p.textln("------------------")
-        # p.qr("Hello World ! :)",size=1)
-        p.image("configuration/hello_world.png",center=True,impl='bitImageColumn')
-        # p.cut()
+        # Setting up the printing options.
+        p.set(align='center', font='a', bold=False, underline=0, width=1, height=1, density=9, invert=False, smooth=False, flip=False, double_width=False, double_height=False, custom_size=False)
+        # Beware : if we print this every time the printer becomes ready, it means
+        # we are printing before and after every print !
 
         self.printer = p;
         self.ready = True;
+        self.printer.close();
         return True
 
     def print_sms(self, msg):
         clean_msg = str(msg)
 
         if len(clean_msg) > 256 or len(clean_msg) < 10 :
-            self.app.logger.warning("Could not print message of this length :" + len(clean_msg))
-            return False
+            self.app.logger.warning("Could not print message of this length :" + str(len(clean_msg)))
+            return "Could not print message of this length :" + str(len(clean_msg)) + ", needs to be 10 < x <    256"
         else :
+            self.printer.open(self.usb_args);
             self.printer.textln(strftime("%Y-%m-%d %H:%M:%S", gmtime()))
             self.printer.textln(clean_msg)
+            self.printer.cut()
+            self.printer.close()
+            return "Message printed : " + clean_msg
 
     def print_img(self, path):
 
@@ -91,8 +107,11 @@ class Printer(object):
             self.app.logger.warning("File does not exist : " + str(path))
 
         try:
+            self.printer.open(self.usb_args)
             self.printer.image(path)
+            self.printer.close()
         except Exception as e:
+            self.printer.close()
             return e
         else:
             self.app.logging.debug("Printed an image : " + str(path))