add a stupid shell to interface with a scanner

scanner/main.py

@@ -0,0 +1,149 @@
+from queue import Queue
+from threading import Thread
+from threading import Event
+from time import sleep
+import sane
+from PIL import Image
+import sys
+import os
+import select
+import cv2
+import subprocess
+
+def is_there_line():
+    # Check if there is any data available to be read from stdin
+    if select.select([sys.stdin], [], [], 0)[0]:
+        # Read the next line from stdin
+        return sys.stdin.readline().rstrip('\n')
+    else:
+        return None
+
+class Message:
+    def __init__(self, message, payload):
+        self.message = message
+        self.payload = payload
+
+def interface_thread(i, o):
+    queue = []
+    processing = []
+    scanned = []
+    scanners = []
+    print("<{}>$ ".format(os.getcwd()), end="")
+    sys.stdout.flush()
+    while True:
+        line = is_there_line()
+        if line:
+            # parse the line of input
+            splitted = line.split(' ')
+            if splitted[0] == "queue":
+                if splitted[1] == "add":
+                    if splitted[2]:
+                        if splitted[2][0] != "/":
+                            enqueued = os.path.join(os.getcwd(), splitted[2])
+                        else:
+                            enqueued = splitted[2]
+                        queue.append(enqueued)
+                        print("queued file {}".format(enqueued))
+                    else:
+                        print("specify a file!")
+            elif splitted[0] == "send":
+                print("sending {} to scanner for scanning".format(queue[0]))
+                payload = {
+                        'save_location': queue.pop(0),
+                }
+                message = Message("scan_request", payload)
+                o.put(message)
+            elif splitted[0] == "cd":
+                try:
+                    os.chdir(splitted[1])
+                except IndexError:
+                    os.chdir("/home/usr")
+            elif splitted[0] == "mkdir":
+                os.mkdir(splitted[1])
+            elif splitted[0] == "ls":
+                files = os.listdir()
+                print(files)
+            elif splitted[0] == "feh":
+                subprocess.Popen(["feh", splitted[1]])
+            elif splitted[0] == "scannerlist":
+                o.put(Message("list_scanners", None))
+                data = i.get()
+                if data.message == "list_scanners_resp":
+                    scanners = data.payload["scanner_names"]
+                for x in scanners:
+                    print(x)
+                i.task_done()
+            elif splitted[0] == "setscanner":
+                payload = {
+                        "scanner_name": splitted[1],
+                }
+                message = Message("set_scanner", payload)
+                o.put(message)
+            elif splitted[0] == "sendpredef":
+                o.put(Message("sendpredef", None))
+            elif splitted[0] == "help":
+                print("""help: commands -
+queue:
+    add: add an item to the queue
+send: send the first item on the queue to be scanned
+cd: change directories
+mkdir: make a directory
+ls: list files in directory
+feh: open image viewer
+scannerlist: list scanners connected
+setscanner: set the scanner as the selected scanner
+sendpredef: set the scanner to some predefined settings""")
+
+            print("<{}>$ ".format(os.getcwd()), end="")
+            sys.stdout.flush()
+
+
+def scanner_backend(i, o):
+    sane.init()
+    scanner = None
+    while True:
+        # Get some data
+        data = i.get()
+        if data.message == "scan_request":
+            save_location = data.payload['save_location']
+            if scanner:
+                print("recieved scan_request with {}".format(save_location))
+            else:
+                print("configure a scanner first")
+                i.task_done()
+                continue
+
+            image = scanner.scan()
+            image.save(data.payload["save_location"])
+
+            i.task_done()
+        elif data.message == "list_scanners":
+            devs = sane.get_devices()
+            payload = {
+                    'scanner_names': [x[0] for x in devs],
+            }
+            message = Message("list_scanners_resp", payload)
+            o.put(message)
+            i.task_done()
+        elif data.message == "set_scanner":
+            scanner = sane.open(data.payload["scanner_name"])
+            i.task_done()
+        elif data.message == "sendpredef":
+            # configure the scanner in these predefined ways
+            scanner.resolution = 200
+            scanner.br_x = 320
+            scanner.br_y = 320
+            scanner.calibration_cache = 1
+            i.task_done()
+
+# Create the shared queue and launch both threads
+def main():
+    interface_queue, scanner_queue = Queue(), Queue()
+    threads = [
+            Thread(target=interface_thread, args=(interface_queue, scanner_queue)),
+            Thread(target=scanner_backend, args=(scanner_queue, interface_queue)),
+    ]
+    [ i.start() for i in threads ]
+
+if __name__ == "__main__":
+    main()