p2p_connector.wifi_direct_socket

  1"""
  2This module provides an abstract class for implementing a TCP server socket, which can be used to implement an
  3application which is communicating with an android phone using WIFI-direct.
  4"""
  5import socket
  6import threading
  7from abc import ABC, abstractmethod
  8from _socket import timeout
  9
 10
 11class WifiDirectSocket(ABC):
 12    """
 13    This abstract class can be used as parent class for implementing an application which can communicate with an
 14    Android phone using WIFI-direct.
 15    """
 16    connection: socket
 17    receive_messages_thread: threading.Thread
 18    run_receiving_thread: bool = False
 19
 20    def __init__(self, host: str, port: int):
 21        """
 22        constructor
 23        @param host: IP-address/hostname for the server socket
 24        @param port: port of the server socket
 25        """
 26        self.host: str = host
 27        self.port: int = port
 28
 29    def start_server_socket(self):
 30        """
 31        Initializes the server socket and waits for an incoming connection. After connection to a client was
 32        established the private method '__start_receive_thread' is called. This method starts a new thread which
 33        listens for incoming messages. If message was received the abstract method 'on_receive_message' will be called.
 34        """
 35        server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 36        server_socket.bind((self.host, self.port))
 37        server_socket.listen()
 38        self.connection, addr = server_socket.accept()
 39        self.connection.settimeout(1.0)
 40        print(f'client connected: {addr}')
 41        self.__start_receive_thread()
 42
 43    def __start_receive_thread(self):
 44        """
 45        Starts a new thread which is waiting for incoming messages. The method is called by 'start_server_socket'.
 46        """
 47        self.run_receiving_thread = True
 48        self.__check_connection()
 49        self.on_client_connected()
 50
 51        def receive_loop():
 52            while self.run_receiving_thread:
 53                try:
 54                    data: bytes = self.connection.recv(1024)
 55                    if not data:
 56                        self.on_client_disconnected()
 57                        return
 58                    else:
 59                        print(data)
 60                        self.on_receive_message(data)
 61                except timeout:
 62                    continue
 63
 64        self.receive_messages_thread = threading.Thread(target=receive_loop)
 65        self.receive_messages_thread.start()
 66
 67    def send_message_to_client(self, message: bytes):
 68        """
 69        Sends a message to the client which is connected to the server-socket provided by this application.
 70        @param message: message which should be sent to the client (bytes)
 71        """
 72        self.__check_connection()
 73        self.connection.send(message)
 74
 75    def __check_connection(self):
 76        """
 77        Checks whether a client is already connected to the server-socket
 78        @raise ConnectionError: raises a ConnectionError if no client is connected
 79        """
 80
 81    def stop_receive_thread(self):
 82        """
 83        Stops the thread which is receiving incoming messages.
 84        """
 85        self.run_receiving_thread = False
 86        self.receive_messages_thread.join()
 87
 88    @abstractmethod
 89    def on_receive_message(self, message: bytes):
 90        """
 91        Is called when a new message was received.
 92        @param message: received message (bytes)
 93        """
 94
 95    @abstractmethod
 96    def on_client_connected(self):
 97        """
 98        Is called when a client has connected to the server socket.
 99        """
100
101    @abstractmethod
102    def on_client_disconnected(self):
103        """
104        is called if the client has been disconnected from the server socket.
105        """