Inheritable Method Callbacks

examples/more_pythonic_client.py

@@ -0,0 +1,140 @@
+#!/usr/bin/env python3
+
+"""Create a JACK client that prints a lot of information with methods.
+
+This client is like chatty_client in functionality but also defines a class
+which has a lot of overridable methods (instead of using set_*_callback
+all the time).
+
+"""
+import jack
+
+class PythonicClient(jack.Client):
+    def __init__(self, name, method_callbacks=True, *args, **kwargs):
+        super().__init__(name, *args, **kwargs)
+        if method_callbacks:
+            self.set_method_callbacks()
+
+    def set_method_callbacks(self):
+        # NOTE: these are actually jack lib global, if one instanciates more
+        # than one clients, only the last one's methods will get these called
+        jack.set_error_function(self.error_function)
+        jack.set_info_function(self.info_function)
+
+        # per jack client instance callbacks
+        self.set_blocksize_callback(self.on_blocksize_change)
+        self.set_client_registration_callback(self.on_client_registration)
+        self.set_freewheel_callback(self.on_freewheel_change)
+        self.set_graph_order_callback(self.on_graph_order_change)
+        self.set_port_connect_callback(self.on_port_connect)
+        self.set_port_registration_callback(self.on_port_registration)
+        self.set_port_rename_callback(self.on_port_rename)
+        self.set_process_callback(self.process)
+        self.set_samplerate_callback(self.on_samplerate_change)
+        self.set_shutdown_callback(self.on_shutdown)
+        self.set_xrun_callback(self.on_xrun)
+
+    def error_function(self, message):
+        print("Jack Error:", message)
+
+    def info_function(self, message):
+        print("Jack Info:", message)
+
+    def on_blocksize_change(self, blocksize):
+        pass
+
+    def on_client_registration(self, name, register):
+        pass
+
+    def on_freewheel_change(self, starting):
+        pass
+
+    def on_graph_order_change(self):
+        pass
+
+    def on_port_connect(self, a, b, connect):
+        pass
+
+    def on_port_registration(self, port, register):
+        pass
+
+    def on_port_rename(self, port, old, new):
+        pass
+
+    def process(self, frames):
+        pass
+
+    def on_samplerate_change(self, samplerate):
+        pass
+
+    def on_shutdown(self, status, reason):
+        pass
+
+    def on_xrun(self, delayed_usecs):
+        pass
+
+class ChattyClient(PythonicClient):
+    def __init__(self, name="Chatty-Client", *args, **kwargs):
+        print("starting chatty client")
+        super().__init__(name, method_callbacks=False, *args, **kwargs)
+
+        if self.status.server_started:
+            print("JACK server was started")
+        else:
+            print("JACK server was already running")
+        if self.status.name_not_unique:
+            print("unique client name generated:", self.name)
+
+        print("setting error/info functions and registering callbacks")
+        self.set_method_callbacks()
+
+    def error_function(self, msg):
+        print("Error:", msg)
+
+    def info_function(self, msg):
+        print("Info:", msg)
+
+    def on_shutdown(self, status, reason):
+        print("JACK shutdown!")
+        print("status:", status)
+        print("reason:", reason)
+
+    def on_freewheel_change(self, starting):
+        print(["stopping", "starting"][starting], "freewheel mode")
+
+    def on_blocksize_change(self, blocksize):
+        print("blocksize changed to", blocksize)
+
+    def on_samplerate_change(self, samplerate):
+        print("samplerate changed to", samplerate)
+
+    def on_client_registration(self, name, register):
+        print("client", repr(name), ["unregistered", "registered"][register])
+
+    def on_port_connect(self, a, b, connect):
+        print(["disconnected", "connected"][connect], a, "and", b)
+
+    def on_port_registration(self, port, register):
+        print(repr(port), ["unregistered", "registered"][register])
+
+    def on_port_rename(self, port, old, new):
+        print("renamed", port, "from", repr(old), "to", repr(new))
+
+    def on_graph_order_change(self):
+        print("graph order change")
+
+    def on_xrun(self, delayed_usecs):
+        print("xrun; delay", delayed_usecs, "microseconds")
+
+    def activate(self):
+        print("activating JACK")
+        super().activate()
+
+client = ChattyClient("Chatty-Client")
+
+with client:
+    print("#" * 80)
+    print("press Return to quit")
+    print("#" * 80)
+    input()
+    print("closing JACK")