Implement Port.alias() property. (#45)

Author: jofemodo

examples/aliases.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+
+"""Create a JACK client and test port-alias functionality.
+
+This client test the 3 functions related with port-aliases
+
+"""
+
+import jack
+
+print("starting TestAlias client")
+
+client = jack.Client('TestAlias')
+
+if client.status.server_started:
+    print("JACK server was started")
+else:
+    print("JACK server was already running")
+    if client.status.name_not_unique:
+        print("unique client name generated: {}".format(client.name))
+
+ports = client.get_ports()
+
+print("Testing set_alias() ...")
+for i, port in enumerate(ports):
+    alias_name = "Alias Name {}".format(i)
+    print("port '{}' => set_alias('{}')".format(port.shortname,alias_name))
+    port.set_alias(alias_name)
+
+print('Testing aliases property ...')
+for port in ports:
+    for i, alias in enumerate(port.aliases):
+        print("port '{}', alias {} => '{}'".format(port.shortname,i,alias))
+
+print('Testing unset_alias() ...')
+for i, port in enumerate(ports):
+    alias_name = "Alias Name {}".format(i)
+    print("port '{}' => unset_alias('{}')".format(port.shortname,alias_name))
+    port.unset_alias(alias_name)
+
+print('Testing aliases property ...')
+for port in ports:
+    for i, alias in enumerate(port.aliases):
+        print("port '{}', alias {} => '{}'".format(port.shortname,i,alias))

jack_build.py

@@ -141,9 +141,9 @@
 /* deprecated: jack_port_tie */
 /* deprecated: jack_port_untie */
 int jack_port_set_name(jack_port_t* port, const char* port_name);
-/* TODO: jack_port_set_alias */
-/* TODO: jack_port_unset_alias */
-/* TODO: jack_port_get_aliases */
+int jack_port_set_alias(jack_port_t *port, const char *alias);
+int jack_port_unset_alias(jack_port_t *port, const char *alias);
+int jack_port_get_aliases(const jack_port_t * port, char *const aliases[2]);
 int jack_port_request_monitor(jack_port_t *port, int onoff);
 /* not implemented (use jack_port_request_monitor): jack_port_request_monitor_by_name */
 /* TODO: jack_port_ensure_monitor */

src/jack.py

@@ -1445,6 +1445,40 @@ def shortname(self, shortname):
         _check(_lib.jack_port_set_name(self._ptr, shortname.encode()),
                'Error setting port name')
 
+    @property
+    def aliases(self):
+        """Returns a list of strings with the aliases for the JACK port."""
+        ctype = "char[{}]".format(_lib.jack_port_name_size())
+        aliases = [_ffi.new(ctype), _ffi.new(ctype)]
+        aliasesptr = _ffi.new("char *[]", aliases)
+        result = []
+        if _lib.jack_port_get_aliases(self._ptr, aliasesptr) > 0:
+            for i in 0, 1:
+                alias = _ffi.string(aliases[i]).decode()
+                if alias:
+                    result.append(alias)
+
+        return result
+
+    def set_alias(self, alias):
+        """Set an alias for the JACK port.
+
+        Ports can have up to two aliases. If both are already set,
+        this function will return an error.
+
+        """
+        _check(_lib.jack_port_set_alias(self._ptr, alias.encode()),
+               'Error setting port alias')
+
+    def unset_alias(self, alias):
+        """Remove an alias for the JACK port.
+        
+        If the alias doesn't exist this function will return an error.
+
+        """
+        _check(_lib.jack_port_unset_alias(self._ptr, alias.encode()),
+               'Error unsetting port alias')
+
     @property
     def uuid(self):
         """The UUID of the JACK port."""
@@ -2427,6 +2461,7 @@ def callback_wrapper(msg):
         _keepalive[setter] = callback_wrapper
     setter(callback_wrapper)
 
+
 _keepalive = {}