added to draft: minimal example for exposing classes and methods using decorators

draft/decorator_example.py

@@ -0,0 +1,151 @@
+### decorator code
+
+class SequencerObjectManager:
+
+    def __init__(self):
+        self.objects = []
+
+    def register(self, obj):
+        self.objects.append(obj)
+
+
+sequencer_object_manager = SequencerObjectManager()
+
+
+def expose(method):
+    method._exposed = True
+    return method
+
+
+def expose_to_sequencer(manager):
+
+    def decorator(cls):
+
+        decorator_exposed_methods = [
+            name for name in cls.__dict__
+            if getattr(getattr(cls, name), "_exposed", False)
+            # default False if attr _exposed not present
+        ]
+
+        if hasattr(cls, 'exposed_methods'):
+            for name in decorator_exposed_methods:
+                if name not in cls.exposed_methods:
+                    cls.exposed_methods.append(name)
+        else:
+            cls.exposed_methods = decorator_exposed_methods
+
+        original_init = cls.__init__
+
+        def __init__(self, *args, **kwargs):
+            original_init(self, *args, **kwargs)
+            manager.register(self)
+
+        cls.__init__ = __init__
+        return cls
+
+    return decorator
+
+
+### examples and testing
+
+# class written for the sequencer
+@expose_to_sequencer(sequencer_object_manager)
+class ExposedClassA:
+
+    exposed_methods = ['method_a', 'method_b']
+
+    def __init__(self, name):
+        self.name = name
+
+    def method_a(self):
+        pass
+
+    def method_b(self):
+        pass
+
+    def method_c(self):
+        pass
+
+    def method_d(self):
+        pass
+
+
+# also written for the sequencer, but with method decorator approach
+@expose_to_sequencer(sequencer_object_manager)
+class ExposedClassB:
+
+    def __init__(self, name):
+        self.name = name
+
+    @expose
+    def method_a(self):
+        pass
+
+    def method_b(self):
+        pass
+
+    @expose
+    def method_c(self):
+        pass
+
+    def method_d(self):
+        pass
+
+
+# also written for the sequencer, mixing both approaches because @expose is not
+# compatible with @property (and possibly other decorators)
+@expose_to_sequencer(sequencer_object_manager)
+class ExposedClassC:
+
+    exposed_methods = ['method_b']
+
+    def __init__(self, name):
+        self.name = name
+
+    @expose
+    def method_a(self):
+        pass
+
+    @property
+    def method_b(self):
+        return "something"
+
+    def method_c(self):
+        pass
+
+    def method_d(self):
+        pass
+
+
+# some PyMoDAQ class to be exposed to the sequencer without modifying the class
+class OriginalClass:
+
+    def __init__(self, name):
+        self.name = name
+
+    def method_a(self):
+        pass
+
+    def method_b(self):
+        pass
+
+    def method_c(self):
+        pass
+
+    def method_d(self):
+        pass
+
+
+
+@expose_to_sequencer(sequencer_object_manager)
+class ExposedOriginalClass(OriginalClass):
+    exposed_methods = ['method_c', 'method_d']
+
+
+inst1 = ExposedClassA("With Dict")
+inst2 = ExposedClassB("With Decorator")
+inst2 = ExposedClassC("Mixed")
+inst3 = ExposedOriginalClass("Derived Class")
+
+print([f'{o.name}: {o.exposed_methods}'
+       for o in sequencer_object_manager.objects])