From 5aa63e6f5c99895549435580cb3a24567d0948b4 Mon Sep 17 00:00:00 2001
From: Arjan Molenaar <gaphor@gmail.com>
Date: Mon, 6 May 2019 21:20:49 +0200
Subject: [PATCH] Remove zope event handlers from component registry

---
 gaphor/application.py                | 14 --------
 gaphor/core.py                       |  3 +-
 gaphor/services/componentregistry.py | 54 ++++++++++++++++------------
 3 files changed, 34 insertions(+), 37 deletions(-)

diff --git a/gaphor/application.py b/gaphor/application.py
index 047a589fc..5e231da61 100644
--- a/gaphor/application.py
+++ b/gaphor/application.py
@@ -219,17 +219,3 @@ class inject:
         if not obj:
             return self
         return Application.get_service(self._name)
-
-
-def event_handler(event_type):
-    """
-    Mark a function/method as an event handler for a particular type of event.
-    """
-    from zope import component
-
-    def wrapper(func):
-        func.__event_handler__ = event_type
-        component.adapter(event_type)(func)
-        return func
-
-    return wrapper
diff --git a/gaphor/core.py b/gaphor/core.py
index 6104b9a7b..b174a3157 100644
--- a/gaphor/core.py
+++ b/gaphor/core.py
@@ -4,7 +4,8 @@ The Core module provides an entry point for Gaphor's core constructs.
 An average module should only need to import this module.
 """
 
-from gaphor.application import inject, event_handler, Application
+from gaphor.application import inject, Application
+from gaphor.services.componentregistry import event_handler
 from gaphor.transaction import Transaction, transactional
 from gaphor.action import action, toggle_action, radio_action, build_action_group
 from gaphor.i18n import _
diff --git a/gaphor/services/componentregistry.py b/gaphor/services/componentregistry.py
index 3ad3718b0..83a93df31 100644
--- a/gaphor/services/componentregistry.py
+++ b/gaphor/services/componentregistry.py
@@ -1,17 +1,22 @@
 """
-TODO: Move component information (event handling, and other stuff done by
-zope.component) to this service.
-
-Maybe we should split the ComponentRegistry in a Dispatcher (register_handler,
-unregister_handler, handle), a AdapterRegistry and a Subscription registry.
+A registry for components (e.g. services) and event handling.
 """
 
-from zope import component
-
-from zope.interface import registry
-
 from gaphor.abc import Service
 from gaphor.application import ComponentLookupError
+from gaphor.misc.generic.event import Manager
+
+
+def event_handler(*event_types):
+    """
+    Mark a function/method as an event handler for a particular type of event.
+    """
+
+    def wrapper(func):
+        func.__event_types__ = event_types
+        return func
+
+    return wrapper
 
 
 class ComponentRegistry(Service):
@@ -19,13 +24,9 @@ class ComponentRegistry(Service):
     The ComponentRegistry provides a home for application wide components.
     """
 
-    def __init__(self):
-        self._comp = set()
-
     def init(self, app):
-        self._components = registry.Components(
-            name="component_registry", bases=(component.getGlobalSiteManager(),)
-        )
+        self._comp = set()
+        self._events = Manager()
 
     def shutdown(self):
         pass
@@ -57,23 +58,32 @@ class ComponentRegistry(Service):
     def all(self, base):
         return ((c, n) for c, n in self._comp if isinstance(c, base))
 
-    # Wrap zope.component's Components methods
-
-    def register_handler(self, factory, adapts=None):
+    def register_handler(self, handler):
         """
         Register a handler. Handlers are triggered (executed) when specific
         events are emitted through the handle() method.
         """
-        self._components.registerHandler(factory, adapts, event=False)
+        event_types = getattr(handler, "__event_types__", None)
+        if not event_types:
+            raise Exception(f"No event types provided for function {handler}")
 
-    def unregister_handler(self, factory=None, required=None):
+        for et in event_types:
+            self._events.subscribe(handler, et)
+
+    def unregister_handler(self, handler=None, event_types=None):
         """
         Unregister a previously registered handler.
         """
-        self._components.unregisterHandler(factory, required)
+        event_types = getattr(handler, "__event_types__", None)
+        if not event_types:
+            raise Exception(f"No event types provided for function {handler}")
+
+        for et in event_types:
+            self._events.unsubscribe(handler, et)
 
     def handle(self, *events):
         """
         Send event notifications to registered handlers.
         """
-        list(map(self._components.handle, events))
+        for e in events:
+            self._events.fire(e)