Let ElementFactory manage the ElementDispatcher

The dispatcher is only used in model elements and therefore does not need to be available as system wide service.

docs/framework.rst

@@ -59,5 +59,6 @@ element_dispatcher
   elements reaching from the root (e.g. from a diagram item) to the element of
   interest and will only signal in case this element changes.
   This makes complex dispatching very efficient.
+  The dispatcher functionality is available through `Element.watcher()`.
 
 .. autoclass:: gaphor.UML.elementdispatcher.ElementDispatcher

gaphor/UML/element.py

@@ -115,7 +115,8 @@ class Element:
             model.handle(event)
 
     def watcher(self, default_handler=None):
-        return EventWatcher(self, default_handler)
+        dispatcher = self.model.element_dispatcher if self.model else None
+        return EventWatcher(self, dispatcher, default_handler)
 
     # OCL methods: (from SMW by Ivan Porres (http://www.abo.fi/~iporres/smw))
 

gaphor/UML/elementdispatcher.py

@@ -20,10 +20,9 @@ class EventWatcher:
     A helper for easy registering and unregistering event handlers.
     """
 
-    element_dispatcher = inject("element_dispatcher")
-
-    def __init__(self, element, default_handler=None):
+    def __init__(self, element, element_dispatcher, default_handler=None):
         self.element = element
+        self.element_dispatcher = element_dispatcher
         self.default_handler = default_handler
         self._watched_paths = dict()
 

gaphor/UML/elementfactory.py

@@ -6,6 +6,7 @@ from contextlib import contextmanager
 
 from gaphor.UML.diagram import Diagram
 from gaphor.UML.element import Element, UnlinkEvent
+from gaphor.UML.elementdispatcher import ElementDispatcher
 from gaphor.UML.event import (
     ElementChangeEvent,
     ElementCreateEvent,
@@ -33,6 +34,9 @@ class ElementFactory(Service):
 
     def __init__(self, event_manager=None):
         self.event_manager = event_manager
+        self.element_dispatcher = (
+            ElementDispatcher(event_manager) if event_manager else None
+        )
         self._elements = odict.odict()
         self._observers = list()
         self._block_events = 0

gaphor/UML/tests/test_elementdispatcher.py

@@ -216,16 +216,13 @@ A.two = association("two", A, lower=0, upper=2, composite=True)
 
 
 class ElementDispatcherAsServiceTestCase(TestCase):
-
-    services = TestCase.services + ["element_dispatcher"]
-
     def A(self):
         return self.element_factory.create(A)
 
     def setUp(self):
         super(ElementDispatcherAsServiceTestCase, self).setUp()
         self.events = []
-        self.dispatcher = Application.get_service("element_dispatcher")
+        self.dispatcher = self.element_factory.element_dispatcher
 
     def tearDown(self):
         super(ElementDispatcherAsServiceTestCase, self).tearDown()
@@ -324,7 +321,7 @@ class ElementDispatcherAsServiceTestCase(TestCase):
         """
         A = self.A
         a = A()
-        watcher = EventWatcher(a, self._handler)
+        watcher = EventWatcher(a, self.dispatcher, self._handler)
         watcher.watch("one.two.one.two")
         # watcher.watch('one.one.one.one')
         watcher.subscribe_all()
@@ -348,7 +345,7 @@ class ElementDispatcherAsServiceTestCase(TestCase):
         """
         A = self.A
         a = A()
-        watcher = EventWatcher(a, self._handler)
+        watcher = EventWatcher(a, self.dispatcher, self._handler)
         watcher.watch("one.two.one.two")
         # watcher.watch('one.one.one.one')
         watcher.subscribe_all()
@@ -374,7 +371,7 @@ class ElementDispatcherAsServiceTestCase(TestCase):
         """
         A = self.A
         a = A()
-        watcher = EventWatcher(a, self._handler)
+        watcher = EventWatcher(a, self.dispatcher, self._handler)
         watcher.watch("one.two.one.two")
         # watcher.watch('one.one.one.one')
         watcher.subscribe_all()
@@ -402,7 +399,7 @@ class ElementDispatcherAsServiceTestCase(TestCase):
         """
         A = self.A
         a = A()
-        watcher = EventWatcher(a, self._handler)
+        watcher = EventWatcher(a, self.dispatcher, self._handler)
         watcher.watch("one.two.one.two")
         # watcher.watch('one.one.one.one')
         watcher.subscribe_all()

gaphor/application.py

@@ -29,7 +29,7 @@ class ComponentLookupError(LookupError):
     pass
 
 
-_ESSENTIAL_SERVICES = ["component_registry", "event_manager", "element_dispatcher"]
+_ESSENTIAL_SERVICES = ["component_registry", "event_manager"]
 
 
 class _Application:

gaphor/diagram/classes/tests/test_association.py

@@ -12,9 +12,6 @@ from gaphor.diagram.classes.association import AssociationItem
 
 
 class AssociationItemTestCase(TestCase):
-
-    services = TestCase.services + ["element_dispatcher"]
-
     def setUp(self):
         super().setUp()
         self.assoc = self.create(AssociationItem)
@@ -73,7 +70,6 @@ class AssociationItemTestCase(TestCase):
         assert a.subject.memberEnd[1] is a.tail_end.subject
         assert a.subject.memberEnd[0].name is None
 
-        dispatcher = self.get_service("element_dispatcher")
         a.subject.memberEnd[0].name = "blah"
         self.diagram.canvas.update()
 

gaphor/tests/testcase.py

@@ -49,7 +49,7 @@ class TestCaseExtras:
 
 class TestCase(TestCaseExtras, unittest.TestCase):
 
-    services = ["element_factory", "element_dispatcher", "sanitizer"]
+    services = ["element_factory", "sanitizer"]
 
     def setUp(self):
         Application.init(services=self.services)

gaphor/ui/tests/test_diagrampage.py

@@ -11,13 +11,7 @@ from gaphor.ui.mainwindow import DiagramPage
 class DiagramPageTestCase(unittest.TestCase):
     def setUp(self):
         Application.init(
-            services=[
-                "element_factory",
-                "main_window",
-                "action_manager",
-                "properties",
-                "element_dispatcher",
-            ]
+            services=["element_factory", "main_window", "action_manager", "properties"]
         )
         main_window = Application.get_service("main_window")
         main_window.open()

gaphor/ui/tests/test_diagramtoolbox.py

@@ -16,7 +16,7 @@ class WindowOwner:
 
 class DiagramToolboxTestCase(TestCase):
 
-    services = ["element_factory", "properties", "element_dispatcher"]
+    services = ["element_factory", "properties"]
 
     def setUp(self):
         TestCase.setUp(self)

gaphor/ui/tests/test_handletool.py

@@ -28,7 +28,6 @@ class DiagramItemConnectorTestCase(unittest.TestCase):
                 "properties_manager",
                 "action_manager",
                 "properties",
-                "element_dispatcher",
             ]
         )
         self.main_window = Application.get_service("main_window")
@@ -77,7 +76,6 @@ class HandleToolTestCase(unittest.TestCase):
                 "properties_manager",
                 "action_manager",
                 "properties",
-                "element_dispatcher",
             ]
         )
         self.component_registry = Application.get_service("component_registry")

pyproject.toml

@@ -62,7 +62,6 @@ gaphorconvert = 'gaphor.tools.gaphorconvert:main'
 "main_window" = "gaphor.ui.mainwindow:MainWindow"
 "copy" = "gaphor.services.copyservice:CopyService"
 "sanitizer" = "gaphor.services.sanitizerservice:SanitizerService"
-"element_dispatcher" = "gaphor.UML.elementdispatcher:ElementDispatcher"
 "xmi_export" = "gaphor.plugins.xmiexport:XMIExport"
 "diagram_layout" = "gaphor.plugins.diagramlayout:DiagramLayout"
 "pynsource" = "gaphor.plugins.pynsource:PyNSource"

setup.py

@@ -113,7 +113,6 @@ setup(
             "main_window = gaphor.ui.mainwindow:MainWindow",
             "copy = gaphor.services.copyservice:CopyService",
             "sanitizer = gaphor.services.sanitizerservice:SanitizerService",
-            "element_dispatcher = gaphor.UML.elementdispatcher:ElementDispatcher",
             "xmi_export = gaphor.plugins.xmiexport:XMIExport",
             "diagram_layout = gaphor.plugins.diagramlayout:DiagramLayout",
             "pynsource = gaphor.plugins.pynsource:PyNSource",