Convert dynamic on_trait_change to observe part 2

docs/source/timer.rst

@@ -165,16 +165,21 @@ EventTimer
 Another common use case is that you want a Traits Event to be fired
 periodically or at some future time.  This permits many possible listeners
 to be called from the same timer, and have them be turned on and turned off
-dynamically, if desired.  The :py:class:`~pyface.timer.timer.EventTimer`
-provides this functionality via its
-:py:class:`~pyface.timer.timer.EventTimer.timeout` event trait.
+dynamically, if desired, via
+`Traits' observe <https://docs.enthought.com/traits/traits_user_manual/notification.html>`_
+(note that observe listeners are required to take a single event argument).
+The :py:class:`~pyface.timer.timer.EventTimer` provides this functionality via
+its :py:class:`~pyface.timer.timer.EventTimer.timeout` event trait.
 
 .. code-block:: python
 
     from pyface.timer.api import EventTimer
 
+    def print_time(event):
+        print("The time is {}".format(datetime.datetime.now()))
+
     timer = EventTimer(interval=0.5, expire=60)
-    timer.on_trait_change(print_time, 'timeout')
+    timer.observe(print_time, 'timeout')
 
     timer.start()
 

pyface/action/listening_action.py

@@ -17,6 +17,7 @@
 
 from pyface.action.action import Action
 from traits.api import Any, Str
+from traits.observation.api import trait
 
 # Logging.
 logger = logging.getLogger(__name__)
@@ -55,11 +56,15 @@ def destroy(self):
         """
 
         if self.object:
-            self.object.on_trait_change(
-                self._enabled_update, self.enabled_name, remove=True
+            self.object.observe(
+                self._enabled_update,
+                trait(self.enabled_name, optional=True),
+                remove=True
             )
-            self.object.on_trait_change(
-                self._visible_update, self.visible_name, remove=True
+            self.object.observe(
+                self._visible_update,
+                trait(self.visible_name, optional=True),
+                remove=True
             )
 
     def perform(self, event=None):
@@ -102,32 +107,31 @@ def _enabled_name_changed(self, old, new):
         obj = self.object
         if obj is not None:
             if old:
-                obj.on_trait_change(self._enabled_update, old, remove=True)
+                obj.observe(self._enabled_update, old, remove=True)
             if new:
-                obj.on_trait_change(self._enabled_update, new)
+                obj.observe(self._enabled_update, new)
         self._enabled_update()
 
     def _visible_name_changed(self, old, new):
         obj = self.object
         if obj is not None:
             if old:
-                obj.on_trait_change(self._visible_update, old, remove=True)
+                obj.observe(self._visible_update, old, remove=True)
             if new:
-                obj.on_trait_change(self._visible_update, new)
+                obj.observe(self._visible_update, new)
         self._visible_update()
 
     def _object_changed(self, old, new):
         for kind in ("enabled", "visible"):
             method = getattr(self, "_%s_update" % kind)
             name = getattr(self, "%s_name" % kind)
-            if name:
-                if old:
-                    old.on_trait_change(method, name, remove=True)
-                if new:
-                    new.on_trait_change(method, name)
+            if old:
+                old.observe(method, trait(name, optional=True), remove=True)
+            if new:
+                new.observe(method, trait(name, optional=True))
             method()
 
-    def _enabled_update(self):
+    def _enabled_update(self, event=None):
         if self.enabled_name:
             if self.object:
                 self.enabled = bool(
@@ -138,7 +142,7 @@ def _enabled_update(self):
         else:
             self.enabled = bool(self.object)
 
-    def _visible_update(self):
+    def _visible_update(self, event=None):
         if self.visible_name:
             if self.object:
                 self.visible = bool(

pyface/fields/i_combo_field.py

@@ -69,8 +69,8 @@ def _initialize_control(self):
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super(MComboField, self)._add_event_listeners()
-        self.on_trait_change(
-            self._values_updated, "values[],formatter", dispatch="ui"
+        self.observe(
+            self._values_updated, "values.items,formatter", dispatch="ui"
         )
         if self.control is not None:
             self._observe_control_value()
@@ -79,9 +79,9 @@ def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
         if self.control is not None:
             self._observe_control_value(remove=True)
-        self.on_trait_change(
+        self.observe(
             self._values_updated,
-            "values[],formatter",
+            "values.items,formatter",
             dispatch="ui",
             remove=True,
         )
@@ -99,6 +99,6 @@ def _set_control_values(self, values):
 
     # Trait change handlers --------------------------------------------------
 
-    def _values_updated(self):
+    def _values_updated(self, event):
         if self.control is not None:
             self._set_control_values(self.values)

pyface/fields/i_field.py

@@ -58,9 +58,9 @@ class MField(HasTraits):
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super(MField, self)._add_event_listeners()
-        self.on_trait_change(self._value_updated, "value", dispatch="ui")
-        self.on_trait_change(self._tooltip_updated, "tooltip", dispatch="ui")
-        self.on_trait_change(
+        self.observe(self._value_updated, "value", dispatch="ui")
+        self.observe(self._tooltip_updated, "tooltip", dispatch="ui")
+        self.observe(
             self._context_menu_updated, "context_menu", dispatch="ui"
         )
         if self.control is not None and self.context_menu is not None:
@@ -70,13 +70,13 @@ def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
         if self.control is not None and self.context_menu is not None:
             self._observe_control_context_menu(remove=True)
-        self.on_trait_change(
+        self.observe(
             self._value_updated, "value", dispatch="ui", remove=True
         )
-        self.on_trait_change(
+        self.observe(
             self._tooltip_updated, "tooltip", dispatch="ui", remove=True
         )
-        self.on_trait_change(
+        self.observe(
             self._context_menu_updated,
             "context_menu",
             dispatch="ui",
@@ -160,17 +160,20 @@ def _handle_control_context_menu(self, event):
 
     # Trait change handlers -------------------------------------------------
 
-    def _value_updated(self, value):
+    def _value_updated(self, event):
+        value = event.new
         if self.control is not None:
             self._set_control_value(value)
 
-    def _tooltip_updated(self, tooltip):
+    def _tooltip_updated(self, event):
+        tooltip = event.new
         if self.control is not None:
             self._set_control_tooltip(tooltip)
 
-    def _context_menu_updated(self, old, new):
+    def _context_menu_updated(self, event):
+
         if self.control is not None:
-            if new is None:
+            if event.new is None:
                 self._observe_control_context_menu(remove=True)
-            if old is None:
+            if event.old is None:
                 self._observe_control_context_menu()

pyface/fields/i_spin_field.py

@@ -73,15 +73,15 @@ def _initialize_control(self):
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super(MSpinField, self)._add_event_listeners()
-        self.on_trait_change(self._bounds_updated, "bounds", dispatch="ui")
+        self.observe(self._bounds_updated, "bounds", dispatch="ui")
         if self.control is not None:
             self._observe_control_value()
 
     def _remove_event_listeners(self):
         """ Remove toolkit-specific bindings for events """
         if self.control is not None:
             self._observe_control_value(remove=True)
-        self.on_trait_change(
+        self.observe(
             self._bounds_updated, "bounds", dispatch="ui", remove=True
         )
         super(MSpinField, self)._remove_event_listeners()
@@ -127,6 +127,6 @@ def _value_default(self):
 
     # Trait change handlers --------------------------------------------------
 
-    def _bounds_updated(self):
+    def _bounds_updated(self, event):
         if self.control is not None:
             self._set_control_bounds(self.bounds)

pyface/fields/i_text_field.py

@@ -68,16 +68,10 @@ def _initialize_control(self):
     def _add_event_listeners(self):
         """ Set up toolkit-specific bindings for events """
         super(MTextField, self)._add_event_listeners()
-        self.on_trait_change(
-            self._update_text_updated, "update_text", dispatch="ui"
-        )
-        self.on_trait_change(
-            self._placeholder_updated, "placeholder", dispatch="ui"
-        )
-        self.on_trait_change(self._echo_updated, "echo", dispatch="ui")
-        self.on_trait_change(
-            self._read_only_updated, "read_only", dispatch="ui"
-        )
+        self.observe(self._update_text_updated, "update_text", dispatch="ui")
+        self.observe(self._placeholder_updated, "placeholder", dispatch="ui")
+        self.observe(self._echo_updated, "echo", dispatch="ui")
+        self.observe(self._read_only_updated, "read_only", dispatch="ui")
         if self.control is not None:
             if self.update_text == "editing_finished":
                 self._observe_control_editing_finished()
@@ -91,22 +85,22 @@ def _remove_event_listeners(self):
                 self._observe_control_editing_finished(remove=True)
             else:
                 self._observe_control_value(remove=True)
-        self.on_trait_change(
+        self.observe(
             self._update_text_updated,
             "update_text",
             dispatch="ui",
             remove=True,
         )
-        self.on_trait_change(
+        self.observe(
             self._placeholder_updated,
             "placeholder",
             dispatch="ui",
             remove=True,
         )
-        self.on_trait_change(
+        self.observe(
             self._echo_updated, "echo", dispatch="ui", remove=True
         )
-        self.on_trait_change(
+        self.observe(
             self._read_only_updated, "read_only", dispatch="ui", remove=True
         )
         super(MTextField, self)._remove_event_listeners()
@@ -148,22 +142,22 @@ def _observe_control_editing_finished(self, remove=False):
 
     # Trait change handlers --------------------------------------------------
 
-    def _placeholder_updated(self):
+    def _placeholder_updated(self, event):
         if self.control is not None:
             self._set_control_placeholder(self.placeholder)
 
-    def _echo_updated(self):
+    def _echo_updated(self, event):
         if self.control is not None:
             self._set_control_echo(self.echo)
 
-    def _read_only_updated(self):
+    def _read_only_updated(self, event):
         if self.control is not None:
             self._set_control_read_only(self.read_only)
 
-    def _update_text_updated(self, new):
+    def _update_text_updated(self, event):
         """ Change how we listen to for updates to text value. """
         if self.control is not None:
-            if new == "editing_finished":
+            if event.new == "editing_finished":
                 self._observe_control_value(remove=True)
                 self._observe_control_editing_finished()
             else: