Merge pull request #2433 from cvwillegen/command-action-property

Implement property for Command.action.

changes/2433.feature.rst

@@ -0,0 +1 @@
+An action for a Toga command can now be easily modified after initial construction.

core/src/toga/command.py

@@ -203,7 +203,7 @@ def __init__(
         self.section = section
         self.order = order
 
-        self.action = wrapped_handler(self, action)
+        self.action = action
 
         self.factory = get_platform_factory()
         self._impl = self.factory.Command(interface=self)
@@ -244,6 +244,19 @@ def icon(self, icon_or_name: IconContent | None):
         else:
             self._icon = Icon(icon_or_name)
 
+    @property
+    def action(self) -> ActionHandler | None:
+        """The Action attached to the command."""
+        return self._action
+
+    @action.setter
+    def action(self, action: ActionHandler | None):
+        """Set the action attached to the command
+
+        Needs to be a valid ActionHandler or ``None``
+        """
+        self._action = wrapped_handler(self, action)
+
     def __lt__(self, other: Any) -> bool:
         if not isinstance(other, (Group, Command)):
             return False

core/tests/command/test_command.py

@@ -63,6 +63,31 @@ def test_create():
     )
 
 
+def test_change_action():
+    """A command's action can be changed to another handler"""
+    action1 = Mock()
+
+    cmd = toga.Command(action1, "Test command")
+
+    assert cmd.text == "Test command"
+    assert cmd.shortcut is None
+    assert cmd.tooltip is None
+    assert cmd.group == toga.Group.COMMANDS
+    assert cmd.section == 0
+    assert cmd.order == 0
+    assert cmd.action._raw == action1
+
+    # Change the action to a something new
+    action2 = Mock()
+    cmd.action = action2
+
+    assert cmd.action._raw == action2
+
+    # Clear the action
+    cmd.action = None
+    assert cmd.action._raw is None
+
+
 def test_create_explicit(app):
     """A command can be created with explicit arguments"""
     grp = toga.Group("Test group", order=10)