Merge pull request #5159 from TomJGooding/feat-events-add-control-property-to-enter-and-leave

feat(events): add control property to Enter and Leave

Author: willmcgugan

CHANGELOG.md

@@ -5,7 +5,6 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
-
 ## Unreleased
 
 ### Changed
@@ -29,6 +28,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - Added new demo `python -m textual`, not *quite* finished but better than the old one https://github.com/Textualize/textual/pull/5174
 - Added `Screen.can_view_partial` and `Widget.can_view_partial` https://github.com/Textualize/textual/pull/5174
 - Added `App.is_web` property to indicate if the app is running via a web browser https://github.com/Textualize/textual/pull/5128
+- `Enter` and `Leave` events can now be used with the `on` decorator https://github.com/Textualize/textual/pull/5159
 
 ### Fixed
 

src/textual/events.py

@@ -572,6 +572,11 @@ def __init__(self, node: DOMNode) -> None:
         """The node directly under the mouse."""
         super().__init__()
 
+    @property
+    def control(self) -> DOMNode:
+        """Alias for the `node` under the mouse."""
+        return self.node
+
 
 class Leave(Event, bubble=True, verbose=True):
     """Sent when the mouse is moved away from a widget, or if a widget is
@@ -592,6 +597,11 @@ def __init__(self, node: DOMNode) -> None:
         """The node that was previously directly under the mouse."""
         super().__init__()
 
+    @property
+    def control(self) -> DOMNode:
+        """Alias for the `node` that was previously under the mouse."""
+        return self.node
+
 
 class Focus(Event, bubble=False):
     """Sent when a widget is focussed.

tests/test_on.py

@@ -7,6 +7,7 @@
 from textual import on
 from textual._on import OnDecoratorError
 from textual.app import App, ComposeResult
+from textual.events import Enter, Leave
 from textual.message import Message
 from textual.widget import Widget
 from textual.widgets import Button, TabbedContent, TabPane
@@ -352,3 +353,28 @@ def on_mount(self) -> None:
         pass
 
     assert posted == ["parent", "child", "parent"]
+
+
+async def test_on_with_enter_and_leave_events():
+    class EnterLeaveApp(App):
+        messages = []
+
+        def compose(self) -> ComposeResult:
+            yield Button("OK")
+
+        @on(Enter, "Button")
+        @on(Leave, "Button")
+        def record(self, event: Enter | Leave) -> None:
+            self.messages.append(event.__class__.__name__)
+
+    app = EnterLeaveApp()
+    async with app.run_test() as pilot:
+        expected_messages = []
+
+        await pilot.hover(Button)
+        expected_messages.append("Enter")
+        assert app.messages == expected_messages
+
+        await pilot.hover(Button, offset=(0, 20))
+        expected_messages.append("Leave")
+        assert app.messages == expected_messages