Loading indicator (#2018)

* loading indicator and tests

* docs

* snapshot

* remove snapshot

* remove debug main [skip ci]

* changelog [skip ci]

* make start time private

docs/api/loading_indicator.md

@@ -0,0 +1 @@
+::: textual.widgets.LoadingIndicator

docs/examples/widgets/loading_indicator.py

@@ -0,0 +1,12 @@
+from textual.app import App, ComposeResult
+from textual.widgets import LoadingIndicator
+
+
+class LoadingApp(App):
+    def compose(self) -> ComposeResult:
+        yield LoadingIndicator()
+
+
+if __name__ == "__main__":
+    app = LoadingApp()
+    app.run()

docs/widget_gallery.md

@@ -109,6 +109,15 @@ Display a list of items (items may be other widgets).
 ```{.textual path="docs/examples/widgets/list_view.py"}
 ```
 
+## LoadingIndicator
+
+Display an animation while data is loading.
+
+[LoadingIndicator reference](./widgets/loading_indicator.md){ .md-button .md-button--primary }
+
+```{.textual path="docs/examples/widgets/loading_indicator.py"}
+```
+
 ## MarkdownViewer
 
 Display and interact with a Markdown document (adds a table of contents and browser-like navigation to Markdown).

docs/widgets/loading_indicator.md

@@ -0,0 +1,24 @@
+# LoadingIndicator
+
+Displays pulsating dots to indicate when data is being loaded.
+
+- [ ] Focusable
+- [ ] Container
+
+
+=== "Output"
+
+    ```{.textual path="docs/examples/widgets/loading_indicator.py"}
+    ```
+
+=== "loading_indicator.py"
+
+    ```python
+    --8<-- "docs/examples/widgets/loading_indicator.py"
+    ```
+
+
+
+## See Also
+
+* [LoadingIndicator](../api/loading_indicator.md) code reference