Add an animation to the LSP checking indicator (#9463)

Spinner go spinny.

Extra thanks to @kvark for helping me with the shaders.



https://github.com/zed-industries/zed/assets/2280405/9d5f4f4e-0d43-44d2-a089-5d69939938e9


Release Notes:

- Added a spinning animation to the LSP checking indicator

---------

Co-authored-by: Dzmitry Malyshau <kvark@fastmail.com>

crates/gpui/examples/animation.rs

@@ -0,0 +1,74 @@
+use std::time::Duration;
+
+use gpui::*;
+
+struct Assets {}
+
+impl AssetSource for Assets {
+    fn load(&self, path: &str) -> Result<std::borrow::Cow<'static, [u8]>> {
+        std::fs::read(path).map(Into::into).map_err(Into::into)
+    }
+
+    fn list(&self, path: &str) -> Result<Vec<SharedString>> {
+        Ok(std::fs::read_dir(path)?
+            .filter_map(|entry| {
+                Some(SharedString::from(
+                    entry.ok()?.path().to_string_lossy().to_string(),
+                ))
+            })
+            .collect::<Vec<_>>())
+    }
+}
+
+struct AnimationExample {}
+
+impl Render for AnimationExample {
+    fn render(&mut self, _cx: &mut ViewContext<Self>) -> impl IntoElement {
+        div().flex().flex_col().size_full().justify_around().child(
+            div().flex().flex_row().w_full().justify_around().child(
+                div()
+                    .flex()
+                    .bg(rgb(0x2e7d32))
+                    .size(Length::Definite(Pixels(300.0).into()))
+                    .justify_center()
+                    .items_center()
+                    .shadow_lg()
+                    .text_xl()
+                    .text_color(black())
+                    .child("hello")
+                    .child(
+                        svg()
+                            .size_8()
+                            .path("examples/image/arrow_circle.svg")
+                            .text_color(black())
+                            .with_animation(
+                                "image_circle",
+                                Animation::new(Duration::from_secs(2))
+                                    .repeat()
+                                    .with_easing(bounce(ease_in_out)),
+                                |svg, delta| {
+                                    svg.with_transformation(Transformation::rotate(percentage(
+                                        delta,
+                                    )))
+                                },
+                            ),
+                    ),
+            ),
+        )
+    }
+}
+
+fn main() {
+    App::new()
+        .with_assets(Assets {})
+        .run(|cx: &mut AppContext| {
+            let options = WindowOptions {
+                bounds: Some(Bounds::centered(size(px(300.), px(300.)), cx)),
+                ..Default::default()
+            };
+            cx.open_window(options, |cx| {
+                cx.activate(false);
+                cx.new_view(|_cx| AnimationExample {})
+            });
+        });
+}