Get playground app launching

Not sure if it should be in the workspace, but it's easier for now.

Co-Authored-By: Derek Briggs <derek.briggs@me.com>

Cargo.lock

@@ -5037,6 +5037,15 @@ version = "0.3.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "26072860ba924cbfa98ea39c8c19b4dd6a4a25423dbdf219c1eca91aa0cf6964"
 
+[[package]]
+name = "playground"
+version = "0.1.0"
+dependencies = [
+ "gpui",
+ "log",
+ "simplelog",
+]
+
 [[package]]
 name = "plist"
 version = "1.5.0"

Cargo.toml

@@ -28,6 +28,7 @@ members = [
     "crates/git",
     "crates/go_to_line",
     "crates/gpui",
+    "crates/gpui/playground",
     "crates/gpui_macros",
     "crates/install_cli",
     "crates/journal",

crates/gpui/playground/Cargo.toml

@@ -0,0 +1,13 @@
+[[bin]]
+name = "playground"
+path = "src/playground.rs"
+
+[package]
+name = "playground"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+gpui = { path = ".." }
+log.workspace = true
+simplelog = "0.9"

crates/gpui/playground/src/playground.rs

@@ -0,0 +1,80 @@
+use gpui::{
+    color::Color,
+    elements::Text,
+    fonts::{HighlightStyle, TextStyle},
+    platform::{CursorStyle, MouseButton},
+    AnyElement, CursorRegion, Element, MouseRegion,
+};
+use log::LevelFilter;
+use simplelog::SimpleLogger;
+
+fn main() {
+    SimpleLogger::init(LevelFilter::Info, Default::default()).expect("could not initialize logger");
+
+    gpui::App::new(()).unwrap().run(|cx| {
+        cx.platform().activate(true);
+        cx.add_window(Default::default(), |_| TextView);
+    });
+}
+
+struct TextView;
+
+impl gpui::Entity for TextView {
+    type Event = ();
+}
+
+impl gpui::View for TextView {
+    fn ui_name() -> &'static str {
+        "View"
+    }
+
+    fn render(&mut self, cx: &mut gpui::ViewContext<Self>) -> AnyElement<TextView> {
+        let font_size = 12.;
+        let family = cx
+            .font_cache
+            .load_family(&["Monaco"], &Default::default())
+            .unwrap();
+        let font_id = cx
+            .font_cache
+            .select_font(family, &Default::default())
+            .unwrap();
+        let view_id = cx.view_id();
+
+        let underline = HighlightStyle {
+            underline: Some(gpui::fonts::Underline {
+                thickness: 1.0.into(),
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+
+        Text::new(
+            "The text:\nHello, beautiful world, hello!",
+            TextStyle {
+                font_id,
+                font_size,
+                color: Color::red(),
+                font_family_name: "".into(),
+                font_family_id: family,
+                underline: Default::default(),
+                font_properties: Default::default(),
+            },
+        )
+        .with_highlights(vec![(17..26, underline), (34..40, underline)])
+        .with_custom_runs(vec![(17..26), (34..40)], move |ix, bounds, scene, _| {
+            scene.push_cursor_region(CursorRegion {
+                bounds,
+                style: CursorStyle::PointingHand,
+            });
+            scene.push_mouse_region(
+                MouseRegion::new::<Self>(view_id, ix, bounds).on_click::<Self, _>(
+                    MouseButton::Left,
+                    move |_, _, _| {
+                        eprintln!("clicked link {ix}");
+                    },
+                ),
+            );
+        })
+        .into_any()
+    }
+}