Add fireside crate demoing GPUI things

Cargo.lock

@@ -2603,6 +2603,13 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8fcfdc7a0362c9f4444381a9e697c79d435fe65b52a37466fc2c1184cee9edc6"
 
+[[package]]
+name = "fireside"
+version = "0.1.0"
+dependencies = [
+ "gpui",
+]
+
 [[package]]
 name = "fixedbitset"
 version = "0.4.2"

Cargo.toml

@@ -84,7 +84,7 @@ members = [
     "crates/workspace",
     "crates/welcome",
     "crates/zed",
-    "crates/zed_actions",
+    "crates/zed_actions", "crates/fireside",
 ]
 default-members = ["crates/zed"]
 resolver = "2"

crates/fireside/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "fireside"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+gpui = { path = "../gpui" }

crates/fireside/src/main.rs

@@ -0,0 +1,96 @@
+use gpui::*;
+
+struct Counter {
+    value: usize,
+}
+
+impl Counter {
+    fn increment(&mut self, cx: &mut ModelContext<Self>) {
+        self.value += 1;
+        cx.notify();
+    }
+}
+
+struct Observer {
+    value: usize,
+}
+
+impl Observer {
+    fn new(counter: &Model<Counter>, cx: &mut ModelContext<Self>) -> Self {
+        cx.observe(counter, Self::counter_changed).detach();
+        Self {
+            value: counter.read(cx).value * 2,
+        }
+    }
+
+    fn counter_changed(&mut self, counter: Model<Counter>, cx: &mut ModelContext<Self>) {
+        self.value = counter.read(cx).value * 2;
+        cx.notify();
+    }
+}
+
+struct RootView {
+    counter: Model<Counter>,
+    observer: Model<Observer>,
+}
+
+impl RootView {
+    fn new(counter: Model<Counter>, observer: Model<Observer>, cx: &mut ViewContext<Self>) -> Self {
+        cx.observe(&counter, |_, _, cx| cx.notify()).detach();
+        cx.observe(&observer, |_, _, cx| cx.notify()).detach();
+        Self { counter, observer }
+    }
+}
+
+impl Render for RootView {
+    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
+        div()
+            .size_full()
+            .p_4()
+            .border()
+            .border_color(rgb(0x2B2F31))
+            .bg(rgb(0x202425))
+            .text_color(rgb(0xECEDEE))
+            .flex()
+            .flex_col()
+            .gap_2()
+            .child(format!("Counter: {}", self.counter.read(cx).value))
+            .child(format!("Observer: {}", self.observer.read(cx).value))
+            .child(
+                div()
+                    .child("Increment")
+                    .w_32()
+                    .h_32()
+                    .bg(red())
+                    .on_mouse_down(
+                        MouseButton::Left,
+                        cx.listener(|this, _, cx| {
+                            this.counter.update(cx, |counter, cx| {
+                                counter.increment(cx);
+                            })
+                        }),
+                    ),
+            )
+    }
+}
+
+fn main() {
+    App::new().run(|cx| {
+        cx.activate(true);
+
+        let counter: Model<Counter> = cx.new_model(|_| Counter { value: 0 });
+        dbg!(counter.read(cx).value);
+
+        let observer = cx.new_model(|cx| Observer::new(&counter, cx));
+
+        counter.update(cx, |counter, cx| {
+            println!("about to increment counter...");
+            counter.increment(cx);
+            dbg!(counter.value);
+        });
+
+        let window = cx.open_window(WindowOptions::default(), |cx| {
+            cx.new_view(|cx| RootView::new(counter, observer, cx))
+        });
+    });
+}