RustScript GPUI Notepad

A reusable RSS-to-GPUI desktop layer plus a native notepad. The .rss document owns widget declarations, layout nesting, anonymous button callbacks, and application behavior. Rust owns the generic GPUI renderer and explicitly registered host capabilities.

Run

cargo run

Notes are written under ./notes/.

Define a desktop UI in RSS

RssGpuiRuntime executes an RSS source file, turns ui::* declarations into a typed UiTree, and the reusable RssGpuiView renders that tree. To create another desktop app, provide a source file and any application host modules:

let runtime = RssGpuiRuntime::from_source(
    include_str!("../scripts/app.rss"),
    vec![Arc::new(MyHostModule::new(app_services))],
)?;

Buttons receive anonymous RSS callbacks directly:

use ui;
use app;

ui::window("Tasks", 720, 520);
ui::column_begin("root");
ui::text_input("title", "Title", "", "Task title");
ui::button("create", "Create", || create_task());
ui::label("status", ui::get_value("status"));
ui::column_end();
ui::finish();

fn create_task() -> string {
    let title: string = ui::get_value("title");
    let status: string = app::create_task(title);
    ui::set_value("status", status);
    ui::get_value("status")
}

The anonymous callback is retained with its rendered button and invoked through the same VM. After an input or callback changes state, the runtime resets the VM, rebuilds the UiTree, and replaces the prior callback values.

RSS ui surface

RSS call	Result
ui::window(title, width, height)	Declares the window metadata.
ui::column_begin(id) / ui::column_end()	Declares a vertical container.
ui::row_begin(id) / ui::row_end()	Declares a horizontal container.
ui::text_input(id, label, default, placeholder)	Declares a single-line editable control.
ui::text_area(id, label, default, placeholder)	Declares a multi-line editable control.
ui::button(id, label, callback)	Declares a clickable control with an anonymous zero-argument RSS callback.
ui::get_value(id) / ui::set_value(id, value)	Reads and updates UI state.
ui::label(id, text)	Declares text.
ui::finish()	Completes the frame declaration.
ui::bind_value(from, to)	Links two editable ids. Changing either field updates the linked partner without script-side assignment. Both ids must already be registered as text_input or text_area, and self-loops are rejected.

Host capabilities

A desktop app supplies a HostModule. It exposes a fixed list of import names and arities, then binds each host function to the VM. The framework validates every RSS import before execution. The notepad module provides notepad::format_note and notepad::save_note; the anonymous callbacks in scripts/notepad.rss invoke both.

There is no event-name dispatcher or source preprocessor. GPUI input subscriptions and click listeners call RssGpuiRuntime::dispatch; a click resolves the button's retained callable and invokes it directly. The runtime then renders a fresh typed UI tree from the updated state.

Two-way binding example

scripts/two_way.rss demonstrates how ui::bind_value mirrors two inputs without manual assignments:

ui::bind_value("a", "b");
ui::bind_value("b", "a");

When the user types in a, the runtime:

1. Writes the new value to UiState.
2. Walks the value_bindings stored in UiTree and copies the value into each linked target.
3. Renders a fresh UI tree and reconciles each target InputState.

One-way binding remains available for read-only mirrors:

ui::bind_value("source", "read_only_display");

Checks

cargo test
cargo clippy --all-targets --all-features -- -D warnings
cargo run