license SPDX line, implementing first global state

examples/simple_compd.rs

@@ -1,9 +1,29 @@
+// SPDX: GPL-2.0-only
 use std::io;
+use wayland_server::client::Client;
 use wayland_server::display::Display;
+use wayland_server::global::{Global, GlobalState};
+
+
+struct State {
+
+}
+impl GlobalState for State {
+    fn handle_output_bind(&self, client: Client, version: u32, id: u32) {
+        todo!()
+    }
+}
 
 fn main() -> io::Result<()> {
+    // Creating a compositor State 
+    let state = State {};
+
+    // create a wayland display
     let display = Display::new()?;
 
+    // get the global registry 
+    let global = Global::new(&display, state)?;
+
     println!("Running wayland_display on {}", display.get_name());
 
     display.run()?;