license SPDX line, implementing first global state

Cargo.toml

@@ -2,6 +2,12 @@
 name = "wayland_server"
 version = "0.1.0"
 edition = "2024"
+license = "GPL-2.0-only"
+keywords = ["ffi", "wayland"]
+
+[[example]]
+name = "simple_compd"
+path = "examples/simple_compd.rs"
 
 [dependencies]
 libc = "*"

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()?;

src/array.rs

@@ -1,3 +1,5 @@
+// SPDX: GPL-2.0-only
+
 use std::io::{Error, ErrorKind, Result};
 use std::ptr::NonNull;
 use crate::ffi::wl_array;

src/client.rs

@@ -0,0 +1,15 @@
+// SPDX: GPL-2.0-only 
+
+use std::io;
+use std::ptr::NonNull;
+
+use crate::ffi::wl_client;
+
+pub struct Client {
+    raw: NonNull<wl_client>
+}
+impl Client {
+    pub(crate) fn from_raw(raw: *mut wl_client) -> Option<Self> {
+        NonNull::new(raw).map(| raw| Self { raw })
+    }
+}

src/display.rs

@@ -1,3 +1,5 @@
+// SPDX: GPL-2.0-only
+
 use std::{io::Error, ptr::NonNull};
 use std::io::{ErrorKind, Result};
 
@@ -37,7 +39,10 @@ impl<'disp> Display<'disp> {
     pub fn get_name(&self) -> &str {
         self.name
     }
-    
+
+    pub(crate) fn get_raw_ptr(&self) -> *mut wl_display {
+        self.raw.as_ptr()
+    }
     pub fn run(&self) -> Result<()> {
         unsafe { wl_display_run(self.raw.as_ptr()) };
         Ok(())

src/ffi.rs

@@ -1,3 +1,5 @@
+// SPDX: GPL-2.0-only
+
 use std::{ffi::CStr, os::fd::RawFd};
 
 use libc::epoll_event;
@@ -338,6 +340,11 @@ pub(crate) struct wl_shm_pool {
     sigbus_is_impossible: bool
 }
 
+// public static interfaces 
+unsafe extern "C" {
+    pub(crate) unsafe static wl_output_interface: wl_interface;
+}
+
 #[link(name = "wayland-server")]
 unsafe extern "C" {
     pub(crate) unsafe fn wl_array_add(array: *mut wl_array, size: usize) -> *mut libc::c_void;
@@ -406,7 +413,7 @@ unsafe extern "C" {
     pub(crate) unsafe fn wl_event_source_remove(source: *mut wl_event_source) -> i32;
     pub(crate) unsafe fn wl_event_source_timer_update(source: *mut wl_event_source, ms_delay: i32) -> i32;
 
-    pub(crate) unsafe fn wl_global_create(disp: *mut wl_display, interface: *const wl_interface) -> *mut wl_global;
+    pub(crate) unsafe fn wl_global_create(disp: *mut wl_display, interface: *const wl_interface, version: i32, data: *mut libc::c_void, bind: wl_global_bind_func_t) -> *mut wl_global;
     pub(crate) unsafe fn wl_global_destroy(global: *mut wl_global);
     pub(crate) unsafe fn wl_global_get_display(global: *const wl_global) -> *mut wl_display;
     pub(crate) unsafe fn wl_global_get_interface(global: *const wl_global) -> *const wl_interface;

src/global.rs

@@ -0,0 +1,52 @@
+// SPDX: GPL-2.0-only
+
+use std::io;
+use std::ptr::NonNull;
+use crate::client::Client;
+use crate::display::Display;
+use crate::ffi::{wl_client, wl_display, wl_global, wl_output_interface};
+use crate::ffi::wl_global_create;
+
+pub trait GlobalState {
+    fn handle_output_bind(&self, client: Client, version: u32, id: u32);
+}
+
+unsafe extern "C" fn trampoline_handle_output_bind(client: *mut wl_client, data: *mut libc::c_void, version: u32, id: u32) {
+    let Some(client) = Client::from_raw(client) else {
+        return;
+    };
+    let holder = &*(data as *const GlobalStateHolder);
+    holder.state.handle_output_bind(client, version, id);
+}
+
+struct GlobalStateHolder {
+    state: Box<dyn GlobalState>,
+}
+
+pub struct Global {
+    raw: NonNull<wl_global>,
+    state: Box<GlobalStateHolder>,
+}
+impl Global 
+{
+    pub fn new<S>(disp: &Display, state: S) -> io::Result<Self> 
+    where 
+        S: GlobalState + 'static,
+    {
+        let state = Box::new(GlobalStateHolder { state: Box::new(state) });
+        let data = state.as_ref() as *const GlobalStateHolder as *mut libc::c_void;
+
+        let ptr = unsafe { 
+            wl_global_create(disp.get_raw_ptr(),
+                &wl_output_interface,
+                1,
+                data,
+                trampoline_handle_output_bind
+            )
+        };
+        let raw = NonNull::new(ptr)
+            .ok_or_else(||io::Error::last_os_error())?;
+
+        Ok(Self{raw,state})
+    }
+}

src/lib.rs

@@ -1,7 +1,11 @@
+// SPDX: GPL-2.0-only
+
 #![feature(c_variadic)]
 
 pub(crate) mod ffi;
 
 // public api
 pub mod array;
-pub mod display;
+pub mod client;
+pub mod display;
+pub mod global;