defining first Display and Registry structs. Added Callback support for Registry.

.gitignore

@@ -16,3 +16,8 @@ target/
 #  and can be added to the global gitignore or merged into this file.  For a more nuclear
 #  option (not recommended) you can uncomment the following to ignore the entire idea folder.
 #.idea/
+
+
+# Added by cargo
+
+/target

Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "wayland_client"
+version = "0.1.0"

Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "wayland_client"
+version = "0.1.0"
+edition = "2024"
+publish = ["tcraft"]
+license = "GPL-2.0-only"
+keywords = ["ffi", "wayland"]
+
+[dependencies]

examples/globals.rs

@@ -0,0 +1,26 @@
+// SPDIX-Licenes-Identifier: GPL-2.0-later
+
+use std::io;
+use wayland_client::display::Display;
+
+fn main() -> io::Result<()> {
+    let display = Display::new(None)?;
+    let mut registry = display.get_registry();
+
+    // define on_global callback 
+    registry.on_global(|interface, name, version|{
+        println!("interface: {interface}, version: {version}, name: {name}")
+    });
+    // define on_global_remove callback 
+    registry.on_global_remove(|_name| {
+        // left blank 
+    });
+    // register the callbacks in wayland 
+    registry.registry_listener();
+
+    // take a look around
+    let _ = display.roundtrip();
+
+    drop(display);
+    Ok(())
+}

examples/simple_client.rs

@@ -0,0 +1,17 @@
+// SPDX-License-Identifer: GPL-2.0-only
+
+use std::io;
+
+use wayland_client::display::Display;
+
+fn main() -> io::Result<()> {
+    let display = Display::new(None)?;
+    println!("Connection established!");
+
+    while let Some(_events) = display.dispatch() {
+
+    }
+
+    drop(display);
+    Ok(())
+}

src/display.rs

@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-only 
+use std::{env, fmt, io::{Error, ErrorKind}, ptr::NonNull};
+use crate::{display::ffi::{wl_display_dispatch, wl_proxy, wl_proxy_get_version, wl_proxy_marshal_flags, wl_registry_interface}, registry::Registry};
+
+mod ffi {
+    use std::ffi::{c_char, c_int,c_void};
+
+    // relevant type definitions
+    #[repr(C)]
+    #[allow(non_camel_case_types)]
+    pub(super) struct wl_display;
+    #[repr(C)]
+    #[allow(non_camel_case_types)]
+    pub(super) struct wl_proxy;
+    #[repr(C)]
+    #[allow(non_camel_case_types)]
+    pub(super) struct wl_interface;
+    
+    #[link(name = "wayland-client")]
+    unsafe extern "C" {
+        // relevant public static 
+        pub(crate) unsafe static wl_registry_interface: wl_interface;
+
+        // relevant function definitions 
+        pub(super) unsafe fn wl_display_connect(name: *const c_char) -> *mut c_void;
+        pub(super) unsafe fn wl_display_disconnect(disp: *mut wl_display);
+        pub(super) unsafe fn wl_display_dispatch(disp: *mut wl_display) -> c_int;
+        pub(super) unsafe fn wl_display_roundtrip(disp: *mut wl_display) -> c_int;
+        pub(super) unsafe fn wl_proxy_marshal_flags(proxy: *mut wl_proxy, opcode: u32, interface: *const wl_interface, version: u32, flags: u32, ptr: *mut c_void) -> *mut c_void;
+        pub(super) unsafe fn wl_proxy_get_version(proxy: *mut wl_proxy) -> u32;
+    }
+}
+
+use ffi::wl_display;
+
+// core wayland elemenent: Display 
+pub struct Display {
+    raw: NonNull<wl_display>,
+}
+impl Display { 
+    pub fn new(name: Option<String>) -> Result<Self, std::io::Error> {
+        let sock_name: String = if name.is_some() {
+            name.unwrap()
+        } else {
+            let env_name = env::var("WAYLAND_DISPLAY");
+            if env_name.is_ok() {
+                env_name.unwrap()
+            } else {
+                "wayland-0".into()
+            }
+        };
+        let binding = std::ffi::CString::new(sock_name).unwrap();
+        let str = binding.as_c_str();
+        let raw = unsafe { ffi::wl_display_connect(str.as_ptr()) };
+
+        let raw = NonNull::<wl_display>::new(raw as *mut wl_display)
+            .expect("Failed to connect to Wayland display.");
+
+        Ok(Self{raw})
+    }
+    pub fn get_registry(&self) -> Registry {
+        let registry = unsafe {
+            wl_proxy_marshal_flags(self.raw.as_ptr() as *mut wl_proxy, 
+                1, 
+                &wl_registry_interface, 
+                wl_proxy_get_version(self.raw.as_ptr() as *mut wl_proxy), 
+                0,
+                std::ptr::null_mut()
+            )};
+
+        return Registry::from(registry);
+    }
+    pub fn dispatch(&self) -> Option<i32> {
+        let events = unsafe {wl_display_dispatch(self.raw.as_ptr()) };
+
+        if events == -1 {
+            None
+        } else {
+            Some(events)
+        }
+    }
+    pub fn roundtrip(&self) -> std::io::Result<i32> {
+        let r = unsafe { ffi::wl_display_roundtrip(self.raw.as_ptr()) };
+        
+        if r >= 0 {
+            Ok(r)
+        } else {
+            Err(Error::new(ErrorKind::Other, "unable to process server messages"))
+        }
+    }
+}
+
+impl Drop for Display {
+    fn drop(&mut self) {
+        unsafe { ffi::wl_display_disconnect(self.raw.as_ptr()) };
+    }
+}

src/lib.rs

@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+pub mod display;
+pub mod registry;

src/registry.rs

@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-only 
+
+use std::ffi::CStr;
+use std::{ffi::{c_char,c_void}, ptr::NonNull};
+
+use crate::registry::ffi::{wl_proxy, wl_proxy_add_listener, wl_registry, wl_registry_listener};
+
+mod ffi {
+    use std::ffi::{c_char, c_void};
+
+    #[repr(C)]
+    #[allow(non_camel_case_types)]
+    pub(super) struct wl_registry;
+    #[repr(C)]
+    #[allow(non_camel_case_types)]
+    pub(super) struct wl_proxy;
+
+    // function types 
+    #[allow(non_camel_case_types)]
+    pub(super) type registry_global_callback = unsafe extern "C" fn(*mut c_void, *mut wl_registry, u32, *const c_char, u32);
+    #[allow(non_camel_case_types)]
+    pub(super) type registry_global_remove_callback = unsafe extern "C" fn(*mut c_void, *mut wl_registry, u32);
+    #[allow(non_camel_case_types)]
+    pub(super) type cb_implementation = unsafe extern "C" fn();
+
+    #[repr(C)]
+    pub(super) struct wl_registry_listener {
+        pub global: Option<registry_global_callback>,
+        pub global_remove: Option<registry_global_remove_callback>
+    }
+    #[link(name = "wayland-client")]
+    unsafe extern "C" {
+        pub(super) unsafe fn wl_proxy_add_listener(proxy: *mut wl_proxy, implementation: *const cb_implementation, data: *mut c_void);
+    }
+}
+
+// C->Rust trampoline functions 
+unsafe extern "C" fn registry_handle_global(
+    data: *mut c_void, 
+    _registry: *mut wl_registry,
+    name: u32,
+    interface: *const c_char,
+    version: u32,
+) {
+    let registry = unsafe {
+        &mut *(data as *mut RegistryListener)
+    };
+    let interface = unsafe {
+        CStr::from_ptr(interface)
+            .to_string_lossy()
+            .into_owned()
+    };
+
+    if let Some(callback) = registry.global.as_mut() {
+        callback(interface, name, version)
+    }
+}
+
+unsafe extern "C" fn registry_handle_global_remove(
+    data: *mut c_void,
+    _registry: *mut wl_registry,
+    name: u32,
+) {
+    let registry = unsafe { 
+        &mut *(data as *mut RegistryListener)
+    };
+
+    if let Some(callback) = registry.global_remove.as_mut() {
+        callback(name)
+    }
+}
+
+// callback holder cell
+pub struct RegistryListener {
+    global: Option<Box<dyn FnMut(String, u32, u32) + 'static>>,
+    global_remove: Option<Box<dyn FnMut(u32) + 'static>>,
+}
+
+// the main registry cell
+pub struct Registry {
+    raw: NonNull<wl_registry>,
+
+    callbacks: Box<RegistryListener>,
+
+    listener: Box<wl_registry_listener>,
+}
+impl Registry {
+    pub fn on_global<F>(&mut self, global: F) 
+    where
+        F: FnMut(String, u32, u32) + 'static
+    {
+        self.callbacks.global = Some(Box::new(global));
+    }
+    pub fn on_global_remove<F>(&mut self, global_remove: F)
+    where
+        F: FnMut(u32) + 'static 
+    {
+        self.callbacks.global_remove = Some(Box::new(global_remove));
+    }
+    pub fn registry_listener(&mut self) {
+        unsafe {
+            wl_proxy_add_listener(
+                self.raw.as_ptr() as *mut wl_proxy, 
+                &*self.listener as *const _ as *const ffi::cb_implementation,
+                self.callbacks.as_mut() as *mut _ as *mut c_void)
+        };
+    }
+}
+impl From<*mut c_void> for Registry {
+    fn from(value: *mut c_void) -> Self {
+        let raw = NonNull::new(value as *mut wl_registry)
+            .expect("unable to get display registry");
+
+        Self { 
+            raw, 
+            callbacks: Box::new(
+                RegistryListener { global: None, global_remove: None }
+            ),
+            listener: Box::new(ffi::wl_registry_listener {
+                global: Some(registry_handle_global),
+                global_remove: Some(registry_handle_global_remove),
+            }), 
+        }
+    }
+}