x11: run window in a separate thread

there's a thread.join() to mimic the previous semantics (which are the
same as on the other platforms).

examples/open_window.rs

@@ -2,7 +2,7 @@ use baseview::{Event, Window, WindowHandler};
 
 fn main() {
     let window_open_options = baseview::WindowOpenOptions {
-        title: "baseview",
+        title: "baseview".into(),
         width: 512,
         height: 512,
         parent: baseview::Parent::None,
@@ -22,7 +22,7 @@ impl WindowHandler for MyProgram {
 
     fn on_frame(&mut self) {}
 
-    fn on_event(&mut self, window: &mut Window, event: Event) {
+    fn on_event(&mut self, _window: &mut Window, event: Event) {
         match event {
             Event::Mouse(e) => println!("Mouse event: {:?}", e),
             Event::Keyboard(e) => println!("Keyboard event: {:?}", e),

src/lib.rs

@@ -28,8 +28,10 @@ pub enum Parent {
     WithParent(*mut c_void),
 }
 
-pub struct WindowOpenOptions<'a> {
-    pub title: &'a str,
+unsafe impl Send for Parent {}
+
+pub struct WindowOpenOptions {
+    pub title: String,
 
     pub width: usize,
     pub height: usize,

src/x11/window.rs

@@ -1,5 +1,6 @@
 use std::os::raw::{c_ulong, c_void};
 use std::time::*;
+use std::thread;
 
 use raw_window_handle::{unix::XlibHandle, HasRawWindowHandle, RawWindowHandle};
 
@@ -25,6 +26,16 @@ pub struct WindowHandle;
 
 impl Window {
     pub fn open<H: WindowHandler>(options: WindowOpenOptions) -> WindowHandle {
+        let runner = thread::spawn(move || {
+            Self::window_thread::<H>(options);
+        });
+
+        let _ = runner.join();
+
+        WindowHandle
+    }
+
+    fn window_thread<H: WindowHandler>(options: WindowOpenOptions) {
         // Connect to the X server
         // FIXME: baseview error type instead of unwrap()
         let xcb_connection = XcbConnection::new().unwrap();
@@ -119,8 +130,6 @@ impl Window {
         let mut handler = H::build(&mut window);
 
         window.run_event_loop(&mut handler);
-
-        WindowHandle
     }
 
     #[inline]