wayland: add a warning in the examples in case no window is displayed.

examples/cursor.rs

@@ -11,6 +11,12 @@ fn main() {
     let cursors = [MouseCursor::Default, MouseCursor::Crosshair, MouseCursor::Hand, MouseCursor::Arrow, MouseCursor::Move, MouseCursor::Text, MouseCursor::Wait, MouseCursor::Help, MouseCursor::Progress, MouseCursor::NotAllowed, MouseCursor::ContextMenu, MouseCursor::NoneCursor, MouseCursor::Cell, MouseCursor::VerticalText, MouseCursor::Alias, MouseCursor::Copy, MouseCursor::NoDrop, MouseCursor::Grab, MouseCursor::Grabbing, MouseCursor::AllScroll, MouseCursor::ZoomIn, MouseCursor::ZoomOut, MouseCursor::EResize, MouseCursor::NResize, MouseCursor::NeResize, MouseCursor::NwResize, MouseCursor::SResize, MouseCursor::SeResize, MouseCursor::SwResize, MouseCursor::WResize, MouseCursor::EwResize, MouseCursor::NsResize, MouseCursor::NeswResize, MouseCursor::NwseResize, MouseCursor::ColResize, MouseCursor::RowResize];
     let mut cursor_idx = 0;
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         match event {
             Event::WindowEvent { event: WindowEvent::KeyboardInput { input: KeyboardInput { state: ElementState::Pressed, .. }, .. }, .. } => {

examples/fullscreen.rs

@@ -31,6 +31,12 @@ fn main() {
         .build(&events_loop)
         .unwrap();
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         println!("{:?}", event);
 

examples/grabbing.rs

@@ -10,6 +10,12 @@ fn main() {
 
     let mut grabbed = false;
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         println!("{:?}", event);
 

examples/min_max_size.rs

@@ -9,6 +9,12 @@ fn main() {
         .build(&events_loop)
         .unwrap();
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         println!("{:?}", event);
 

examples/multiwindow.rs

@@ -9,6 +9,12 @@ fn main() {
 
     let mut num_windows = 3;
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         match event {
             winit::Event::WindowEvent { event: winit::WindowEvent::Closed, window_id } => {

examples/proxy.rs

@@ -10,6 +10,12 @@ fn main() {
 
     let proxy = events_loop.create_proxy();
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     std::thread::spawn(move || {
         // Wake up the `events_loop` once every second.
         loop {

examples/transparent.rs

@@ -9,6 +9,12 @@ fn main() {
 
     window.set_title("A fantastic window!");
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         println!("{:?}", event);
 

examples/window.rs

@@ -8,6 +8,12 @@ fn main() {
         .build(&events_loop)
         .unwrap();
 
+    if cfg!(target_os = "linux") {
+        println!("Running this example under wayland may not display a window at all.\n\
+                  This is normal and because this example does not actually draw anything in the window,\
+                  thus the compositor does not display it.");
+    }
+
     events_loop.run_forever(|event| {
         println!("{:?}", event);