Properly implement Debug for Window and EventLoop types (#3297)

For EventLoop, EventLoopBuilder, EventLoopProxy and by requiring it as
a supertrait of Window and ActiveEventLoop.

It is especially useful for user to be able to know that Window is Debug.

src/platform_impl/linux/mod.rs

@@ -231,6 +231,7 @@ unsafe extern "C" fn x_error_callback(
     0
 }
 
+#[derive(Debug)]
 pub enum EventLoop {
     #[cfg(wayland_platform)]
     Wayland(Box<wayland::EventLoop>),

src/platform_impl/linux/wayland/event_loop/mod.rs

@@ -45,6 +45,7 @@ pub(crate) enum Event {
 }
 
 /// The Wayland event loop.
+#[derive(Debug)]
 pub struct EventLoop {
     /// Has `run` or `run_on_demand` been called or a call to `pump_events` that starts the loop
     loop_running: bool,
@@ -546,6 +547,7 @@ impl AsRawFd for EventLoop {
     }
 }
 
+#[derive(Debug)]
 pub struct ActiveEventLoop {
     /// Event loop proxy
     event_loop_proxy: CoreEventLoopProxy,
@@ -665,6 +667,7 @@ impl rwh_06::HasDisplayHandle for ActiveEventLoop {
     }
 }
 
+#[derive(Debug)]
 pub struct OwnedDisplayHandle {
     pub(crate) connection: Connection,
 }

src/platform_impl/linux/wayland/event_loop/proxy.rs

@@ -7,6 +7,7 @@ use sctk::reexports::calloop::ping::Ping;
 use crate::event_loop::{EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider};
 
 /// A handle that can be sent across the threads and used to wake up the `EventLoop`.
+#[derive(Debug)]
 pub struct EventLoopProxy {
     ping: Ping,
 }

src/platform_impl/linux/wayland/event_loop/sink.rs

@@ -8,7 +8,7 @@ use crate::window::WindowId;
 
 /// An event loop's sink to deliver events from the Wayland event callbacks
 /// to the winit's user.
-#[derive(Default)]
+#[derive(Default, Debug)]
 pub struct EventSink {
     pub(crate) window_events: Vec<Event>,
 }

src/platform_impl/linux/wayland/seat/pointer/mod.rs

@@ -414,6 +414,7 @@ impl WinitPointerDataExt for WlPointer {
     }
 }
 
+#[derive(Debug)]
 pub struct PointerConstraintsState {
     pointer_constraints: ZwpPointerConstraintsV1,
 }

src/platform_impl/linux/wayland/seat/pointer/relative_pointer.rs

@@ -16,6 +16,7 @@ use crate::event::DeviceEvent;
 use crate::platform_impl::wayland::state::WinitState;
 
 /// Wrapper around the relative pointer.
+#[derive(Debug)]
 pub struct RelativePointerState {
     manager: ZwpRelativePointerManagerV1,
 }

src/platform_impl/linux/wayland/seat/text_input/mod.rs

@@ -14,6 +14,7 @@ use crate::platform_impl::wayland;
 use crate::platform_impl::wayland::state::WinitState;
 use crate::window::ImePurpose;
 
+#[derive(Debug)]
 pub struct TextInputState {
     text_input_manager: ZwpTextInputManagerV3,
 }

src/platform_impl/linux/wayland/state.rs

@@ -36,6 +36,7 @@ use crate::platform_impl::wayland::window::{WindowRequests, WindowState};
 use crate::platform_impl::wayland::WindowId;
 
 /// Winit's Wayland state.
+#[derive(Debug)]
 pub struct WinitState {
     /// The WlRegistry.
     pub registry_state: RegistryState,

src/platform_impl/linux/wayland/types/xdg_activation.rs

@@ -16,6 +16,7 @@ use crate::event_loop::AsyncRequestSerial;
 use crate::platform_impl::wayland::state::WinitState;
 use crate::window::{ActivationToken, WindowId};
 
+#[derive(Debug)]
 pub struct XdgActivationState {
     xdg_activation: XdgActivationV1,
 }

src/platform_impl/linux/wayland/window/mod.rs

@@ -34,6 +34,7 @@ pub(crate) mod state;
 pub use state::WindowState;
 
 /// The Wayland window.
+#[derive(Debug)]
 pub struct Window {
     /// Reference to the underlying SCTK window.
     window: SctkWindow,

src/platform_impl/linux/wayland/window/state.rs

@@ -51,6 +51,7 @@ pub type WinitFrame = sctk::shell::xdg::fallback_frame::FallbackFrame<WinitState
 const MIN_WINDOW_SIZE: LogicalSize<u32> = LogicalSize::new(2, 1);
 
 /// The state of the window which is being updated from the [`WinitState`].
+#[derive(Debug)]
 pub struct WindowState {
     /// The connection to Wayland server.
     pub handle: Arc<OwnedDisplayHandle>,
@@ -1097,7 +1098,7 @@ impl Drop for WindowState {
 }
 
 /// The state of the cursor grabs.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 struct GrabState {
     /// The grab mode requested by the user.
     user_grab_mode: CursorGrabMode,

src/platform_impl/linux/x11/dnd.rs

@@ -39,6 +39,7 @@ impl From<io::Error> for DndDataParseError {
     }
 }
 
+#[derive(Debug)]
 pub struct Dnd {
     xconn: Arc<XConnection>,
     // Populated by XdndEnter event handler

src/platform_impl/linux/x11/event_processor.rs

@@ -45,6 +45,7 @@ pub const MAX_MOD_REPLAY_LEN: usize = 32;
 /// The X11 documentation states: "Keycodes lie in the inclusive range `[8, 255]`".
 const KEYCODE_OFFSET: u8 = 8;
 
+#[derive(Debug)]
 pub struct EventProcessor {
     pub dnd: Dnd,
     pub ime_receiver: ImeReceiver,

src/platform_impl/linux/x11/ime/mod.rs

@@ -5,6 +5,7 @@ mod context;
 mod inner;
 mod input_method;
 
+use std::fmt;
 use std::sync::mpsc::{Receiver, Sender};
 use std::sync::Arc;
 
@@ -56,6 +57,12 @@ pub(crate) struct Ime {
     inner: Box<ImeInner>,
 }
 
+impl fmt::Debug for Ime {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Ime").finish_non_exhaustive()
+    }
+}
+
 impl Ime {
     pub fn new(
         xconn: Arc<XConnection>,

src/platform_impl/linux/x11/mod.rs

@@ -71,6 +71,7 @@ type X11rbConnection = x11rb::xcb_ffi::XCBConnection;
 
 type X11Source = Generic<BorrowedFd<'static>>;
 
+#[derive(Debug)]
 struct WakeSender<T> {
     sender: Sender<T>,
     waker: Ping,
@@ -91,6 +92,7 @@ impl<T> WakeSender<T> {
     }
 }
 
+#[derive(Debug)]
 struct PeekableReceiver<T> {
     recv: Receiver<T>,
     first: Option<T>,
@@ -127,6 +129,7 @@ impl<T> PeekableReceiver<T> {
     }
 }
 
+#[derive(Debug)]
 pub struct ActiveEventLoop {
     xconn: Arc<XConnection>,
     wm_delete_window: xproto::Atom,
@@ -144,6 +147,7 @@ pub struct ActiveEventLoop {
     device_events: Cell<DeviceEvents>,
 }
 
+#[derive(Debug)]
 pub struct EventLoop {
     loop_running: bool,
     event_loop: Loop<'static, EventLoopState>,
@@ -157,6 +161,7 @@ pub struct EventLoop {
 
 type ActivationToken = (WindowId, crate::event_loop::AsyncRequestSerial);
 
+#[derive(Debug)]
 struct EventLoopState {
     /// The latest readiness state for the x11 file descriptor
     x11_readiness: Readiness,
@@ -762,7 +767,7 @@ impl Deref for DeviceInfo<'_> {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct EventLoopProxy {
     ping: Ping,
 }

src/platform_impl/linux/x11/window.rs

@@ -39,6 +39,7 @@ use crate::window::{
     WindowAttributes, WindowButtons, WindowId, WindowLevel,
 };
 
+#[derive(Debug)]
 pub(crate) struct Window(Arc<UnownedWindow>);
 
 impl Deref for Window {
@@ -411,6 +412,7 @@ impl SharedState {
 unsafe impl Send for UnownedWindow {}
 unsafe impl Sync for UnownedWindow {}
 
+#[derive(Debug)]
 pub struct UnownedWindow {
     pub(crate) xconn: Arc<XConnection>, // never changes
     xwindow: xproto::Window,            // never changes