Implement version 0.4 of the HasRawWindowHandle trait

This makes Winit 0.27 compatible with crates like Wgpu 0.13 that are
using the raw_window_handle v0.4 crate and aren't able to upgrade to 0.5
until they do a new release (since it requires a semver change).

The change is intended to be self-contained (instead of pushing
the details into all the platform_impl backends) since this is only
intended to be a temporary trait implementation for backwards
compatibility that will likely be removed before the next Winit release.

Addresses: rust-windowing#2415

CHANGELOG.md

@@ -10,6 +10,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 
 - On X11, fix min, max and resize increment hints not persisting for resizable windows (e.g. on DPI change).
 - On Windows, respect min/max inner sizes when creating the window.
+- For backwards compatibility, `Window` now (additionally) implements the old version (`0.4`) of the `HasRawWindowHandle` trait
 
 # 0.27.1 (2022-07-30)
 

Cargo.toml

@@ -46,7 +46,8 @@ instant = { version = "0.1", features = ["wasm-bindgen"] }
 once_cell = "1.12"
 log = "0.4"
 serde = { version = "1", optional = true, features = ["serde_derive"] }
-raw-window-handle = "0.5.0"
+raw_window_handle_05 = { package = "raw-window-handle", version = "0.5" }
+raw_window_handle_04 = { package = "raw-window-handle", version = "0.4" }
 bitflags = "1"
 mint = { version = "0.5.6", optional = true }
 

src/event_loop.rs

@@ -13,7 +13,7 @@ use std::{error, fmt};
 
 use instant::Instant;
 use once_cell::sync::OnceCell;
-use raw_window_handle::{HasRawDisplayHandle, RawDisplayHandle};
+use raw_window_handle_05::{HasRawDisplayHandle, RawDisplayHandle};
 
 use crate::{event::Event, monitor::MonitorHandle, platform_impl};
 

src/platform_impl/windows/event_loop.rs

@@ -19,7 +19,7 @@ use std::{
 
 use once_cell::sync::Lazy;
 use parking_lot::Mutex;
-use raw_window_handle::{RawDisplayHandle, WindowsDisplayHandle};
+use raw_window_handle_05::{RawDisplayHandle, WindowsDisplayHandle};
 
 use windows_sys::Win32::{
     Devices::HumanInterfaceDevice::MOUSE_MOVE_RELATIVE,

src/platform_impl/windows/window.rs

@@ -1,7 +1,7 @@
 #![cfg(target_os = "windows")]
 
 use parking_lot::Mutex;
-use raw_window_handle::{
+use raw_window_handle_05::{
     RawDisplayHandle, RawWindowHandle, Win32WindowHandle, WindowsDisplayHandle,
 };
 use std::{

src/window.rs

@@ -1,7 +1,7 @@
 //! The [`Window`] struct and associated types.
 use std::fmt;
 
-use raw_window_handle::{
+use raw_window_handle_05::{
     HasRawDisplayHandle, HasRawWindowHandle, RawDisplayHandle, RawWindowHandle,
 };
 
@@ -1056,7 +1056,6 @@ unsafe impl HasRawWindowHandle for Window {
         self.window.raw_window_handle()
     }
 }
-
 unsafe impl HasRawDisplayHandle for Window {
     /// Returns a [`raw_window_handle::RawDisplayHandle`] used by the [`EventLoop`] that
     /// created a window.
@@ -1066,6 +1065,117 @@ unsafe impl HasRawDisplayHandle for Window {
         self.window.raw_display_handle()
     }
 }
+unsafe impl raw_window_handle_04::HasRawWindowHandle for Window {
+    /// Returns a [`raw_window_handle_04::RawWindowHandle`] for the Window
+    ///
+    /// This provides backwards compatibility for downstream crates that have not yet
+    /// upgraded to `raw_window_handle` version 0.5, such as Wgpu version 0.13.
+    ///
+    /// ## Platform-specific
+    ///
+    /// ### Android
+    ///
+    /// Only available after receiving [`Event::Resumed`] and before [`Event::Suspended`]. *If you
+    /// try to get the handle outside of that period, this function will panic*!
+    ///
+    /// Make sure to release or destroy any resources created from this `RawWindowHandle` (ie. Vulkan
+    /// or OpenGL surfaces) before returning from [`Event::Suspended`], at which point Android will
+    /// release the underlying window/surface: any subsequent interaction is undefined behavior.
+    ///
+    /// [`Event::Resumed`]: crate::event::Event::Resumed
+    /// [`Event::Suspended`]: crate::event::Event::Suspended
+    fn raw_window_handle(&self) -> raw_window_handle_04::RawWindowHandle {
+        use raw_window_handle_04::{
+            AndroidNdkHandle, AppKitHandle, HaikuHandle, OrbitalHandle, UiKitHandle, WaylandHandle,
+            WebHandle, Win32Handle, WinRtHandle, XcbHandle, XlibHandle,
+        };
+
+        // XXX: Ideally this would be encapsulated either through a compatibility API from
+        // raw_window_handle_05 or else within the backends but since this is only
+        // to provide short-term backwards compatibility to make it easier to crates to
+        // adopt Winit 0.27 then we just handle the full mapping inline here
+        match self.window.raw_window_handle() {
+            RawWindowHandle::UiKit(window_handle) => {
+                let mut handle = UiKitHandle::empty();
+                handle.ui_view = window_handle.ui_view;
+                handle.ui_window = window_handle.ui_window;
+                handle.ui_view_controller = window_handle.ui_view_controller;
+                raw_window_handle_04::RawWindowHandle::UiKit(handle)
+            },
+            RawWindowHandle::AppKit(window_handle) => {
+                let mut handle = AppKitHandle::empty();
+                handle.ns_window = window_handle.ns_window;
+                handle.ns_view = window_handle.ns_view;
+                raw_window_handle_04::RawWindowHandle::AppKit(handle)
+            },
+            RawWindowHandle::Orbital(window_handle) => {
+                let mut handle = OrbitalHandle::empty();
+                handle.window = window_handle.window;
+                raw_window_handle_04::RawWindowHandle::Orbital(handle)
+            },
+            RawWindowHandle::Xlib(window_handle) => {
+                if let RawDisplayHandle::Xlib(display_handle) = self.window.raw_display_handle() {
+                    let mut handle = XlibHandle::empty();
+                    handle.display = display_handle.display;
+                    handle.window = window_handle.window;
+                    handle.visual_id = window_handle.visual_id;
+                    raw_window_handle_04::RawWindowHandle::Xlib(handle)
+                } else {
+                    panic!("Unsupported display handle associated with Xlib window");
+                }
+            },
+            RawWindowHandle::Xcb(window_handle) => {
+                if let RawDisplayHandle::Xcb(display_handle) = self.window.raw_display_handle() {
+                    let mut handle = XcbHandle::empty();
+                    handle.connection = display_handle.connection;
+                    handle.window = window_handle.window;
+                    handle.visual_id = window_handle.visual_id;
+                    raw_window_handle_04::RawWindowHandle::Xcb(handle)
+                } else {
+                    panic!("Unsupported display handle associated with Xcb window");
+                }
+            },
+            RawWindowHandle::Wayland(window_handle) => {
+                if let RawDisplayHandle::Wayland(display_handle) = self.window.raw_display_handle() {
+                    let mut handle = WaylandHandle::empty();
+                    handle.display = display_handle.display;
+                    handle.surface = window_handle.surface;
+                    raw_window_handle_04::RawWindowHandle::Wayland(handle)
+                } else {
+                    panic!("Unsupported display handle associated with Xcb window");
+                }
+            },
+            RawWindowHandle::Win32(window_handle) => {
+                let mut handle = Win32Handle::empty();
+                handle.hwnd = window_handle.hwnd;
+                handle.hinstance = window_handle.hinstance;
+                raw_window_handle_04::RawWindowHandle::Win32(handle)
+            },
+            RawWindowHandle::WinRt(window_handle) => {
+                let mut handle = WinRtHandle::empty();
+                handle.core_window = window_handle.core_window;
+                raw_window_handle_04::RawWindowHandle::WinRt(handle)
+            },
+            RawWindowHandle::Web(window_handle) => {
+                let mut handle = WebHandle::empty();
+                handle.id = window_handle.id;
+                raw_window_handle_04::RawWindowHandle::Web(handle)
+            },
+            RawWindowHandle::AndroidNdk(window_handle) => {
+                let mut handle = AndroidNdkHandle::empty();
+                handle.a_native_window = window_handle.a_native_window;
+                raw_window_handle_04::RawWindowHandle::AndroidNdk(handle)
+            },
+            RawWindowHandle::Haiku(window_handle) => {
+                let mut handle = HaikuHandle::empty();
+                handle.b_window = window_handle.b_window;
+                handle.b_direct_window = window_handle.b_direct_window;
+                raw_window_handle_04::RawWindowHandle::Haiku(handle)
+            },
+            _ => panic!("No HasRawWindowHandle version 0.4 backwards compatibility for new Winit window type"),
+        }
+    }
+}
 
 /// The behavior of cursor grabbing.
 ///