On Web, implement DeviceEvents (#2871)

src/platform_impl/web/web_sys/canvas.rs

@@ -12,6 +12,8 @@ use crate::window::{WindowAttributes, WindowId as RootWindowId};
 
 use std::cell::{Cell, RefCell};
 use std::rc::Rc;
+use std::sync::atomic::AtomicBool;
+use std::sync::Arc;
 
 use js_sys::Promise;
 use smol_str::SmolStr;
@@ -24,6 +26,7 @@ use web_sys::{Event, FocusEvent, HtmlCanvasElement, KeyboardEvent, WheelEvent};
 pub struct Canvas {
     common: Common,
     id: WindowId,
+    pub has_focus: Arc<AtomicBool>,
     on_touch_start: Option<EventListenerHandle<dyn FnMut(Event)>>,
     on_touch_end: Option<EventListenerHandle<dyn FnMut(Event)>>,
     on_focus: Option<EventListenerHandle<dyn FnMut(FocusEvent)>>,
@@ -91,6 +94,7 @@ impl Canvas {
                 wants_fullscreen: Rc::new(RefCell::new(false)),
             },
             id,
+            has_focus: Arc::new(AtomicBool::new(false)),
             on_touch_start: None,
             on_touch_end: None,
             on_blur: None,

src/platform_impl/web/web_sys/event.rs

@@ -57,6 +57,17 @@ pub fn mouse_button(event: &MouseEvent) -> Option<MouseButton> {
     }
 }
 
+impl MouseButton {
+    pub fn to_id(self) -> u32 {
+        match self {
+            MouseButton::Left => 0,
+            MouseButton::Right => 1,
+            MouseButton::Middle => 2,
+            MouseButton::Other(value) => value.into(),
+        }
+    }
+}
+
 pub fn mouse_position(event: &MouseEvent) -> LogicalPosition<f64> {
     LogicalPosition {
         x: event.offset_x() as f64,

src/platform_impl/web/web_sys/mod.rs

@@ -1,5 +1,5 @@
 mod canvas;
-mod event;
+pub mod event;
 mod event_handle;
 mod media_query_handle;
 mod pointer;
@@ -8,6 +8,7 @@ mod timeout;
 
 pub use self::canvas::Canvas;
 pub use self::event::ButtonsState;
+pub use self::event_handle::EventListenerHandle;
 pub use self::resize_scaling::ResizeScaleHandle;
 pub use self::timeout::{IdleCallback, Timeout};