Refine Window::set_cursor_grab API

This commit renames `Window::set_cursor_grab` to
`Window::set_cursor_grab_mode`. The new API now accepts enumeration
to control the way cursor grab is performed. The value could be: `lock`,
`confine`, or `none`.

This commit also implements `Window::set_cursor_position` for Wayland,
since it's tied to locked cursor.

Implements API from #1677.

src/platform_impl/web/web_sys/canvas.rs

@@ -89,8 +89,8 @@ impl Canvas {
         })
     }
 
-    pub fn set_cursor_grab(&self, grab: bool) -> Result<(), RootOE> {
-        if grab {
+    pub fn set_cursor_lock(&self, lock: bool) -> Result<(), RootOE> {
+        if lock {
             self.raw().request_pointer_lock();
         } else {
             let window = web_sys::window()

src/platform_impl/web/window.rs

@@ -4,7 +4,7 @@ use crate::event;
 use crate::icon::Icon;
 use crate::monitor::MonitorHandle as RootMH;
 use crate::window::{
-    CursorIcon, Fullscreen, UserAttentionType, WindowAttributes, WindowId as RootWI,
+    CursorGrabMode, CursorIcon, Fullscreen, UserAttentionType, WindowAttributes, WindowId as RootWI,
 };
 
 use raw_window_handle::{RawWindowHandle, WebHandle};
@@ -216,10 +216,18 @@ impl Window {
     }
 
     #[inline]
-    pub fn set_cursor_grab(&self, grab: bool) -> Result<(), ExternalError> {
+    pub fn set_cursor_grab(&self, mode: CursorGrabMode) -> Result<(), ExternalError> {
+        let lock = match mode {
+            CursorGrabMode::None => false,
+            CursorGrabMode::Locked => true,
+            CursorGrabMode::Confined => {
+                return Err(ExternalError::NotSupported(NotSupportedError::new()))
+            }
+        };
+
         self.canvas
             .borrow()
-            .set_cursor_grab(grab)
+            .set_cursor_lock(lock)
             .map_err(ExternalError::Os)
     }