monitor: refactor MonitorHandle to store dyn object

This also alters `VideoMode` to be a regular object and not reference
the `MonitorHandle`, since it's a static data.

Given that `VideoMode` set may change during runtime keeping the
reference as a some sort of validity may not be idea and propagating
errors when changing video mode could be more reliable.

src/platform_impl/android/mod.rs

@@ -20,12 +20,11 @@ use crate::event_loop::{
     EventLoopProxy as CoreEventLoopProxy, EventLoopProxyProvider,
     OwnedDisplayHandle as CoreOwnedDisplayHandle,
 };
-use crate::monitor::{MonitorHandle as RootMonitorHandle, VideoMode};
+use crate::monitor::{Fullscreen, MonitorHandle as CoreMonitorHandle};
 use crate::platform::pump_events::PumpStatus;
 use crate::window::{
-    self, CursorGrabMode, CustomCursor, CustomCursorSource, Fullscreen, ImePurpose,
-    ResizeDirection, Theme, Window as CoreWindow, WindowAttributes, WindowButtons, WindowId,
-    WindowLevel,
+    self, CursorGrabMode, CustomCursor, CustomCursorSource, ImePurpose, ResizeDirection, Theme,
+    Window as CoreWindow, WindowAttributes, WindowButtons, WindowId, WindowLevel,
 };
 
 mod keycodes;
@@ -700,11 +699,11 @@ impl RootActiveEventLoop for ActiveEventLoop {
         Err(NotSupportedError::new("create_custom_cursor is not supported").into())
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = RootMonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(std::iter::empty())
     }
 
-    fn primary_monitor(&self) -> Option<RootMonitorHandle> {
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         None
     }
 
@@ -824,15 +823,15 @@ impl CoreWindow for Window {
         GLOBAL_WINDOW
     }
 
-    fn primary_monitor(&self) -> Option<RootMonitorHandle> {
+    fn primary_monitor(&self) -> Option<CoreMonitorHandle> {
         None
     }
 
-    fn available_monitors(&self) -> Box<dyn Iterator<Item = RootMonitorHandle>> {
+    fn available_monitors(&self) -> Box<dyn Iterator<Item = CoreMonitorHandle>> {
         Box::new(std::iter::empty())
     }
 
-    fn current_monitor(&self) -> Option<RootMonitorHandle> {
+    fn current_monitor(&self) -> Option<CoreMonitorHandle> {
         None
     }
 
@@ -1018,31 +1017,6 @@ impl Display for OsError {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct MonitorHandle;
-
-impl MonitorHandle {
-    pub fn name(&self) -> Option<String> {
-        unreachable!()
-    }
-
-    pub fn position(&self) -> Option<PhysicalPosition<i32>> {
-        unreachable!()
-    }
-
-    pub fn scale_factor(&self) -> f64 {
-        unreachable!()
-    }
-
-    pub fn current_video_mode(&self) -> Option<VideoMode> {
-        unreachable!()
-    }
-
-    pub fn video_modes(&self) -> std::iter::Empty<VideoMode> {
-        unreachable!()
-    }
-}
-
 fn screen_size(app: &AndroidApp) -> PhysicalSize<u32> {
     if let Some(native_window) = app.native_window() {
         PhysicalSize::new(native_window.width() as _, native_window.height() as _)