Desktop: Text clipboard support (#3461)

* gray background for viewport texture

* cust copy paste support

* connect clipboard read on web

* fix eyedropper bounds

* cleanup

* add missing char events for some named keys like enter

desktop/src/window.rs

@@ -38,6 +38,7 @@ pub(crate) struct Window {
 	#[allow(dead_code)]
 	native_handle: native::NativeWindowImpl,
 	custom_cursors: HashMap<CustomCursorSource, CustomCursor>,
+	clipboard: window_clipboard::Clipboard,
 }
 
 impl Window {
@@ -57,10 +58,12 @@ impl Window {
 
 		let winit_window = event_loop.create_window(attributes).unwrap();
 		let native_handle = native::NativeWindowImpl::new(winit_window.as_ref(), app_event_scheduler);
+		let clipboard = unsafe { window_clipboard::Clipboard::connect(&winit_window) }.expect("failed to create clipboard");
 		Self {
 			winit_window: winit_window.into(),
 			native_handle,
 			custom_cursors: HashMap::new(),
+			clipboard,
 		}
 	}
 
@@ -136,6 +139,22 @@ impl Window {
 	pub(crate) fn update_menu(&self, entries: Vec<MenuItem>) {
 		self.native_handle.update_menu(entries);
 	}
+
+	pub(crate) fn clipboard_read(&self) -> Option<String> {
+		match self.clipboard.read() {
+			Ok(data) => Some(data),
+			Err(e) => {
+				tracing::error!("Failed to read from clipboard: {e}");
+				None
+			}
+		}
+	}
+
+	pub(crate) fn clipboard_write(&mut self, data: String) {
+		if let Err(e) = self.clipboard.write(data) {
+			tracing::error!("Failed to write to clipboard: {e}")
+		}
+	}
 }
 
 pub(crate) enum Cursor {