Desktop: Focus app window when loading a document (#4124)

desktop/src/app.rs

@@ -368,6 +368,11 @@ impl App {
 					window.start_drag();
 				}
 			}
+			DesktopFrontendMessage::WindowFocus => {
+				if let Some(window) = &self.window {
+					window.focus();
+				}
+			}
 			DesktopFrontendMessage::WindowHide => {
 				if let Some(window) = &self.window {
 					window.hide();

desktop/src/window.rs

@@ -140,6 +140,11 @@ impl Window {
 		let _ = self.winit_window.drag_window();
 	}
 
+	pub(crate) fn focus(&self) {
+		self.winit_window.set_minimized(false);
+		self.winit_window.focus_window();
+	}
+
 	pub(crate) fn hide(&self) {
 		self.native_handle.hide();
 	}

desktop/wrapper/src/intercept_frontend_message.rs

@@ -139,6 +139,9 @@ pub(super) fn intercept_frontend_message(dispatcher: &mut DesktopWrapperMessageD
 		FrontendMessage::WindowDrag => {
 			dispatcher.respond(DesktopFrontendMessage::WindowDrag);
 		}
+		FrontendMessage::WindowFocus => {
+			dispatcher.respond(DesktopFrontendMessage::WindowFocus);
+		}
 		FrontendMessage::WindowHide => {
 			dispatcher.respond(DesktopFrontendMessage::WindowHide);
 		}

desktop/wrapper/src/messages.rs

@@ -72,6 +72,7 @@ pub enum DesktopFrontendMessage {
 	WindowMaximize,
 	WindowFullscreen,
 	WindowDrag,
+	WindowFocus,
 	WindowHide,
 	WindowHideOthers,
 	WindowShowAll,