Desktop: Add support for UI scaling (#3310)

* desktop support ui scaling * fix some warnings * use browser zoom if needed * fix infinite footprint size * fix web canvas scale * always set zoom * use only zoom for scaling * prevent user zoom * remove mouse position scaling
2026-09-19 10:58:04 +08:00 · 2025-11-08 11:32:04 +00:00
parent 7254c470ef
commit f02f834097
25 changed files with 286 additions and 162 deletions
--- a/desktop/src/app.rs
+++ b/desktop/src/app.rs
@@ -8,6 +8,7 @@ use std::thread;
 use std::time::Duration;
 use std::time::Instant;
 use winit::application::ApplicationHandler;
+use winit::dpi::PhysicalSize;
 use winit::event::WindowEvent;
 use winit::event_loop::ActiveEventLoop;
 use winit::event_loop::ControlFlow;
@@ -25,8 +26,9 @@ use crate::wrapper::{DesktopWrapper, NodeGraphExecutionResult, WgpuContext, seri
 pub(crate) struct App {
 	cef_context: Box<dyn cef::CefContext>,
 	window: Option<Window>,
+	window_scale: f64,
 	cef_schedule: Option<Instant>,
-	cef_window_size_sender: Sender<cef::WindowSize>,
+	cef_view_info_sender: Sender<cef::ViewInfoUpdate>,
 	graphics_state: Option<GraphicsState>,
 	wgpu_context: WgpuContext,
 	app_event_receiver: Receiver<AppEvent>,
@@ -44,7 +46,7 @@ pub(crate) struct App {
 impl App {
 	pub(crate) fn new(
 		cef_context: Box<dyn cef::CefContext>,
-		window_size_sender: Sender<cef::WindowSize>,
+		cef_view_info_sender: Sender<cef::ViewInfoUpdate>,
 		wgpu_context: WgpuContext,
 		app_event_receiver: Receiver<AppEvent>,
 		app_event_scheduler: AppEventScheduler,
@@ -66,9 +68,10 @@ impl App {
 		Self {
 			cef_context,
 			window: None,
+			window_scale: 1.0,
 			cef_schedule: Some(Instant::now()),
 			graphics_state: None,
-			cef_window_size_sender: window_size_sender,
+			cef_view_info_sender,
 			wgpu_context,
 			app_event_receiver,
 			app_event_scheduler,
@@ -147,19 +150,19 @@ impl App {
 					}
 				});
 			}
-			DesktopFrontendMessage::UpdateViewportBounds { x, y, width, height } => {
+			DesktopFrontendMessage::UpdateViewportPhysicalBounds { x, y, width, height } => {
 				if let Some(graphics_state) = &mut self.graphics_state
 					&& let Some(window) = &self.window
 				{
 					let window_size = window.surface_size();

-					let viewport_offset_x = x / window_size.width as f32;
-					let viewport_offset_y = y / window_size.height as f32;
-					graphics_state.set_viewport_offset([viewport_offset_x, viewport_offset_y]);
+					let viewport_offset_x = x / window_size.width as f64;
+					let viewport_offset_y = y / window_size.height as f64;
+					graphics_state.set_viewport_offset([viewport_offset_x as f32, viewport_offset_y as f32]);

-					let viewport_scale_x = if width != 0.0 { window_size.width as f32 / width } else { 1.0 };
-					let viewport_scale_y = if height != 0.0 { window_size.height as f32 / height } else { 1.0 };
-					graphics_state.set_viewport_scale([viewport_scale_x, viewport_scale_y]);
+					let viewport_scale_x = if width != 0.0 { window_size.width as f64 / width } else { 1.0 };
+					let viewport_scale_y = if height != 0.0 { window_size.height as f64 / height } else { 1.0 };
+					graphics_state.set_viewport_scale([viewport_scale_x as f32, viewport_scale_y as f32]);
 				}
 			}
 			DesktopFrontendMessage::UpdateOverlays(scene) => {
@@ -179,7 +182,7 @@ impl App {
 			}
 			DesktopFrontendMessage::DragWindow => {
 				if let Some(window) = &self.window {
-					let _ = window.start_drag();
+					window.start_drag();
 				}
 			}
 			DesktopFrontendMessage::CloseWindow => {
@@ -352,14 +355,17 @@ impl App {
 impl ApplicationHandler for App {
 	fn can_create_surfaces(&mut self, event_loop: &dyn ActiveEventLoop) {
 		let window = Window::new(event_loop, self.app_event_scheduler.clone());
+
+		self.window_scale = window.scale_factor();
+		let _ = self.cef_view_info_sender.send(cef::ViewInfoUpdate::Scale(self.window_scale));
+		self.cef_context.notify_view_info_changed();
+
 		self.window = Some(window);

 		let graphics_state = GraphicsState::new(self.window.as_ref().unwrap(), self.wgpu_context.clone());

 		self.graphics_state = Some(graphics_state);

-		tracing::info!("Winit window created and ready");
-
 		self.desktop_wrapper.init(self.wgpu_context.clone());

 		#[cfg(target_os = "windows")]
@@ -384,14 +390,22 @@ impl ApplicationHandler for App {
 			WindowEvent::CloseRequested => {
 				self.app_event_scheduler.schedule(AppEvent::CloseWindow);
 			}
-			WindowEvent::SurfaceResized(size) => {
-				let _ = self.cef_window_size_sender.send(size.into());
-				self.cef_context.notify_of_resize();
+			WindowEvent::SurfaceResized(PhysicalSize { width, height }) => {
+				let _ = self.cef_view_info_sender.send(cef::ViewInfoUpdate::Size {
+					width: width as usize,
+					height: height as usize,
+				});
+				self.cef_context.notify_view_info_changed();
 				if let Some(window) = &self.window {
 					let maximized = window.is_maximized();
 					self.app_event_scheduler.schedule(AppEvent::DesktopWrapperMessage(DesktopWrapperMessage::UpdateMaximized { maximized }));
 				}
 			}
+			WindowEvent::ScaleFactorChanged { scale_factor, .. } => {
+				self.window_scale = scale_factor;
+				let _ = self.cef_view_info_sender.send(cef::ViewInfoUpdate::Scale(self.window_scale));
+				self.cef_context.notify_view_info_changed();
+			}
 			WindowEvent::RedrawRequested => {
 				let Some(ref mut graphics_state) = self.graphics_state else { return };
 				// Only rerender once we have a new UI texture to display
--- a/desktop/src/cef.rs
+++ b/desktop/src/cef.rs
@@ -38,8 +38,8 @@ use texture_import::SharedTextureHandle;

 pub(crate) use context::{CefContext, CefContextBuilder, InitError};

-pub(crate) trait CefEventHandler: Clone + Send + Sync + 'static {
-	fn window_size(&self) -> WindowSize;
+pub(crate) trait CefEventHandler: Send + Sync + 'static {
+	fn view_info(&self) -> ViewInfo;
 	fn draw<'a>(&self, frame_buffer: FrameBufferRef<'a>);
 	#[cfg(feature = "accelerated_paint")]
 	fn draw_gpu(&self, shared_texture: SharedTextureHandle);
@@ -50,24 +50,54 @@ pub(crate) trait CefEventHandler: Clone + Send + Sync + 'static {
 	fn schedule_cef_message_loop_work(&self, scheduled_time: Instant);
 	fn initialized_web_communication(&self);
 	fn receive_web_message(&self, message: &[u8]);
+	fn duplicate(&self) -> Self
+	where
+		Self: Sized;
 }

 #[derive(Clone, Copy)]
-pub(crate) struct WindowSize {
-	pub(crate) width: usize,
-	pub(crate) height: usize,
+pub(crate) struct ViewInfo {
+	width: usize,
+	height: usize,
+	scale: f64,
 }
-impl WindowSize {
-	pub(crate) fn new(width: usize, height: usize) -> Self {
-		Self { width, height }
+impl ViewInfo {
+	pub(crate) fn new() -> Self {
+		Self { width: 1, height: 1, scale: 1. }
+	}
+	pub(crate) fn apply_update(&mut self, update: ViewInfoUpdate) {
+		match update {
+			ViewInfoUpdate::Size { width, height } if width > 0 && height > 0 => {
+				self.width = width;
+				self.height = height;
+			}
+			ViewInfoUpdate::Scale(scale) if scale > 0. => {
+				self.scale = scale;
+			}
+			_ => {}
+		}
+	}
+	pub(crate) fn zoom(&self) -> f64 {
+		self.scale.ln() / 1.2_f64.ln()
+	}
+	pub(crate) fn width(&self) -> usize {
+		self.width
+	}
+	pub(crate) fn height(&self) -> usize {
+		self.height
 	}
 }
-impl From<winit::dpi::PhysicalSize<u32>> for WindowSize {
-	fn from(size: winit::dpi::PhysicalSize<u32>) -> Self {
-		Self::new(size.width as usize, size.height as usize)
+impl Default for ViewInfo {
+	fn default() -> Self {
+		Self::new()
 	}
 }

+pub(crate) enum ViewInfoUpdate {
+	Size { width: usize, height: usize },
+	Scale(f64),
+}
+
 #[derive(Clone)]
 pub(crate) struct Resource {
 	pub(crate) reader: ResourceReader,
@@ -89,34 +119,33 @@ impl Read for ResourceReader {
 	}
 }

-#[derive(Clone)]
 pub(crate) struct CefHandler {
 	wgpu_context: WgpuContext,
 	app_event_scheduler: AppEventScheduler,
-	window_size_receiver: Arc<Mutex<WindowSizeReceiver>>,
+	view_info_receiver: Arc<Mutex<ViewInfoReceiver>>,
 }

 impl CefHandler {
-	pub(crate) fn new(wgpu_context: WgpuContext, app_event_scheduler: AppEventScheduler, window_size_receiver: Receiver<WindowSize>) -> Self {
+	pub(crate) fn new(wgpu_context: WgpuContext, app_event_scheduler: AppEventScheduler, view_info_receiver: Receiver<ViewInfoUpdate>) -> Self {
 		Self {
 			wgpu_context,
 			app_event_scheduler,
-			window_size_receiver: Arc::new(Mutex::new(WindowSizeReceiver::new(window_size_receiver))),
+			view_info_receiver: Arc::new(Mutex::new(ViewInfoReceiver::new(view_info_receiver))),
 		}
 	}
 }

 impl CefEventHandler for CefHandler {
-	fn window_size(&self) -> WindowSize {
-		let Ok(mut guard) = self.window_size_receiver.lock() else {
-			tracing::error!("Failed to lock window_size_receiver");
-			return WindowSize::new(1, 1);
+	fn view_info(&self) -> ViewInfo {
+		let Ok(mut guard) = self.view_info_receiver.lock() else {
+			tracing::error!("Failed to lock view_info_receiver");
+			return ViewInfo::new();
 		};
-		let WindowSizeReceiver { receiver, window_size } = &mut *guard;
-		for new_window_size in receiver.try_iter() {
-			*window_size = new_window_size;
+		let ViewInfoReceiver { receiver, view_info } = &mut *guard;
+		for update in receiver.try_iter() {
+			view_info.apply_update(update);
 		}
-		*window_size
+		*view_info
 	}
 	fn draw<'a>(&self, frame_buffer: FrameBufferRef<'a>) {
 		let width = frame_buffer.width() as u32;
@@ -244,17 +273,25 @@ impl CefEventHandler for CefHandler {
 		};
 		self.app_event_scheduler.schedule(AppEvent::DesktopWrapperMessage(desktop_wrapper_message));
 	}
-}

-struct WindowSizeReceiver {
-	window_size: WindowSize,
-	receiver: Receiver<WindowSize>,
-}
-impl WindowSizeReceiver {
-	fn new(window_size_receiver: Receiver<WindowSize>) -> Self {
+	fn duplicate(&self) -> Self
+	where
+		Self: Sized,
+	{
 		Self {
-			window_size: WindowSize { width: 1, height: 1 },
-			receiver: window_size_receiver,
+			wgpu_context: self.wgpu_context.clone(),
+			app_event_scheduler: self.app_event_scheduler.clone(),
+			view_info_receiver: self.view_info_receiver.clone(),
 		}
 	}
 }
+
+struct ViewInfoReceiver {
+	view_info: ViewInfo,
+	receiver: Receiver<ViewInfoUpdate>,
+}
+impl ViewInfoReceiver {
+	fn new(receiver: Receiver<ViewInfoUpdate>) -> Self {
+		Self { view_info: ViewInfo::new(), receiver }
+	}
+}
--- a/desktop/src/cef/context.rs
+++ b/desktop/src/cef/context.rs
@@ -10,7 +10,7 @@ pub(crate) trait CefContext {

 	fn handle_window_event(&mut self, event: &winit::event::WindowEvent);

-	fn notify_of_resize(&self);
+	fn notify_view_info_changed(&self);

 	fn send_web_message(&self, message: Vec<u8>);
 }
--- a/desktop/src/cef/context/builder.rs
+++ b/desktop/src/cef/context/builder.rs
@@ -3,7 +3,7 @@ use std::path::{Path, PathBuf};
 use cef::args::Args;
 use cef::sys::{CEF_API_VERSION_LAST, cef_resultcode_t};
 use cef::{
-	App, BrowserSettings, CefString, Client, DictionaryValue, ImplCommandLine, ImplRequestContext, RenderHandler, RequestContextSettings, SchemeHandlerFactory, Settings, WindowInfo, api_hash,
+	App, BrowserSettings, CefString, Client, DictionaryValue, ImplCommandLine, ImplRequestContext, RequestContextSettings, SchemeHandlerFactory, Settings, WindowInfo, api_hash,
 	browser_host_create_browser_sync, execute_process,
 };

@@ -13,7 +13,7 @@ use crate::cef::CefEventHandler;
 use crate::cef::consts::{RESOURCE_DOMAIN, RESOURCE_SCHEME};
 use crate::cef::dirs::create_instance_dir;
 use crate::cef::input::InputState;
-use crate::cef::internal::{BrowserProcessAppImpl, BrowserProcessClientImpl, RenderHandlerImpl, RenderProcessAppImpl, SchemeHandlerFactoryImpl};
+use crate::cef::internal::{BrowserProcessAppImpl, BrowserProcessClientImpl, RenderProcessAppImpl, SchemeHandlerFactoryImpl};

 pub(crate) struct CefContextBuilder<H: CefEventHandler> {
 	pub(crate) args: Args,
@@ -131,7 +131,7 @@ impl<H: CefEventHandler> CefContextBuilder<H> {

 	fn initialize_inner(self, event_handler: &H, settings: Settings) -> Result<(), InitError> {
 		// Attention! Wrapping this in an extra App is necessary, otherwise the program still compiles but segfaults
-		let mut cef_app = App::new(BrowserProcessAppImpl::new(event_handler.clone()));
+		let mut cef_app = App::new(BrowserProcessAppImpl::new(event_handler.duplicate()));

 		let result = cef::initialize(Some(self.args.as_main_args()), Some(&settings), Some(&mut cef_app), std::ptr::null_mut());
 		if result != 1 {
@@ -146,8 +146,7 @@ impl<H: CefEventHandler> CefContextBuilder<H> {
 }

 fn create_browser<H: CefEventHandler>(event_handler: H, instance_dir: PathBuf, disable_gpu_acceleration: bool) -> Result<SingleThreadedCefContext, InitError> {
-	let render_handler = RenderHandler::new(RenderHandlerImpl::new(event_handler.clone()));
-	let mut client = Client::new(BrowserProcessClientImpl::new(render_handler, event_handler.clone()));
+	let mut client = Client::new(BrowserProcessClientImpl::new(&event_handler));

 	#[cfg(feature = "accelerated_paint")]
 	let use_accelerated_paint = if disable_gpu_acceleration {
@@ -180,7 +179,7 @@ fn create_browser<H: CefEventHandler>(event_handler: H, instance_dir: PathBuf, d
 		return Err(InitError::RequestContextCreationFailed);
 	};

-	let mut scheme_handler_factory = SchemeHandlerFactory::new(SchemeHandlerFactoryImpl::new(event_handler.clone()));
+	let mut scheme_handler_factory = SchemeHandlerFactory::new(SchemeHandlerFactoryImpl::new(event_handler.duplicate()));
 	incognito_request_context.clear_scheme_handler_factories();
 	incognito_request_context.register_scheme_handler_factory(Some(&CefString::from(RESOURCE_SCHEME)), Some(&CefString::from(RESOURCE_DOMAIN)), Some(&mut scheme_handler_factory));

@@ -197,6 +196,7 @@ fn create_browser<H: CefEventHandler>(event_handler: H, instance_dir: PathBuf, d

 	if let Some(browser) = browser {
 		Ok(SingleThreadedCefContext {
+			event_handler: Box::new(event_handler),
 			browser,
 			input_state: InputState::default(),
 			instance_dir,
--- a/desktop/src/cef/context/multithreaded.rs
+++ b/desktop/src/cef/context/multithreaded.rs
@@ -30,11 +30,11 @@ impl CefContext for MultiThreadedCefContextProxy {
 		});
 	}

-	fn notify_of_resize(&self) {
+	fn notify_view_info_changed(&self) {
 		run_on_ui_thread(move || {
 			CONTEXT.with(|b| {
 				if let Some(context) = b.borrow_mut().as_mut() {
-					context.notify_of_resize();
+					context.notify_view_info_changed();
 				}
 			});
 		});
--- a/desktop/src/cef/context/singlethreaded.rs
+++ b/desktop/src/cef/context/singlethreaded.rs
@@ -1,13 +1,14 @@
 use cef::{Browser, ImplBrowser, ImplBrowserHost};
 use winit::event::WindowEvent;

-use crate::cef::input;
 use crate::cef::input::InputState;
 use crate::cef::ipc::{MessageType, SendMessage};
+use crate::cef::{CefEventHandler, input};

 use super::CefContext;

 pub(super) struct SingleThreadedCefContext {
+	pub(super) event_handler: Box<dyn CefEventHandler>,
 	pub(super) browser: Browser,
 	pub(super) input_state: InputState,
 	pub(super) instance_dir: std::path::PathBuf,
@@ -19,11 +20,14 @@ impl CefContext for SingleThreadedCefContext {
 	}

 	fn handle_window_event(&mut self, event: &WindowEvent) {
-		input::handle_window_event(&self.browser, &mut self.input_state, event)
+		input::handle_window_event(&self.browser, &mut self.input_state, event);
 	}

-	fn notify_of_resize(&self) {
-		self.browser.host().unwrap().was_resized();
+	fn notify_view_info_changed(&self) {
+		let view_info = self.event_handler.view_info();
+		let host = self.browser.host().unwrap();
+		host.set_zoom_level(view_info.zoom());
+		host.was_resized();
 	}

 	fn send_web_message(&self, message: Vec<u8>) {
--- a/desktop/src/cef/input.rs
+++ b/desktop/src/cef/input.rs
@@ -12,14 +12,14 @@ use super::consts::{MULTICLICK_ALLOWED_TRAVEL, MULTICLICK_TIMEOUT, PINCH_ZOOM_SP
 pub(crate) fn handle_window_event(browser: &Browser, input_state: &mut InputState, event: &WindowEvent) {
 	match event {
 		WindowEvent::PointerMoved { position, .. } | WindowEvent::PointerEntered { position, .. } => {
-			input_state.cursor_move(position);
+			input_state.cursor_move(&position);

 			let Some(host) = browser.host() else { return };
 			host.send_mouse_move_event(Some(&input_state.into()), 0);
 		}
 		WindowEvent::PointerLeft { position, .. } => {
 			if let Some(position) = position {
-				input_state.cursor_move(position);
+				input_state.cursor_move(&position);
 			}

 			let Some(host) = browser.host() else { return };
--- a/desktop/src/cef/internal.rs
+++ b/desktop/src/cef/internal.rs
@@ -2,6 +2,7 @@ mod browser_process_app;
 mod browser_process_client;
 mod browser_process_handler;
 mod browser_process_life_span_handler;
+mod browser_process_load_handler;

 mod render_process_app;
 mod render_process_handler;
@@ -19,6 +20,5 @@ pub(super) mod task;

 pub(super) use browser_process_app::BrowserProcessAppImpl;
 pub(super) use browser_process_client::BrowserProcessClientImpl;
-pub(super) use render_handler::RenderHandlerImpl;
 pub(super) use render_process_app::RenderProcessAppImpl;
 pub(super) use scheme_handler_factory::SchemeHandlerFactoryImpl;
--- a/desktop/src/cef/internal/browser_process_app.rs
+++ b/desktop/src/cef/internal/browser_process_app.rs
@@ -13,7 +13,7 @@ pub(crate) struct BrowserProcessAppImpl<H: CefEventHandler> {
 	object: *mut RcImpl<_cef_app_t, Self>,
 	event_handler: H,
 }
-impl<H: CefEventHandler + Clone> BrowserProcessAppImpl<H> {
+impl<H: CefEventHandler> BrowserProcessAppImpl<H> {
 	pub(crate) fn new(event_handler: H) -> Self {
 		Self {
 			object: std::ptr::null_mut(),
@@ -22,9 +22,9 @@ impl<H: CefEventHandler + Clone> BrowserProcessAppImpl<H> {
 	}
 }

-impl<H: CefEventHandler + Clone> ImplApp for BrowserProcessAppImpl<H> {
+impl<H: CefEventHandler> ImplApp for BrowserProcessAppImpl<H> {
 	fn browser_process_handler(&self) -> Option<BrowserProcessHandler> {
-		Some(BrowserProcessHandler::new(BrowserProcessHandlerImpl::new(self.event_handler.clone())))
+		Some(BrowserProcessHandler::new(BrowserProcessHandlerImpl::new(self.event_handler.duplicate())))
 	}

 	fn on_register_custom_schemes(&self, registrar: Option<&mut SchemeRegistrar>) {
@@ -80,7 +80,7 @@ impl<H: CefEventHandler + Clone> ImplApp for BrowserProcessAppImpl<H> {
 	}
 }

-impl<H: CefEventHandler + Clone> Clone for BrowserProcessAppImpl<H> {
+impl<H: CefEventHandler> Clone for BrowserProcessAppImpl<H> {
 	fn clone(&self) -> Self {
 		unsafe {
 			let rc_impl = &mut *self.object;
@@ -88,7 +88,7 @@ impl<H: CefEventHandler + Clone> Clone for BrowserProcessAppImpl<H> {
 		}
 		Self {
 			object: self.object,
-			event_handler: self.event_handler.clone(),
+			event_handler: self.event_handler.duplicate(),
 		}
 	}
 }
@@ -100,7 +100,7 @@ impl<H: CefEventHandler> Rc for BrowserProcessAppImpl<H> {
 		}
 	}
 }
-impl<H: CefEventHandler + Clone> WrapApp for BrowserProcessAppImpl<H> {
+impl<H: CefEventHandler> WrapApp for BrowserProcessAppImpl<H> {
 	fn wrap_rc(&mut self, object: *mut RcImpl<_cef_app_t, Self>) {
 		self.object = object;
 	}
--- a/desktop/src/cef/internal/browser_process_client.rs
+++ b/desktop/src/cef/internal/browser_process_client.rs
@@ -1,26 +1,30 @@
 use cef::rc::{Rc, RcImpl};
 use cef::sys::{_cef_client_t, cef_base_ref_counted_t};
-use cef::{DisplayHandler, ImplClient, LifeSpanHandler, RenderHandler, WrapClient};
+use cef::{DisplayHandler, ImplClient, LifeSpanHandler, LoadHandler, RenderHandler, WrapClient};

 use crate::cef::CefEventHandler;
 use crate::cef::ipc::{MessageType, UnpackMessage, UnpackedMessage};

 use super::browser_process_life_span_handler::BrowserProcessLifeSpanHandlerImpl;
+use super::browser_process_load_handler::LoadHandlerImpl;
 use super::display_handler::DisplayHandlerImpl;
+use super::render_handler::RenderHandlerImpl;

 pub(crate) struct BrowserProcessClientImpl<H: CefEventHandler> {
 	object: *mut RcImpl<_cef_client_t, Self>,
-	render_handler: RenderHandler,
 	event_handler: H,
+	load_handler: LoadHandler,
+	render_handler: RenderHandler,
 	display_handler: DisplayHandler,
 }
 impl<H: CefEventHandler> BrowserProcessClientImpl<H> {
-	pub(crate) fn new(render_handler: RenderHandler, event_handler: H) -> Self {
+	pub(crate) fn new(event_handler: &H) -> Self {
 		Self {
 			object: std::ptr::null_mut(),
-			render_handler,
-			event_handler: event_handler.clone(),
-			display_handler: DisplayHandler::new(DisplayHandlerImpl::new(event_handler)),
+			event_handler: event_handler.duplicate(),
+			load_handler: LoadHandler::new(LoadHandlerImpl::new(event_handler.duplicate())),
+			render_handler: RenderHandler::new(RenderHandlerImpl::new(event_handler.duplicate())),
+			display_handler: DisplayHandler::new(DisplayHandlerImpl::new(event_handler.duplicate())),
 		}
 	}
 }
@@ -52,6 +56,10 @@ impl<H: CefEventHandler> ImplClient for BrowserProcessClientImpl<H> {
 		1
 	}

+	fn load_handler(&self) -> Option<cef::LoadHandler> {
+		Some(self.load_handler.clone())
+	}
+
 	fn render_handler(&self) -> Option<RenderHandler> {
 		Some(self.render_handler.clone())
 	}
@@ -77,8 +85,9 @@ impl<H: CefEventHandler> Clone for BrowserProcessClientImpl<H> {
 		}
 		Self {
 			object: self.object,
+			event_handler: self.event_handler.duplicate(),
+			load_handler: self.load_handler.clone(),
 			render_handler: self.render_handler.clone(),
-			event_handler: self.event_handler.clone(),
 			display_handler: self.display_handler.clone(),
 		}
 	}
--- a/desktop/src/cef/internal/browser_process_handler.rs
+++ b/desktop/src/cef/internal/browser_process_handler.rs
@@ -19,7 +19,7 @@ impl<H: CefEventHandler> BrowserProcessHandlerImpl<H> {
 	}
 }

-impl<H: CefEventHandler + Clone> ImplBrowserProcessHandler for BrowserProcessHandlerImpl<H> {
+impl<H: CefEventHandler> ImplBrowserProcessHandler for BrowserProcessHandlerImpl<H> {
 	fn on_schedule_message_pump_work(&self, delay_ms: i64) {
 		self.event_handler.schedule_cef_message_loop_work(Instant::now() + Duration::from_millis(delay_ms as u64));
 	}
@@ -33,7 +33,7 @@ impl<H: CefEventHandler + Clone> ImplBrowserProcessHandler for BrowserProcessHan
 	}
 }

-impl<H: CefEventHandler + Clone> Clone for BrowserProcessHandlerImpl<H> {
+impl<H: CefEventHandler> Clone for BrowserProcessHandlerImpl<H> {
 	fn clone(&self) -> Self {
 		unsafe {
 			let rc_impl = &mut *self.object;
@@ -41,7 +41,7 @@ impl<H: CefEventHandler + Clone> Clone for BrowserProcessHandlerImpl<H> {
 		}
 		Self {
 			object: self.object,
-			event_handler: self.event_handler.clone(),
+			event_handler: self.event_handler.duplicate(),
 		}
 	}
 }
@@ -53,7 +53,7 @@ impl<H: CefEventHandler> Rc for BrowserProcessHandlerImpl<H> {
 		}
 	}
 }
-impl<H: CefEventHandler + Clone> WrapBrowserProcessHandler for BrowserProcessHandlerImpl<H> {
+impl<H: CefEventHandler> WrapBrowserProcessHandler for BrowserProcessHandlerImpl<H> {
 	fn wrap_rc(&mut self, object: *mut RcImpl<_cef_browser_process_handler_t, Self>) {
 		self.object = object;
 	}
--- a/desktop/src/cef/internal/browser_process_load_handler.rs
+++ b/desktop/src/cef/internal/browser_process_load_handler.rs
@@ -0,0 +1,60 @@
+use cef::rc::{Rc, RcImpl};
+use cef::sys::{_cef_load_handler_t, cef_base_ref_counted_t, cef_load_handler_t};
+use cef::{ImplBrowser, ImplBrowserHost, ImplLoadHandler, WrapLoadHandler};
+
+use crate::cef::CefEventHandler;
+
+pub(crate) struct LoadHandlerImpl<H: CefEventHandler> {
+	object: *mut RcImpl<cef_load_handler_t, Self>,
+	event_handler: H,
+}
+impl<H: CefEventHandler> LoadHandlerImpl<H> {
+	pub(crate) fn new(event_handler: H) -> Self {
+		Self {
+			object: std::ptr::null_mut(),
+			event_handler,
+		}
+	}
+}
+
+impl<H: CefEventHandler> ImplLoadHandler for LoadHandlerImpl<H> {
+	fn on_loading_state_change(&self, browser: Option<&mut cef::Browser>, is_loading: ::std::os::raw::c_int, _can_go_back: ::std::os::raw::c_int, _can_go_forward: ::std::os::raw::c_int) {
+		let view_info = self.event_handler.view_info();
+
+		if let Some(browser) = browser
+			&& is_loading == 0
+		{
+			browser.host().unwrap().set_zoom_level(view_info.zoom());
+		}
+	}
+
+	fn get_raw(&self) -> *mut _cef_load_handler_t {
+		self.object.cast()
+	}
+}
+
+impl<H: CefEventHandler> Clone for LoadHandlerImpl<H> {
+	fn clone(&self) -> Self {
+		unsafe {
+			let rc_impl = &mut *self.object;
+			rc_impl.interface.add_ref();
+		}
+		Self {
+			object: self.object,
+			event_handler: self.event_handler.duplicate(),
+		}
+	}
+}
+impl<H: CefEventHandler> Rc for LoadHandlerImpl<H> {
+	fn as_base(&self) -> &cef_base_ref_counted_t {
+		unsafe {
+			let base = &*self.object;
+			std::mem::transmute(&base.cef_object)
+		}
+	}
+}
+impl<H: CefEventHandler> WrapLoadHandler for LoadHandlerImpl<H> {
+	fn wrap_rc(&mut self, object: *mut RcImpl<_cef_load_handler_t, Self>) {
+		self.object = object;
+	}
+}
--- a/desktop/src/cef/internal/display_handler.rs
+++ b/desktop/src/cef/internal/display_handler.rs
@@ -122,7 +122,7 @@ impl<H: CefEventHandler> Clone for DisplayHandlerImpl<H> {
 		}
 		Self {
 			object: self.object,
-			event_handler: self.event_handler.clone(),
+			event_handler: self.event_handler.duplicate(),
 		}
 	}
 }
--- a/desktop/src/cef/internal/render_handler.rs
+++ b/desktop/src/cef/internal/render_handler.rs
@@ -21,12 +21,12 @@ impl<H: CefEventHandler> RenderHandlerImpl<H> {
 impl<H: CefEventHandler> ImplRenderHandler for RenderHandlerImpl<H> {
 	fn view_rect(&self, _browser: Option<&mut Browser>, rect: Option<&mut Rect>) {
 		if let Some(rect) = rect {
-			let view = self.event_handler.window_size();
+			let view_info = self.event_handler.view_info();
 			*rect = Rect {
 				x: 0,
 				y: 0,
-				width: view.width as i32,
-				height: view.height as i32,
+				width: view_info.width() as i32,
+				height: view_info.height() as i32,
 			};
 		}
 	}
@@ -78,7 +78,7 @@ impl<H: CefEventHandler> Clone for RenderHandlerImpl<H> {
 		}
 		Self {
 			object: self.object,
-			event_handler: self.event_handler.clone(),
+			event_handler: self.event_handler.duplicate(),
 		}
 	}
 }
--- a/desktop/src/cef/internal/scheme_handler_factory.rs
+++ b/desktop/src/cef/internal/scheme_handler_factory.rs
@@ -55,7 +55,7 @@ impl<H: CefEventHandler> Clone for SchemeHandlerFactoryImpl<H> {
 		}
 		Self {
 			object: self.object,
-			event_handler: self.event_handler.clone(),
+			event_handler: self.event_handler.duplicate(),
 		}
 	}
 }
--- a/desktop/src/lib.rs
+++ b/desktop/src/lib.rs
@@ -44,9 +44,9 @@ pub fn start() {
 	let (app_event_sender, app_event_receiver) = std::sync::mpsc::channel();
 	let app_event_scheduler = event_loop.create_app_event_scheduler(app_event_sender);

-	let (window_size_sender, window_size_receiver) = std::sync::mpsc::channel();
+	let (cef_view_info_sender, cef_view_info_receiver) = std::sync::mpsc::channel();

-	let cef_handler = cef::CefHandler::new(wgpu_context.clone(), app_event_scheduler.clone(), window_size_receiver);
+	let cef_handler = cef::CefHandler::new(wgpu_context.clone(), app_event_scheduler.clone(), cef_view_info_receiver);
 	let cef_context = match cef_context_builder.initialize(cef_handler, cli.disable_ui_acceleration) {
 		Ok(c) => {
 			tracing::info!("CEF initialized successfully");
@@ -70,7 +70,7 @@ pub fn start() {
 		}
 	};

-	let mut app = App::new(Box::new(cef_context), window_size_sender, wgpu_context, app_event_receiver, app_event_scheduler, cli.files);
+	let mut app = App::new(Box::new(cef_context), cef_view_info_sender, wgpu_context, app_event_receiver, app_event_scheduler, cli.files);

 	event_loop.run_app(&mut app).unwrap();
 }
--- a/desktop/src/window.rs
+++ b/desktop/src/window.rs
@@ -68,6 +68,10 @@ impl Window {
 		self.winit_window.surface_size()
 	}

+	pub(crate) fn scale_factor(&self) -> f64 {
+		self.winit_window.scale_factor()
+	}
+
 	pub(crate) fn minimize(&self) {
 		self.winit_window.set_minimized(true);
 	}