Fix touch events not working for wasm builds

internal/backends/winit/Cargo.toml

@@ -43,7 +43,8 @@ lyon_path = "1.0"
 once_cell = "1.5"
 pin-weak = "1"
 scoped-tls-hkt = "0.1"
-winit = { version = "0.28.2", default-features = false }
+# Pinned due to https://github.com/slint-ui/slint/issues/2424
+winit = { version = "=0.28.3", default-features = false }
 instant = "0.1"
 raw-window-handle = { version = "0.5", features = ["alloc"] }
 scopeguard =  { version = "1.1.0", default-features = false }

internal/backends/winit/event_loop.rs

@@ -33,6 +33,7 @@ pub trait WinitWindow: WindowAdapter {
     /// Returns true if during the drawing request_redraw() was called.
     fn draw(&self) -> bool;
     fn with_window_handle(&self, callback: &mut dyn FnMut(&winit::window::Window));
+    fn winit_window(&self) -> Option<Rc<winit::window::Window>>;
     fn constraints(&self) -> (corelib::layout::LayoutInfo, corelib::layout::LayoutInfo);
     fn set_constraints(
         &self,
@@ -408,7 +409,18 @@ fn process_window_event(
             runtime_window.process_mouse_input(ev);
         }
         WindowEvent::Touch(touch) => {
-            let location = touch.location.to_logical(runtime_window.scale_factor() as f64);
+            let location = touch.location;
+            // https://github.com/slint-ui/slint/issues/2424: Work around winit reporting absolute coordinates for touch - until https://github.com/rust-windowing/winit/pull/2704 is merged & released.
+            #[cfg(target_family = "wasm")]
+            let location = {
+                let window_pos =
+                    window.winit_window().and_then(|w| w.inner_position().ok()).unwrap_or_default();
+                winit::dpi::PhysicalPosition::new(
+                    location.x - window_pos.x as f64,
+                    location.y - window_pos.y as f64,
+                )
+            };
+            let location = location.to_logical(runtime_window.scale_factor() as f64);
             let position = euclid::point2(location.x, location.y);
             let ev = match touch.phase {
                 winit::event::TouchPhase::Started => {

internal/backends/winit/glwindow.rs

@@ -208,6 +208,10 @@ impl<Renderer: WinitCompatibleRenderer + 'static> WinitWindow for GLWindow<Rende
         }
     }
 
+    fn winit_window(&self) -> Option<Rc<winit::window::Window>> {
+        self.borrow_mapped_window().map(|mapped_window| mapped_window.winit_window.clone())
+    }
+
     fn constraints(&self) -> (corelib::layout::LayoutInfo, corelib::layout::LayoutInfo) {
         self.borrow_mapped_window().map(|window| window.constraints.get()).unwrap_or_default()
     }
@@ -287,50 +291,46 @@ impl<Renderer: WinitCompatibleRenderer + 'static> WindowAdapterSealed for GLWind
     }
 
     fn apply_window_properties(&self, window_item: Pin<&i_slint_core::items::WindowItem>) {
-        // Make the unwrap() calls on self.borrow_mapped_window*() safe
-        if !self.is_mapped() {
-            return;
-        }
+        let winit_window = match self.winit_window() {
+            Some(handle) => handle,
+            None => return,
+        };
 
         let mut width = window_item.width().get() as f32;
         let mut height = window_item.height().get() as f32;
 
         let mut must_resize = false;
 
-        self.with_window_handle(&mut |winit_window| {
-            winit_window.set_window_icon(icon_to_winit(window_item.icon()));
-            winit_window.set_title(&window_item.title());
-            winit_window
-                .set_decorations(!window_item.no_frame() || winit_window.fullscreen().is_some());
+        winit_window.set_window_icon(icon_to_winit(window_item.icon()));
+        winit_window.set_title(&window_item.title());
+        winit_window
+            .set_decorations(!window_item.no_frame() || winit_window.fullscreen().is_some());
 
-            if width <= 0. || height <= 0. {
-                must_resize = true;
+        if width <= 0. || height <= 0. {
+            must_resize = true;
 
-                let winit_size =
-                    winit_window.inner_size().to_logical(self.window.scale_factor() as f64);
+            let winit_size =
+                winit_window.inner_size().to_logical(self.window.scale_factor() as f64);
 
-                if width <= 0. {
-                    width = winit_size.width;
-                }
-                if height <= 0. {
-                    height = winit_size.height;
-                }
+            if width <= 0. {
+                width = winit_size.width;
+            }
+            if height <= 0. {
+                height = winit_size.height;
             }
+        }
 
-            let existing_size: winit::dpi::LogicalSize<f32> =
-                winit_window.inner_size().to_logical(self.window.scale_factor().into());
+        let existing_size: winit::dpi::LogicalSize<f32> =
+            winit_window.inner_size().to_logical(self.window.scale_factor().into());
 
-            if (existing_size.width - width).abs() > 1.
-                || (existing_size.height - height).abs() > 1.
-            {
-                // If we're in fullscreen state, don't try to resize the window but maintain the surface
-                // size we've been assigned to from the windowing system. Weston/Wayland don't like it
-                // when we create a surface that's bigger than the screen due to constraints (#532).
-                if winit_window.fullscreen().is_none() {
-                    winit_window.set_inner_size(winit::dpi::LogicalSize::new(width, height));
-                }
+        if (existing_size.width - width).abs() > 1. || (existing_size.height - height).abs() > 1. {
+            // If we're in fullscreen state, don't try to resize the window but maintain the surface
+            // size we've been assigned to from the windowing system. Weston/Wayland don't like it
+            // when we create a surface that's bigger than the screen due to constraints (#532).
+            if winit_window.fullscreen().is_none() {
+                winit_window.set_inner_size(winit::dpi::LogicalSize::new(width, height));
             }
-        });
+        }
 
         if must_resize {
             self.window.set_size(i_slint_core::api::LogicalSize::new(width, height));

internal/renderers/skia/Cargo.toml

@@ -46,7 +46,7 @@ glow = { version = "0.12" }
 unicode-segmentation = { version = "1.8.0" }
 
 glutin = { version = "0.30", default-features = false, features = ["egl", "wgl"] }
-winit = { version = "0.28.2", optional = true, default-features = false }
+winit = { version = "0.28.3", optional = true, default-features = false }
 
 [target.'cfg(target_family = "windows")'.dependencies]
 winapi = { version = "0.3", features = ["impl-default", "dwrite", "d3d12", "dxgi", "dxgi1_2", "dxgi1_3", "dxgi1_4", "d3d12sdklayers", "synchapi", "winbase"] }