Prevent text selection

CHANGELOG.md

@@ -66,6 +66,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 - On Web, send mouse position on button release as well.
 - On Web, fix touch input not gaining or loosing focus.
 - **Breaking:** On Web, dropped support for Safari versions below 13.
+- On Web, prevent clicks on the canvas to select text.
 
 # 0.28.6
 

src/platform_impl/web/event_loop/window_target.rs

@@ -349,14 +349,8 @@ impl<T> EventLoopWindowTarget<T> {
             {
                 let runner = self.runner.clone();
                 let modifiers = self.modifiers.clone();
-                let has_focus = has_focus.clone();
 
                 move |pointer_id, position, button, active_modifiers| {
-                    let focus_changed = (!has_focus.replace(true)).then_some(Event::WindowEvent {
-                        window_id: RootWindowId(id),
-                        event: WindowEvent::Focused(true),
-                    });
-
                     let modifiers_changed = (modifiers.get() != active_modifiers).then(|| {
                         modifiers.set(active_modifiers);
                         Event::WindowEvent {
@@ -368,7 +362,7 @@ impl<T> EventLoopWindowTarget<T> {
                     // A mouse down event may come in without any prior CursorMoved events,
                     // therefore we should send a CursorMoved event to make sure that the
                     // user code has the correct cursor position.
-                    runner.send_events(focus_changed.into_iter().chain(modifiers_changed).chain([
+                    runner.send_events(modifiers_changed.into_iter().chain([
                         Event::WindowEvent {
                             window_id: RootWindowId(id),
                             event: WindowEvent::CursorMoved {
@@ -389,16 +383,9 @@ impl<T> EventLoopWindowTarget<T> {
             },
             {
                 let runner = self.runner.clone();
-                let has_focus = has_focus.clone();
 
                 move |device_id, location, force| {
-                    let focus_changed = (!has_focus.replace(true)).then_some(Event::WindowEvent {
-                        window_id: RootWindowId(id),
-                        event: WindowEvent::Focused(true),
-                    });
-
-                    runner.send_events(focus_changed.into_iter().chain(iter::once(
-                        Event::WindowEvent {
+                    runner.send_event(Event::WindowEvent {
                         window_id: RootWindowId(id),
                         event: WindowEvent::Touch(Touch {
                             id: device_id as u64,
@@ -407,10 +394,10 @@ impl<T> EventLoopWindowTarget<T> {
                             force: Some(force),
                             location,
                         }),
-                        },
-                    )));
+                    })
                 }
             },
+            prevent_default,
         );
 
         canvas.on_mouse_release(

src/platform_impl/web/web_sys/canvas.rs

@@ -235,13 +235,21 @@ impl Canvas {
             .on_mouse_release(&self.common, mouse_handler, touch_handler)
     }
 
-    pub fn on_mouse_press<M, T>(&mut self, mouse_handler: M, touch_handler: T)
-    where
+    pub fn on_mouse_press<M, T>(
+        &mut self,
+        mouse_handler: M,
+        touch_handler: T,
+        prevent_default: bool,
+    ) where
         M: 'static + FnMut(i32, PhysicalPosition<f64>, MouseButton, ModifiersState),
         T: 'static + FnMut(i32, PhysicalPosition<f64>, Force),
     {
-        self.pointer_handler
-            .on_mouse_press(&self.common, mouse_handler, touch_handler)
+        self.pointer_handler.on_mouse_press(
+            &self.common,
+            mouse_handler,
+            touch_handler,
+            prevent_default,
+        )
     }
 
     pub fn on_cursor_move<MOD, M, T, B>(

src/platform_impl/web/web_sys/pointer.rs

@@ -104,6 +104,7 @@ impl PointerHandler {
         canvas_common: &Common,
         mut mouse_handler: M,
         mut touch_handler: T,
+        prevent_default: bool,
     ) where
         M: 'static + FnMut(i32, PhysicalPosition<f64>, MouseButton, ModifiersState),
         T: 'static + FnMut(i32, PhysicalPosition<f64>, Force),
@@ -112,6 +113,13 @@ impl PointerHandler {
         self.on_pointer_press = Some(canvas_common.add_user_event(
             "pointerdown",
             move |event: PointerEvent| {
+                if prevent_default {
+                    // prevent text selection
+                    event.prevent_default();
+                    // but still focus element
+                    let _ = canvas.focus();
+                }
+
                 match event.pointer_type().as_str() {
                     "touch" => {
                         touch_handler(
@@ -192,6 +200,13 @@ impl PointerHandler {
                         "expect pointer type of a chorded button event to be a mouse"
                     );
 
+                    if prevent_default {
+                        // prevent text selection
+                        event.prevent_default();
+                        // but still focus element
+                        let _ = canvas.focus();
+                    }
+
                     button_handler(
                         id,
                         event::mouse_position(&event).to_physical(super::scale_factor()),