move enable_web_page_scroll into prevent_default option

Author: rukai

CHANGELOG.md

@@ -16,7 +16,7 @@ And please only add new entries to the top of this list, right below the `# Unre
 - On Windows, added `WindowExtWindows::set_undecorated_shadow` and `WindowBuilderExtWindows::with_undecorated_shadow` to draw the drop shadow behind a borderless window.
 - On Windows, fixed default window features (ie snap, animations, shake, etc.) when decorations are disabled.
 - **Breaking:** On macOS, add support for two-finger touchpad magnification and rotation gestures with new events `WindowEvent::TouchpadMagnify` and `WindowEvent::TouchpadRotate`.
-- On web, by default, when the canvas is focused, scrolling of the webpage is disabled. It can however be enabled via the `WindowBuilderExtWebSys::enable_web_page_scroll` method.
+- On web, the `WindowBuilderExtWebSys::with_prevent_default` setting (enabled by default), now additionally prevents scrolling of the webpage in mobile browsers, previously it only disabled scrolling on desktop.
 - On Wayland, `wayland-csd-adwaita` now uses `ab_glyph` instead of `crossfont` to render the title for decorations.
 - On Wayland, a new `wayland-csd-adwaita-crossfont` feature was added to use `crossfont` instead of `ab_glyph` for decorations.
 - On Wayland, if not otherwise specified use upstream automatic CSD theme selection.

src/platform/web.rs

@@ -19,15 +19,6 @@ pub trait WindowExtWebSys {
 }
 
 pub trait WindowBuilderExtWebSys {
-    /// Enable scrolling of the web page the canvas is in when the canvas is focused.
-    ///
-    /// Scrolling is disabled by default because the scroll input on many mobile devices
-    /// is the same as click and dragging which is a very common input method for many applications.
-    ///
-    /// So only call this method if you know that you will never need to handle mouse wheel inputs
-    /// or click and dragging.
-    fn enable_web_page_scroll(self) -> Self;
-
     fn with_canvas(self, canvas: Option<HtmlCanvasElement>) -> Self;
 
     /// Whether `event.preventDefault` should be automatically called to prevent event propagation
@@ -43,12 +34,6 @@ pub trait WindowBuilderExtWebSys {
 }
 
 impl WindowBuilderExtWebSys for WindowBuilder {
-    fn enable_web_page_scroll(mut self) -> Self {
-        self.platform_specific.enable_web_page_scroll = true;
-
-        self
-    }
-
     fn with_canvas(mut self, canvas: Option<HtmlCanvasElement>) -> Self {
         self.platform_specific.canvas = canvas;
 

src/platform_impl/web/web_sys/canvas.rs

@@ -32,7 +32,7 @@ pub struct Canvas {
     on_fullscreen_change: Option<EventListener>,
     on_dark_mode: Option<MediaQueryListHandle>,
     mouse_state: MouseState,
-    disable_web_scroll: Option<[EventListener; 5]>,
+    disable_mobile_scroll: Option<[EventListener; 3]>,
 }
 
 struct Common {
@@ -82,11 +82,8 @@ impl Canvas {
             wants_fullscreen: Rc::new(RefCell::new(false)),
         };
 
-        let disable_web_scroll = if !attr.enable_web_page_scroll && attr.prevent_default {
+        let disable_mobile_scroll = if attr.prevent_default {
             Some([
-                common.add_event("pointermove", move |event: Event| {
-                    event.prevent_default();
-                }),
                 common.add_event("pointermove", move |event: Event| {
                     event.prevent_default();
                 }),
@@ -96,9 +93,6 @@ impl Canvas {
                 common.add_event("touchend", move |event: Event| {
                     event.prevent_default();
                 }),
-                common.add_event("wheel", move |event: Event| {
-                    event.prevent_default();
-                }),
             ])
         } else {
             None
@@ -114,7 +108,7 @@ impl Canvas {
             on_fullscreen_change: None,
             on_dark_mode: None,
             mouse_state,
-            disable_web_scroll,
+            disable_mobile_scroll,
             common,
         })
     }
@@ -300,11 +294,15 @@ impl Canvas {
         }
     }
 
-    pub fn on_mouse_wheel<F>(&mut self, mut handler: F, _prevent_default: bool)
+    pub fn on_mouse_wheel<F>(&mut self, mut handler: F, prevent_default: bool)
     where
         F: 'static + FnMut(i32, MouseScrollDelta, ModifiersState),
     {
         self.on_mouse_wheel = Some(self.common.add_event("wheel", move |event: WheelEvent| {
+            if prevent_default {
+                event.prevent_default();
+            }
+
             if let Some(delta) = event::mouse_scroll_delta(&event) {
                 handler(0, delta, event::mouse_modifiers(&event));
             }

src/platform_impl/web/window.rs

@@ -404,7 +404,6 @@ pub struct PlatformSpecificWindowBuilderAttributes {
     pub(crate) canvas: Option<backend::RawCanvasType>,
     pub(crate) prevent_default: bool,
     pub(crate) focusable: bool,
-    pub(crate) enable_web_page_scroll: bool,
 }
 
 impl Default for PlatformSpecificWindowBuilderAttributes {
@@ -413,7 +412,6 @@ impl Default for PlatformSpecificWindowBuilderAttributes {
             canvas: None,
             prevent_default: true,
             focusable: true,
-            enable_web_page_scroll: false,
         }
     }
 }