diff --git a/src/platform_impl/web/web_sys/scaling.rs b/src/platform_impl/web/web_sys/scaling.rs index 0b2fe68480..1c13e1b04e 100644 --- a/src/platform_impl/web/web_sys/scaling.rs +++ b/src/platform_impl/web/web_sys/scaling.rs @@ -21,7 +21,7 @@ impl ScaleChangeDetector { struct ScaleChangeDetectorInternal { window: web_sys::Window, callback: Box, - mql: Option, + mql: MediaQueryListHandle, last_scale: f64, } @@ -31,24 +31,21 @@ impl ScaleChangeDetectorInternal { F: 'static + FnMut(ScaleChangeArgs), { let current_scale = super::scale_factor(&window); - let new_self = Rc::new(RefCell::new(Self { - window: window.clone(), - callback: Box::new(handler), - mql: None, - last_scale: current_scale, - })); + Rc::new_cyclic(|weak_self| { + let weak_self = weak_self.clone(); + let mql = Self::create_mql(&window, move |mql| { + if let Some(rc_self) = weak_self.upgrade() { + Self::handler(rc_self, mql); + } + }); - let weak_self = Rc::downgrade(&new_self); - let mql = Self::create_mql(&window, move |mql| { - if let Some(rc_self) = weak_self.upgrade() { - Self::handler(rc_self, mql); - } - }); - { - let mut borrowed_self = new_self.borrow_mut(); - borrowed_self.mql = Some(mql); - } - new_self + RefCell::new(Self { + window, + callback: Box::new(handler), + mql, + last_scale: current_scale, + }) + }) } fn create_mql(window: &web_sys::Window, closure: F) -> MediaQueryListHandle @@ -65,7 +62,7 @@ impl ScaleChangeDetectorInternal { assert!( mql.mql().matches(), "created media query doesn't match, {current_scale} != {}", - super::scale_factor(window,) + super::scale_factor(window) ); mql } @@ -75,21 +72,31 @@ impl ScaleChangeDetectorInternal { let mut this = this.borrow_mut(); let old_scale = this.last_scale; let new_scale = super::scale_factor(&this.window); + + // TODO: confirm/reproduce this problem, see: + // . + // This should never happen, but if it does then apparently the scale factor didn't change. + if mql.matches() { + warn!( + "media query tracking scale factor was triggered without a change:\n\ + Media Query: {}\n\ + Current Scale: {new_scale}", + mql.media(), + ); + return; + } + (this.callback)(ScaleChangeArgs { old_scale, new_scale, }); - // If this matches, then the scale factor is back to it's - // old value again, so we won't need to update the query. - if !mql.matches() { - let new_mql = Self::create_mql(&this.window, move |mql| { - if let Some(rc_self) = weak_self.upgrade() { - Self::handler(rc_self, mql); - } - }); - this.mql = Some(new_mql); - this.last_scale = new_scale; - } + let new_mql = Self::create_mql(&this.window, move |mql| { + if let Some(rc_self) = weak_self.upgrade() { + Self::handler(rc_self, mql); + } + }); + this.mql = new_mql; + this.last_scale = new_scale; } }