From fac220fd64274a6cda4e5b34fefeab7a5b936b82 Mon Sep 17 00:00:00 2001
From: Alexander Mescheryakov <freecoder.xx@gmail.com>
Date: Thu, 20 Jan 2022 22:30:36 +0300
Subject: [PATCH] Fix add a listener to VTag when the listeners is None (#2375)

* Fix add listener and remove unused listener code

* Format code
---
 packages/yew/src/html/listener/macros.rs  | 64 -----------------------
 packages/yew/src/virtual_dom/listeners.rs | 32 ------------
 packages/yew/src/virtual_dom/vtag.rs      | 19 ++++---
 3 files changed, 12 insertions(+), 103 deletions(-)
 delete mode 100644 packages/yew/src/html/listener/macros.rs

diff --git a/packages/yew/src/html/listener/macros.rs b/packages/yew/src/html/listener/macros.rs
deleted file mode 100644
index 32eee2cfc..000000000
--- a/packages/yew/src/html/listener/macros.rs
+++ /dev/null
@@ -1,64 +0,0 @@
-macro_rules! impl_action {
-    ($($action:ident(name: $name:literal, event: $type:ident) -> $ret:ty => $convert:expr)*) => {$(
-        /// An abstract implementation of a listener.
-        #[doc(hidden)]
-        pub mod $action {
-            use crate::callback::Callback;
-            #[allow(unused_imports)]
-            use crate::html::{listener::*, IntoPropValue};
-            use crate::virtual_dom::Listener;
-            use gloo::events::{EventListener, EventListenerOptions};
-            use wasm_bindgen::JsValue;
-            use web_sys::{$type as WebSysType, Element, EventTarget};
-            use std::rc::Rc;
-
-            /// A wrapper for a callback which attaches event listeners to elements.
-            #[derive(Clone, Debug)]
-            pub struct Wrapper {
-                callback: Callback<Event>,
-            }
-
-            impl Wrapper {
-                /// Create a wrapper for an event-typed callback
-                pub fn new(callback: Callback<Event>) -> Self {
-                    Wrapper { callback }
-                }
-
-                #[doc(hidden)]
-                #[inline]
-                pub fn __macro_new(callback: impl IntoEventCallback<Event>) -> Option<Rc<dyn Listener>> {
-                    let callback = callback.into_event_callback()?;
-                    Some(Rc::new(Self::new(callback)))
-                }
-            }
-
-            /// And event type which keeps the returned type.
-            pub type Event = $ret;
-
-            impl Listener for Wrapper {
-                fn kind(&self) -> &'static str {
-                    stringify!($action)
-                }
-
-                fn attach(&self, element: &Element) -> EventListener {
-                    let this = element.clone();
-                    let callback = self.callback.clone();
-                    let listener = move |
-                        event: &web_sys::Event
-                    | {
-                        let event: WebSysType = JsValue::from(event).into();
-                        callback.emit($convert(&this, event));
-                    };
-                    // We should only set passive event listeners for `touchstart` and `touchmove`.
-                    // See here: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener#Improving_scrolling_performance_with_passive_listeners
-                    if $name == "touchstart" || $name == "touchmove" {
-                        EventListener::new(&EventTarget::from(element.clone()), $name, listener)
-                    } else {
-                        let options = EventListenerOptions::enable_prevent_default();
-                        EventListener::new_with_options(&EventTarget::from(element.clone()), $name, options, listener)
-                    }
-                }
-            }
-        }
-    )*};
-}
diff --git a/packages/yew/src/virtual_dom/listeners.rs b/packages/yew/src/virtual_dom/listeners.rs
index 7a9c0c0f5..0506ec680 100644
--- a/packages/yew/src/virtual_dom/listeners.rs
+++ b/packages/yew/src/virtual_dom/listeners.rs
@@ -525,7 +525,6 @@ mod tests {
     use crate::{html, html::TargetCast, AppHandle, Component, Context, Html};
     use gloo_utils::document;
     use wasm_bindgen::JsCast;
-    use wasm_bindgen_futures::JsFuture;
 
     #[derive(Clone)]
     enum Message {
@@ -655,37 +654,6 @@ mod tests {
         assert_count(&el, 2);
     }
 
-    async fn await_animation_frame() {
-        JsFuture::from(js_sys::Promise::new(&mut |resolve, _| {
-            gloo_utils::window()
-                .request_animation_frame(&resolve)
-                .unwrap();
-        }))
-        .await
-        .unwrap();
-    }
-
-    async fn assert_async<M: Mixin + 'static>() {
-        let (link, el) = init::<M>("a");
-
-        macro_rules! assert_after_click {
-            ($c:expr) => {
-                el.click();
-                await_animation_frame().await;
-                assert_count(&el, $c);
-            };
-        }
-
-        assert_count(&el, 0);
-
-        assert_after_click!(1);
-
-        assert_after_click!(2);
-
-        link.send_message(Message::StopListening);
-        assert_after_click!(2);
-    }
-
     #[test]
     async fn non_bubbling_event() {
         struct NonBubbling;
diff --git a/packages/yew/src/virtual_dom/vtag.rs b/packages/yew/src/virtual_dom/vtag.rs
index 01d425ca5..e524e43c3 100644
--- a/packages/yew/src/virtual_dom/vtag.rs
+++ b/packages/yew/src/virtual_dom/vtag.rs
@@ -434,14 +434,19 @@ impl VTag {
     /// Add event listener on the [VTag]'s  [Element].
     /// Returns `true` if the listener has been added, `false` otherwise.
     pub fn add_listener(&mut self, listener: Rc<dyn Listener>) -> bool {
-        if let Listeners::Pending(listeners) = &mut self.listeners {
-            let mut listeners = mem::take(listeners).into_vec();
-            listeners.push(Some(listener));
+        match &mut self.listeners {
+            Listeners::None => {
+                self.set_listeners([Some(listener)].into());
+                true
+            }
+            Listeners::Pending(listeners) => {
+                let mut listeners = mem::take(listeners).into_vec();
+                listeners.push(Some(listener));
 
-            self.set_listeners(listeners.into_boxed_slice());
-            true
-        } else {
-            false
+                self.set_listeners(listeners.into());
+                true
+            }
+            Listeners::Registered(_) => false,
         }
     }