use an event channel instead of callbacks

Cargo.toml

@@ -3,15 +3,20 @@ name = "menu-rs"
 version = "0.0.0"
 edition = "2021"
 
-[target.'cfg(target_os = "windows")'.dependencies]
+[dependencies]
-windows-sys = { version = "0.34", features = [
+crossbeam-channel = "0.5"
+once_cell = "1.10"
+
+[target.'cfg(target_os = "windows")'.dependencies.windows-sys]
+version = "0.34"
+features = [
     "Win32_UI_WindowsAndMessaging",
     "Win32_Foundation",
-    "Win32_Graphics_Gdi"
+    "Win32_Graphics_Gdi",
-] }
+]
 
 [target.'cfg(target_os = "linux")'.dependencies]
-parking_lot = "0.12.0"
+parking_lot = "0.12"
 gtk = "0.15"
 
 [dev-dependencies]

examples/tao.rs

@@ -1,4 +1,4 @@
-use menu_rs::Menu;
+use menu_rs::{menu_event_receiver, Menu};
 #[cfg(target_os = "linux")]
 use tao::platform::unix::WindowExtUnix;
 #[cfg(target_os = "windows")]
@@ -9,12 +9,8 @@ use tao::{
     window::WindowBuilder,
 };
 
-enum UserEvent {
-    MenuEvent(u64),
-}
-
 fn main() {
-    let event_loop = EventLoop::<UserEvent>::with_user_event();
+    let event_loop = EventLoop::new();
 
     let window = WindowBuilder::new().build(&event_loop).unwrap();
     let window2 = WindowBuilder::new().build(&event_loop).unwrap();
@@ -23,19 +19,13 @@ fn main() {
     let mut file_menu = menu_bar.add_submenu("File", true);
     let mut edit_menu = menu_bar.add_submenu("Edit", true);
 
-    let mut open_item = file_menu.add_text_item("Open", true, |_| {});
+    let mut open_item = file_menu.add_text_item("Open", true);
 
-    let proxy = event_loop.create_proxy();
+    let mut save_item = file_menu.add_text_item("Save", true);
-    let mut counter = 0;
+    let _quit_item = file_menu.add_text_item("Quit", true);
-    let save_item = file_menu.add_text_item("Save", true, move |i| {
-        counter += 1;
-        i.set_label(format!("Save triggered {} times", counter));
-        let _ = proxy.send_event(UserEvent::MenuEvent(i.id()));
-    });
-    let _quit_item = file_menu.add_text_item("Quit", true, |_| {});
 
-    let _copy_item = edit_menu.add_text_item("Copy", true, |_| {});
+    let _copy_item = edit_menu.add_text_item("Copy", true);
-    let _cut_item = edit_menu.add_text_item("Cut", true, |_| {});
+    let _cut_item = edit_menu.add_text_item("Cut", true);
 
     #[cfg(target_os = "windows")]
     {
@@ -48,10 +38,29 @@ fn main() {
         menu_bar.init_for_gtk_window(window2.gtk_window());
     }
 
+    let menu_channel = menu_event_receiver();
     let mut open_item_disabled = false;
+    let counter = 0;
+
     event_loop.run(move |event, _, control_flow| {
         *control_flow = ControlFlow::Wait;
 
+        if let Ok(event) = menu_channel.try_recv() {
+            match event.id {
+                _ if event.id == save_item.id() => {
+                    println!("Save menu item triggered");
+
+                    save_item.set_label(format!("Save triggered {counter} times"));
+                    if !open_item_disabled {
+                        println!("Open item disabled!");
+                        open_item.set_enabled(false);
+                        open_item_disabled = true;
+                    }
+                }
+                _ => {}
+            }
+        }
+
         match event {
             Event::WindowEvent {
                 event: WindowEvent::CloseRequested,
@@ -60,20 +69,6 @@ fn main() {
             Event::MainEventsCleared => {
                 window.request_redraw();
             }
-
-            Event::UserEvent(e) => match e {
-                UserEvent::MenuEvent(id) => {
-                    if id == save_item.id() {
-                        println!("Save menu item triggered");
-
-                        if !open_item_disabled {
-                            println!("Open item disabled!");
-                            open_item.set_enabled(false);
-                            open_item_disabled = true;
-                        }
-                    }
-                }
-            },
             _ => (),
         }
     })

examples/winit.rs

@@ -1,4 +1,4 @@
-use menu_rs::Menu;
+use menu_rs::{menu_event_receiver, Menu};
 #[cfg(target_os = "windows")]
 use winit::platform::windows::WindowExtWindows;
 use winit::{
@@ -7,63 +7,61 @@ use winit::{
     window::WindowBuilder,
 };
 
-enum UserEvent {
-    MenuEvent(u64),
-}
-
 fn main() {
-    let event_loop = EventLoop::<UserEvent>::with_user_event();
+    let event_loop = EventLoop::new();
 
-    let _window = WindowBuilder::new().build(&event_loop).unwrap();
+    let window = WindowBuilder::new().build(&event_loop).unwrap();
-    let _window2 = WindowBuilder::new().build(&event_loop).unwrap();
+    let window2 = WindowBuilder::new().build(&event_loop).unwrap();
 
     let mut menu_bar = Menu::new();
     let mut file_menu = menu_bar.add_submenu("File", true);
     let mut edit_menu = menu_bar.add_submenu("Edit", true);
 
-    let mut open_item = file_menu.add_text_item("Open", true, |_| {});
+    let mut open_item = file_menu.add_text_item("Open", true);
 
-    let proxy = event_loop.create_proxy();
+    let mut save_item = file_menu.add_text_item("Save", true);
-    let mut counter = 0;
+    let _quit_item = file_menu.add_text_item("Quit", true);
-    let save_item = file_menu.add_text_item("Save", true, move |i| {
-        counter += 1;
-        i.set_label(format!("Save triggered {} times", counter));
-        let _ = proxy.send_event(UserEvent::MenuEvent(i.id()));
-    });
-    let _quit_item = file_menu.add_text_item("Quit", true, |_| {});
 
-    let _copy_item = edit_menu.add_text_item("Copy", true, |_| {});
+    let _copy_item = edit_menu.add_text_item("Copy", true);
-    let _cut_item = edit_menu.add_text_item("Cut", true, |_| {});
+    let _cut_item = edit_menu.add_text_item("Cut", true);
 
     #[cfg(target_os = "windows")]
     {
-        menu_bar.init_for_hwnd(_window.hwnd() as _);
+        menu_bar.init_for_hwnd(window.hwnd() as _);
-        menu_bar.init_for_hwnd(_window2.hwnd() as _);
+        menu_bar.init_for_hwnd(window2.hwnd() as _);
     }
 
+    let menu_channel = menu_event_receiver();
     let mut open_item_disabled = false;
+    let counter = 0;
+
     event_loop.run(move |event, _, control_flow| {
         *control_flow = ControlFlow::Wait;
 
+        if let Ok(event) = menu_channel.try_recv() {
+            match event.id {
+                _ if event.id == save_item.id() => {
+                    println!("Save menu item triggered");
+
+                    save_item.set_label(format!("Save triggered {counter} times"));
+                    if !open_item_disabled {
+                        println!("Open item disabled!");
+                        open_item.set_enabled(false);
+                        open_item_disabled = true;
+                    }
+                }
+                _ => {}
+            }
+        }
+
         match event {
             Event::WindowEvent {
                 event: WindowEvent::CloseRequested,
                 ..
             } => *control_flow = ControlFlow::Exit,
-
+            Event::MainEventsCleared => {
-            Event::UserEvent(e) => match e {
+                window.request_redraw();
-                UserEvent::MenuEvent(id) => {
+            }
-                    if id == save_item.id() {
-                        println!("Save menu item triggered");
-
-                        if !open_item_disabled {
-                            println!("Open item disabled!");
-                            open_item.set_enabled(false);
-                            open_item_disabled = true;
-                        }
-                    }
-                }
-            },
             _ => (),
         }
     })

src/lib.rs

@@ -1,6 +1,21 @@
+use crossbeam_channel::{unbounded, Receiver, Sender};
+use once_cell::sync::Lazy;
+
 mod platform_impl;
 mod util;
 
+static MENU_CHANNEL: Lazy<(Sender<MenuEvent>, Receiver<MenuEvent>)> = Lazy::new(|| unbounded());
+
+/// Event channel for receiving menu events.
+pub fn menu_event_receiver<'a>() -> &'a Receiver<MenuEvent> {
+    &MENU_CHANNEL.1
+}
+
+/// Describes a menu event emitted when a menu item is activated
+pub struct MenuEvent {
+    pub id: u64,
+}
+
 pub struct Menu(platform_impl::Menu);
 
 impl Menu {
@@ -36,13 +51,8 @@ impl Submenu {
         Submenu(self.0.add_submenu(label, enabled))
     }
 
-    pub fn add_text_item<F: FnMut(&mut TextMenuItem) + 'static>(
+    pub fn add_text_item(&mut self, label: impl AsRef<str>, enabled: bool) -> TextMenuItem {
-        &mut self,
+        TextMenuItem(self.0.add_text_item(label, enabled))
-        label: impl AsRef<str>,
-        enabled: bool,
-        f: F,
-    ) -> TextMenuItem {
-        TextMenuItem(self.0.add_text_item(label, enabled, f))
     }
 }
 

src/platform_impl/linux.rs

@@ -1,5 +1,5 @@
 use parking_lot::Mutex;
-use std::{cell::RefCell, rc::Rc, sync::Arc};
+use std::sync::Arc;
 
 use gtk::{prelude::*, Orientation};
 
@@ -17,7 +17,6 @@ struct MenuEntry {
     enabled: bool,
     entries: Option<Vec<Arc<Mutex<MenuEntry>>>>,
     etype: MenuEntryType,
-    item_handler: Option<Rc<RefCell<dyn FnMut(&mut crate::TextMenuItem) + 'static>>>,
     item_id: Option<u64>,
     menu_gtk_items: Option<Arc<Mutex<Vec<(gtk::MenuItem, gtk::Menu)>>>>,
     item_gtk_items: Option<Arc<Mutex<Vec<gtk::MenuItem>>>>,
@@ -46,7 +45,6 @@ impl Menu {
             enabled,
             entries: Some(Vec::new()),
             etype: MenuEntryType::Submenu,
-            item_handler: None,
             item_id: None,
             menu_gtk_items: Some(gtk_items.clone()),
             item_gtk_items: None,
@@ -78,7 +76,6 @@ impl Menu {
 
 fn add_entries_to_menu<M: IsA<gtk::MenuShell>>(gtk_menu: &M, entries: &Vec<Arc<Mutex<MenuEntry>>>) {
     for entry in entries {
-        let entry_clone = entry.clone();
         let mut entry = entry.lock();
         let gtk_item = gtk::MenuItem::with_label(&entry.label);
         gtk_menu.append(&gtk_item);
@@ -94,18 +91,9 @@ fn add_entries_to_menu<M: IsA<gtk::MenuShell>>(gtk_menu: &M, entries: &Vec<Arc<M
                 .lock()
                 .push((gtk_item, gtk_menu));
         } else {
-            let handler = Rc::clone(&entry.item_handler.as_mut().unwrap());
+            let id = entry.item_id.unwrap_or_default();
-            let item = TextMenuItem {
-                label: entry.label.clone(),
-                enabled: entry.enabled,
-                id: entry.item_id.unwrap(),
-                entry: entry_clone,
-                gtk_items: entry.item_gtk_items.as_ref().unwrap().clone(),
-            };
             gtk_item.connect_activate(move |_| {
-                let mut handler = handler.borrow_mut();
+                let _ = crate::MENU_CHANNEL.0.send(crate::MenuEvent { id });
-                let mut item = crate::TextMenuItem(item.clone());
-                handler(&mut item);
             });
             entry.item_gtk_items.as_mut().unwrap().lock().push(gtk_item);
         }
@@ -148,7 +136,6 @@ impl Submenu {
             enabled,
             entries: Some(Vec::new()),
             etype: MenuEntryType::Submenu,
-            item_handler: None,
             item_id: None,
             menu_gtk_items: Some(gtk_items.clone()),
             item_gtk_items: None,
@@ -167,12 +154,7 @@ impl Submenu {
         }
     }
 
-    pub fn add_text_item<F: FnMut(&mut crate::TextMenuItem) + 'static>(
+    pub fn add_text_item(&mut self, label: impl AsRef<str>, enabled: bool) -> TextMenuItem {
-        &mut self,
-        label: impl AsRef<str>,
-        enabled: bool,
-        f: F,
-    ) -> TextMenuItem {
         let id = COUNTER.next();
         let label = label.as_ref().to_string();
         let gtk_items = Arc::new(Mutex::new(Vec::new()));
@@ -181,7 +163,6 @@ impl Submenu {
             enabled,
             entries: None,
             etype: MenuEntryType::Text,
-            item_handler: Some(Rc::new(RefCell::new(f))),
             item_id: Some(id),
             menu_gtk_items: None,
             item_gtk_items: Some(gtk_items.clone()),