Route id (#1978)

* implemented route

Signed-off-by: Christoph <xarvix@web.de>

* update CHANGELOG.md

Signed-off-by: Christoph <xarvix@web.de>

* reformat

Signed-off-by: Christoph <xarvix@web.de>

* Update command.rs

* Update druid/src/command.rs

Co-authored-by: Manmeet Maan <49202620+Maan2003@users.noreply.github.com>

* add send notifications test

Signed-off-by: Christoph <xarvix@web.de>

* fix

Signed-off-by: Christoph <xarvix@web.de>

* fix

Signed-off-by: Christoph <xarvix@web.de>

Co-authored-by: Christoph <xarvix@web.de>
Co-authored-by: Manmeet Maan <49202620+Maan2003@users.noreply.github.com>

CHANGELOG.md

@@ -58,6 +58,7 @@ You can find its changes [documented below](#070---2021-01-01).
 - Add #[data(eq)] shorthand attribute for Data derive macro ([#1884] by [@Maan2003])
 - X11: detect keyboard layout ([#1779] by [@Maan2003])
 - WindowDesc::with_config ([#1929] by [@Maan2003])
+- `Notification::route` ([#1978] by [@xarvic])
 
 ### Changed
 
@@ -793,8 +794,9 @@ Last release without a changelog :(
 [#1919]: https://github.com/linebender/druid/pull/1919
 [#1929]: https://github.com/linebender/druid/pull/1929
 [#1947]: https://github.com/linebender/druid/pull/1947
-[#1967]: https://github.com/linebender/druid/pull/1967
 [#1953]: https://github.com/linebender/druid/pull/1953
+[#1967]: https://github.com/linebender/druid/pull/1967
+[#1978]: https://github.com/linebender/druid/pull/1978
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.7.0...master
 [0.7.0]: https://github.com/linebender/druid/compare/v0.6.0...v0.7.0

druid/src/command.rs

@@ -103,6 +103,7 @@ pub struct Notification {
     symbol: SelectorSymbol,
     payload: Arc<dyn Any>,
     source: WidgetId,
+    route: WidgetId,
 }
 
 /// A wrapper type for [`Command`] payloads that should only be used once.
@@ -407,6 +408,7 @@ impl Command {
             symbol: self.symbol,
             payload: self.payload,
             source,
+            route: source,
         }
     }
 
@@ -528,6 +530,34 @@ impl Notification {
     pub fn source(&self) -> WidgetId {
         self.source
     }
+
+    /// Change the route id
+    pub(crate) fn with_route(mut self, widget_id: WidgetId) -> Self {
+        self.route = widget_id;
+        self
+    }
+
+    /// The [`WidgetId`] of the last [`Widget`] that this [`Notification`] was passed through.
+    ///
+    /// # Example
+    ///
+    /// ```ignore
+    /// fn event(&mut self, ctx: &mut EventCtx, event: &Event, data: &mut (), env: &Env) {
+    ///     if let Event::Notification(notification) = event {
+    ///         if notification.route() == self.widget1.id() {
+    ///             // the notification came from inside of widget1
+    ///         }
+    ///         if notification.route() == self.widget2.id() {
+    ///             // the notification came from inside of widget2
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    ///
+    /// [`Widget`]: crate::Widget
+    pub fn route(&self) -> WidgetId {
+        self.route
+    }
 }
 
 impl<T: Any> SingleUse<T> {

druid/src/core.rs

@@ -903,7 +903,9 @@ impl<T: Data, W: Widget<T>> WidgetPod<T, W> {
                     inner_ctx.is_handled = false;
                 } else if let Event::Notification(notification) = event {
                     // we will try again with the next parent
-                    inner_ctx.notifications.push_back(notification);
+                    inner_ctx
+                        .notifications
+                        .push_back(notification.with_route(self_id));
                 } else {
                     // could be unchecked but we avoid unsafe in druid :shrug:
                     unreachable!()
@@ -1376,7 +1378,7 @@ mod tests {
     use super::*;
     use crate::ext_event::ExtEventHost;
     use crate::text::ParseFormatter;
-    use crate::widget::{Flex, Scroll, Split, TextBox};
+    use crate::widget::{Button, Flex, Scroll, Split, TextBox};
     use crate::{WidgetExt, WindowHandle, WindowId};
     use test_env_log::test;
 
@@ -1438,4 +1440,60 @@ mod tests {
         // A textbox is composed of three components with distinct ids
         assert_eq!(ctx.widget_state.children.entry_count(), 15);
     }
+
+    #[test]
+    fn send_notifications() {
+        let mut widget = WidgetPod::new(Button::new("test".to_owned())).boxed();
+
+        let mut command_queue: CommandQueue = VecDeque::new();
+        let mut widget_state = WidgetState::new(WidgetId::next(), None);
+        let window = WindowHandle::default();
+        let ext_host = ExtEventHost::default();
+        let ext_handle = ext_host.make_sink();
+        let mut state = ContextState::new::<Option<u32>>(
+            &mut command_queue,
+            &ext_handle,
+            &window,
+            WindowId::next(),
+            None,
+        );
+
+        let mut ctx = EventCtx {
+            widget_state: &mut widget_state,
+            notifications: &mut Default::default(),
+            is_handled: false,
+            state: &mut state,
+            is_root: false,
+        };
+
+        let ids = [
+            WidgetId::next(),
+            WidgetId::next(),
+            WidgetId::next(),
+            WidgetId::next(),
+        ];
+
+        let env = Env::with_default_i10n();
+
+        let notification = Command::new(druid::command::sys::CLOSE_WINDOW, (), Target::Global);
+
+        let mut notifictions = VecDeque::from(vec![
+            notification.clone().into_notification(ids[0]),
+            notification.clone().into_notification(ids[1]),
+            notification.clone().into_notification(ids[2]),
+            notification.into_notification(ids[3]),
+        ]);
+
+        widget.send_notifications(&mut ctx, &mut notifictions, &mut (), &env);
+
+        assert_eq!(ctx.notifications.len(), 4);
+        assert_eq!(ctx.notifications[0].source(), ids[0]);
+        assert_eq!(ctx.notifications[0].route(), widget.id());
+        assert_eq!(ctx.notifications[1].source(), ids[1]);
+        assert_eq!(ctx.notifications[1].route(), widget.id());
+        assert_eq!(ctx.notifications[2].source(), ids[2]);
+        assert_eq!(ctx.notifications[2].route(), widget.id());
+        assert_eq!(ctx.notifications[3].source(), ids[3]);
+        assert_eq!(ctx.notifications[3].route(), widget.id());
+    }
 }