Provide get_external_handle on DelegateCtx

CHANGELOG.md

@@ -10,6 +10,8 @@ You can find its changes [documented below](#070---2021-01-01).
 ### Added
 - Sub windows: Allow opening windows that share state with arbitrary parts of the widget hierarchy ([#1254] by [@rjwittams])
 - WindowCloseRequested/WindowDisconnected event when a window is closing ([#1254] by [@rjwittams])
+- RichTextBuilder ([#1520] by [@Maan2003])
+- `get_external_handle` on `DelegateCtx` ([#1526] by [@Maan2003])
 
 ### Changed
 
@@ -19,7 +21,7 @@ You can find its changes [documented below](#070---2021-01-01).
 
 ### Fixed
 
-- Fixed docs of derived Lens ([(#1523)] by [@Maan2003])
+- Fixed docs of derived Lens ([#1523] by [@Maan2003])
 
 ### Visual
 
@@ -592,7 +594,9 @@ Last release without a changelog :(
 [#1448]: https://github.com/linebender/druid/pull/1448
 [#1463]: https://github.com/linebender/druid/pull/1463
 [#1452]: https://github.com/linebender/druid/pull/1452
+[#1520]: https://github.com/linebender/druid/pull/1520
 [#1523]: https://github.com/linebender/druid/pull/1523
+[#1526]: https://github.com/linebender/druid/pull/1523
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.6.0...master
 [0.6.0]: https://github.com/linebender/druid/compare/v0.5.0...v0.6.0

druid/src/app_delegate.rs

@@ -17,15 +17,16 @@
 use std::any::{Any, TypeId};
 
 use crate::{
-    commands, core::CommandQueue, Command, Data, Env, Event, Handled, MenuDesc, SingleUse, Target,
-    WindowDesc, WindowId,
+    commands, core::CommandQueue, ext_event::ExtEventHost, Command, Data, Env, Event, ExtEventSink,
+    Handled, MenuDesc, SingleUse, Target, WindowDesc, WindowId,
 };
 
 /// A context passed in to [`AppDelegate`] functions.
 ///
 /// [`AppDelegate`]: trait.AppDelegate.html
 pub struct DelegateCtx<'a> {
     pub(crate) command_queue: &'a mut CommandQueue,
+    pub(crate) ext_event_host: &'a ExtEventHost,
     pub(crate) app_data_type: TypeId,
 }
 
@@ -45,6 +46,14 @@ impl<'a> DelegateCtx<'a> {
             .push_back(command.into().default_to(Target::Global))
     }
 
+    /// Returns an [`ExtEventSink`] that can be moved between threads,
+    /// and can be used to submit commands back to the application.
+    ///
+    /// [`ExtEventSink`]: struct.ExtEventSink.html
+    pub fn get_external_handle(&self) -> ExtEventSink {
+        self.ext_event_host.make_sink()
+    }
+
     /// Create a new window.
     /// `T` must be the application's root `Data` type (the type provided to [`AppLauncher::launch`]).
     ///

druid/src/win_handler.rs

@@ -193,20 +193,22 @@ impl<T: Data> Inner<T> {
     /// is configured.
     fn with_delegate<R, F>(&mut self, f: F) -> Option<R>
     where
-        F: FnOnce(&mut Box<dyn AppDelegate<T>>, &mut T, &Env, &mut DelegateCtx) -> R,
+        F: FnOnce(&mut dyn AppDelegate<T>, &mut T, &Env, &mut DelegateCtx) -> R,
     {
         let Inner {
             ref mut delegate,
             ref mut command_queue,
             ref mut data,
+            ref ext_event_host,
             ref env,
             ..
         } = self;
         let mut ctx = DelegateCtx {
             command_queue,
             app_data_type: TypeId::of::<T>(),
+            ext_event_host,
         };
-        if let Some(delegate) = delegate {
+        if let Some(delegate) = delegate.as_deref_mut() {
             Some(f(delegate, data, env, &mut ctx))
         } else {
             None