Write some documentation for the LocalObserver
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@ -39,12 +39,19 @@ where
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result
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}
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/// LocalObserver creates a task on the current thread which watches the specified observer for notifications and calls the handler function with each one.
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///
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/// The LocalObserver starts a task which listens for notifications during the constructor. When the observer goes out of scope, it will make a point of aborting the task. This combination means that anything which uses the observer can create it, hold on to a reference of it, and then drop it when done, and not have to do anything else with the observer object.
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struct LocalObserver<T> {
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join_handle: glib::JoinHandle<()>,
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handler: Rc<dyn Fn(T)>,
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}
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impl<T: 'static> LocalObserver<T> {
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/// Construct a new LocalObserver and start it running.
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///
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/// observable -- any object which emits events
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/// handler -- a function which can process events
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fn new(observable: &dyn Observable<T>, handler: impl Fn(T) + 'static) -> Self {
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let listener = observable.subscribe();
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let handler = Rc::new(handler);
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@ -54,8 +61,9 @@ impl<T: 'static> LocalObserver<T> {
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loop {
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match listener.recv().await {
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Ok(msg) => handler(msg),
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Err(err) => {
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unimplemented!("Should display an error message in the UI: {}", err)
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Err(_) => {
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// recv only fails if the channel has been closed and no other notifications are pending. This will break out of the loop and terminate the observer.
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return;
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}
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}
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yield_now().await;
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@ -71,6 +79,7 @@ impl<T: 'static> LocalObserver<T> {
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impl<T> Drop for LocalObserver<T> {
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fn drop(&mut self) {
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// Abort the task when the observer goes out of scope.
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self.join_handle.abort();
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}
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}
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@ -17,7 +17,7 @@ You should have received a copy of the GNU General Public License along with Kif
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use crate::LocalObserver;
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use kifu_core::{Core, CoreNotification};
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/// DatabaseViewModel controls the view that the user sees when starting the application if the application has been configured and if there are no games in progress. It provides a window into the database, showing a list of recently recorded games (whether from this app or from a main database). It also provides the UI for starting a new game. This will render an empty database view if the user hasn't configured a database yet.
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/// Home controls the view that the user sees when starting the application if there are no games in progress. It provides a window into the database, showing a list of recently recorded games. It also provides the UI for starting a new game. This will render an empty database view if the user hasn't configured a database yet.
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pub struct HomeViewModel {
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core: Core,
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notification_observer: LocalObserver<CoreNotification>,
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