popover: Able to receive screensaver events

src/actors/popover.rs

@@ -11,30 +11,52 @@ but it cannot get the user-selected overlay, because it's stored in state.
 To solve this, overlay will be cached in the popover actor,
 and updated by main state every time it changes.
 */
+use super::Destination;
 
 pub mod c {
     use super::*;
     use crate::util::c::Wrapped;
     /// The mutable instance of state
     pub type Actor = Wrapped<State>;
+    /// It's the same because the state is a simple mutex-protected type.
+    /// There are no channels involved.
+    pub type Destination = Wrapped<State>;
+}
+
+pub enum Event {
+    Overlay(Option<String>),
+    ScreensaverActive(bool),
+}
+
+impl Destination for c::Destination {
+    type Event = Event;
+    fn send(&self, event: Self::Event) {
+        let actor = self.clone_ref();
+        let mut actor = actor.borrow_mut();
+        *actor = actor.clone().handle_event(event);
+    }
 }
 
 #[derive(Clone)]
 pub struct State {
     pub overlay: Option<String>,
+    /// Settings button active
+    pub settings_active: bool,
 }
 
 impl State {
-    pub fn new() -> Self {
-        Self { overlay: None }
+    pub fn new(settings_active: bool) -> Self {
+        Self {
+            overlay: None,
+            settings_active,
+        }
+    }
+    
+    fn handle_event(mut self, event: Event) -> Self {
+        match event {
+            Event::Overlay(overlay) => { self.overlay = overlay; },
+            Event::ScreensaverActive(lock_active) => { self.settings_active = !lock_active; },
+        };
+        self
     }
 }
-
-pub fn set_overlay(
-    actor: &c::Actor,
-    overlay: Option<String>,
-) {
-    let actor = actor.clone_ref();
-    let mut actor = actor.borrow_mut();
-    actor.overlay = overlay;
-}