example: Add an idler action to thirst example

examples/thirst.rs

@@ -98,6 +98,42 @@ fn drink_action_system(
     }
 }
 
+#[derive(Debug, Clone)]
+struct Idle;
+
+impl Idle {
+    fn build() -> IdleBuilder {
+        IdleBuilder
+    }
+}
+
+#[derive(Debug, Clone)]
+struct IdleBuilder;
+
+impl ActionBuilder for IdleBuilder {
+    fn build(&self, cmd: &mut Commands, action: Entity, _actor: Entity) {
+        cmd.entity(action).insert(Idle);
+    }
+}
+
+fn idle_system(mut query: Query<&mut ActionState, With<Idle>>) {
+    for mut state in query.iter_mut() {
+        match *state {
+            ActionState::Requested => {
+                println!("Idling...");
+                *state = ActionState::Executing;
+            }
+            ActionState::Cancelled => {
+                println!("Idling cancelled");
+                *state = ActionState::Success;
+            }
+            ActionState::Executing => {
+                println!("Idled");
+            }
+            _ => {}
+        }
+    }
+}
 // Then, we have something called "Scorers". These are special components that
 // run in the background, calculating a "Score" value, which is what Big Brain
 // will use to pick which actions to execute.
@@ -156,7 +192,8 @@ pub fn init_entities(mut cmd: Commands) {
         Thinker::build()
             .picker(FirstToScore { threshold: 80.0 })
             // Note that what we pass in are _builders_, not components!
-            .when(Thirsty::build(), Drink::build()),
+            .when(Thirsty::build(), Drink::build())
+            .otherwise(Idle::build()),
     );
 }
 
@@ -169,5 +206,6 @@ fn main() {
         .add_system(thirst_system.system())
         .add_system(drink_action_system.system())
         .add_system(thirsty_scorer_system.system())
+        .add_system(idle_system.system())
         .run();
 }

src/thinker.rs

@@ -243,7 +243,6 @@ pub fn thinker_system(
                     // ...and then execute it (details below).
                     exec_picked_action(
                         &mut cmd,
-                        thinker_ent,
                         *actor,
                         &mut thinker,
                         &choice.action,
@@ -254,7 +253,6 @@ pub fn thinker_system(
                     let default_action_ent = default_action_ent.clone();
                     exec_picked_action(
                         &mut cmd,
-                        thinker_ent,
                         *actor,
                         &mut thinker,
                         &default_action_ent,
@@ -289,7 +287,6 @@ pub fn thinker_system(
 
 fn exec_picked_action(
     cmd: &mut Commands,
-    thinker_ent: Entity,
     actor: Entity,
     thinker: &mut Mut<Thinker>,
     picked_action: &ActionBuilderWrapper,