feat(ecs): add stopping event loop

1 files changed, 115 insertions, 0 deletions

diff --git a/ecs/examples/event_loop.rs b/ecs/examples/event_loop.rs
new file mode 100644
index 0000000..f9fd85f
--- /dev/null
+++ b/ecs/examples/event_loop.rs
@@ -0,0 +1,115 @@
+use ecs::event::{Event, Id as EventId};
+use ecs::flags::Flags;
+use ecs::{Component, Query, World};
+
+#[derive(Component)]
+struct Wool
+{
+    remaining: u32,
+}
+
+#[derive(Component)]
+struct Health
+{
+    health: u32,
+}
+
+#[derive(Component)]
+struct Name
+{
+    name: &'static str,
+}
+
+fn sheer(query: Query<(Wool, Name)>)
+{
+    for (mut wool, name) in &query {
+        if wool.remaining == 0 {
+            println!("{} Has no wool left", name.name);
+
+            continue;
+        }
+
+        // Sheer the whool
+        wool.remaining -= 5;
+
+        println!("Sheered 5 wool from {}", name.name);
+    }
+}
+
+fn feed(query: Query<(Health, Name)>)
+{
+    for (mut health, name) in &query {
+        health.health += 1;
+
+        println!("Feeded {} which gained 1 health", name.name);
+    }
+}
+
+fn age(query: Query<(Health, Name)>, mut flags: Flags)
+{
+    for (mut health, name) in &query {
+        if health.health <= 2 {
+            health.health = 0;
+
+            println!("{} passed away", name.name);
+
+            flags.stop();
+
+            continue;
+        }
+
+        health.health -= 2;
+
+        println!("{} aged and lost 2 health", name.name);
+    }
+}
+
+#[derive(Debug)]
+struct EventA;
+
+impl Event for EventA
+{
+    fn id(&self) -> EventId
+    {
+        EventId::of::<Self>()
+    }
+}
+
+#[derive(Debug)]
+struct EventB;
+
+impl Event for EventB
+{
+    fn id(&self) -> EventId
+    {
+        EventId::of::<Self>()
+    }
+}
+
+#[derive(Debug)]
+struct EventC;
+
+impl Event for EventC
+{
+    fn id(&self) -> EventId
+    {
+        EventId::of::<Self>()
+    }
+}
+
+fn main()
+{
+    let mut world = World::new();
+
+    world.register_system(&EventA, sheer);
+    world.register_system(&EventB, feed);
+    world.register_system(&EventC, age);
+
+    world.create_entity((
+        Wool { remaining: 30 },
+        Health { health: 3 },
+        Name { name: "Bessy" },
+    ));
+
+    world.event_loop::<(EventA, EventB, EventC)>();
+}