Synced resource example

examples/sync_resource_to_ui.rs

@@ -0,0 +1,50 @@
+use bevy::input::mouse::MouseMotion;
+use games::*;
+
+fn main() {
+    App::new()
+        .init_resource::<Thing>()
+        .add_plugins(BaseGamePlugin { camera: CameraType::Camera3d })
+        .add_systems(Startup, init_ui)
+        .add_systems(Update, (
+            sync_resource_to_ui::<Thing>.run_if(resource_changed::<Thing>),
+            update_foo.run_if(on_event::<MouseMotion>)
+        ))
+        .run();
+}
+
+#[derive(Resource, Debug, Default)]
+struct Thing(u8);
+
+impl Display for Thing {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+fn init_ui(
+    mut commands: Commands
+) {
+    commands.spawn((
+            Node {
+                align_self: AlignSelf::Start,
+                justify_self: JustifySelf::Center,
+                ..default()
+            },
+            Text("Displays a sync'd resource tracking the number of mouse events (mod 256)".into()),
+            ));
+    commands.spawn((Node {
+        align_self: AlignSelf::Center,
+        justify_self: JustifySelf::Center,
+        ..default()
+    }, Text("Placeholder".into()), SyncResource::<Thing>::default()));
+}
+
+fn update_foo(
+    mut events: EventReader<MouseMotion>,
+    mut thing: ResMut<Thing>,
+) {
+    events.read().for_each(|_| {
+        thing.0 = thing.0.overflowing_add(1).0;
+    });
+}

src/bin/hello/main.rs

@@ -1,16 +0,0 @@
-use games::*;
-
-fn main() {
-    App::new()
-        .add_plugins(BaseGamePlugin { camera: CameraType::Camera3d })
-        .add_systems(Update, (
-            f.run_if(any_component_added::<Foo>),
-            f.run_if(any_component_changed::<Foo>),
-        ))
-        .run();
-}
-
-#[derive(Component)]
-struct Foo;
-
-fn f() { }

src/debug.rs

@@ -1,5 +1,3 @@
-use bevy::color::palettes::css::{BLACK, RED, WHITE};
-
 use super::*;
 
 /// Debugging systems, resources, events, etc.

src/lib.rs

@@ -1,9 +1,13 @@
 mod base_game;
 mod debug;
 mod scheduling;
+mod ui;
 
-pub use bevy::{prelude::*, input::{keyboard::KeyboardInput, ButtonState}};
+pub use std::fmt::Display;
+
+pub use bevy::{prelude::*, input::{keyboard::KeyboardInput, ButtonState}, color::palettes::css::{BLACK, RED, WHITE}};
 
 pub use base_game::*;
 pub use debug::*;
 pub use scheduling::*;
+pub use ui::*;

src/ui.rs

@@ -0,0 +1,17 @@
+use super::*;
+
+/// Marker component for handling Resource -> Ui Sync
+#[derive(Component, Default, Debug)]
+pub struct SyncResource<R: Resource + Default + Display>(R);
+
+/// Sync a generic resource to the UI
+///
+/// Mostly useful for quick n' dirty getting data to the user
+pub fn sync_resource_to_ui<R: Resource + Default + Display>(
+    mut q: Query<&mut Text, With<SyncResource<R>>>,
+    r: Res<R>,
+) {
+    q.iter_mut().for_each(|mut t| {
+        t.0 = format!("{}", *r);
+    });
+}