Asset events and AddAsset builder

crates/bevy_asset/Cargo.toml

@@ -5,6 +5,8 @@ authors = ["Carter Anderson <mcanders1@gmail.com>"]
 edition = "2018"
 
 [dependencies]
+bevy_app = { path = "../bevy_app" }
 bevy_core = { path = "../bevy_core" }
+legion = { path = "../bevy_legion" }
 
 uuid = { version = "0.8", features = ["v4", "serde"] }

crates/bevy_asset/src/lib.rs

@@ -1,12 +1,19 @@
 mod handle;
 pub use handle::*;
 
+use bevy_app::{stage, AppBuilder, Events};
 use bevy_core::bytes::GetBytes;
+use legion::prelude::*;
 use std::collections::HashMap;
 
+pub enum AssetEvent<T> {
+    Created { handle: Handle<T> },
+}
+
 pub struct AssetStorage<T> {
     assets: HashMap<HandleId, T>,
     names: HashMap<String, Handle<T>>,
+    events: Events<AssetEvent<T>>,
 }
 
 impl<T> AssetStorage<T> {
@@ -14,6 +21,7 @@ impl<T> AssetStorage<T> {
         AssetStorage {
             assets: HashMap::new(),
             names: HashMap::new(),
+            events: Events::default(),
         }
     }
 
@@ -24,16 +32,21 @@ impl<T> AssetStorage<T> {
     pub fn add(&mut self, asset: T) -> Handle<T> {
         let id = HandleId::new();
         self.assets.insert(id, asset);
-        Handle::from_id(id)
+        let handle = Handle::from_id(id);
+        self.events.send(AssetEvent::Created { handle });
+        handle
     }
 
     pub fn add_with_handle(&mut self, handle: Handle<T>, asset: T) {
         self.assets.insert(handle.id, asset);
+        self.events.send(AssetEvent::Created { handle });
     }
 
     pub fn add_default(&mut self, asset: T) -> Handle<T> {
         self.assets.insert(DEFAULT_HANDLE_ID, asset);
-        Handle::default()
+        let handle = Handle::default();
+        self.events.send(AssetEvent::Created { handle });
+        handle
     }
 
     pub fn set_name(&mut self, name: &str, handle: Handle<T>) {
@@ -59,6 +72,13 @@ impl<T> AssetStorage<T> {
     pub fn iter(&self) -> impl Iterator<Item = (Handle<T>, &T)> {
         self.assets.iter().map(|(k, v)| (Handle::from_id(*k), v))
     }
+
+    pub fn asset_event_system(
+        mut events: ResourceMut<Events<AssetEvent<T>>>,
+        mut storage: ResourceMut<AssetStorage<T>>,
+    ) {
+        events.extend(storage.events.drain())
+    }
 }
 
 impl<T> GetBytes for Handle<T> {
@@ -70,3 +90,23 @@ impl<T> GetBytes for Handle<T> {
         None
     }
 }
+
+pub trait AddAsset {
+    fn add_asset<T>(&mut self) -> &mut Self
+    where
+        T: Send + Sync + 'static;
+}
+
+impl AddAsset for AppBuilder {
+    fn add_asset<T>(&mut self) -> &mut Self
+    where
+        T: Send + Sync + 'static,
+    {
+        self.add_resource(AssetStorage::<T>::new())
+            .add_system_to_stage(
+                stage::EVENT_UPDATE,
+                AssetStorage::<T>::asset_event_system.system(),
+            )
+            .add_event::<AssetEvent<T>>()
+    }
+}

crates/bevy_pbr/src/lib.rs

@@ -8,7 +8,7 @@ mod forward_pbr_render_graph;
 pub use forward_pbr_render_graph::*;
 
 use bevy_app::{stage, AppBuilder, AppPlugin};
-use bevy_asset::AssetStorage;
+use bevy_asset::AddAsset;
 use bevy_render::{render_graph::RenderGraph, shader};
 use legion::prelude::IntoSystem;
 use material::StandardMaterial;
@@ -19,11 +19,10 @@ pub struct PbrPlugin;
 
 impl AppPlugin for PbrPlugin {
     fn build(&self, app: &mut AppBuilder) {
-        app.add_resource(AssetStorage::<StandardMaterial>::new())
-            .add_system_to_stage(
-                stage::POST_UPDATE,
-                shader::asset_handle_shader_def_system::<StandardMaterial>.system(),
-            );
+        app.add_asset::<StandardMaterial>().add_system_to_stage(
+            stage::POST_UPDATE,
+            shader::asset_handle_shader_def_system::<StandardMaterial>.system(),
+        );
         let resources = app.resources();
         let mut render_graph = resources.get_mut::<RenderGraph>().unwrap();
         render_graph.add_pbr_graph(resources);

crates/bevy_render/src/lib.rs

@@ -41,7 +41,7 @@ use self::{
 
 use base_render_graph::{BaseRenderGraphBuilder, BaseRenderGraphConfig};
 use bevy_app::{stage, AppBuilder, AppPlugin};
-use bevy_asset::AssetStorage;
+use bevy_asset::AddAsset;
 use mesh::mesh_resource_provider_system;
 use render_graph::RenderGraph;
 
@@ -71,11 +71,11 @@ impl AppPlugin for RenderPlugin {
         app.add_stage_after(stage::POST_UPDATE, RENDER_RESOURCE_STAGE)
             .add_stage_after(RENDER_RESOURCE_STAGE, RENDER_STAGE)
             // resources
+            .add_asset::<Mesh>()
+            .add_asset::<Texture>()
+            .add_asset::<Shader>()
+            .add_asset::<PipelineDescriptor>()
             .add_resource(render_graph)
-            .add_resource(AssetStorage::<Mesh>::new())
-            .add_resource(AssetStorage::<Texture>::new())
-            .add_resource(AssetStorage::<Shader>::new())
-            .add_resource(AssetStorage::<PipelineDescriptor>::new())
             .add_resource(PipelineAssignments::new())
             .add_resource(PipelineCompiler::new())
             .add_resource(RenderResourceAssignments::default())

crates/bevy_ui/src/lib.rs

@@ -18,7 +18,7 @@ pub use sprite::*;
 pub use ui_update_system::*;
 
 use bevy_app::{stage, AppBuilder, AppPlugin};
-use bevy_asset::{AssetStorage, Handle};
+use bevy_asset::{AddAsset, AssetStorage, Handle};
 use bevy_render::{
     mesh::{shape::Quad, Mesh},
     render_graph::RenderGraph,
@@ -35,10 +35,7 @@ pub const QUAD_HANDLE: Handle<Mesh> = Handle::from_u128(142404619811301375266013
 
 impl AppPlugin for UiPlugin {
     fn build(&self, app: &mut AppBuilder) {
-        let mut color_materials = AssetStorage::<ColorMaterial>::new();
-        color_materials.add_default(ColorMaterial::default());
-
-        app.add_resource(color_materials)
+        app.add_asset::<ColorMaterial>()
             .add_system_to_stage(
                 stage::POST_UPDATE,
                 asset_handle_shader_def_system::<ColorMaterial>.system(),
@@ -57,5 +54,8 @@ impl AppPlugin for UiPlugin {
                 size: Vec2::new(1.0, 1.0),
             }),
         );
+
+        let mut color_materials = resources.get_mut::<AssetStorage<ColorMaterial>>().unwrap();
+        color_materials.add_default(ColorMaterial::default());
     }
 }

examples/shader/shader_custom_material.rs

@@ -3,6 +3,7 @@ use bevy::prelude::*;
 fn main() {
     App::build()
         .add_default_plugins()
+        .add_asset::<MyMaterial>()
         .add_startup_system(setup)
         .run();
 }
@@ -66,11 +67,10 @@ fn setup(world: &mut World, resources: &mut Resources) {
     };
 
     // create materials
-    let mut material_storage = AssetStorage::<MyMaterial>::new();
+    let mut material_storage = resources.get_mut::<AssetStorage<MyMaterial>>().unwrap();
     let material = material_storage.add(MyMaterial {
         color: Color::rgb(0.0, 0.8, 0.0),
     });
-    resources.insert(material_storage);
 
     let mut mesh_storage = resources.get_mut::<AssetStorage<Mesh>>().unwrap();
     let cube_handle = mesh_storage.add(Mesh::from(shape::Cube));

examples/shader/shader_defs.rs

@@ -3,6 +3,7 @@ use bevy::{prelude::*, render::shader};
 fn main() {
     App::build()
         .add_default_plugins()
+        .add_asset::<MyMaterial>()
         .add_startup_system(setup)
         .add_system_to_stage(
             stage::POST_UPDATE,
@@ -76,7 +77,7 @@ fn setup(world: &mut World, resources: &mut Resources) {
     };
 
     // create materials
-    let mut material_storage = AssetStorage::<MyMaterial>::new();
+    let mut material_storage = resources.get_mut::<AssetStorage<MyMaterial>>().unwrap();
     let green_material = material_storage.add(MyMaterial {
         color: Color::rgb(0.0, 0.8, 0.0),
         always_red: false,
@@ -86,7 +87,6 @@ fn setup(world: &mut World, resources: &mut Resources) {
         color: Color::rgb(0.0, 0.0, 0.0),
         always_red: true,
     });
-    resources.insert(material_storage);
 
     let mut mesh_storage = resources.get_mut::<AssetStorage<Mesh>>().unwrap();
     let cube_handle = mesh_storage.add(Mesh::from(shape::Cube));

src/prelude.rs

@@ -1,5 +1,5 @@
 #[cfg(feature = "asset")]
-pub use crate::asset::{AssetStorage, Handle};
+pub use crate::asset::{AddAsset, AssetEvent, AssetStorage, Handle};
 #[cfg(feature = "core")]
 pub use crate::core::{
     time::Time,