fixes #120, support reload tab from disk

Author: yjpark

crates/notation_bevy/src/app/app.rs

@@ -104,6 +104,7 @@ impl NotationApp {
         app.init_resource::<NotationAppState>();
 
         app.add_startup_system(setup_camera.system());
+        //app.add_startup_system(setup_hot_reloading.system());
 
         app.add_system_set(
             SystemSet::on_enter(NotationAssetsStates::Loaded)
@@ -116,6 +117,7 @@ impl NotationApp {
                 .with_system(handle_mouse_inputs.system())
                 .with_system(handle_touch_inputs.system())
                 .with_system(load_tab.system())
+                .with_system(on_tab_asset.system())
         );
 
         extra(&mut app);
@@ -136,9 +138,34 @@ fn setup_camera(mut commands: Commands) {
     commands.spawn_bundle(OrthographicCameraBundle::new_2d());
 }
 
+/*
+ * The open tab logic is using some trick in the asset server, which can load from absolute path
+ * (outside assets folder), but the hot reloading is not working this way.
+ * Ideally can use hot-reloading to update tabs automatically, but that means need to patch bevy
+ * to bypass the assumption with asset path under assets folder in reloading.
+ * Leave the codes here in case that want to revisit this feature in the future.
+ *
+ * The crash error is:
+ *
+ * thread 'Compute Task Pool (2)' panicked at 'called `Result::unwrap()` on an `Err` value: StripPrefixError(())', C:\Users\yjpark\scoop\persist\rustup-msvc\.cargo\registry\src\github.com-1ecc6299db9ec823\bevy_asset-0.5.1\src\io\file_asset_io.rs:135:84
+ *
+fn setup_hot_reloading(asset_server: Res<AssetServer>) {
+    asset_server.watch_for_changes().unwrap();
+}
+ */
+
+fn on_tab_asset(
+    mut evts: EventReader<AssetEvent<TabAsset>>,
+) {
+    for evt in evts.iter() {
+        println!("AssetEvent<TabAsset> {:?}", evt);
+    }
+}
+
 fn load_tab(
     mut commands: Commands,
     time: Res<Time>,
+    asset_server: Res<AssetServer>,
     mut windows: ResMut<Windows>,
     mut state: ResMut<NotationAppState>,
     mut theme: ResMut<NotationTheme>,
@@ -171,13 +198,15 @@ fn load_tab(
             }
             return;
         }
+        asset_server.free_unused_assets();
         if state._load_tab_delay_seconds > 0.0 {
             state._load_tab_delay_seconds -= time.delta_seconds();
             println!("load_tab(): Waiting to Load tab: -> {}", state._load_tab_delay_seconds);
             return;
         }
         println!("\nload_tab(): Loading: {}", state.tab_path);
-        if let Some(asset) = assets.get(&state.tab_asset) {
+        let tab_asset: Handle<TabAsset> = asset_server.load(state.tab_path.as_str());
+        if let Some(asset) = assets.get(&tab_asset) {
             match Tab::try_parse_arc(asset.tab.clone()) {
                 Ok(tab) => {
                     state.tab = Some(tab.clone());
@@ -216,6 +245,8 @@ fn handle_keyboard_inputs(
         if !ControlView::HUD_MODE {
             window_resized_evts.send(WindowResizedEvent());
         }
+    } else if keyboard_input.just_released(KeyCode::F5) {
+        Control::reload_tab(&mut app_state, &mut theme);
     } else if keyboard_input.just_released(KeyCode::Space) {
         Control::play_or_pause(&mut midi_state, &mut play_control_evts);
     } else if keyboard_input.just_released(KeyCode::Return) {

crates/notation_bevy/src/app/app_state.rs

@@ -11,7 +11,6 @@ pub struct NotationAppState {
     pub window_height: f32,
     pub scale_factor_override: Option<f64>,
     pub tab_path: String,
-    pub tab_asset: Handle<TabAsset>,
     pub tab: Option<Arc<Tab>>,
     pub hide_control: bool,
     pub parse_error: Option<ParseError>,
@@ -21,14 +20,12 @@ pub struct NotationAppState {
 }
 
 impl NotationAppState {
-    pub fn new(asset_server: &AssetServer, tab_path: String) -> Self {
-        let tab_asset = asset_server.load(tab_path.as_str());
+    pub fn new(tab_path: String) -> Self {
         Self {
             window_width: 0.0,
             window_height: 0.0,
             scale_factor_override: None,
             tab_path,
-            tab_asset,
             tab: None,
             hide_control: true,
             parse_error: None,
@@ -39,17 +36,15 @@ impl NotationAppState {
     }
     pub fn change_tab(
         &mut self,
-        asset_server: &AssetServer,
         theme: &mut NotationTheme,
         tab_path: String
     ) {
         theme._bypass_systems = true;
         self.tab_path = tab_path;
-        self.tab_asset = asset_server.load(self.tab_path.as_str());
         self.parse_error = None;
-        self.reset_tab()
+        self.reload_tab()
     }
-    pub fn reset_tab(&mut self) {
+    pub fn reload_tab(&mut self) {
         self.tab = None;
         self._despawn_delay_seconds = 0.1;
         self._load_tab_delay_seconds = 0.2;
@@ -64,8 +59,7 @@ impl NotationAppState {
 
 impl FromWorld for NotationAppState {
     fn from_world(world: &mut World) -> Self {
-        let server = world.get_resource::<AssetServer>().unwrap();
         let tab_pathes = world.get_resource::<TabPathes>().unwrap();
-        Self::new(server, tab_pathes.0[0].clone())
+        Self::new(tab_pathes.0[0].clone())
     }
 }

crates/notation_bevy/src/viewer/control.rs

@@ -23,7 +23,7 @@ impl Control {
         if state.tab.is_none() {
             return;
         }
-        state.reset_tab();
+        state.reload_tab();
         theme._bypass_systems = true;
     }
     pub fn sync_speed_factor(

crates/notation_bevy/src/viewer/control_view.rs

@@ -426,7 +426,6 @@ impl ControlView {
     }
     pub fn tab_ui(
         ui: &mut Ui,
-        asset_server: &AssetServer,
         pathes: &mut TabPathes,
         state: &mut NotationAppState,
         _settings: &mut NotationSettings,
@@ -437,9 +436,10 @@ impl ControlView {
             return;
         }
         ui.horizontal(|ui| {
-            if ui.button("Reset Tab").clicked() {
+            if ui.button("Reload Tab").clicked() {
                 Control::reload_tab(state, theme);
             }
+            ui.separator();
             #[cfg(not(target_arch = "wasm32"))]
             if ui.button("Open Tab").clicked() {
                 if let Some(path) = rfd::FileDialog::new()
@@ -448,7 +448,7 @@ impl ControlView {
                     let path_str = path.clone().into_os_string().into_string();
                     if let Ok(path_str) = path_str {
                         pathes.0.insert(0, path_str.clone());
-                        state.change_tab(asset_server, theme, path_str.clone());
+                        state.change_tab(theme, path_str.clone());
                     } else {
                         println!("Failed to convert path to string: {:?} -> {:?}", path, path_str);
                     }
@@ -464,7 +464,7 @@ impl ControlView {
                     for path in pathes.0.iter() {
                         if ui.selectable_label(*path == state.tab_path, path).clicked()
                         {
-                            state.change_tab(asset_server, theme, path.clone());
+                            state.change_tab(theme, path.clone());
                         }
                     }
                 });
@@ -640,7 +640,6 @@ impl ControlView {
     pub fn control_ui(
         egui_ctx: Res<EguiContext>,
         mut windows: ResMut<Windows>,
-        asset_server: Res<AssetServer>,
         mut pathes: ResMut<TabPathes>,
         mut state: ResMut<NotationAppState>,
         mut settings: ResMut<NotationSettings>,
@@ -668,7 +667,7 @@ impl ControlView {
                     }
                     ui.separator();
                      */
-                    Self::tab_ui(ui, &asset_server, &mut pathes, &mut state, &mut settings, &mut theme);
+                    Self::tab_ui(ui, &mut pathes, &mut state, &mut settings, &mut theme);
                     ui.separator();
                     Self::play_control_ui(ui, &mut settings, &mut midi_state, &mut play_control_evts);
                     ui.separator();