feat: implement initial persisted storage API.

There is a lot that should be improved on, but it is
usable for now.

demos/features/assets/locales/en-US/menu.ftl

@@ -4,3 +4,5 @@ sprite-demo = Sprite Demo
 atlas-demo = Atlas Demo
 tilemap-demo = Tilemap Demo
 path2d-demo = Path2D Demo
+save = Save
+persisted-text-box-content = Persisted text box content

demos/features/src/main.rs

@@ -77,11 +77,13 @@ struct TileMeta {
     idx: u32,
 }
 
+#[derive(HasSchema, Default, Clone)]
+#[repr(C)]
+struct PersistedTextData(String);
+
 fn main() {
-    assert!(Color::schema()
-        .type_data
-        .get::<SchemaDeserialize>()
-        .is_some());
+    // Register persistent data's schema so that it can be loaded by the storage loader.
+    PersistedTextData::schema();
 
     // Create a bones bevy renderer from our bones game
     BonesBevyRenderer::new(create_game())
@@ -141,6 +143,7 @@ fn menu_system(
     ctx: Egui,
     mut sessions: ResMut<Sessions>,
     mut session_options: ResMut<SessionOptions>,
+    mut storage: ResMut<Storage>,
     // Get the localization field from our `GameMeta`
     localization: Localization<GameMeta>,
 ) {
@@ -208,6 +211,21 @@ fn menu_system(
 
                     ui.add_space(20.0);
 
+                    ui.vertical_centered(|ui| {
+                        ui.set_width(300.0);
+                        {
+                            let data = storage.get_or_insert_default_mut::<PersistedTextData>();
+                            egui::TextEdit::singleline(&mut data.0)
+                                .hint_text(localization.get("persisted-text-box-content"))
+                                .show(ui);
+                        }
+                        if ui.button(localization.get("save")).clicked() {
+                            storage.save()
+                        }
+                    });
+
+                    ui.add_space(10.0);
+
                     // We can use the `widget()` method on the `Egui` to conveniently run bones
                     // systems that can modify the `egui::Ui` and return an `egui::Response`.
                     //
@@ -447,5 +465,5 @@ fn demo_widget(
     ui.label("Demo Widget");
     // When using a bones image in egui, we have to get it's corresponding egui texture
     // from the egui textures resource.
-    ui.image(egui_textures.get(meta.menu_image), [100., 100.])
+    ui.image(egui_textures.get(meta.menu_image), [50., 50.])
 }

framework_crates/bones_bevy_renderer/Cargo.toml

@@ -20,8 +20,14 @@ bones_framework = { version = "0.3", path = "../bones_framework" }
 bevy_egui           = "0.21"
 glam                = { version = "0.24", features = ["serde"] }
 bevy_prototype_lyon = "0.9"
+serde_yaml          = "0.9"
+serde = "1.0.188"
+anyhow    = "1.0"
 
 [dependencies.bevy]
 default-features = false
 features         = ["bevy_render", "bevy_core_pipeline", "bevy_sprite", "x11", "bevy_gilrs"]
 version          = "0.11"
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+directories = "5.0"

framework_crates/bones_bevy_renderer/src/lib.rs

@@ -7,6 +7,7 @@
 
 use std::path::PathBuf;
 
+use anyhow::Context;
 pub use bevy;
 
 use bevy::{
@@ -24,8 +25,9 @@ use bevy_egui::EguiContext;
 use glam::*;
 
 use bevy_prototype_lyon::prelude as lyon;
-use bones_framework::prelude as bones;
+use bones_framework::prelude::{self as bones, SchemaBox};
 use prelude::convert::{IntoBevy, IntoBones};
+use serde::{de::Visitor, Deserialize, Serialize};
 
 /// The prelude
 pub mod prelude {
@@ -47,6 +49,11 @@ pub struct BonesBevyRenderer {
     pub game: bones::Game,
     /// The version of the game, used for the asset loader.
     pub game_version: bones::Version,
+    /// The (qualifier, organization, application) that will be used to pick a persistent storage
+    /// location for the game.
+    ///
+    /// For example: `("org", "fishfolk", "jumpy")`
+    pub app_namespace: (String, String, String),
     /// The path to load assets from.
     pub asset_dir: PathBuf,
     /// The path to load asset packs from.
@@ -178,6 +185,7 @@ impl BonesBevyRenderer {
             pixel_art: true,
             game,
             game_version: bones::Version::new(0, 1, 0),
+            app_namespace: ("org".into(), "fishfolk".into(), "bones_demo_game".into()),
             asset_dir: PathBuf::from("assets"),
             packs_dir: PathBuf::from("packs"),
         }
@@ -236,6 +244,15 @@ impl BonesBevyRenderer {
             );
         }
 
+        // Configure and load the persitent storage
+        let mut storage = bones::Storage::with_backend(Box::new(StorageBackend::new(
+            &self.app_namespace.0,
+            &self.app_namespace.1,
+            &self.app_namespace.2,
+        )));
+        storage.load();
+        self.game.insert_shared_resource(storage);
+
         self.game.insert_shared_resource(bones_egui_textures);
         app.insert_resource(bones_image_ids);
 
@@ -280,6 +297,129 @@ impl BonesBevyRenderer {
     }
 }
 
+struct StorageBackend {
+    storage_path: PathBuf,
+}
+impl StorageBackend {
+    fn new(qualifier: &str, organization: &str, application: &str) -> Self {
+        let project_dirs = directories::ProjectDirs::from(qualifier, organization, application)
+            .expect("Identify system data dir path");
+        Self {
+            storage_path: project_dirs.data_dir().join("storage.yml"),
+        }
+    }
+}
+#[cfg(not(target_arch = "wasm32"))]
+impl bones::StorageApi for StorageBackend {
+    fn save(&mut self, data: Vec<bones::SchemaBox>) {
+        let file = std::fs::OpenOptions::new()
+            .write(true)
+            .truncate(true)
+            .create(true)
+            .open(&self.storage_path)
+            .expect("Failed to open storage file");
+        let mut serializer = serde_yaml::Serializer::new(file);
+        LoadedStorage(data)
+            .serialize(&mut serializer)
+            .expect("Failed to serialize to storage file.");
+    }
+
+    fn load(&mut self) -> Vec<bones::SchemaBox> {
+        if self.storage_path.exists() {
+            let result: anyhow::Result<LoadedStorage> = (|| {
+                let file = std::fs::OpenOptions::new()
+                    .read(true)
+                    .open(&self.storage_path)
+                    .context("Failed to open storage file")?;
+                let loaded: LoadedStorage =
+                    serde_yaml::from_reader(file).context("Failed to deserialize storage file")?;
+
+                anyhow::Result::Ok(loaded)
+            })();
+            match result {
+                Ok(loaded) => loaded.0,
+                Err(e) => {
+                    error!(
+                        "Error deserializing storage file, ignoring file, \
+                        data will be overwritten when saved: {e:?}"
+                    );
+                    default()
+                }
+            }
+        } else {
+            std::fs::create_dir_all(self.storage_path.parent().unwrap()).unwrap();
+            default()
+        }
+    }
+}
+struct LoadedStorage(Vec<SchemaBox>);
+impl Serialize for LoadedStorage {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        let data: HashMap<String, bones::SchemaRef> = self
+            .0
+            .iter()
+            .map(|x| (x.schema().full_name.to_string(), x.as_ref()))
+            .collect();
+
+        use serde::ser::SerializeMap;
+        let mut map = serializer.serialize_map(Some(data.len()))?;
+
+        for (key, value) in data {
+            map.serialize_key(&key)?;
+            map.serialize_value(&bones::SchemaSerializer(value))?;
+        }
+
+        map.end()
+    }
+}
+impl<'de> Deserialize<'de> for LoadedStorage {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        deserializer.deserialize_map(LoadedStorageVisitor).map(Self)
+    }
+}
+struct LoadedStorageVisitor;
+impl<'de> Visitor<'de> for LoadedStorageVisitor {
+    type Value = Vec<SchemaBox>;
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(formatter, "Mapping of string type names to type data.")
+    }
+    fn visit_map<A>(self, mut map: A) -> Result<Self::Value, A::Error>
+    where
+        A: serde::de::MapAccess<'de>,
+    {
+        let mut data = Vec::new();
+        while let Some(type_name) = map.next_key::<String>()? {
+            let reg = bones::SCHEMA_REGISTRY.borrow();
+            let Some(schema) = reg
+                .schemas
+                .iter()
+                .map(|(_id, schema)| schema)
+                .find(|schema| schema.full_name.as_ref() == type_name)
+            else {
+                error!(
+                    "\n\nCannot find schema registration for `{}` while loading persisted \
+                    storage. This means you that you need to call \
+                    `{}::schema()` to register your persisted storage type before \
+                    creating the `BonesBevyRenderer` or that there is data from an old \
+                    version of the app inside of the persistent storage file.\n\n",
+                    type_name, type_name,
+                );
+                continue;
+            };
+
+            data.push(map.next_value_seed(bones::SchemaDeserializer(schema))?);
+        }
+
+        Ok(data)
+    }
+}
+
 /// Startup system to load egui fonts and textures.
 fn setup_egui(world: &mut World) {
     world.resource_scope(|world: &mut World, mut bones_data: Mut<BonesData>| {