resources dir on android

.changes/inject-mobile-resources.md

@@ -3,4 +3,4 @@
 "@tauri-apps/cli": patch:feat
 ---
 
-Inject configured resources on mobil apps.
+Inject configured resources on mobile apps.

.changes/resource-dir-android.md

@@ -0,0 +1,5 @@
+---
+"tauri-utils": patch:bug
+---
+
+Implemented `resource_dir` on Android, which returns a URI that needs to be resolved using [AssetManager::open](https://developer.android.com/reference/android/content/res/AssetManager#open(java.lang.String,%20int)). This will be handled by the file system plugin.

core/tauri-utils/src/platform.rs

@@ -15,6 +15,9 @@ use crate::{Env, PackageInfo};
 
 mod starting_binary;
 
+#[cfg(target_os = "android")]
+pub const ANDROID_ASSET_PROTOCOL_URI_PREFIX: &str = "asset://localhost/";
+
 /// Platform target.
 #[derive(PartialEq, Eq, Copy, Debug, Clone, Serialize, Deserialize)]
 #[cfg_attr(feature = "schema", derive(schemars::JsonSchema))]
@@ -256,7 +259,13 @@ fn is_cargo_output_directory(path: &Path) -> bool {
 /// `${exe_dir}/../lib/${exe_name}`.
 ///
 /// On MacOS, it's `${exe_dir}../Resources` (inside .app).
+///
+/// On iOS, it's `${exe_dir}/assets`.
+///
+/// Android uses a special URI prefix that is resolved by the Tauri file system plugin `asset://localhost/`
 pub fn resource_dir(package_info: &PackageInfo, env: &Env) -> crate::Result<PathBuf> {
+  #[cfg(target_os = "android")]
+  return Ok(PathBuf::from(ANDROID_ASSET_PROTOCOL_URI_PREFIX));
   let exe = current_exe()?;
   resource_dir_from(exe, package_info, env)
 }

core/tauri/mobile/android/src/main/java/app/tauri/PathPlugin.kt

@@ -12,6 +12,8 @@ import app.tauri.plugin.Plugin
 import app.tauri.plugin.Invoke
 import app.tauri.plugin.JSObject
 
+const val TAURI_ASSETS_DIRECTORY_URI = "asset://localhost/"
+
 @TauriPlugin
 class PathPlugin(private val activity: Activity): Plugin(activity) {
     private fun resolvePath(invoke: Invoke, path: String?) {
@@ -67,8 +69,7 @@ class PathPlugin(private val activity: Activity): Plugin(activity) {
 
     @Command
     fun getResourcesDir(invoke: Invoke) {
-        // TODO
-        resolvePath(invoke, activity.cacheDir.absolutePath)
+        resolvePath(invoke, TAURI_ASSETS_DIRECTORY_URI)
     }
 
     @Command