android: a playlist's cover from a photo on the phone

The storage plugin gains pick_image — the document picker limited to
images, the picked content copied into the app's cache so the Rust side
gets a plain path. playlist_cover_set(id, path) is the desktop pick's
install step split out and shared (squared, the master cover, the row's
revision moved). A playlist's sheet offers Choose cover photo and Remove
custom cover; the mock walk exercises both.

crates/tauri-plugin-storage/android/src/main/java/com/soulstream/storage/StoragePlugin.kt

@@ -91,4 +91,37 @@ class StoragePlugin(private val activity: Activity) : Plugin(activity) {
         }
         invoke.resolve()
     }
+    /** A photo from the phone: the document picker limited to images, the
+     *  picked content copied into the app's cache so the Rust side gets a
+     *  plain path (a content URI is not one). */
+    @Command
+    fun pickImage(invoke: Invoke) {
+        val intent = Intent(Intent.ACTION_OPEN_DOCUMENT)
+        intent.addCategory(Intent.CATEGORY_OPENABLE)
+        intent.type = "image/*"
+        startActivityForResult(invoke, intent, "imagePicked")
+    }
+
+    @ActivityCallback
+    fun imagePicked(invoke: Invoke, result: ActivityResult) {
+        when (result.resultCode) {
+            Activity.RESULT_OK -> {
+                val uri = result.data?.data
+                if (uri == null) { invoke.reject("no image came back"); return }
+                try {
+                    val target = java.io.File(activity.cacheDir, "picked-cover-" + System.currentTimeMillis() + ".img")
+                    val input = activity.contentResolver.openInputStream(uri)
+                    if (input == null) { invoke.reject("the image could not be read"); return }
+                    input.use { i -> target.outputStream().use { o -> i.copyTo(o) } }
+                    val out = JSObject()
+                    out.put("path", target.absolutePath)
+                    invoke.resolve(out)
+                } catch (e: Exception) {
+                    invoke.reject("the image could not be read: " + e.message)
+                }
+            }
+            Activity.RESULT_CANCELED -> invoke.reject("cancelled")
+            else -> invoke.reject("the picker failed")
+        }
+    }
 }

crates/tauri-plugin-storage/build.rs

@@ -1,6 +1,6 @@
 // The three commands, as the Rust functions are named; the ACL slugs them
 // (`allow-pick-folder`, …) into permissions/autogenerated.
-const COMMANDS: &[&str] = &["pick_folder", "all_files_access", "request_all_files_access"];
+const COMMANDS: &[&str] = &["pick_folder", "all_files_access", "request_all_files_access", "pick_image"];
 
 fn main() {
     // Registers the command permissions and, on Android, hands the Gradle

crates/tauri-plugin-storage/permissions/autogenerated/commands/pick_image.toml

@@ -0,0 +1,13 @@
+# Automatically generated - DO NOT EDIT!
+
+"$schema" = "../../schemas/schema.json"
+
+[[permission]]
+identifier = "allow-pick-image"
+description = "Enables the pick_image command without any pre-configured scope."
+commands.allow = ["pick_image"]
+
+[[permission]]
+identifier = "deny-pick-image"
+description = "Denies the pick_image command without any pre-configured scope."
+commands.deny = ["pick_image"]

crates/tauri-plugin-storage/permissions/autogenerated/reference.md

@@ -9,6 +9,7 @@ whether it is granted, and the system screen that grants it.
 - `allow-pick-folder`
 - `allow-all-files-access`
 - `allow-request-all-files-access`
+- `allow-pick-image`
 
 ## Permission Table
 
@@ -74,6 +75,32 @@ Denies the pick_folder command without any pre-configured scope.
 <tr>
 <td>
 
+`storage:allow-pick-image`
+
+</td>
+<td>
+
+Enables the pick_image command without any pre-configured scope.
+
+</td>
+</tr>
+
+<tr>
+<td>
+
+`storage:deny-pick-image`
+
+</td>
+<td>
+
+Denies the pick_image command without any pre-configured scope.
+
+</td>
+</tr>
+
+<tr>
+<td>
+
 `storage:allow-request-all-files-access`
 
 </td>

crates/tauri-plugin-storage/permissions/default.toml

@@ -6,4 +6,4 @@ The phone's storage: pick a library folder (a Storage Access Framework tree,
 resolved to a path when the volume allows), and Android's all-files access —
 whether it is granted, and the system screen that grants it.
 """
-permissions = ["allow-pick-folder", "allow-all-files-access", "allow-request-all-files-access"]
+permissions = ["allow-pick-folder", "allow-all-files-access", "allow-request-all-files-access", "allow-pick-image"]

crates/tauri-plugin-storage/permissions/schemas/schema.json

@@ -318,6 +318,18 @@
           "const": "deny-pick-folder",
           "markdownDescription": "Denies the pick_folder command without any pre-configured scope."
         },
+        {
+          "description": "Enables the pick_image command without any pre-configured scope.",
+          "type": "string",
+          "const": "allow-pick-image",
+          "markdownDescription": "Enables the pick_image command without any pre-configured scope."
+        },
+        {
+          "description": "Denies the pick_image command without any pre-configured scope.",
+          "type": "string",
+          "const": "deny-pick-image",
+          "markdownDescription": "Denies the pick_image command without any pre-configured scope."
+        },
         {
           "description": "Enables the request_all_files_access command without any pre-configured scope.",
           "type": "string",
@@ -331,10 +343,10 @@
           "markdownDescription": "Denies the request_all_files_access command without any pre-configured scope."
         },
         {
-          "description": "The phone's storage: pick a library folder (a Storage Access Framework tree,\nresolved to a path when the volume allows), and Android's all-files access —\nwhether it is granted, and the system screen that grants it.\n\n#### This default permission set includes:\n\n- `allow-pick-folder`\n- `allow-all-files-access`\n- `allow-request-all-files-access`",
+          "description": "The phone's storage: pick a library folder (a Storage Access Framework tree,\nresolved to a path when the volume allows), and Android's all-files access —\nwhether it is granted, and the system screen that grants it.\n\n#### This default permission set includes:\n\n- `allow-pick-folder`\n- `allow-all-files-access`\n- `allow-request-all-files-access`\n- `allow-pick-image`",
           "type": "string",
           "const": "default",
-          "markdownDescription": "The phone's storage: pick a library folder (a Storage Access Framework tree,\nresolved to a path when the volume allows), and Android's all-files access —\nwhether it is granted, and the system screen that grants it.\n\n#### This default permission set includes:\n\n- `allow-pick-folder`\n- `allow-all-files-access`\n- `allow-request-all-files-access`"
+          "markdownDescription": "The phone's storage: pick a library folder (a Storage Access Framework tree,\nresolved to a path when the volume allows), and Android's all-files access —\nwhether it is granted, and the system screen that grants it.\n\n#### This default permission set includes:\n\n- `allow-pick-folder`\n- `allow-all-files-access`\n- `allow-request-all-files-access`\n- `allow-pick-image`"
         }
       ]
     }

crates/tauri-plugin-storage/src/lib.rs

@@ -33,6 +33,12 @@ pub struct AccessState {
     pub granted: bool,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct PickedImage {
+    pub path: Option<String>,
+}
+
 #[cfg(mobile)]
 pub struct Storage<R: Runtime>(tauri::plugin::PluginHandle<R>);
 
@@ -91,9 +97,30 @@ fn request_all_files_access<R: Runtime>(app: tauri::AppHandle<R>) -> Result<(),
     }
 }
 
+/// A photo from the phone: the document picker limited to images, the
+/// picked content copied into the app's cache — a plain path for the Rust
+/// side (a playlist's cover, for one).
+#[tauri::command]
+async fn pick_image<R: Runtime>(app: tauri::AppHandle<R>) -> Result<PickedImage, String> {
+    #[cfg(mobile)]
+    {
+        use tauri::Manager;
+        let storage = app.state::<Storage<R>>();
+        storage
+            .0
+            .run_mobile_plugin::<PickedImage>("pickImage", ())
+            .map_err(|e| e.to_string())
+    }
+    #[cfg(not(mobile))]
+    {
+        let _ = app;
+        Err("the image picker here is the desktop's dialog".into())
+    }
+}
+
 pub fn init<R: Runtime>() -> TauriPlugin<R> {
     Builder::new("storage")
-        .invoke_handler(tauri::generate_handler![pick_folder, all_files_access, request_all_files_access])
+        .invoke_handler(tauri::generate_handler![pick_folder, all_files_access, request_all_files_access, pick_image])
         .setup(|app, api| {
             #[cfg(target_os = "android")]
             {