recursive file writing via SAF with permission request intent example

src/android/app/src/main/java/org/yuzu/yuzu_emu/ui/GamesFragment.kt

@@ -44,6 +44,17 @@ import androidx.core.content.edit
 import androidx.core.view.doOnNextLayout
 
 class GamesFragment : Fragment() {
+    private lateinit var safRecursiveTimestampWriter: org.yuzu.yuzu_emu.utils.SAFWriter
+    private val REQUEST_CODE_OPEN_DOCUMENT_TREE = 1001
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: android.content.Intent?) {
+        super.onActivityResult(requestCode, resultCode, data)
+        if (requestCode == REQUEST_CODE_OPEN_DOCUMENT_TREE && resultCode == android.app.Activity.RESULT_OK) {
+            val uri = data?.data ?: return
+            safRecursiveTimestampWriter.handlePermissionResult(uri)
+        }
+    }
+
     private var _binding: FragmentGamesBinding? = null
     private val binding get() = _binding!!
 
@@ -112,9 +123,25 @@ class GamesFragment : Fragment() {
 
         applyGridGamesBinding()
 
+    safRecursiveTimestampWriter = org.yuzu.yuzu_emu.utils.SAFWriter(requireContext())
+
         binding.swipeRefresh.apply {
             (binding.swipeRefresh as? SwipeRefreshLayout)?.setOnRefreshListener {
-                gamesViewModel.reloadGames(false)
+                safRecursiveTimestampWriter.refreshGamesFolder(
+                    folders = gamesViewModel.folders.value,
+                    requestPermission = { uri ->
+                        val intent = android.content.Intent(android.content.Intent.ACTION_OPEN_DOCUMENT_TREE)
+                        intent.putExtra(android.provider.DocumentsContract.EXTRA_INITIAL_URI, uri)
+                        intent.addFlags(
+                            android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION or
+                            android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION or
+                            android.content.Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
+                            android.content.Intent.FLAG_GRANT_PREFIX_URI_PERMISSION
+                        )
+                        startActivityForResult(intent, REQUEST_CODE_OPEN_DOCUMENT_TREE)
+                    },
+                    reloadGames = { gamesViewModel.reloadGames(false) }
+                )
             }
             (binding.swipeRefresh as? SwipeRefreshLayout)?.setProgressBackgroundColorSchemeColor(
                 com.google.android.material.color.MaterialColors.getColor(

src/android/app/src/main/java/org/yuzu/yuzu_emu/utils/SAFWriter.kt

@@ -0,0 +1,87 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package org.yuzu.yuzu_emu.utils
+
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.util.Log
+import androidx.documentfile.provider.DocumentFile
+
+class SAFWriter(private val context: Context) {
+    fun refreshGamesFolder(
+        folders: List<Any>,
+        requestPermission: (Uri) -> Unit,
+        reloadGames: () -> Unit
+    ) {
+        if (folders.isNotEmpty()) {
+            val gamesDirUriString = try {
+                val uriField = folders[0]::class.java.getDeclaredField("uriString")
+                uriField.isAccessible = true
+                uriField.get(folders[0]) as? String
+            } catch (e: Exception) {
+                Log.e("YuzuDebug", "[SAFWriter] [SAF] Error accessing uriString: $e")
+                null
+            }
+            if (gamesDirUriString != null) {
+                val gamesRootDocFile = DocumentFile.fromTreeUri(context, Uri.parse(gamesDirUriString))
+                Log.i("YuzuDebug", "[SAFWriter] [SAF] Refresh triggered. gamesDirUri: $gamesDirUriString, gamesRootDocFile: $gamesRootDocFile")
+                if (gamesRootDocFile != null && gamesRootDocFile.isDirectory) {
+                    val dirtreeDocFile = gamesRootDocFile.findFile("dirtree")
+                    if (dirtreeDocFile != null && dirtreeDocFile.isDirectory) {
+                        createRecursiveTimestampFilesInSAF(dirtreeDocFile, requestPermission)
+                    } else {
+                        Log.e("YuzuDebug", "[SAFWriter] [SAF] 'dirtree' subfolder not found or not a directory.")
+                    }
+                } else {
+                    Log.e("YuzuDebug", "[SAFWriter] [SAF] Invalid games folder DocumentFile.")
+                }
+            } else {
+                Log.e("YuzuDebug", "[SAFWriter] [SAF] Could not get gamesDirUriString from folders.")
+            }
+        } else {
+            Log.e("YuzuDebug", "[SAFWriter] [SAF] No games folder found in gamesViewModel.folders.")
+        }
+        reloadGames()
+    }
+    private var pendingSAFAction: (() -> Unit)? = null
+    private val REQUEST_CODE_OPEN_DOCUMENT_TREE = 1001
+
+    // Recursively create a timestamp file in each subfolder using SAF
+    fun createRecursiveTimestampFilesInSAF(root: DocumentFile, requestPermission: (Uri) -> Unit, onPermissionGranted: (() -> Unit)? = null) {
+        Log.i("YuzuDebug", "[SAFWriter] [SAF] Processing folder: ${root.uri}, name: ${root.name}, canWrite: ${root.canWrite()}, isDirectory: ${root.isDirectory}, mimeType: ${root.type}")
+        if (!root.isDirectory) return
+        if (!root.canWrite()) {
+            Log.w("YuzuDebug", "[SAFWriter] [SAF] Cannot write to folder: ${root.uri}, requesting permission...")
+            // Save the action to retry after permission
+            pendingSAFAction = { createRecursiveTimestampFilesInSAF(root, requestPermission, onPermissionGranted) }
+            requestPermission(root.uri)
+            return
+        }
+        val timestamp = java.text.SimpleDateFormat("yyyyMMddHHmmss", java.util.Locale.US).format(java.util.Date())
+        try {
+            val exists = root.findFile(timestamp)
+            if (exists == null) {
+                val file = root.createFile("text/plain", timestamp)
+                Log.i("YuzuDebug", "[SAFWriter] [SAF] Attempted to create file: $timestamp, result: ${file?.uri}")
+            } else {
+                Log.i("YuzuDebug", "[SAFWriter] [SAF] File already exists: ${exists.uri}")
+            }
+        } catch (e: Exception) {
+            Log.e("YuzuDebug", "[SAFWriter] [SAF] Error creating file in ${root.uri}: $e")
+        }
+        root.listFiles()?.filter { it.isDirectory }?.forEach { createRecursiveTimestampFilesInSAF(it, requestPermission, onPermissionGranted) }
+    }
+
+    fun handlePermissionResult(uri: Uri) {
+        context.contentResolver.takePersistableUriPermission(
+            uri,
+            Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
+        )
+        Log.i("YuzuDebug", "[SAFWriter] [SAF] Permission granted for uri: $uri")
+        // Retry the pending action if any
+        pendingSAFAction?.invoke()
+        pendingSAFAction = null
+    }
+}