recursive file writing via SAF with permission request intent example

Guys please don't delete this one yet as it will serve as an example for something else soon

for convenience i wired it into game list refresh.
just create a dirtree folder inside games folder, and then create any random dirtree inside it, then go to games list and refresh.
you should be requested to provide write permission to that folder and then empty files with current time's yyyymmddhhmmss.txt name will be created recursively.

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
+    }
+}