updated README.md

README.md

@@ -58,6 +58,11 @@ allprojects {
 
 Simple Storage is built in Kotlin. Follow this [documentation](JAVA_COMPATIBILITY.md) to use it in your Java project.
 
+Note that some long-running functions like copy, move, compress, and unzip are now only available in Kotlin.
+They are powered by Kotlin Coroutines & Flow, which are easy to use.
+You can still use these Java features in your project, but you will need [v1.5.6](https://github.com/anggrayudi/SimpleStorage/releases/tag/1.5.6) which is the latest version that
+supports Java.
+
 ## Terminology
 
 ![Alt text](art/terminology.png?raw=true "Simple Storage Terms")
@@ -73,7 +78,7 @@ To check whether you have access to particular paths, call `DocumentFileCompat.g
 ![Alt text](art/getAccessibleAbsolutePaths.png?raw=true "DocumentFileCompat.getAccessibleAbsolutePaths()")
 
 All paths in those locations are accessible via functions `DocumentFileCompat.from*()`, otherwise your action will be denied by the system if you want to
-access paths other than those. Functions `DocumentFileCompat.from*()` (next section) will return null as well. On API 28-, you can obtain it by requesting
+access paths other than those, then functions `DocumentFileCompat.from*()` (next section) will return null as well. On API 28-, you can obtain it by requesting
 the runtime permission. For API 29+, it is obtained automatically by calling `SimpleStorageHelper#requestStorageAccess()` or
 `SimpleStorageHelper#openFolderPicker()`. The granted paths are persisted by this library via `ContentResolver#takePersistableUriPermission()`,
 so you don't need to remember them in preferences:
@@ -246,44 +251,43 @@ For example, you can move a folder with few lines of code:
 val folder: DocumentFile = ...
 val targetFolder: DocumentFile = ...
 
-// Since moveFolderTo() is annotated with @WorkerThread, you must execute it in the background thread
-folder.moveFolderTo(applicationContext, targetFolder, skipEmptyFiles = false, callback = object : FolderCallback() {
-    override fun onPrepare() {
-        // Show notification or progress bar dialog with indeterminate state
-    }
-
-    override fun onCountingFiles() {
-        // Inform user that the app is counting & calculating files
-    }
-
-    override fun onStart(folder: DocumentFile, totalFilesToCopy: Int, workerThread: Thread): Long {
-        return 1000 // update progress every 1 second
-    }
-
-    override fun onParentConflict(destinationFolder: DocumentFile, action: FolderCallback.ParentFolderConflictAction, canMerge: Boolean) {
-        handleParentFolderConflict(destinationFolder, action, canMerge)
+ioScope.launch {
+  folder.moveFolderTo(applicationContext, targetFolder, skipEmptyFiles = false, updateInterval = 1000, onConflict = object : FolderConflictCallback(uiScope) {
+    override fun onParentConflict(destinationFolder: DocumentFile, action: ParentFolderConflictAction, canMerge: Boolean) {
+      handleParentFolderConflict(destinationFolder, action, canMerge)
     }
 
     override fun onContentConflict(
-        destinationFolder: DocumentFile,
-        conflictedFiles: MutableList<FolderCallback.FileConflict>,
-        action: FolderCallback.FolderContentConflictAction
+      destinationFolder: DocumentFile,
+      conflictedFiles: MutableList<FileConflict>,
+      action: FolderContentConflictAction
     ) {
-        handleFolderContentConflict(action, conflictedFiles)
-    }
-
-    override fun onReport(report: Report) {
-        Timber.d("onReport() -> ${report.progress.toInt()}% | Copied ${report.fileCount} files")
+      handleFolderContentConflict(action, conflictedFiles)
     }
-
-    override fun onCompleted(result: Result) {
-        Toast.makeText(baseContext, "Copied ${result.totalCopiedFiles} of ${result.totalFilesToCopy} files", Toast.LENGTH_SHORT).show()
+  }).onCompletion {
+    if (it is CancellationException) {
+      Timber.d("Folder move is aborted")
     }
-
-    override fun onFailed(errorCode: ErrorCode) {
-        Toast.makeText(baseContext, "An error has occurred: $errorCode", Toast.LENGTH_SHORT).show()
+  }.collect { result ->
+    when (result) {
+      is FolderResult.Validating -> Timber.d("Validating...")
+      is FolderResult.Preparing -> Timber.d("Preparing...")
+      is FolderResult.CountingFiles -> Timber.d("Counting files...")
+      is FolderResult.DeletingConflictedFiles -> Timber.d("Deleting conflicted files...")
+      is FolderResult.Starting -> Timber.d("Starting...")
+      is FolderResult.InProgress -> Timber.d("Progress: ${result.progress.toInt()}% | ${result.fileCount} files")
+      is FolderResult.Completed -> uiScope.launch {
+        Timber.d("Completed: ${result.totalCopiedFiles} of ${result.totalFilesToCopy} files")
+        Toast.makeText(baseContext, "Moved ${result.totalCopiedFiles} of ${result.totalFilesToCopy} files", Toast.LENGTH_SHORT).show()
+      }
+
+      is FolderResult.Error -> uiScope.launch {
+        Timber.e(result.errorCode.name)
+        Toast.makeText(baseContext, "An error has occurred: ${result.errorCode.name}", Toast.LENGTH_SHORT).show()
+      }
     }
-})
+  }
+}
 ```
 
 The coolest thing of this library is you can ask users to choose Merge, Replace, Create New, or Skip Duplicate folders & files