android_media_store #

A safe and modern Flutter plugin for accessing and managing media files on Android, addressing the challenges of Scoped Storage and content:// URI handling. This plugin simplifies complex tasks like file creation, reading, editing, and deletion while automatically managing Android 10+ (API 29+) storage permissions.

Key Features #

• Scoped Storage Compatibility: Seamlessly handles Android 10+ (API 29+) Scoped Storage restrictions, automatically requesting necessary permissions and ensuring data integrity.
• Safe content:// URI Handling: Converts content:// URIs to file paths safely, reading files in a memory-efficient, chunked manner.
• Automatic Permission Management: Automatically requests the MANAGE_MEDIA and other essential permissions (if needed) when required, streamlining the development process.
• OOM and TransactionTooLargeException Prevention: Implements safe reading techniques to prevent Out-Of-Memory errors, and handles the Android IPC (Binder) transaction size limit.
• Comprehensive File Operations: Supports creating, reading, editing, copying, and deleting media files within the MediaStore.
• Easy-to-Use API: Simple, well-documented methods to perform common media file operations.
• Robust Example App: Includes a fully functional example app that demonstrates all the features of the plugin.

Getting Started #

1. Add the dependency #

Add android_media_store to your project's pubspec.yaml:

dependencies:
  android_media_store: ^0.0.1 # Replace with the latest version

Then, run flutter pub get.

2. Android Setup (AndroidManifest.xml) #

Add the following permissions to your android/app/src/main/AndroidManifest.xml file:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="YOUR_PACKAGE_NAME">  <!-- Replace with your app's package name -->

    <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" />
    <uses-permission android:name="android.permission.READ_MEDIA_AUDIO" />
    <uses-permission android:name="android.permission.READ_MEDIA_VIDEO" />
    <uses-permission android:name="android.permission.MANAGE_MEDIA" />
    <uses-permission android:name="android.permission.ACCESS_MEDIA_LOCATION" />

    <!-- For Android 12 and below -->
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <!-- For devices running Android 9 (API 28) and lower -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <application
        ... >
      </application>
</manifest>

Important: The MANAGE_MEDIA permission is a "Special Permission." Google Play has strict policies on using this. Ensure your app's primary function is a File Manager or Media Manager; otherwise, your app may be rejected during review.

3. Import the Plugin #

import 'package:android_media_store/android_media_store.dart';

4. Usage #

Create an instance of AndroidMediaStore:

final mediaStore = AndroidMediaStore.instance;

Now, you can use the various methods:

// 1. Request Permissions (Recommended, but handled internally by the plugin)
// if (await mediaStore.canManageMedia() == false) {
//   await mediaStore.requestManageMedia();
// }

// 2. Path to URI conversion
final String? uri = await mediaStore.pathToUri(
  '/storage/emulated/0/Download/my_audio.mp3', // Replace with your path
  mimeType: 'audio/mpeg', // OPTIONAL: Improves accuracy
);

// 3. Create a file
final Uint8List data = Uint8List.fromList('Your file content'.codeUnits);
final String? createdUri = await mediaStore.createMediaFile(
  'my_document.txt',
  data,
  mimeType: 'text/plain',
);

// 4.  Read a file (Safe! Handles large files by caching)
final bytes = await mediaStore.readMediaFile(createdUri!);

// 5. Delete a file
final success = await mediaStore.deleteMediaFile(createdUri!);

// 6. Edit an existing file (e.g., a video or image)
final newData = Uint8List.fromList('New content'.codeUnits);
final editResult = await mediaStore.editMediaFile(createdUri!, newData);

// 7. Copy a file
final String? copiedUri = await mediaStore.copyMediaFileToRelative(
    createdUri!,
    'copied_file.txt',
    relativePath: 'Download/',  // target dir
    mimeType: 'text/plain',
  );

5. Example App #

A complete example app is available in the example/ directory. This app demonstrates all of the plugin's features and handles all the necessary permission requests.

Methods #

• Future<String?> pathToUri(String path, {String? mimeType}):

  • Converts a file system path to a MediaStore or FileProvider compatible URI.
  • If you provide a mimeType, the result is more accurate.
  • Returns the content URI as a String.
  • Returns null if the conversion fails.

• Future<String?> uriToPath(String uri):

  • Converts a MediaStore or FileProvider URI back to a file system path.
  • Returns the file path as a String.
  • Returns null if no path is found.

• Future<String?> editMediaFile(String pathOrUri, List<int> data, {String? mimeType, void Function(String?)? onSuccess, void Function(Exception)? onFail}):

  • Overwrites an existing media file with new binary data.
  • If the app doesn't own the file, it triggers a permission dialog automatically.
  • Uses onSuccess callback to be notified of success and onFail callback to handle failures.
  • Returns the URI of the edited file (as a string), or calls the onFail callback.
  • If an error occurs, the onFail callback is invoked with an AndroidMediaStoreException.

• Future<String?> getReadableMediaFilePath(String pathOrUri):

  • Returns a physical, readable file path for a given media URI.
  • If the URI is content://, the plugin will stream the content into a file in the app's cache directory to avoid OOM errors.
  • This is the preferred method to read large files safely.
  • Remember to delete cached files: File(path).delete().

• Future<Uint8List?> readMediaFile(String pathOrUri, {String? mimeType}):

  • Reads the complete binary content of a media file directly into memory.
  • Important: This method includes a built-in size limit (1MB) to prevent OutOfMemoryError and TransactionTooLargeException crashes.
  • If the file exceeds the 1MB limit, the plugin will throw an AndroidMediaStoreException with the code FILE_TOO_LARGE. The caller should then use getReadableMediaFilePath() to safely read the file.

• Future<bool> deleteMediaFile(String pathOrUri, {void Function(bool)? onSuccess, void Function(Exception)? onFail}):

  • Permanently deletes a media file from storage.
  • Handles permission requests automatically.
  • Uses onSuccess and onFail callbacks.
  • Returns true if the deletion was successful (or queued).

• Future<String?> createMediaFileAtRelative(String displayName, String relativePath, List<int> data, {String? mimeType, void Function(String?)? onSuccess, void Function(Exception)? onFail}):

  • Creates a new media file in a specific MediaStore relative directory (e.g., DIRECTORY_PICTURES).
  • Uses onSuccess and onFail callbacks.
  • Returns the content URI of the created file.

• Future<String?> createMediaFile(String displayName, List<int> data, {String? mimeType, void Function(String?)? onSuccess, void Function(Exception)? onFail}):

  • Creates a new media file with automatic directory selection based on the mimeType.
  • Uses onSuccess and onFail callbacks.
  • Returns the content URI of the created file.

• Future<String?> copyMediaFileToRelative(String pathOrUri, String displayName, {String? relativePath, String? mimeType, void Function(String?)? onSuccess, void Function(Exception)? onFail}):

  • Copies a media file to a new location within a relative directory.
  • Handles permissions automatically.
  • Uses onSuccess and onFail callbacks.
  • Returns the content URI of the new copy.

• Future<String?> copyMediaFileToPathOrUri(String toPathOrUri, String fromPathOrUri, {String? mimeType, void Function(String?)? onSuccess, void Function(Exception)? onFail}):

  • Copies a media file to a specific destination path or URI.
  • Handles permissions automatically.
  • Uses onSuccess and onFail callbacks.
  • Returns the content URI of the new copy.

• Future<bool> canManageMedia():

  • Checks whether the app currently has media management privileges.

• Future<void> requestManageMedia():

  • Opens the system settings screen where the user can grant media management access.

Troubleshooting #

• "MEDIA_STORE_ERROR" or Permissions Issues: Double-check that you have added the necessary permissions to your AndroidManifest.xml. Android 11+ may require the user to explicitly grant media management permissions via the System Settings.
• "File is too large": The readMediaFile method has a 1MB limit. For larger files, use getReadableMediaFilePath() and stream the data.
• Test builds on real devices: Testing the plugin requires real devices. It is highly recommended that you test on Android 10+ (API 29+) and Android 12+ (API 31+).
• android.os.TransactionTooLargeException: This is a classic Binder limit error. Use getReadableMediaFilePath() to avoid this for files larger than 1MB.
• Permissions: Older android API may need permission_handler plugin for more specific permissions

Contributions #

Contributions are welcome! Please see the contributing guidelines for details.

License #

This project is licensed under the MIT License.