flutter_android

Flutter Android Bindings

This is a Flutter plugin for using Android's numerous platform-specific APIs in Flutter apps.

Screenshot

Prerequisites

• Dart 2.8+ and Flutter 1.17+

Compatibility

Android only.

Installation

dependencies:
  flutter_android: ^0.8.0

Features

• Implements bindings to a growing set of Android's platform-specific APIs.

• Reduces duplication of effort by centralizing Android bindings in a single package.

Feature Table

Feature	Flutter API
Activity launch	android_content.Intent#startActivity()
Bluetooth scanning	android_bluetooth.BluetoothLeScanner
Distance calculation	android_location.Location.distanceBetween()
Face detection	android_media.FaceDetector
Heart-rate monitoring	android_hardware.SensorManager.getDefaultSensor()
Parcel serialization	android_os.Parcel
Sensor event streams	android_hardware.Sensor#subscribe()

TODO: dirs

Examples

Activity launch

import 'package:flutter_android/android_content.dart' show Intent;

await Intent(
  action: "android.intent.action.VIEW", // Intent.ACTION_VIEW
  data: Uri.parse("https://flutter.dev"),
).startActivity();

Parcel serialization

import 'package:flutter_android/android_os.dart' show Parcel;

var parcel = Parcel.obtain()
  ..writeBoolean(true)
  ..writeInt(42)
  ..writeDouble(3.1415)
  ..writeString("Hello, world!")
  ..writeList(<Object>[1, 2, 3])
  ..writeMap(<String, Object>{"a": 1, "b": 2, "c": 3});

await _channel.invokeMethod('someJavaMethod', parcel.asUint8List());

// In Java, your MethodCallHandler's call.arguments contains the marshaled Parcel

Face detection

import 'package:flutter_android/android_graphics.dart' show Bitmap;
import 'package:flutter_android/android_media.dart' show Face, FaceDetector;

var photo = Image.asset("images/einstein.png");

var bitmap = Bitmap.fromAssetImage(photo.image as AssetImage);
var detector = FaceDetector(width: 280, height: 396);

for (var face in await detector.findFaces(bitmap)) {
  if (face.confidence < Face.CONFIDENCE_THRESHOLD) {
    continue; // skip dubious results below the cut-off threshold
  }
  print("Found a face at (${face.midPoint.x}, ${face.midPoint.y}) with confidence ${face.confidence}");
}

Heart-rate monitoring

import 'package:flutter_android/android_hardware.dart'
    show Sensor, SensorEvent, SensorManager;

var sensor = await SensorManager.getDefaultSensor(Sensor.TYPE_HEART_RATE);

var events = await sensor.subscribe();
events.listen((SensorEvent event) {
  print(event.values[0]);
});

Frequently Asked Questions

TODO

Caveats

• iOS is not and cannot be supported. All flutter_android APIs throw an AssertionError if they are invoked when running on iOS. For cross-platform apps, we recommend that you depend on the platform package to conditionalize your use of Android APIs.

Reference

android

import 'package:flutter_android/android.dart' as android;

android_app

import 'package:flutter_android/android_app.dart' as android_app;

• Notification
• NotificationAction
• WallpaperColors

android_bluetooth

import 'package:flutter_android/android_bluetooth.dart' as android_bluetooth;

• BluetoothAdapter
• BluetoothDevice
• BluetoothHeadset
• BluetoothLeScanner
• BluetoothManager

android_content

import 'package:flutter_android/android_content.dart' as android_content;

• ComponentName
• ContentValues
• Context.cacheDir
• Context.codeCacheDir
• Context.dataDir
• Context.externalCacheDir
• Context.externalFilesDir
• Context.filesDir
• Context.getSharedPreferences()
• Context.getSystemService()
• Context.noBackupFilesDir
• Context.packageCodePath
• Context.packageName
• Context.packageResourcePath
• Intent
• SharedPreferences

android_database

import 'package:flutter_android/android_database.dart' as android_database;

• Cursor
• DatabaseUtils
• MatrixCursor

android_graphics

import 'package:flutter_android/android_graphics.dart' as android_graphics;

• Bitmap
• Point
• PointF

android_hardware

import 'package:flutter_android/android_hardware.dart' as android_hardware;

• Sensor
• SensorEvent
• SensorEventListener
• SensorManager

android_location

import 'package:flutter_android/android_location.dart' as android_location;

• Location

android_media

import 'package:flutter_android/android_media.dart' as android_media;

• Face
• FaceDetector

android_os

import 'package:flutter_android/android_os.dart' as android_os;

• Bundle
• Environment.dataDirectory
• Environment.downloadCacheDirectory
• Environment.externalStorageDirectory
• Environment.externalStorageState
• Environment.rootDirectory
• Environment.isExternalStorageEmulated
• Environment.isExternalStorageRemovable

Cross-Reference

Android	Flutter
android.app	android_app
android.app.Activity	android_app.Activity
android.app.ActivityManager	android_app.ActivityManager
android.app.AlarmManager	android_app.AlarmManager
android.app.AuthenticationRequiredException	android_app.AuthenticationRequiredException
android.app.DownloadManager	android_app.DownloadManager
android.app.KeyguardManager	android_app.KeyguardManager
android.app.Notification	android_app.Notification
android.app.Notification.Action	android_app.NotificationAction
android.app.Notification.Builder	android_app.NotificationBuilder
android.app.NotificationManager	android_app.NotificationManager
android.app.PendingIntent	android_app.PendingIntent
android.app.SearchManager	android_app.SearchManager
android.app.WallpaperColors	android_app.WallpaperColors
android.app.WallpaperInfo	android_app.WallpaperInfo
android.app.WallpaperManager	android_app.WallpaperManager
android.bluetooth	android_bluetooth
android.bluetooth.BluetoothAdapter	android_bluetooth.BluetoothAdapter
android.bluetooth.BluetoothDevice	android_bluetooth.BluetoothDevice
android.bluetooth.BluetoothHeadset	android_bluetooth.BluetoothHeadset
android.bluetooth.BluetoothManager	android_bluetooth.BluetoothManager
android.bluetooth.le.BluetoothLeScanner	android_bluetooth.BluetoothLeScanner
android.bluetooth.le	android_bluetooth
android.content	android_content
android.content.ActivityNotFoundException	android_content.ActivityNotFoundException
android.content.ComponentName	android_content.ComponentName
android.content.ContentValues	android_content.ContentValues
android.content.Context	android_content.Context
android.content.Intent	android_content.Intent
android.content.IntentFilter	android_content.IntentFilter
android.content.SharedPreferences	android_content.SharedPreferences
android.database	android_database
android.database.Cursor	android_database.Cursor
android.database.CursorIndexOutOfBoundsException	android_database.CursorIndexOutOfBoundsException
android.database.DatabaseUtils	android_database.DatabaseUtils
android.database.MatrixCursor	android_database.MatrixCursor
android.database.SQLException	android_database.SQLException
android.graphics	android_graphics
android.graphics.Bitmap	android_graphics.Bitmap
android.graphics.Color	dart-ui.Color
android.graphics.Point	android_graphics.Point
android.graphics.PointF	android_graphics.PointF
android.graphics.drawable.Icon	flutter.Icon
android.hardware	android_hardware
android.hardware.Sensor	android_hardware.Sensor
android.hardware.SensorEvent	android_hardware.SensorEvent
android.hardware.SensorEventListener	android_hardware.SensorEventListener
android.hardware.SensorManager	android_hardware.SensorManager
android.location	android_location
android.location.Location	android_location.Location
android.media	android_media
android.media.FaceDetector	android_media.FaceDetector
android.media.FaceDetector.Face	android_media.Face
android.net	android_net
android.nfc	android_nfc
android.os	android_os
android.os.BatteryManager	android_os.BatteryManager
android.os.Build	android_os.Build
android.os.Bundle	android_os.Bundle
android.os.Environment	android_os.Environment
android.os.HardwarePropertiesManager	android_os.HardwarePropertiesManager
android.os.Parcel	android_os.Parcel
android.os.Parcelable	android_os.Parcelable
android.os.PowerManager	android_os.PowerManager
android.os.Process	android_os.Process
android.os.StatFs	android_os.StatFs
android.os.SystemClock	android_os.SystemClock
android.os.UserManager	android_os.UserManager
android.os.VibrationEffect	android_os.VibrationEffect
android.os.Vibrator	android_os.Vibrator
android.provider	android_provider
android.security	android_security
android.speech	android_speech
android.telephony	android_telephony
android.view	android_view
java.util.Locale	dart-ui.Locale

See Also

• The win32 package provides bindings to the most common Win32 APIs.