Develop Reference

How to get the battery level in background and announce it?

In my app, I want to get the battery level in the background because I want to announce it in the text to speech when the battery level is low or when the battery is full or at any level. I have used the broadcast receivers and can get the battery level but don't know how to get it in the background.
Anyone can help?

The thing that you want to achieve can be done via intent Service, if you dig in the docs you can find it yourself, here is the link Intent Service, This type of intent can be fired in the background and can be used to perform various simple operations such as yours, because they don't have any interface but rather just operations executed in background.
Also here is a video guide Background Services which you can use for yourself to get battery percentage and announce it after a certain condition
Edit 2:
(Nothing Required in XML as this is a background process/operation)
This is a code to get the battery percentage and announce it using Text to speech in broadcast receiver,
MainActivity.java
package com.example.text_to_speech;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.speech.tts.TextToSpeech;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent intent=new Intent(this,myBackgroundProcess.class);
intent.setAction("BackgroundProcess");
PendingIntent pendingIntent=PendingIntent.getBroadcast(this,0,intent,0);
AlarmManager alarmManger= (AlarmManager) getSystemService(Context.ALARM_SERVICE);
alarmManger.setRepeating(AlarmManager.RTC_WAKEUP,0,10,pendingIntent);//change this time based on your liking which will fire the intent
}
}
customerclass- myBackgroundProcess.java
package com.example.text_to_speech;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.BatteryManager;
import android.speech.tts.TextToSpeech;
import android.util.Log;
import java.util.Locale;
import static android.content.Context.BATTERY_SERVICE;
public class myBackgroundProcess extends BroadcastReceiver {
private TextToSpeech mTTS;
#Override
public void onReceive(Context context, Intent intent) {
mTTS = new TextToSpeech(context.getApplicationContext(), new TextToSpeech.OnInitListener() {
#Override
public void onInit(int status) {
if (status != TextToSpeech.ERROR) {
int result = mTTS.setLanguage(Locale.US);
if (result == TextToSpeech.LANG_MISSING_DATA
|| result == TextToSpeech.LANG_NOT_SUPPORTED) {
Log.e("TTS", "Language not supported");
} else {
BatteryManager bm = (BatteryManager) context.getSystemService(BATTERY_SERVICE);
int batLevel = bm.getIntProperty(BatteryManager.BATTERY_PROPERTY_CAPACITY);
if(batLevel==100 || batLevel<=10 || batLevel==50)
speak(context,batLevel);
}
} else {
Log.e("TTS", "Initialization failed");
}
}
});
}
public void speak(Context context, int batlevel)
{
mTTS.setPitch(10);
mTTS.setSpeechRate(1);
String text=String.valueOf(batlevel);
mTTS.speak(text, TextToSpeech.QUEUE_FLUSH, null);
}
}
In Android Manifest Register the receiver and add intent filter to it as shown below (below application tag)
<receiver android:name=".myBackgroundProcess"
android:enabled="true"
android:exported="true"
>
<intent-filter>
<action android:name="BackgroundProcess"/>
</intent-filter>
</receiver>

Broadcast receiver is not working on Ice cream sandwitch 4.0.3

I want to start service on reboot of the device.
First I used broadcast receiver.It worked on my android phone having version 7. But I want to implement it on Xixun controller which is android based having version 4.0.3
Broadcast receiver did not work. I have gone through reading that, for API levels below 26, one should use WakefulBroadcastReceiver. When I did that, it worked on my phone but not on Xixun controller.
The process to reboot Xixun controller is just to power on and power off using supply.I have also used power intent of broadcast receiver. But it didn't work because device is batteryless.
What would be reason behind my service is not working?
[manifest receiver]
Following is service code
package com.example.serviceexample;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.SystemClock;
import android.util.Log;
import android.view.Gravity;
import android.widget.Toast;
public class MyService extends Service {
#Override
public void onCreate()
{
super.onCreate();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast myToast =Toast.makeText(this,"service started",Toast.LENGTH_LONG);
myToast.setGravity(Gravity.TOP|Gravity.LEFT, 0, 0);
myToast.setDuration(Toast.LENGTH_LONG);
myToast.show();
return Service.START_STICKY;
}
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
When I used broadcast receiver, codes are same except basic syntax.

NotificationListenerService in androidTv

I am working on an android app which will run in androidTv(currently i am using MiBox for my testing purposes)
The requirement is like i need capture the number active notifications received by the android OS and show it somewhere in the APP.
Service which i've written:
package org.libsdl.app;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Notification;
import android.app.Notification.Action;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.service.notification.NotificationListenerService;
import android.service.notification.StatusBarNotification;
import android.text.TextUtils;
import android.util.Log;
import android.widget.Toast;
import org.haxe.lime.HaxeObject;
public class AndroidNotificationListener extends NotificationListenerService {
private static final int EVENT_UPDATE_CURRENT_NOS = 0;
public static List<StatusBarNotification[]> mCurrentNotifications = new
ArrayList<StatusBarNotification[]>();
public static int mActiveNotificationsCount = 0;
public static StatusBarNotification mPostedNotification;
public static StatusBarNotification mRemovedNotification;
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Override
public IBinder onBind(Intent intent) {
return super.onBind(intent);
}
#Override
public boolean onUnbind(Intent mIntent) {
return super.onUnbind(mIntent);
}
#Override
public void onNotificationPosted(StatusBarNotification sbn) {
updateCurrentNotifications();
mPostedNotification = sbn;
// Get the text from notification
// CharSequence notificationText = sbn.getNotification().extras.getCharSequence(Notification.EXTRA_TEXT);
// Show a toast with your Notification Text
// Toast.makeText(getApplicationContext(), notificationText, Toast.LENGTH_SHORT).show();
}
#Override
public void onNotificationRemoved(StatusBarNotification sbn) {
updateCurrentNotifications();
mRemovedNotification = sbn;
}
public void onListenerConnected() {
// Add some prints here to check if our service is connected to OS or not?
}
private void updateCurrentNotifications() {
try {
StatusBarNotification[] activeNos = getActiveNotifications();
if (mCurrentNotifications.size() == 0) {
mCurrentNotifications.add(null);
}
mCurrentNotifications.set(0, activeNos);
mActiveNotificationsCount = activeNos.length;
} catch (Exception e) {
System.out.println("Anil : AndroidNotificationListener : Should not be here!!");
e.printStackTrace();
}
}
public static StatusBarNotification[] getCurrentNotifications() {
if (mCurrentNotifications.size() == 0) {
return null;
}
return mCurrentNotifications.get(0);
}
}
AndroidManifest.xml part is:
<service
android:name="org.libsdl.app.AndroidNotificationListener"
android:permission="android.permission.BIND_NOTIFICATION_LISTENER_SERVICE"
android:enabled="true" >
<intent-filter>
<action android:name="android.service.notification.NotificationListenerService" />
</intent-filter>
</service>
Same service is working for my phone but in my androidTv(MiBox) it is not working.
and as in phone we have settings from where we can enable/disable our app to receive notifications the same option is not available in MiBox.
My MiBox has Android M and my phone has Android N. am i missing something which i should know before running this service in Android service?
So my question is about why this service is not working in androidTv?
any help on this will be much appreciated..

I've found the reason why my dummy app worked on my phone and did not work on miBox.
On my phone, when i installed the dummy app it asked for permission to receive the notification and when i gave the permission it started to receive permission.
On miBox, we do not have any way to give permission to our app to receive notification.
In short, the app was not able to receive the notification on miBox because the app did not have the permission because or listener/app to receive the notification was attached.
and there are no way we can attach the listener for notification to our app in android tvs. But we can do it only when the app is signed as a system app.

if (verifyNotificationPermission()) {
//You have the permission to listen to the System Notification
} else {
//can ask for permission if it not yet granted
// show dialog why you need this permission and if
// user is ok with the permission then call
//openNotificationPermissionPanel
}
fun openNotificationPermissionPanel(){
//Below code will open side panel and will show list of apps and there is a way to unable and disable the Permission
startActivity(new Intent("android.settings.ACTION_NOTIFICATION_LISTENER_SETTINGS"));
}
// fun to check if your launcher app has permission or not
fun verifyNotificationPermission(): Boolean? {
val theList = Settings.Secure.getString(
activity.getContentResolver(),
"enabled_notification_listeners"
)
val theListList = theList.split(":").toTypedArray()
val me = ComponentName(activity, NotificationService::class.java).flattenToString()
for (next in theListList) {
if (me == next) {
return true
}
}
return false
}

Restarting a service in the onDestroy method

I have made an app in which a service runs in the background. But if the android system requires resources, it will stop the service. However I may still require my service to run.
Is it a bad practice to restart the service (if condition relevant to my app still holds true) in the onDestroy method of my service?
How can I make sure my service runs indefinitely (if condition relevant to my app still holds true)? Or atleast on high priority?

Probably the best you can do is use the START_STICKY flag, which tells Android to attempt to restart the service if it has stopped. Beyond that ensure that it consumes as few resources as possible, so that it is less likely to be destroyed.
Android prioritizes the UI over everything. Then processes that are related to the UI. Then processes that are consuming the least amount of resources. A Service runs in the background, so unless it has resources that are also in use on the UI or connected to the UI in some way, it should be a lower priority.
Also you cannot tell Android how to prioritize your Service (everyone would make theirs the "highest priority" right?). So it goes by how well you minimize the impact on overall resources - why kill 3 Services when it could kill 1 and regain all the resources it needs?
To help understand how to manage memory better: http://developer.android.com/training/articles/memory.html

set it START_STICKY. It Causes after killing service the service will restart again. it is my code :
android manifest :
<application
....
<service android:name=".UpdateService" />
</application>
service class :
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;
public class UpdateService extends Service {
BroadcastReceiver mReceiver;
#Override
public void onCreate() {
super.onCreate();
// register receiver that handles screen on and screen off logic
IntentFilter filter = new IntentFilter(Intent.....);
filter.addAction(Intent....);
mReceiver = new MyReceiver();
registerReceiver(mReceiver, filter);
}
#Override
public void onDestroy() {
unregisterReceiver(mReceiver);
Log.i("onDestroy Reciever", "Called");
super.onDestroy();
}
#Override
public void onStart(Intent intent, int startId) {
Log.i("log", "action Called");
}
}
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return Service.START_STICKY;
}
}
receiver class :
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
public class MyReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Log.i("Log", "recevid");
}
}
in StartupActivity :
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Context context = getApplicationContext();
Intent service = new Intent(context, UpdateService.class);
context.startService(service);
}

changing UI elements if app is in the foreground from a broadcast receiver

I Have a BroadcastReceiver set up to turn Bluetooth on and off according to power state (when plugged in, bluetooth is on, unplugged, bluetooth is off). This is working just fine (yay!). however, my very simple app has a single button, which also turns Bluetooth on and off, and has the text "Bluetooth on" or "Bluetooth Off", as applicable. I would like to update this single button, BUT, I only have to update it if the app is in the foreground.
Inside onResume on m,y main activity, I'm calling my updateUI method, which checks the Bluetooth state, and updates the button accordingly. however, that only applies if the program was open and in the background, and is resumed, NOT if i'm in the program while plugging/unplugging the power.
I created a new activity (CheckIfAppIsRunningActivity.java) with this code which is supposed to check if my app is running in the foreground, and if so, take it to the activity (BluetoothOnActivity) which will update the button:
package vermel.BluetoothOn;
import java.util.List;
import android.app.Activity;
import android.app.ActivityManager;
import android.app.ActivityManager.RunningAppProcessInfo;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;
public class CheckIfAppIsRunningActivity extends Activity{
public void onCreate() {
checkStatus();
}
private BroadcastReceiver myBroadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Intent it = new Intent();
it.setClassName("vermel.BluetoothOn", "vermel.BluetoothOn.BluetoothOnActivity");
context.startActivity(it);
}
};
public void checkStatus() {
ActivityManager activityManager = (ActivityManager) getApplicationContext().getSystemService(Context.ACTIVITY_SERVICE);
List<RunningAppProcessInfo> runningProcInfo = activityManager.getRunningAppProcesses();
for(int i = 0; i < runningProcInfo.size(); i++){
if(runningProcInfo.get(i).processName.equals("vermel.BluetoothOn")) {
if (runningProcInfo.get(i).lru == RunningAppProcessInfo.IMPORTANCE_FOREGROUND){
//start activity
/* Intent it = new Intent();
it.setClassName("vermel.BluetoothOn", "vermel.BluetoothOn.BluetoothOnActivity");
context.startActivity(it); */
}
}
}
}
}
and i'm pointing to it from my broadcast receiver:
package vermel.BluetoothOn;
import android.bluetooth.BluetoothAdapter;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Button;
import android.widget.Toast;
public class BTDetector extends BroadcastReceiver {
BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
public void onReceive(Context context , Intent intent) {
String action = intent.getAction();
if (action.equals(Intent.ACTION_POWER_CONNECTED)) {
if (!mBluetoothAdapter.isEnabled()) {
mBluetoothAdapter.enable();
//TODO if app is open, change text on button to on
//Toast.makeText(context, "turned on bluetooth", Toast.LENGTH_LONG).show();
Intent i = new Intent();
i.setClassName("vermel.BluetoothOn", "vermel.BluetoothOn.CheckIfAppIsRunningActivity");
context.startActivity(i);
}
} else if (action.equals(Intent.ACTION_POWER_DISCONNECTED)) {
if (mBluetoothAdapter.isEnabled()){
mBluetoothAdapter.disable();
//TODO if app is open, change text on button to off
//Toast.makeText(context, "turned off bluetooth", Toast.LENGTH_LONG).show();
Intent i = new Intent();
i.setClassName("vermel.BluetoothOn", "vermel.BluetoothOn.CheckIfAppIsRunningActivity");
context.startActivity(i);
}
}
}
}
a few things: yes, I know i'm not supposed to use .enable() without user permission. in a weird way, plugging in the phone IS my user permission, since this is ALL that this app does, so, it's not sneaky, since you know what you're getting when you're installing the app.
The commented stuff is mostly things i've tried in vain..
I'm very open to the fact that i'm making this WAY harder than I need to...
so, as i said, it does turn Bluetooth on and off beautifully, but simply crashes after that. I can't debug it, since the emulator doesn't have Bluetooth , and i'm disconnecting the phone to get the crash result, so, it's not logging anything, since it's now connected...
I'm new in both Java and Android, and would appreciate a bit of patience. I try reading the official android documentation, but that's like chinese to me... so, an extended explanation would be great...
Thanks for reading!