Develop Reference

How to unregister incoming call and outgoing call receivers?

I'm developing an application for Android.
I use Samsung Galaxy S3 with original ROM Jelly Bean 4.3.
I have a problem with the receivers of incoming call and outgoing call.
Here is the code of IncomingCallReceiver:
public void onReceive(Context context, Intent intent) {
String state = intent.getStringExtra(TelephonyManager.EXTRA_STATE);
if (state.equals(TelephonyManager.EXTRA_STATE_RINGING)) {
if (Start.getMusicService().isPlaying()) {
pauseMusicService();
isMusicPlaying = true;
}
}
else if (state.equals(TelephonyManager.EXTRA_STATE_IDLE)) {
if (isMusicPlaying){
restartMusicService();
isMusicPlaying = false;
}
}
}
However this is not the problem, this code works and also the outgoing call receiver works perfectly.
My problem is that when i exit the application this receivers still work.
It's happened that, days after the last time i opened the application, i received a phone call and the application crashed.
I think that it's happened because i write the code:
if (Start.getMusicService().isPlaying())
because Start (my first activity) doesn't exist.
I never register this receiver, they work without that i "call" them.
I don't know if i have to unregister and in case when i have to do it.
So, can anyone help me please?
Andrea

When declaring a BroadcastReceiver or other Intent receiver in your AndroidManifest it is always "on". Move the registration and deregistration to the beginning and end of the execution of your app, or other times in your app; then you will be able to control when its on at runtime.

Above answer is correct. If you want to register and/or unregister receiver yourself at you should register in onResume and unregister in onPause in case of activity. Look out this example http://sohailaziz05.blogspot.com/2012/05/broadcast-receiver-two-ways-to.html

Android- Telephone app that keeps focus on outgoing & incoming phoneCall

Using this simple example to create a PhoneCall application that dials out a hard coded # and monitors phone state.
http://www.mkyong.com/android/how-to-make-a-phone-call-in-android/
Unfortunately, on making the phone call, we always switch to the actual built -in phone application.
I want to avoid this, or at the very least hide the dialer pad button. The user SHOULD NOT have the option to enter a phone#.
Does anyone know of a way to achieve this?
i.e. keep the actual built-in phone application in the background
(I would need to add buttons for speaker, and end call in the primary application)
OR
alternatively, hide just the dial pad button in the native, built-in phone application?

Here is a solution I came up with to hide the caller app shortly after the call is placed. I don't believe there is a way to make it totally transparent without re-writing the Android system. I believe this could be improved by detecting when the caller app is set up and dialing instead of the postDelayed() I'm using which could be unreliable.
EDIT: I tried making a receiver to listen for NEW_OUTGOING_CALL to restart the original Activity, but it doesn't really improve anything, the dialer app must be running for an arbitrary amount of time before it can start it's background service.
EDIT: I tried making a PhoneStateListener that listens for CALL_STATE_OFFHOOK and re starts the Activity there. This doesn't work either as it happens before the dialing app is fully ready to go into the background.
EDIT: You can look at this thread: Reflection to access advanced telephony features, but I believe Google has since locked down all methods of placing a call outside the standard app.
This solution will start the dialing, and then switch back to the original Activity after a couple of seconds.
In my manifest I have:
android:launchMode="singleInstance"
on my Activity so I don't get a new instance.
public class MainActivity extends Activity
{
....
public void clickMe(View view)
{
startService(new Intent(this, PhoneService.class));
}
}
public class PhoneService extends Service
{
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Intent call = new Intent(Intent.ACTION_CALL);
call.setData(Uri.parse("tel:XXXXXXXXX"));
call.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(call);
Handler h = new Handler();
h.postDelayed(new Runnable() {
#Override
public void run()
{
Intent act = new Intent(PhoneService.this, MainActivity.class);
act.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(act);
}
}, 4000);
return super.onStartCommand(intent, flags, startId);
}
#Override
public IBinder onBind(Intent arg0)
{
// TODO Auto-generated method stub
return null;
}
}
I believe it impossible to provide a cleaner solution, given the constraints of the SDK.

The functionality you are wanting isn't possible without some type of hack-ish work around. The Android system only allows the Phone app to control the underlying RIL and telephony stack and the Phone app UI responds to the dial URI by presenting this user with the dial screen where they must confirm (or alter) the number. This is a security provision to prevent unwanted apps from using the telephone device without the user knowing about it. Also, due to the way the Intent system works in Android, it is possible for other apps to handle calls using SIP or other VoIP functionality (i.e. Skype). In this case the user may have set a global preference to always use the other app and you have no control over how that app behaves with the dial Intent.

How to capture key events from bluetooth headset with android

My app can be controlled by normal headset. It simply overrides "onKeyDown". But key events from bluetooth headset are not captured - why? Or how to capture bluetooth key events?
the "log cat" shows the following if i press button on headset:
Bluetooth AT recv(3043): AT+VGS=15
AudioPolicyManagerBase(13654): FM radio recording off
AudioService(2261): sendVolumeUpdate, isKeyguardLocked...Not to update Volume Panel.
VolumePanel(2261): change volume by MSG_VOLUME_CHANGED
VolumePanel(2261): onVolumeChanged(streamType: 6, flags: 0)
VolumePanel(2261): Call setChangeSeekbarColor(false)
i also tried to handle media button actions but this isn't working. my idea is a free configurable key mapping: the user chooses "set key" my app hears on all keys (hardware, media buttons, bluetooth headset) then the user presses a key and the event/key code is stored in config.
Summerizing not working Answers:
Volume buttons must be captured by "VOLUME_CHANGED_ACTION". The problem is this intents are broadcasted to other apps and abortBroadcast() doesn't work (it works only for "ordered" Broadcasts). Another problem is that keys on cable headset and on phone trigger onReceive() twice (why?) the bluetooth headset trigger it once.
The next Problem is the 3rd key on Bluetooth headset. It triggers voice-command (s-voice starts on s3), i tried to capture many different intents regarding this but i can't "receive" this button press and don't know why.
At the end i want capture all kinds of buttons and don't want them handled by other apps (like using onKeyDown and returning true).

Add a broadcast listener to MEDIA_BUTTON:
<intent-filter android:priority="<some number>">
<action android:name="android.intent.action.MEDIA_BUTTON" />
</intent-filter>
You should register your broadcast receiver inside your application (not in manifest file). Otherwise Google Music player will catch your broadcast and aboard it.
Your IntentFilter priority should be higher that other media players priorities in your phone)
Add android.permission.BLUETOOTH permission in manifest to support Bluetooth headset
After received you key you have to manually abort the broadcast using abortBroadcast().
However priorities and abortBroadcast() work fine as long as each app only responds while
e.g. something is played.
But several users also expect a "default player" to be launched (or start playing) upon button press, like the default player, so it might happen some app with a higher priority number won't let the intent come through to your app
In the onReceive, you can get the button event with
KeyEvent key = (KeyEvent)
intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
key.getKeyAction() tells you whether the button was released or pressed, key.getKeyCode() tells which button is pressed.
If you want to handle single button cable headsets as well, also
regard the key code KEYCODE_HEADSETHOOK
Override the onKeyDown method in any activity and check for
the KeyEvent.KEYCODE_MEDIA_KEYCODE_pressed_key
e.g.
boolean onKeyDown(int keyCode, KeyEvent event) {
AudibleReadyPlayer abc;
switch (keyCode) {
case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
// code for fast forward
return true;
case KeyEvent.KEYCODE_MEDIA_NEXT:
// code for next
return true;
case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
// code for play/pause
return true;
case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
// code for previous
return true;
case KeyEvent.KEYCODE_MEDIA_REWIND:
// code for rewind
return true;
case KeyEvent.KEYCODE_MEDIA_STOP:
// code for stop
return true;
}
return false;
}
Volume key integration example
Android - Volume Buttons used in my application
This one may need permission
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
Or you can try slimier implementations over the following link
Android Developer Blog : Handling remote control buttons
Android Tales : Add Headset button support to your Android application

Check out this article. It explains how to implement something similar using media button actions.
I know you've mentioned that you walked this way without success, still give it a try. Point your attention to gotchas related to registering broadcast receiver, setting intent filter priorities and adding permissions (all explained in the article).
Hope this will help.

If you are trying to listen for this from an activity, use onKeyDown() and catch the KEYCODE_MEDIA_PLAY_PAUSE (KEYCODE_MEDIA_PLAY and KEYCODE_MEDIA_PAUSE post ICS) key events.
Also for the broadcast receiver solution to work make sure there arent other apps installed and running in the background that catch these events which might take priority over yours.
Also look at this: Android - registering a headset button click with BroadcastReceiver

Programmatically check for Android OTA system updates

If you go to Settings->About Phone->Check for updates a check is initiated to see if theres any system updates ready for your phone.
How can I do this action programmatically? Further, I am trying to locate where in the Android source code this happens so I can see it fully and understand it better. Does anyone have any suggestions?

As far as I know, there is no known broadcast, intent or API to do this programmatically.
And it depends on the ROM, and manufacturer.
Sony for example uses a service which, when the wifi is activated, the service checks on Sony's servers for any updates and informs of it.
But when talking about AOSP source, that I do not think happens.
The nearest point of System update is found in packages/apps/Settings/src/com/android/settings/DeviceInfoSettings.java
Protip: grep the string "System update" within the res/values directory and work backwords and find out where that string variable identifier is used!
Edit:
Here's an example broadcast receiver:
public class SystemUpdateClass extends BroadcastReceiver{
#Override
public void onReceive(Context context, Intent intent){
if (intent.getAction().equals("android.settings.SYSTEM_UPDATE_SETTINGS")){
Toast.makeText(context,
"Yup! Received a system update broadcast",
Toast.LENGTH_SHORT).show();
}
}
}
Here's an example code, from within a activity's onCreate:
SystemUpdateClass sysUpdate = new SystemUpdateClass();
IntentFilter filter = new IntentFilter();
filter.addAction("android.settings.SYSTEM_UPDATE_SETTINGS");
registerReceiver(sysUpdate, filter);
Now, what should happen is your app should receive the broadcast, unless I am mistaken that the broadcast is only for system-signed apps... however the rest is left as an exercise :)

What is the correct way of handling the action NEW_OUTGOING_CALL while looping?

At the moment I am developing an application which catches the action NEW_OUTGOING_CALL with the help of a BroadcastReceiver. I am aborting the call by calling setResultData(null). After that I am showing the user a dialog which allows him to decide if he wants to use my application to rewrite its number. When the users decision has happened I am placing the new call depending on the decision. Now my broadcast receiver gets called up once again.
What is the correct way of getting to know that I have already processed the number? I got a working solution that uses a timestamp to guess if it could be already processed. Another solution would be to add a "+" at the end of the processed number.
These methods are working fine for my application being the only one catching the NEW_OUTGOING_CALL event. But what should I do when other applications (like Sipdroid or Google Voice) are also sitting there catching the NEW_OUTGOING_CALL broadcast aborting it and restarting it again? I don't see a possibility to get to know if we are still in the same "call flow" and if I already processed the number.
I would love to hear your ideas about this problem!

What API level are you working with? If it's >= 11, check out the new BroadcastReceiver.goAsync function that lets you extend the processing of the broadcast outside of the onReceive function of your receiver. This could bypass the need to loop altogether.
If, like me, you're stuck trying to do this before level 11, it is surprisingly tricky to do this elegantly. You may have done this as well, but I tried to include a "processed" flag as an extra in the ACTION_CALL intent that my code generated, hoping that it would somehow get included in the resulting ACTION_NEW_OUTGOING_CALL broadcast, but that sadly does not work.
The best solution I have been able to find is including a fragment in the URI for the ACTION_CALL intent that you generate. This fragment will be included for the resulting ACTION_NEW_OUTGOING_CALL broadcast, so your broadcast receiver can differentiate between the original call and the one that you generate, but it won't interfere with handlers that aren't looking for it.
Here's the basic code.
In your BroadcastReceiver for the ACTION_NEW_OUTGOING_CALL
public class YourBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// extract the fragment from the URI
String uriFragment = Uri.parse(
intent.getStringExtra("android.phone.extra.ORIGINAL_URI")).getFragment();
// if the fragment is missing or does not have your flag, it is new
if (uriFragment == null || !uriFragment.contains("your_flag")) {
// launch your activity, pass the phone number, etc.
// use getResultData to get the number in order to respect
// earlier broadcast receivers
...
// abort the broadcast
this.setResultData(null);
this.abortBroadcast();
}
// otherwise, your code is there, this call was triggered by you
else {
// unless you have a special need, you'll probably just let the broadcast
// go through here
// note that resultData ignores the fragment, so other receivers should
// be blissfully unaware of it
}
}
}
When the user first dials the number, the fragment will either be missing altogether or your flag won't be present, so you'll abort the broadcast and start your activity. In your activity, if you decide to place the call again, do something like the following:
startActivity(new Intent(Intent.ACTION_CALL,
Uri.parse("tel:" + modified_number + "#your_flag")));
The "your_flag" fragment will then be present in the subsequent NEW_OUTGOING_CALL broadcast and thus allow you to handle this case differently in your broadcast receiver.
The nice thing about this is the the fragment is completely ignored unless you look for it in the ORIGINAL_URI, so other broadcast receivers can continue to function. If you want to be really nice, you may want to look for an existing fragment and add your flag to it (perhaps with a comma separator).
I hope that helps. Good luck!

I don't see a possibility to get to
know if we are still in the same "call
flow" and if I already processed the
number.
Technically, you are not in the same "call flow" as placing a new call is asynchronous. You have to use hints (such as a timestamp) as you seem to be doing already.
If you are confident that other applications will not rewrite the number except to change the prefix or to add a suffix, you may want to add another "proximity check" hint to avoid false positives/negatives, but I'm afraid that's about all you can do.

The onReceive() method in Broadcast receiver receives an Intent as an argument.
Extract the Bundle from the Intent using Intent.getExtras().
This Bundle contains 3 key-value pairs as follows :
android.phone.extra.ALREADY_CALLED = null
android.intent.extra.PHONE_NUMBER = 98xxxxxx98
android.phone.extra.ORIGINAL_URI = tel:98xxxxxx98
98xxxxxx98 is the number dialled by the user.
When the onReceive() is called again, this number changes to 98xxxxxx98* or 0*
By checking for the asterisk(*) at the end of the dialled number, it can be inferred if the onReceive() method is called for the first time or the next subsequent times.

One of the answers would be to track the boolean extra in the intent. It is done in similar way by the Google Phone app. You can check this BroadcastReceiver here (look for alreadyCalled usage)
The other way would be just to pass that "rewritten" number from your broadcast to the next broadcast receiver down the road (can be any app, like Sipdroid, Google Voice, or custom VoIP app) without calling ACTION_CALL intent (this is why you get loop and you broadcast receiver called again) The following code is example of how I am handling call in my custom VoIP app. When I intercept NEW_OUTGOING_CALL in my broadcast receiver, I first check if there is internet connection. If phone is connected to internet I use custom defined intent action of my activity to place call through my VoIP app. If there is no internet connection, I just set original phone number to the broadcast receiver result data. This is used by the next broadcast receiver (probably default phone app, but doesn't have to be) in the flow to place a call.
public class BHTTalkerCallReceiver extends BroadcastReceiver {
private static final String TAG = "BHTTalkerCallReceiver";
#Override
public void onReceive(Context context, Intent intent) {
Log.d(TAG, "Broadcast successfull ... ");
// Extract phone number reformatted by previous receivers
String phoneNumber = getResultData();
if (phoneNumber == null) {
// No reformatted number, use the original
phoneNumber = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);
}
if (isNetworkAvailable(context)) { // Make sure this app handles call only if there is internet connection
// My app will bring up the call, so cancel the broadcast
setResultData(null);
// Start my app to bring up the call
Intent voipCallIntent = new Intent(context, TalkerActivity.class);
voipCallIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
voipCallIntent.putExtra(TalkerActivity.OUT_CALL_NUMBER, phoneNumber);
voipCallIntent.setAction(TalkerActivity.BHT_TALKER_OUT_CALL);
context.startActivity(voipCallIntent);
} else { //otherwise make a regular call...
// Forward phone data to standard phone call
setResultData(phoneNumber);
}
}
private boolean isNetworkAvailable(final Context context) {
final ConnectivityManager connectivityManager = ((ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE));
return connectivityManager.getActiveNetworkInfo() != null && connectivityManager.getActiveNetworkInfo().isConnected();
}
}