Develop Reference

How to get a callback from Android system to the app?

I'm making an app in which you can chat and call with other contacts. But in case of calling, I've designed the app in such a way that after typing the number and clicking on the call icon, it takes you to native calls app for calling and updates the call log in my current app.
For this process, this is the code I've written:
if (nativeCall(mobileNumber)) {
Intent intent = new Intent(Intent.ACTION_CALL).setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setData(Uri.parse("tel:" + mobileNumber));
if (((BaseActivity) context).isNetworkOk()) {
addToUserCallLogs(context, DateUtils.convertTimestampToDate(), contactUri, "Out", System.currentTimeMillis());
}
context.startActivity(intent);
return true;
}
You can see that I'm putting mobile number into the intent and starting it. And I'm using addToUserCallLogs() function to show it in my app's call logs.
This works fine usually, but in the issue is in the following case.
When the user has multiple calling applications(For eg, the user has installed application named SMARTalk. Now he has native caller app and SMARTalk app to call from), in that case the Android system gives options to chose from like this:
Now, if he choses from one of them, even in that case there is no issue. Say he didn't chose any of those and clicked on the other part of the screen. Then this options bar will be closed. Since all this is happening after starting the intent, this call will be added in the call logs of the app from the function addToUserCallLogs(). But I don't want the call to be shown in the call Logs because I haven't done any call.
But according to the code I've written, before starting the intent, I'm adding into my app's call logs database. Is there a way the information of whether the call has happened or not can be sent back from the system to the app?
Or a way to get these options to be shown manually from the app?
Please comment if you need any more explanation.

I guess no way to receive the callback information because ACTION_CALL does not return a result. You can see the output is nothing from docs even you use startActivityForResult

Android: Measuring time spent on another app from current activity

I have an activity and using an intent I call a certain portion of another app. That is lets say my app A has an activity 1 from which I call activity 1 of app B which I have no control over using the following mechanism
Activity A
Intent intent = null;
try {
intent = Intent.parseUri("URI://sample/100/1000",
Intent.URI_INTENT_SCHEME);
} catch (URISyntaxException e) {
--ERROR
}
startActivity(intent);
When I press the back button it returns to Activity 1 of my app A. Since I lose control I am not able to figure how I can capture the amount of time the user spent on the Activity from app B. Is there some way I can capture this? I know if the user goes to the home screen from that app my data will be skewed but I am ok with that. But using system time in seconds can I capture the time?

May be you can use "startActivityForResult". This way, you can write "onActivityResult" and check how much time has elapsed since you started the intent.
More about it can be found here: How to manage `startActivityForResult` on Android?

Stay on my activity when dialing

I am using the intent with ACTION_CALL to make call in my app:
str="tel:0123456789";
Intent intent = new Intent(Intent.ACTION_CALL);
intent.setData(Uri.parse(str));
startActivity(intent);
But it pops up the system dialing screen. I understand this is built into ROM and can not be customized. But Can I hide this screen and keep the user staying on my activity?
Did some googling and research here. But no clear answer so far.

It looks like you can't customize the dialing screen, but you can use a PhoneStateListener to get certain information about the phone call. See this link.

Programmatically enter secret code like *#*#4636#*#* on Android

On many Android devices you can get into a secret settings menu from Phone app by typing in
*#*#4636#*#*
http://technology-headlines.com/2010/09/17/4636-android-secret-codes/
There are also some other codes.
Is it also possible to open this stuff programmatically?
I've tried this:
Intent intent = new Intent(Intent.ACTION_CALL);
intent.setData(Uri.parse("tel:*#*#4636#*#*"));
startActivity(intent);
But it just tries to initiate a phone call and of course fails, hangs up and closes the Phone app.
EDIT: The phone *#*#4636#*#* gets saved to my Contact list as "Unknown" but the call just fails. In fact, the secret code only works when you type manually on buttons in Phone app without pressing Call in the end. Is it probably just a hidden feature of Phone app which has nothing to do with calling?
If so, one could open the Phone app programmatically and simulate typing on the buttons.
According to this post
Programmatically press a button in another appplication's activity
this should NOT be possible because if any app on non-rooted phone could just start other apps and press something there, it could take over control of the whole device and do bad things.
Here are some more details but I guess the post is a bit old and even if it worked it may have been changed in current Android versions:
http://mylifewithandroid.blogspot.de/2009/01/generating-keypresses-programmatically.html
So, no easier way to enter secret code?

Is it also possible to open this stuff programmatically?
Yes:
Intent in = new Intent(Intent.ACTION_MAIN);
in.setClassName("com.android.settings", "com.android.settings.TestingSettings");
startActivity(in);
You just need to watch logcat output to learn what this magic combination actually opens:
I/ActivityManager(31362): START {act=android.intent.action.MAIN
flg=0x10000000 cmp=com.android.settings/.TestingSettings} from pid
4257

Secret codes exist and work independent of the dialer application. The dialer application just provides a handy interface for these codes. It recognizes the special string and then calls a special intent to invoke the action. You shouldn't use the dialer to call these dialogs. Instead you can call the secret codes directly yourself like the dialer does internally:
Invoking built in secret codes:
What the dialer really does when you enter the code is extracting the number between *#*# and #*#* and then broadcasting the following intent:
sendBroadcast(new Intent("android.provider.Telephony.SECRET_CODE", Uri.parse("android_secret_code://4636")));
Register your own secret codes (if you like):
You can even register your own secret code actions using:
<action android:name="android.provider.Telephony.SECRET_CODE" />
<data android:scheme="android_secret_code" android:host="4636" />
Source: http://android.amberfog.com/?p=422
Edit: Fixed a bug in the original code (see comment)

try this
String ussdCode = "*" +Uri.encode ("#")+"*"+Uri.encode ("#")+ "4636" + Uri.encode ("#")+"*"+Uri.encode ("#")+"*";
startActivity (new Intent ("android.intent.action.CALL", Uri.parse ("tel:" + ussdCode)));
finally you must encode '#' using Uri.encode()

ACTION_DIAL sends the user to the dialer with the given code (it does not call). So that would be :
Intent intent = new Intent(Intent.ACTION_DIAL);
intent.setData(Uri.parse("tel:*#*#4636#*#*"));
startActivity(intent);
It would appear that codes are to be dialed, rather than to be called

looking for this
Intent intent = new Intent("android.intent.action.MAIN");
intent.setClassName("com.android.settings", "com.android.settings.Settings$TestingSettingsActivity");
startActivity(intent);

There are different activities for different phone, we can jump to the activity through typing in ##4636##.
And use
adb shell dumsys activity activities
to find the realActivity package and name.
e.g: Xiaomi 8
Intent intent = new Intent("android.intent.action.MAIN");
intent.setClassName("com.android.settings", "com.android.settings.Settings$TestingSettingsActivity");
startActivity(intent);

Launching an activity at its current state

I am trying to make a task switcher and I succeeded in it. My only problem is that when I launch activities, they are relaunched as they were new activities ( for instance, I am writing an email, I press home and go into my activity,launch email, and then the app launch the email bout goes back to the inbox and the email is lost) So that's not true multitasking.
Here are my steps:
1) getting all the running apps:
List<ActivityManager.RunningTaskInfo> allTasks = activityManager.getRunningTasks(30);
2) getting the intent:
for (ActivityManager.RunningTaskInfo aTask : allTasks) {
Intent i = new Intent(Intent.ACTION_MAIN);
i.setComponent(aTask.baseActivity);
(...)
3) Launching the application when clicking on the button:
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK| Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED).addCategory(Intent.CATEGORY_LAUNCHER);
monthis.startActivity(intent);
`
What is wrong with this code? Should I do something different to get it?
Thank a lot for any answer.

When creating the Intents you should not use Intent.FLAG_ACTIVITY_NEW_TASK, you should use FLAG_ACTIVITY_REORDER_TO_FRONT.

Sorry if I made mistakes in my explanation, I am quite a "noob" and just tell here my experience to improve the result of people searching for the same answer than me.
In fact, I had to Use intent.setFlag(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_REORDER_TO_FRONT) for the best result. Replacing was not the best Idea.
Not using FLAG_ACTIVITY_NEW_TASK make the email application launch when I wanted to launch my own application. Because email was "linked" with the same task than my Application.
But Lucas, I keep your answer as the best.

I think I found the answer. Let me tell what i have done in simple words,
Suppose i am having two activities activity1 and activity2 and i am navigating from activity1 to activity2(i have done some works in activity2) and again back to activity 1 by clicking on a button in activity1. Now at this stage I wanted to go back to activity2 and i want to see my activity2 in the same condition when I last left activity2.
For the above scenario what i have done is that in the manifest i made some changes like this:
<activity android:name=".activity2"
android:alwaysRetainTaskState="True"
android:launchMode="singleInstance">
</activity>
And in the activity1 on the button click event i have done like this:
Intent intent=new Intent();
intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
intent.setClassName(this,"com.mainscreen.activity2");
startActivity(intent);
And in activity2 on button click event i have done like this:
Intent intent=new Intent();
intent.setClassName(this,"com.mainscreen.activity1");
startActivity(intent);
Now what will happen is that whatever the changes we have made in the activity2 will not be lost, and we can view activity2 in the same state as we left previously.
I believe this is the answer and this works fine for me. Correct me if i am wrong.