Android活动意图启动

Question

I'm stuck for a couple of hours on a stupid problem.

My application is composed by 2 activities: A (master) and B. There is also one service S. The "normal" tasks stack is AB and S is running in background.

My issue is appeared when I would like directly reach the activity B with a notification. I have to construct the tasks stack to obtain AB in order to keep the default behaviour of the return button. (I want the user could back to A).

Because I have use the API 7, I can't use an intent array as show in the android developpers tutorial http://developer.android.com/guide/topics/ui/notifiers/notifications.html . So I have decided to add a custom action (S.ACTION_CUSTOM) in the intent sent by the notification in order to distinguish this case in the onCreate() of the activity A.

Intent associated to the notification declared in the service S :

Intent notificationIntent = new Intent(this, A.class);
       notificationIntent.setAction(ACTION_CUSTOM);

Now in A, at the end of the onCreate() method, I add:

if (S.ACTION_CUSTOM.equals(getIntent().getAction())) {
        Intent intent = new Intent(this, B.class);
        intent.setAction(S.ACTION_CUSTOM);
        startActivity(intent); 
 }

This code works to go directly to B from notification and it authorize the return to A. But once I have use the notification "shorcut", then B is directly reached when the application start, even from the home menu. I have tried many things to understand what happen but even if I add getIntent().setAction(ANYTHING) at the end of the if statement in A, the behaviour is the same.

Could anyone tell me what happening with my code please ? Morover I'm open minded with an other method to get my wishes.

Thanks.

Edit:

Part of the XML manifest:

<activity
        android:name=".A"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
</activity>
<activity
        android:name=".B"
        android:label="@string/app_name" >
</activity>

But I think intent filters have nothing to do with my problem.

Answer 1

With more tests, I have found the cause and a solution.

In fact, when I said I relaunched the application from the home menu, It was not true. I had relauched it from the "recent activities" (long press on home). However, it seems that android, in this case, launches the application with the last intent which did ran it. So it works fine from the home (because a new intent with Intent.ACTION_MAIN is fire) but not from recent activities because an intent with the same action as precedently is fired (ACTION_CUSTOM in my case) again and again.

In order to differenciate intent from "recent activies" and "notification" I have used flags. In the case of recent activities, the intent has the flag Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY.

So I fixe my code by add a condition in the if statement:

if (S.ACTION_CUSTOM.equals(getIntent().getAction()) && (getIntent().getFlags() & Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY) == 0) {
        startActivity(getIntent().setClass(this, B.class));  
}

My real code is a little more complicated with 4 activities instead of 2 but all works fine, each activity transmits the intent to the next. The stack is well builded and when the user start the application from elsewhere than the notification, the default behaviour is kept.

Hope this will help someone to avoid to lose his time to understand why intents seems crazy.