在不使用android：launchMode =“ singleTask”的情况下在新任务中打开android活动

Question

I've created a browser application with main activity which response to the following intents:

 <intent-filter> 
       <data android:scheme="http"/>
       <data android:scheme="https"/>
       <category android:name="android.intent.category.DEFAULT"/>
       <category android:name="android.intent.category.BROWSABLE"/>
       <action android:name="android.intent.action.VIEW"/>
 </intent-filter>

On url click from other task (gmail, sms) if i choose my application, the activity is open in the same task as the calling task. When I choose different browser (Mozila firefox, chrome, dolphine) they are opening in different task.

Looking on other browsers manifest, I see that no one using .

I don't want to use single task flag since it is not recommended by google and also makes me other prolems.

I tried to understand how does other browsers do it but didn't figure it out.

any ideas? is there other way to open my activity in different task without using singleTask flag?

Answer 1

You can check in onCreate if the activity is running in a single task. If not just finish() it and create it again with using FLAG_ACTIVITY_NEW_TASK

This may help you

   ActivityManager activityManager = (ActivityManager) ctx.getSystemService(Context.ACTIVITY_SERVICE);
    List<RunningTaskInfo> tasks = activityManager.getRunningTasks(Integer.MAX_VALUE);

    for (RunningTaskInfo task : tasks) {
        if (ctx.getPackageName().equalsIgnoreCase(task.baseActivity.getPackageName())) 
          // check if it's the only one activity or whatever                               
    }

Answer 2

I have found the following description on Android Developers site :

As another example, the Android Browser application declares that the web browser activity should always open in its own task—by specifying the singleTask launch mode in the element. This means that if your application issues an intent to open the Android Browser, its activity is not placed in the same task as your application. Instead, either a new task starts for the Browser or, if the Browser already has a task running in the background, that task is brought forward to handle the new intent.

As you can see android:launchMode=singleTask is the right choice in your case. You already mentioned that you had issues with this property so maybe let's focus on them.

Update 28.05.2014

Note from Google regarding singleTask launchMode:

The other modes — singleTask and singleInstance — are not appropriate for most applications, since they result in an interaction model that is likely to be unfamiliar to users and is very different from most other applications.

singleTask and singleInstance use case from Google:

Specialized launches (not recommended for general use)

As you can see singleTask may not be recommended for general use but your case is not general, actually it's one of the cases where singleTask fits perfectly. In other words, singleTask is not forbidden, it's just need to be used with caution in order to provide end users common experience with your app.

I hope I made it clear now for you. Feel comfortable with this launch mode in your case.

Answer 3

You're trying to "bend the rules" a little, and you're not clear enough on what you're trying to avoid by not using android:launchMode="singleTask" .

So I would suggest researching into either:

1. Creating a Service and having that Service listen to the intent filter. Then having this Service open your Activity , and having the Activity 's affinity set correctly to match the Service 's. This would allow you to get over the issue where affinity is not binding the Activity correctly.

2. Having a silent Activity starting a new Activity and quiting. The silent Activity would start in a new stack (not in a singletask mode), and would shut itself down upon starting the Activity you actually need.