How to prevent custom home launcher app restart activity?

Question

I am working on my own home launcher replacement and it works fine but one thing bothers me. When I press a home key, current home activity (the one defined in manifest as main/defualt/launcher/home) restarts - current activity instance onpause is executed and oncreate is fired again, so new activity is brought up.

On the other hand, ADW launcher and LauncherPRo does not behave like that - I do not a refresh like in my case. Launcher Pro even can do several actions:

1. If you are on the main screen with app icons, it zooms out to see a snapshot of all screens,
2. If you open a drawer and press Home, it just go back to the main screen.

Any ideas how to do that?

I just did a very simple prototype from scratch with just one activity (defined in manifest as main/defualt/launcher/home) and I see the same thing - it gets recreated if I press Home.

Antler

Answer 1

Add

if (!isTaskRoot()) {
    finish();
    return;
}

to the onCreate() of your first Activity (see Android application restarts when opened by clicking the application icon).

Langill

isTaskRoot is true in both the activity's instance. When I use the above snippet, the screen is blank. Older activity instance is not destroyed as well. – Tybie

Answer 2

Add android:launchMode="singleInstance" to your <activity> element in the manifest.

Jerrelljerri

android:launchMode="singleTop" should also work fine. it would not be possible to call other activities from his one if singleInstance is used as I understand. – Trichotomy

@mishkin: I am going by the Home sample application from the SDK, which uses singleInstance. Curiously, the AOSP launchers use singleTask. – Jerrelljerri

adding related @Jerrelljerri answer for info on the "extra" questions posed: Android launcher press home in launcher to go to default screen – Hew