Splash screen re-showing when launched from 3rd party app

Question

I have implemented a splash screen for my app. I made the splash screen activity the launch activity. The splash activity does the startup work (loading data, etc.), and then launches the "real" main activity.

The problem is this: I am using a 3rd party app that has the ability to launch other apps. Let's say my app is already running (it is past the splash screen, and is on to the real main screen). I then press the Home button to put the app in the background. I then do something that causes the 3rd party app to launch my app. What I want is for my app to be simply restored (as it would if I had tapped the app icon from the phone's regular launcher). Instead, it launches the splash screen all over again, and my initialization code runs again, which I don't want.

Since this is a 3rd party app that is starting my app, I don't have the ability to change how it launches my app. I am assuming that it is just querying the package manager to get the launch intent and starting that. So, I need to find a way to fix this in my app itself.

Is there a way that I can find out from my splash screen's onCreate method if my "real" main activity is already running, and if so, skip the initialization code and bring the existing main activity to the foreground?

Answer 1

Keep a static boolean in your Application class.

When initialization is done, set it to true.
When splash screen starts, check the value of the boolean, if true, go straight to your main activity without doing any logic, and instantly finish the splash activity.
If false, then assume it's a cold start and you need to run the initialization code.

There is no way to look at the Activity stack from within an Android app, so you can't check if the Main activity is already running.

There is also no way for the 3rd party app to check if your app is running, and then launch a different activity depending on that.