CODEWITHSUNDEEP
javaandroid
Mahbubur Rahman Khan
Mahbubur Rahman Khan

Reputation: 415

How to check AppCompatActivity comes from which fragment in Android

I can pass an AppCompatActivity through a function parameter from a Fragment. But I can't figure out how to check which fragment pass inside that function. How instanceof checking could be possible.

Suppose, I have two fragments.

  1. OptionsFragment
  2. HomeFragment

Both Can pass AppCompatActivity like this.

StaticAccess.checkSignal((AppCompatActivity) OptionsFragment.this.getActivity())

Or

StaticAccess.checkSignal((AppCompatActivity) HomeFragment.this.getActivity())

Inside StaticAccess Class...

public class StaticAccess{

    public static void checkSignal(final AppCompatActivity context){
        //how to check context is instanceof which fragment when 
        //if(context instanceof OptionFragment) not comparable
    }

}

Upvotes: 0

Views: 134

Answers (1)

omz1990
omz1990

Reputation: 742

You can't compare Activity with a Fragment (for obvious reasons), they are totally separate things. A Fragment is not bound to any particular Activity, it can be triggered from any Activity.

When you pass OptionsFragment.this.getActivity(), you are not passing the Fragment, you are passing the Activity that the Fragment is currently in. So the context in your checkSignal() function is of the Activity.

There are a couple of ways to go about it, and it all depends on what implementation you use in your app.

For example, if you have a patter where OptionsFragment and HomeFragment are always called from separate activities, Then for example if OptionsFragment was triggered from Activity1 and HomeFragment from Activity2 in your checkSignal function you would do something like if (context instanceof Activity1) { // Do stuff } etc. However, this would be a bad and not scalable approach in my opinion.

Now, if your patter is such that the checkSignal function is only called from Fragments, then you can change the constructor to static void checkSignal(final Fragment context), call the function from the fragment like StaticAccess.checkSignal(this), and check for the type like this if (context instanceof HomeFragment) { // Do stuff }. However, this too is a bad and not scalable approach.

If I were you, I would create an enum with the different possible signal types, and pass that as the parameter. This will remove the dependency of whether you call it from an Activity, Fragment, or wherever you want (especially since it is static, it can be called from anywhere). Something like this:

public enum SignalSource {
    HOME,
    OPTIONS
}

public class StaticAccess{

    public static void checkSignal(SignalSource source){
        if (source == SignalSource.HOME) {
            // Do something...
        } else if (source == SignalSource.OPTIONS) {
            // Do something...
        }
    }

}

// Call it like this from anywhere
StaticAccess.checkSignal(SignalSource.HOME)

Upvotes: 1

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