How to use Shared Preferences in MVP without Dagger and not causing Presenter to be Context dependent?

Question

I\'m trying to implement MVP without Dagger (for learning purposes). But I got to the problem - I use Repository patter to get raw data either from cache (Shared Preferences

Answer 1

This is how I do it. I have a singleton "SharedPreferencesManager" class that will handle all the read write operations to shared prefs like below

public final class SharedPreferencesManager {
    private  static final String MY_APP_PREFERENCES = "ca7eed88-2409-4de7-b529-52598af76734";
    private static final String PREF_USER_LEARNED_DRAWER = "963dfbb5-5f25-4fa9-9a9e-6766bfebfda8";
    ... // other shared preference keys

    private SharedPreferences sharedPrefs;
    private static SharedPreferencesManager instance;

    private SharedPreferencesManager(Context context){
        //using application context just to make sure we don't leak any activities
        sharedPrefs = context.getApplicationContext().getSharedPreferences(MY_APP_PREFERENCES, Context.MODE_PRIVATE);
    }

    public static synchronized SharedPreferencesManager getInstance(Context context){
        if(instance == null)
            instance = new SharedPreferencesManager(context);

        return instance;
    }

    public boolean isNavigationDrawerLearned(){
        return sharedPrefs.getBoolean(PREF_USER_LEARNED_DRAWER, false);
    }

    public void setNavigationDrawerLearned(boolean value){
        SharedPreferences.Editor editor = sharedPrefs.edit();
        editor.putBoolean(PREF_USER_LEARNED_DRAWER, value);
        editor.apply();
    }

    ... // other shared preference accessors
}

Then whenever access to shared preference is needed I pass the SharedPreferencesManager object in the relevant Presenter's constructor. For example :

if(null == presenter){
    presenter = new Presenter(SharedPreferencesManager.getInstance(getApplicationContext()));
}

Hope this helps!