In MVP you dont use Context or anything else from the Android SDK/Framework in the Presenter (P) layer! This layer is for anything else than Android related stuff.
1) how to access shared preferences inside presenter.
You don't. If you need a value from a SharedPrefences in the Presenter then you could pass the value to the Presenter via a method call.
Example:
class MainActivity{
String birthday = SharedPrefence.getString(..);
presenter.setSavedBirtday(birthday);
}
2) how to access other system services inside presenter.
As metioned before; You don't acesss System services in the Presenter.
What you can do is call the a System Service from the Presenter.
Example with Vibrator:
1 - Create an interface:
interface OnSystemServiceCaller{
onVibratorCall();
}
2 - Implement it in a Activity
class MainActivity implements OnSystemServiceCaller{
@Override
onVibratorCall(){
Vibrator v = (Vibrator) getSystemService(VIBRATOR);
v.vibrate(50);
}
}
3 - Call from presenter
class Presenter{
OnSystemServiceCaller listener;
public void ifButtonClicked(){
listener.onVibrateCall();
}
}
3) if i am working on SQLite Databases then during any transaction in my database which is done by call from presenter to my SQLite Helper class need context to access database.
Some wont like this answers other will, this is just a suggestion.
You can access your SQLite by using a global ApplicationContext() in your app class (Class that extend Application; see how here since your SQLlite is global for the whole app and not just a particular Activity And when you need to pass data from SQLite to a Activity then you pass it first to the Presenter and from Presenter to your Activity the same way we send a call to our Vibrator method
