MainActivity.java

package io.github.multilateralis.android_furk_app;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuItem;


public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_main);

        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);

        if(getIntent().getAction() != null && getIntent().getAction().equals("io.github.multilateralis.android_furk_app.LOGOUT"))
        {
            preferences.edit().remove("api_key").apply();
        }


        String apiKey = preferences.getString("api_key","");

        if(apiKey.isEmpty())
        {
            Intent intent = new Intent(this,LoginActivity.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
            startActivityForResult(intent,1);
        }
        else {
            Intent intent = new Intent(this,Furk.class);
            intent.setAction(getIntent().getAction());
            intent.setData(getIntent().getData());
            intent.putExtras(getIntent());
            startActivity(intent);
            finish();
        }
    }

    @Override
    protected void onActivityResult (int requestCode, int resultCode, Intent data)
    {
        if(requestCode == 1 && resultCode == 200)
        {
            Intent intent = new Intent(this,Furk.class);
            intent.setData(getIntent().getData());
            startActivity(intent);
            finish();
        }
        else
            finish();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

//    @Override
//    public boolean onOptionsItemSelected(MenuItem item) {
//        // Handle action bar item clicks here. The action bar will
//        // automatically handle clicks on the Home/Up button, so long
//        // as you specify a parent activity in AndroidManifest.xml.
//        int id = item.getItemId();
//        if (id == R.id.action_settings) {
//            return true;
//        }
//        return super.onOptionsItemSelected(item);
//    }

}