SingleFragmentActivity

SingleFragmentActivity.java

package com.example.ashish.ci;    import android.os.Bundle;  import android.support.v4.app.Fragment;  import android.support.v4.app.FragmentActivity;  import android.support.v4.app.FragmentManager;    /**   * Created by Ashish on 9/20/15.   */  public abstract class SingleFragmentActivity extends FragmentActivity {        protected abstract Fragment createFragment();   // this is an abstract method which subclasses need to implement        @Override      protected void onCreate(Bundle savedInstanceState) {          super.onCreate(savedInstanceState);          setContentView(R.layout.activity_fragment);            FragmentManager fm = getSupportFragmentManager();          Fragment frag = fm.findFragmentById(R.id.fragment_container);          if (frag == null){              frag = createFragment();    // note: earlier we had "= new CrimeFragment()" as it was a class, now we don't have new                                          // because "createFragment()" is a method              fm.beginTransaction().add(R.id.fragment_container,frag).commit();          }      }        }