dont know what is this yet / java

//MainActivity //

import android.app.Activity;

import android.app.Fragment;

import android.app.FragmentManager;

import android.app.FragmentTransaction;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.Toast;

public class MainActivity extends Activity {

        @Override

        protected void onCreate(Bundle savedInstanceState) {           

                super.onCreate(savedInstanceState);

                setContentView(R.layout.activity_main);

                if(savedInstanceState==null){

                        PlaceholderFragment placeholderFragment=new PlaceholderFragment();

                        FragmentManager fragmentManager=getFragmentManager();

                        FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();

                        fragmentTransaction.add(R.id.mainContainer, placeholderFragment);

                        fragmentTransaction.commit();

                }

               

        }

       

        public void onFinishInputDialog(String inputString){

                Toast.makeText(this, inputString, Toast.LENGTH_SHORT).show();

        }

       

        public static class PlaceholderFragment extends Fragment{

                @Override

                public View onCreateView(LayoutInflater inflater, ViewGroup container,

                                Bundle savedInstanceState) {

                        View rootView=inflater.inflate(R.layout.fragment_main, container, false);

                        Button showDialogBtn=(Button)rootView.findViewById(R.id.showDialogBtn);

                        showDialogBtn.setOnClickListener(new View.OnClickListener() {

                               

                                @Override

                                public void onClick(View v) {

                                        FragmentManager fragmentManager=getActivity().getFragmentManager();

                                        InputNameDialogFragment inputNameDialog=new InputNameDialogFragment();

                                        inputNameDialog.setDialogtitle("MyInput Dialog");

                                        inputNameDialog.show(fragmentManager, "input dialog");

                                       

                                }

                        });

                        Button showYesDialogBtn=(Button)rootView.findViewById(R.id.showYesDialogBtn);

                        showYesDialogBtn.setOnClickListener(new View.OnClickListener() {

                               

                                @Override

                                public void onClick(View v) {

                                        // TODO Auto-generated method stub

                                       

                                }

                        });

                        return rootView;

                }

               

        }

       

}

//  InputNameDialogFragment //

package com.example.sample19;

import android.app.DialogFragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.EditText;

public class InputNameDialogFragment extends DialogFragment {

        private String dialogTitle;

        public void setDialogtitle(String title){

                dialogTitle=title;

        }

        @Override

        public View onCreateView(LayoutInflater inflater, ViewGroup container,

                        Bundle savedInstanceState) {

                View rootView=inflater.inflate(R.layout.dialog_fragment_input_name, container,false);

                final EditText txtName=(EditText)rootView.findViewById(R.id.txtName);

                Button btnDone=(Button)rootView.findViewById(R.id.btnDone);

                btnDone.setOnClickListener(new View.OnClickListener() {

                       

                        @Override

                        public void onClick(View v) {

                                MainActivity mainActivity=(MainActivity)getActivity();

                                mainActivity.onFinishInputDialog(txtName.getText().toString());

                                dismiss();

                               

                        }

                });

                getDialog().setTitle(dialogTitle);

                return rootView;

        }

}