MainActivity.java

package id.indrasudirman.tablayoutwithfab;



import android.content.DialogInterface;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.support.annotation.RequiresApi;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.DecelerateInterpolator;
import android.view.animation.RotateAnimation;
import android.view.animation.ScaleAnimation;
import android.widget.EditText;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {


    public TabLayout tabLayout;
    public ViewPager viewPager;
    final String answerQuestion1 = "ngr";
    final String answerQuestion2 = "ivfvgrq";
    final String answerQuestion3 = "yvirq";



    int[] colorIntArray = {R.color.red,R.color.yellow,R.color.green};
    int[] iconIntArray = {R.drawable.ic_menu_forward, R.drawable.ic_check, R.drawable.ic_tab_contacts};







    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.action_bar);
        setSupportActionBar(toolbar);


        tabLayout = findViewById(R.id.tabs);
        viewPager = findViewById(R.id.viewpager);


        setupViewPager(viewPager);

        final FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int position = tabLayout.getSelectedTabPosition();

                switch (position) {
                    case 0:
                        viewPager.setCurrentItem(viewPager.getCurrentItem()+1);
                        break;
                    case 1:
                        checkAnswer(view);
                        break;
                    case 2:
                        Snackbar.make(view, "Berta, Susukan, Banjarnegara", Snackbar.LENGTH_LONG)
                                .setAction("Action", null).show();
                        break;
                }
            }
        });

        viewPager.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                if (viewPager.getCurrentItem() == 0) {
                    viewPager.setCurrentItem(-1, false);
                    return true;
                }
                else if (viewPager.getCurrentItem() == 1) {
                    viewPager.setCurrentItem(1, false);
                    return true;
                }
                else if (viewPager.getCurrentItem() == 2) {
                    viewPager.setCurrentItem(2, false);
                    return true;
                }
                return true;
            }
        });




        tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());
                animateFab(tab.getPosition());
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {

            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {

            }
        });




        tabLayout.setupWithViewPager(viewPager);




    }

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

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }



    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFrag(new OneFragment(),"HAL 1");
        adapter.addFrag(new TwoFragment(), "HAL 2");
        adapter.addFrag(new ThreeFragment(), "HAL 3");
        viewPager.setAdapter(adapter);
    }



    class ViewPagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();
        private final List<String> mFragmentTitleList = new ArrayList<>();

        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }

        @Override
        public int getCount() {
            return mFragmentList.size();
        }

        public void addFrag(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }

    }

    protected void animateFab(final int position) {
        final FloatingActionButton fab = findViewById(R.id.fab);
        fab.clearAnimation();

        // Scale down animation
        ScaleAnimation shrink = new ScaleAnimation(1f, 0.1f, 1f, 0.1f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
        shrink.setDuration(100);     // animation duration in milliseconds
        shrink.setInterpolator(new AccelerateInterpolator());
        shrink.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {
                // Change FAB color and icon
                fab.setBackgroundTintList(ContextCompat.getColorStateList(getApplicationContext(), colorIntArray[position]));
                fab.setImageDrawable(ContextCompat.getDrawable(getApplicationContext(), iconIntArray[position]));

                // Rotate Animation
                Animation rotate = new RotateAnimation(60.0f, 0.0f,
                        Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,
                        0.5f);
                rotate.setDuration(150);
                rotate.setInterpolator(new DecelerateInterpolator());

                // Scale up animation
                ScaleAnimation expand = new ScaleAnimation(0.1f, 1f, 0.1f, 1f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
                expand.setDuration(150);     // animation duration in milliseconds
                expand.setInterpolator(new DecelerateInterpolator());

                // Add both animations to animation state
                AnimationSet s = new AnimationSet(false); //false means don't share interpolators
                s.addAnimation(rotate);
                s.addAnimation(expand);
                fab.startAnimation(s);
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });
        fab.startAnimation(shrink);
    }

    private void checkAnswer(View view) {
        ArrayList<String> incorrectAnswerList = new ArrayList<String>();

        int numberOfQuestionCorrect = 0;

        if (checkQuestion1()) {
            numberOfQuestionCorrect++;
        } else {
            incorrectAnswerList.add("Soal No 1");
        }

        if (checkQuestion2()) {
            numberOfQuestionCorrect++;
        } else {
            incorrectAnswerList.add("Soal No 2");
        }

        if (checkQuestion3()) {
            numberOfQuestionCorrect++;
        } else {
            incorrectAnswerList.add("Soal No 3");
        }

        StringBuilder sb = new StringBuilder();
        for (String s : incorrectAnswerList)
        {
            sb.append(s);
            sb.append("\n");
        }

        if (numberOfQuestionCorrect == 3) {
            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
            alertDialogBuilder
                    .setTitle("Selamat!")
                    .setMessage("Anda berhasil, nilai Anda : " + numberOfQuestionCorrect + "/3\nIni Sempurna. Anda dapat melanjutkan ke pelajaran berikutnya.")
                    .setCancelable(false)
                    .setPositiveButton("Simple Past Tense 2",
                            new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialogInterface, int i) {

                                    viewPager.setCurrentItem(viewPager.getCurrentItem()+1);



                                }
                            });

            AlertDialog alertDialog = alertDialogBuilder.create();
            alertDialog.show();
        } else {
            AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
            alertDialogBuilder
                    .setTitle("Gagal!")
                    .setMessage("Anda gagal, Nilai Anda adalah : " + numberOfQuestionCorrect +   "/3\nAnda belum dapat melanjutkan pelajaran berikutnya.\n\n" + "Perbaiki jawaban Anda : \n\n" + sb.toString())
                    .setCancelable(false)
                    .setPositiveButton("Mulai test lagi",
                            new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialogInterface, int i) {
                                    viewPager.setCurrentItem(viewPager.getCurrentItem());
                                }
                            })

                    .setNegativeButton("Keluar aplikasi",
                            new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialogInterface, int i) {
                                    moveTaskToBack(true);
                                    finish();
                                }
                            });

            AlertDialog alertDialog = alertDialogBuilder.create();
            alertDialog.show();
        }
    }

    private boolean checkQuestion1() {
        EditText editTextQuestion1 = findViewById(R.id.answer_simple_past_test1);


        //Convert to plaintext
        Rot13 mRot13 = new Rot13();
        mRot13.methodRot13(answerQuestion1);

        String rot13 = mRot13.methodRot13(answerQuestion1);

        //Check the answer after converted to plaintext
        return editTextQuestion1.getText().toString().equalsIgnoreCase(rot13);
    }

    private boolean checkQuestion2() {
        EditText editTextQuestion2 = findViewById(R.id.answer_simple_past_test2);

        //Convert to plaintext
        Rot13 mRot13 = new Rot13();
        mRot13.methodRot13(answerQuestion2);

        String rot13 = mRot13.methodRot13(answerQuestion2);

        //Check the answer after converted to plaintext
        return editTextQuestion2.getText().toString().equalsIgnoreCase(rot13);
    }

    private boolean checkQuestion3() {
        EditText editTextQuestion3 = findViewById(R.id.answer_simple_past_test3);

        //Convert to plaintext

        Rot13 mRot13 = new Rot13();
        mRot13.methodRot13(answerQuestion3);

        String rot13 = mRot13.methodRot13(answerQuestion3);

        //Check the answer after converted to plaintext
        return editTextQuestion3.getText().toString().equalsIgnoreCase(rot13);
    }


}