WalkthroughActivity.java

package com.alieeen.smartchair;

import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

import com.alieeen.smartchair.adapter.WalkthroughAdapter;
import com.alieeen.smartchair.util.SharedPrefs;
import com.viewpagerindicator.CirclePageIndicator;
import com.viewpagerindicator.PageIndicator;


public class WalkthroughActivity extends ActionBarActivity {

    private WalkthroughAdapter mAdapter;
    private ViewPager mPager;
    private PageIndicator mIndicator;
    private View SkipButton;
    private View DoneButton;
    private View NextButton;

    private int currentPage;

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

        SkipButton = findViewById(R.id.skip_button);
        DoneButton = findViewById(R.id.done_button);
        NextButton = findViewById(R.id.next_button);

        mAdapter = new WalkthroughAdapter(getSupportFragmentManager());

        mPager = (ViewPager)findViewById(R.id.pager);
        mPager.setAdapter(mAdapter);

        mIndicator = (CirclePageIndicator)findViewById(R.id.indicator);
        mIndicator.setViewPager(mPager);

        mIndicator.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                currentPage = position;

                if (position == 3) {
                    DoneButton.setVisibility(View.VISIBLE);
                    NextButton.setVisibility(View.INVISIBLE);
                } else {
                    DoneButton.setVisibility(View.INVISIBLE);
                    NextButton.setVisibility(View.VISIBLE);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

        NextButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mIndicator.setCurrentItem(currentPage + 1);
            }
        });

        SkipButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(WalkthroughActivity.this, MainActivity.class);
                startActivity(i);
            }
        });

        DoneButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPrefs.setLoggedIn(WalkthroughActivity.this);
                Intent i = new Intent(WalkthroughActivity.this, MainActivity.class);
                startActivity(i);
                finish();
            }
        });

    }

}