package com.example.swipepages;

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.PagerAdapter;
import androidx.viewpager.widget.ViewPager;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    String pageData[];            // Stores the text to swipe.
    LayoutInflater inflater;     // Used to create individual pages
    ViewPager vp;                // Reference to class to swipe views

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //Get the data to be swiped through
        pageData = getResources().getStringArray(R.array.desserts);
        //get an inflater to be used to create single pages
        inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        //Reference ViewPager defined in activity
        vp = (ViewPager) findViewById(R.id.viewPager);
        //set the adapter that will create the individual pages
        vp.setAdapter(new MyPagesAdapter());
    }

    //Implement PagerAdapter Class to handle individual page creation
    class MyPagesAdapter extends PagerAdapter {
        @Override
        public int getCount() {
            //Return total pages, here one for each data item
            return pageData.length;
        }
        // Create the given page (indicated by position)
        @Override
        public Object instantiateItem(ViewGroup container, int position) {
            View page = inflater.inflate(R.layout.page, null);
            ((TextView)page.findViewById(R.id.textMessage)).setText(pageData[position]);
            // Add the page to the front of the queue
            ((ViewPager) container).addView(page, 0);
            return page;
        }
        @Override
        public boolean isViewFromObject(View arg0, Object arg1) {
            //See if object from instantiateItem is related to the given view
            //required by API
            return arg0==(View)arg1;
        }
        @Override
        public void destroyItem(ViewGroup container, int position, Object object) {
            ((ViewPager) container).removeView((View) object);
            object=null;
        }
    }
}