WeekPagerAdapter.java

package by.fksis.schedule.adapters;

import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.view.ViewGroup;
import by.fksis.schedule.R;
import by.fksis.schedule.Util;
import by.fksis.schedule.app.DayScheduleFragment;

import java.util.Calendar;

public class WeekPagerAdapter extends FragmentPagerAdapter {
    public static final int TOTAL_PAGES = 30;
    public static final int NOW_PAGE = 15;

    private final Context context;
    private Calendar[] dates;

    @Override
    public CharSequence getPageTitle(int position) {
        if (position == NOW_PAGE)
            return context.getString(R.string.today);
        if (position == NOW_PAGE + 1)
            return context.getString(R.string.tomorrow);
        if (position == NOW_PAGE - 1)
            return context.getString(R.string.yesterday);
        if (Math.abs(position - NOW_PAGE) < 4)
            return context.getResources().getStringArray(R.array.weekdays)[Util.getDayOfWeekIndex(dates[position])].toUpperCase();

        int day = dates[position].get(Calendar.DAY_OF_MONTH);
        int month = dates[position].get(Calendar.MONTH) + 1;
        return day + "." + (month < 10 ? "0" : "") + month;
    }

    public WeekPagerAdapter(FragmentManager fm, Context context) {
        super(fm);
        this.context = context;

        dates = new Calendar[TOTAL_PAGES];
        Calendar now = Calendar.getInstance();

        for (int i = 0; i < TOTAL_PAGES; i++) {
            dates[i] = (Calendar) now.clone();
            dates[i].add(Calendar.DAY_OF_MONTH, i - NOW_PAGE);
        }
    }

    @Override
    public Fragment getItem(int i) {
        return new DayScheduleFragment(dates[i]);
    }

    @Override
    public int getCount() {
        return TOTAL_PAGES;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {

    }
}