com.dgsd.android.ShiftTracker.Adapter.WeekPagerAdapter.java Source code

Introduction

Here is the source code for com.dgsd.android.ShiftTracker.Adapter.WeekPagerAdapter.java

Source

/*
 * Copyright 2013 Daniel Grech
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

package com.dgsd.android.ShiftTracker.Adapter;

import android.content.Context;
import android.content.SharedPreferences;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.text.format.DateUtils;
import android.text.format.Time;
import com.dgsd.android.ShiftTracker.Const;
import com.dgsd.android.ShiftTracker.Fragment.WeekFragment;
import com.dgsd.android.ShiftTracker.R;
import com.dgsd.android.ShiftTracker.Util.TimeUtils;

import java.util.Formatter;
import java.util.HashMap;
import java.util.Map;

public class WeekPagerAdapter extends FragmentStatePagerAdapter {
    private static final String TAG = WeekPagerAdapter.class.getSimpleName();

    private static int YEAR_IN_WEEKS = 52;

    private Map<Integer, String> posToTitleMap = new HashMap<Integer, String>();
    private Context mContext;

    private int mCenterJulianDay = -1;
    private int mWeekStartDay = 1; //Monday;

    private Time mTime;
    private Formatter mFormatter;
    private StringBuilder mStringBuilder;

    public WeekPagerAdapter(Context context, FragmentManager fm, int weekContainingJulianDay) {
        super(fm);
        mContext = context;
        mTime = new Time();
        mStringBuilder = new StringBuilder();
        mFormatter = new Formatter(mStringBuilder);

        SharedPreferences p = context.getSharedPreferences(Const.SHARED_PREFS_NAME, Context.MODE_PRIVATE);
        String startDayAsStr = p.getString(context.getString(R.string.settings_key_start_day), "1");
        mWeekStartDay = Integer.valueOf(startDayAsStr);

        mCenterJulianDay = adjustJulianDay(mWeekStartDay, weekContainingJulianDay);
    }

    @Override
    public CharSequence getPageTitle(final int pos) {
        if (posToTitleMap.containsKey(pos)) {
            return posToTitleMap.get(pos);
        } else {
            String title = getTitleForPosition(pos);
            posToTitleMap.put(pos, title);
            return title;
        }
    }

    @Override
    public int getCount() {
        //This week, plus 1 year either side
        return (YEAR_IN_WEEKS * 2) + 1;
    }

    public int getCenterPosition() {
        return YEAR_IN_WEEKS + 1;
    }

    @Override
    public Fragment getItem(int pos) {
        return WeekFragment.newInstance(getJulianDayForPosition(pos));
    }

    protected String getTitleForPosition(int pos) {
        mTime.setJulianDay(getJulianDayForPosition(pos));
        if (mTime.weekDay != mWeekStartDay) {
            while (mTime.weekDay != mWeekStartDay) {
                mTime.monthDay--;
                mTime.normalize(true);
            }
        }

        long startMillis = mTime.toMillis(true);
        long endMillis = startMillis + (1000 * 60 * 60 * 24 * 7);
        int flags = DateUtils.FORMAT_SHOW_DATE | DateUtils.FORMAT_NO_YEAR | DateUtils.FORMAT_ABBREV_ALL;
        mStringBuilder.setLength(0);

        return DateUtils.formatDateRange(mContext, mFormatter, startMillis, endMillis, flags, mTime.timezone)
                .toString();
    }

    public int getJulianDayForPosition(int pos) {
        int middle = (getCount() / 2) + 1;
        if (pos > middle) {
            return mCenterJulianDay + (7 * (pos - middle));
        } else if (pos < middle) {
            return mCenterJulianDay - (7 * (middle - pos));
        } else {
            return mCenterJulianDay;
        }
    }

    public int getPositionForJulianDay(int julianDay) {
        final int jd = adjustJulianDay(mWeekStartDay, julianDay);
        if (mCenterJulianDay == jd) {
            return getCenterPosition();
        } else if (mCenterJulianDay < jd) {
            return getCenterPosition() + ((jd - mCenterJulianDay) / 7);
        } else {
            return getCenterPosition() - ((mCenterJulianDay - jd) / 7);
        }
    }

    private int adjustJulianDay(int startWeekday, int jd) {
        mTime.setJulianDay(jd);
        if (mTime.weekDay == startWeekday) {
            //Great, no adjustment needed
            return jd;
        } else {
            while (mTime.weekDay != startWeekday)
                mTime.setJulianDay(jd--);
            return TimeUtils.getJulianDay(mTime);
        }
    }
}