CalendarFragment.java

package org.commcare.views.widgets;

import android.app.Activity;
import android.content.DialogInterface;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.content.res.Configuration;
import android.graphics.Rect;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.GridView;
import android.widget.ImageButton;
import android.widget.LinearLayout;
import android.widget.Spinner;
import android.widget.TextView;
import org.commcare.dalvik.R;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import java.util.Map;

/**
 * Created by Saumya on 5/29/2016.
 * DialogFragment for a popup calendar icon
 * Uses support library for compatibility with pre-honeycomb devices
 * Layout and logic inspired by Ahmed Al-Amir at https://www.toptal.com/android/android-customization-how-to-build-a-ui-component-that-does-what-you-want
 */
public class CalendarFragment extends android.support.v4.app.DialogFragment {

    private GridView calendarGrid;
    private ImageButton cancel;
    private Button today;
    private Spinner monthSpinner;
    private Spinner yearSpinner;
    private LinearLayout layout;

    private Calendar calendar;
    private CalendarCloseListener calendarCloseListener;

    private long todaysDateInMillis;
    private static final int DAYSINWEEK = 7;
    private static final String TIME = "TIME";

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        getDialog().getWindow().requestFeature(Window.FEATURE_NO_TITLE);
        inflateView(inflater, container);

        if(savedInstanceState != null && savedInstanceState.containsKey(TIME)){
            calendar = Calendar.getInstance();
            calendar.setTimeInMillis(savedInstanceState.getLong(TIME));
        }

        disableScreenRotation();
        initDisplay();
        initWeekDays();
        initOnClick();
        refresh();
        setWindowSize();

        return layout;
    }

    private void initWeekDays(){
        final Map<String, Integer> weekDays = calendar.getDisplayNames(Calendar.DAY_OF_WEEK, Calendar.SHORT, Locale.getDefault());

        ArrayList<String> weekDayList = new ArrayList<>(weekDays.keySet());

        DateListHelper.sortCalendarItems(weekDays, weekDayList);

        ((TextView) layout.findViewById(R.id.day1)).setText(weekDayList.get(0));
        ((TextView) layout.findViewById(R.id.day2)).setText(weekDayList.get(1));
        ((TextView) layout.findViewById(R.id.day3)).setText(weekDayList.get(2));
        ((TextView) layout.findViewById(R.id.day4)).setText(weekDayList.get(3));
        ((TextView) layout.findViewById(R.id.day5)).setText(weekDayList.get(4));
        ((TextView) layout.findViewById(R.id.day6)).setText(weekDayList.get(5));
        ((TextView) layout.findViewById(R.id.day7)).setText(weekDayList.get(6));
    }

    private void initOnClick(){

        calendarGrid.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Date date = (Date) parent.getItemAtPosition(position);
                calendar.setTime(date);
                refresh();
            }
        });

        cancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dismiss();
                if(calendarCloseListener != null){
                    calendarCloseListener.onCalendarCancel();
                }
            }
        });

        ImageButton closer = (ImageButton) layout.findViewById(R.id.close_calendar);
        closer.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dismiss();
                if(calendarCloseListener != null){
                    calendarCloseListener.onCalendarClose();
                }
            }
        });

        today.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                calendar.setTimeInMillis(todaysDateInMillis);
                refresh();
            }
        });
    }

    private void setWindowSize() {
        Rect displayRectangle = new Rect();
        Window window = getActivity().getWindow();
        window.getDecorView().getWindowVisibleDisplayFrame(displayRectangle);
        layout.setMinimumWidth((int)(displayRectangle.width() * 0.9f));
    }

    private void initDisplay(){
        calendarGrid = (GridView) layout.findViewById(R.id.calendar_grid);
        setupMonthComponents();
        setupYearComponents();
        cancel = (ImageButton) layout.findViewById(R.id.cancel_calendar);
        today = (Button) layout.findViewById(R.id.today);
    }

    private void setupYearComponents() {
        yearSpinner = (Spinner) layout.findViewById(R.id.year_spinner);

        ArrayList<String> years = new ArrayList<>();

        for(int i =GregorianDateWidget.MINYEAR; i <= calendar.get(Calendar.YEAR)+GregorianDateWidget.YEARSINFUTURE; i++){
            years.add(String.valueOf(i));
        }

        ArrayAdapter<String> yearAdapter = new ArrayAdapter<>(getContext(), R.layout.calendar_date, years);
        yearSpinner.setAdapter(yearAdapter);

        yearSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                calendar.set(Calendar.YEAR, position+GregorianDateWidget.MINYEAR);
                refresh();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {}
        });
    }

    //Have to sort month names because Calendar can't return them in order
    private void setupMonthComponents() {
        monthSpinner = (Spinner) layout.findViewById(R.id.calendar_spinner);

        final Map<String, Integer> monthMap = calendar.getDisplayNames(Calendar.MONTH, Calendar.LONG, Locale.getDefault());
        ArrayList<String> monthList = new ArrayList<>(monthMap.keySet());
        DateListHelper.sortCalendarItems(monthMap, monthList);
        monthSpinner.setAdapter(new ArrayAdapter<>(getContext(), R.layout.calendar_date, monthList));

        monthSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                calendar.set(Calendar.MONTH, position);
                refresh();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {}
        });
    }

    //Redraws the calendar display
    private void refresh(){
        ArrayList<Date> dateList = new ArrayList<>();
        Calendar populator = (Calendar) calendar.clone();

        int totalDays = getNumDaysInMonth(populator);
        populateListOfDates(dateList, populator, totalDays);

        yearSpinner.setSelection(calendar.get(Calendar.YEAR)-GregorianDateWidget.MINYEAR);
        monthSpinner.setSelection(calendar.get(Calendar.MONTH));
        calendarGrid.setAdapter(new CalendarAdapter(getContext(), dateList));
    }

    //Populates an arraylist with dates
    private static void populateListOfDates(ArrayList<Date> dateList, Calendar populator, int totalDays) {
        while(dateList.size() < totalDays){
            dateList.add(populator.getTime());
            populator.add(Calendar.DAY_OF_MONTH, 1);
        }

        int remainingDays = ((DAYSINWEEK + 1)-(populator.get(Calendar.DAY_OF_WEEK)))%DAYSINWEEK;

        for(int i = 0; i < remainingDays; i ++){
            dateList.add(populator.getTime());
            populator.add(Calendar.DAY_OF_MONTH, 1);
        }
    }

    //Calculates the total number of days from most recent Sunday to the first Saturday following the end of the current month to fill the calendar view
    private static int getNumDaysInMonth(Calendar cal){
        int totalDays = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
        cal.set(Calendar.DAY_OF_MONTH, 1);

        //Day of week for the first of the month
        int monthStartWeekDay = cal.get(Calendar.DAY_OF_WEEK) - 1;
        int daysSincePreviousSunday = -monthStartWeekDay;

        totalDays += monthStartWeekDay;

        //Backtracking calendar to the most recent Sunday
        cal.add(Calendar.DAY_OF_MONTH, daysSincePreviousSunday);

        return totalDays;
    }

    private class CalendarAdapter extends ArrayAdapter<Date>{

        private final LayoutInflater mInflater;

        public CalendarAdapter(Context context, ArrayList<Date> dates){
            super(context, R.layout.calendar_date, dates);
            mInflater = LayoutInflater.from(context);
        }

        @Override
        public View getView(int position, View view, ViewGroup parent){
            if(view == null){
                view = mInflater.inflate(R.layout.calendar_date, null);
            }

            TextView text = (TextView) view;

            Date date = getItem(position);
            Calendar gridPopulator = (Calendar) calendar.clone();
            gridPopulator.setTime(date);

            text.setText(String.valueOf(gridPopulator.get(Calendar.DAY_OF_MONTH)));

            Date current = calendar.getTime();

            highlightCalendarGridCell(text, gridPopulator, calendar);
            return text;
        }

        //Current month has white background, previous/next months have gray background, today's date has green background
        protected void highlightCalendarGridCell(TextView text, Calendar calendarDate, Calendar currentDate) {
            if(calendarDate.equals(currentDate)){
                text.setTextColor(getResources().getColor(R.color.white));
                text.setBackgroundColor(getResources().getColor(R.color.cc_attention_positive_color));
            }
            else if(calendarDate.get(Calendar.MONTH) != currentDate.get(Calendar.MONTH)){
                text.setTextColor(getResources().getColor(R.color.grey_dark));
                text.setBackgroundColor(getResources().getColor(R.color.grey_lighter));
            }
            else{
                text.setTextColor(getResources().getColor(R.color.black));
                text.setBackgroundColor(getResources().getColor(R.color.transparent));
            }
        }
    }

    private void inflateView(LayoutInflater inflater, ViewGroup container) {
        layout = (LinearLayout) inflater.inflate(R.layout.scrolling_calendar_widget, container);
    }

    @Override
    public void onSaveInstanceState(Bundle bundle){
        bundle.putLong(TIME, calendar.getTimeInMillis());
    }

    public void setCalendar(Calendar cal, long currentDayInMillis){
        todaysDateInMillis = currentDayInMillis;
        calendar = cal;
    }

    public interface CalendarCloseListener {
        void onCalendarClose();
        void onCalendarCancel();
    }

    public void setListener(CalendarCloseListener listener){
        calendarCloseListener = listener;
    }

    @Override
    public void onDismiss(DialogInterface dialog){
        super.onDismiss(dialog);
        enableScreenRotation();
    }


    private void disableScreenRotation() {
        int currentOrientation = getResources().getConfiguration().orientation;

        if (currentOrientation == Configuration.ORIENTATION_LANDSCAPE) {
            ((Activity) getContext()).setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_LANDSCAPE);
        }
        else {
            ((Activity) getContext()).setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
        }
    }

    private void enableScreenRotation() {
        ((Activity) getContext()).setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);
    }
}