DatePicker.java

/*
 * Copyright (C) 2015 The Android Open Source Project
 *
 * 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 androidx.leanback.widget.picker;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;

import androidx.annotation.VisibleForTesting;
import androidx.core.view.ViewCompat;
import androidx.leanback.R;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import java.util.Locale;
import java.util.TimeZone;

/**
 * {@link DatePicker} is a directly subclass of {@link Picker}.
 * This class is a widget for selecting a date. The date can be selected by a
 * year, month, and day Columns. The "minDate" and "maxDate" from which dates to be selected
 * can be customized.  The columns can be customized by attribute "datePickerFormat" or
 * {@link #setDatePickerFormat(String)}.
 *
 * {@link android.R.attr#maxDate}
 * {@link android.R.attr#minDate}
 * {@link R.attr#datePickerFormat}
 */
public class DatePicker extends Picker {

    private static final String LOG_TAG = "DatePicker";

    private String mDatePickerFormat;
    private PickerColumn mMonthColumn;
    private PickerColumn mDayColumn;
    private PickerColumn mYearColumn;
    private int mColMonthIndex;
    private int mColDayIndex;
    private int mColYearIndex;

    private static final String DATE_FORMAT = "MM/dd/yyyy";
    private final DateFormat mDateFormat = new SimpleDateFormat(DATE_FORMAT, Locale.getDefault());
    private PickerUtility.DateConstant mConstant;

    private Calendar mMinDate;
    private Calendar mMaxDate;
    private Calendar mCurrentDate;
    private Calendar mTempDate;

    public DatePicker(Context context, AttributeSet attrs) {
        this(context, attrs, R.attr.datePickerStyle);
    }

    @SuppressLint("CustomViewStyleable")
    public DatePicker(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        updateCurrentLocale();

        final TypedArray attributesArray = context.obtainStyledAttributes(attrs,
                R.styleable.lbDatePicker);
        ViewCompat.saveAttributeDataForStyleable(
                this, context, R.styleable.lbDatePicker, attrs, attributesArray, 0, 0);
        String minDate;
        String maxDate;
        String datePickerFormat;
        try {
            minDate = attributesArray.getString(R.styleable.lbDatePicker_android_minDate);
            maxDate = attributesArray.getString(R.styleable.lbDatePicker_android_maxDate);
            datePickerFormat = attributesArray
                    .getString(R.styleable.lbDatePicker_datePickerFormat);
        } finally {
            attributesArray.recycle();
        }
        mTempDate.clear();
        if (!TextUtils.isEmpty(minDate)) {
            if (!parseDate(minDate, mTempDate)) {
                mTempDate.set(1900, 0, 1);
            }
        } else {
            mTempDate.set(1900, 0, 1);
        }
        mMinDate.setTimeInMillis(mTempDate.getTimeInMillis());

        mTempDate.clear();
        if (!TextUtils.isEmpty(maxDate)) {
            if (!parseDate(maxDate, mTempDate)) {
                mTempDate.set(2100, 0, 1);
            }
        } else {
            mTempDate.set(2100, 0, 1);
        }
        mMaxDate.setTimeInMillis(mTempDate.getTimeInMillis());

        if (TextUtils.isEmpty(datePickerFormat)) {
            datePickerFormat = new String(
                    android.text.format.DateFormat.getDateFormatOrder(context));
        }
        setDatePickerFormat(datePickerFormat);
    }

    private boolean parseDate(String date, Calendar outDate) {
        try {
            outDate.setTime(mDateFormat.parse(date));
            return true;
        } catch (ParseException e) {
            Log.w(LOG_TAG, "Date: " + date + " not in format: " + DATE_FORMAT);
            return false;
        }
    }

    /**
     * Returns the best localized representation of the date for the given date format and the
     * current locale.
     *
     * @param datePickerFormat The date format skeleton (e.g. "dMy") used to gather the
     *                         appropriate representation of the date in the current locale.
     *
     * @return The best localized representation of the date for the given date format
     */
    @VisibleForTesting
    String getBestYearMonthDayPattern(String datePickerFormat) {
        final String yearPattern;
        if (PickerUtility.SUPPORTS_BEST_DATE_TIME_PATTERN) {
            yearPattern = android.text.format.DateFormat.getBestDateTimePattern(mConstant.locale,
                    datePickerFormat);
        } else {
            final java.text.DateFormat dateFormat = android.text.format.DateFormat.getDateFormat(
                    getContext());
            if (dateFormat instanceof SimpleDateFormat) {
                yearPattern = ((SimpleDateFormat) dateFormat).toLocalizedPattern();
            } else {
                yearPattern = DATE_FORMAT;
            }
        }
        return TextUtils.isEmpty(yearPattern) ? DATE_FORMAT : yearPattern;
    }

    /**
     * Extracts the separators used to separate date fields (including before the first and after
     * the last date field). The separators can vary based on the individual locale date format,
     * defined in the Unicode CLDR and cannot be supposed to be "/".
     *
     * See http://unicode.org/cldr/trac/browser/trunk/common/main
     *
     * For example, for Croatian in dMy format, the best localized representation is "d. M. y". This
     * method returns {"", ".", ".", "."}, where the first separator indicates nothing needs to be
     * displayed to the left of the day field, "." needs to be displayed tos the right of the day
     * field, and so forth.
     *
     * @return The ArrayList of separators to populate between the actual date fields in the
     * DatePicker.
     */
    @VisibleForTesting
    List<CharSequence> extractSeparators() {
        // Obtain the time format string per the current locale (e.g. h:mm a)
        String hmaPattern = getBestYearMonthDayPattern(mDatePickerFormat);

        List<CharSequence> separators = new ArrayList<>();
        StringBuilder sb = new StringBuilder();
        char lastChar = 'eb3b9ed0-f11d-0137-cfb9-0ebaa35b92c0';
        // See http://www.unicode.org/reports/tr35/tr35-dates.html for date formats
        final char[] dateFormats = {'Y', 'y', 'M', 'm', 'D', 'd'};
        boolean processingQuote = false;
        for (int i = 0; i < hmaPattern.length(); i++) {
            char c = hmaPattern.charAt(i);
            if (c == ' ') {
                continue;
            }
            if (c == '