com.propelforwardmedia.app.DatePickerDialogFragment.java Source code

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Here is the source code for com.propelforwardmedia.app.DatePickerDialogFragment.java

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/*
 * Copyright 2012 David Cesarino de Sousa
 *
 * 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.propelforwardmedia.app;

import android.annotation.TargetApi;
import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.DialogInterface;
import android.os.Build;
import android.os.Bundle;
import android.widget.DatePicker;

import java.util.Calendar;

/**
 * <p>This class provides a usable {@link android.app.DatePickerDialog} wrapped as a {@link android.support.v4.app.DialogFragment},
 * using the compatibility package v4. Its main advantage is handling Issue 34833 
 * automatically for you.</p>
 * 
 * <p>Current implementation (because I wanted that way =) ):</p>
 * 
 * <ul>
 * <li>Only two buttons, a {@code BUTTON_POSITIVE} and a {@code BUTTON_NEGATIVE}.
 * <li>Buttons labeled from {@code android.R.string.ok} and {@code android.R.string.cancel}.
 * </ul>
 * 
 * <p><strong>Usage sample:</strong></p>
 * 
 * <pre>class YourActivity extends Activity implements OnDateSetListener
 * 
 * // ...
 * 
 * Bundle b = new Bundle();
 * b.putInt(DatePickerDialogFragment.YEAR, 2012);
 * b.putInt(DatePickerDialogFragment.MONTH, 6);
 * b.putInt(DatePickerDialogFragment.DATE, 17);
 * DialogFragment picker = new DatePickerDialogFragment();
 * picker.setArguments(b);
 * picker.show(getActivity().getSupportFragmentManager(), "fragment_date_picker");</pre>
 * 
 * @author davidcesarino@gmail.com
 * @version 2012.0828
 * @see <a href="http://code.google.com/p/android/issues/detail?id=34833">Android Issue 34833</a>
 * @see <a href="http://stackoverflow.com/q/11444238/489607"
 * >Jelly Bean DatePickerDialog  is there a way to cancel?</a>
 *
 */
public class DatePickerDialogFragment extends DialogFragment {

    public static final String YEAR = "Year";
    public static final String MONTH = "Month";
    public static final String DATE = "Day";

    Calendar mCalendar;

    DatePickerDialogFragment() {
        mCalendar = Calendar.getInstance();
    }

    DatePickerDialogFragment(Calendar calendar) {
        mCalendar = calendar;
    }

    //TODO: Add cancel listener
    private OnDateSetListener mListener;

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        this.mListener = (OnDateSetListener) activity;
    }

    @Override
    public void onDetach() {
        this.mListener = null;
        super.onDetach();
    }

    @TargetApi(11)
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        int year = mCalendar.get(Calendar.YEAR);
        int month = mCalendar.get(Calendar.MONTH);
        int day = mCalendar.get(Calendar.DAY_OF_MONTH);

        // Jelly Bean introduced a bug in DatePickerDialog (and possibly 
        // TimePickerDialog as well), and one of the possible solutions is 
        // to postpone the creation of both the listener and the BUTTON_* .
        // 
        // Passing a null here won't harm because DatePickerDialog checks for a null
        // whenever it reads the listener that was passed here. >>> This seems to be 
        // true down to 1.5 / API 3, up to 4.1.1 / API 16. <<< No worries. For now.
        //
        // See my own question and answer, and details I included for the issue:
        //
        // http://stackoverflow.com/a/11493752/489607
        // http://code.google.com/p/android/issues/detail?id=34833
        //
        // Of course, suggestions welcome.

        final DatePickerDialog picker = new DatePickerDialog(getActivity(), getConstructorListener(), year, month,
                day);

        if (hasJellyBeanAndAbove()) {
            picker.setButton(DialogInterface.BUTTON_POSITIVE, getActivity().getString(android.R.string.ok),
                    new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            DatePicker dp = picker.getDatePicker();
                            mListener.onDateSet(dp, dp.getYear(), dp.getMonth(), dp.getDayOfMonth());
                        }
                    });
            picker.setButton(DialogInterface.BUTTON_NEGATIVE, getActivity().getString(android.R.string.cancel),
                    new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                        }
                    });
        }
        return picker;
    }

    private static boolean hasJellyBeanAndAbove() {
        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN;
    }

    private OnDateSetListener getConstructorListener() {
        return hasJellyBeanAndAbove() ? null : mListener;
    }
}