DDM 2022-11-30

package com.joythis.android.datesdistance;

import java.util.Calendar;

/*
objetivo:
- ajudar na matemática entre datas
- fornecer frases correspondentes a datas
 */
public class AmDate {
    public static int MES_IMPOSSIVEL = -1;

    int mYear;
    int mMonth;
    int mDay;

    /*
    default constructor
    vai representar a "data corrente"
    conforme o relógio do
    dispositivo móvel
     */
    public AmDate(){
        Calendar c =
            Calendar.getInstance();

        int y = c.get(Calendar.YEAR);
        /*
        A Java Calendar is 0-based
        for the month
        0 - January
        ...
        10 - November
        11 - December
         */
        int m = c.get(Calendar.MONTH);
        int d = c.get(Calendar.DAY_OF_MONTH);
        this.mYear = y;
        this.mMonth = m+1; // natural month
        this.mDay = d;
    }//AmDate

    public String toString(){
        String s = String.format(
            "%4d-%2d-%2d",
            this.mYear,
            this.mMonth,
            this.mDay
        );
        return s;
    }//toString

    public static boolean bValidYear(
        int pYear
    ){
        return pYear>=1;
    }//bValidYear

    public static boolean bValidMonth(
        int pMonth
    ){
        return pMonth>=1 && pMonth<=12;
    }//bValidMonth

    public static boolean bValidDate(
        int pY, int pM, int pD
    ){
        boolean bYearOK = bValidYear(pY);
        boolean bMonthOK = bValidMonth(pM);
        boolean bDayOK =
            pD>=1
            &&
            pD<=iHowManyDaysIn(pM, pY);
        return bYearOK && bMonthOK && bDayOK;
    }//bValidDate

    public boolean leapYear(int pY){
        boolean bM400 = pY%400==0;
        boolean bM4NotSecular =
            pY%4==0 && pY%100!=0;
        return bM400 || bM4NotSecular;
    }//leapYear

    public static int iHowManyDaysIn
        (int pM, int pY)
    {
        boolean bCase31 =
            pM==1 || pM==3 || pM==5 || pM==7
            || pM==8 || pM==10 || pM==12;
        if (bCase31) return 31;
        boolean bCase30 =
            pM==4 || pM==6 || pM==9 || pM==11;
        if(bCase30) return 30;
        if(pM==2)
            return leapYear(pY)?29:28;
        return MES_IMPOSSIVEL;
    }//iHowManyDaysIn
}//AmDate


********************
//MainActivity.java
package com.joythis.android.datesdistance;

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

    Activity mA;
    EditText mEtDate1, mEtDate2;
    Button mBtnPickDate1,
            mBtnPickDate2,
            mBtnComputeDistance;

    View.OnClickListener mClickHandler = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch(v.getId()){
                case R.id.idBtnPickDate1:
                    actionPickDate1();
                    break;
                case R.id.idBtnPickDate2:
                    actionPickDate2();
                    break;
            }//switch
        }//onClick
    };//mClickHandler

    void actionPickDate1(){
        //SAFR!!! TODO
        Intent goGoPickDate1 = new Intent(
            MainActivity.this,
            DateInput.class
        );
        startActivity(goGoPickDate1);
    }//actionPickDate1

    void actionPickDate2(){
        //SAFR!!! TODO
        Intent goGoPickDate2 = new Intent(
                MainActivity.this,
                DateInput.class
        );
        startActivity(goGoPickDate2);
    }//actionPickDate2

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rl_distance_dates);

        init();
    }//onCreate

    void init(){
        //1 - assocs
        mEtDate1 = findViewById(R.id.idEtDate1);
        mEtDate2 = findViewById(R.id.idEtDate2);
        mBtnPickDate1 = findViewById(R.id.idBtnPickDate1);
        mBtnPickDate2 = findViewById(R.id.idBtnPickDate2);
        mBtnComputeDistance = findViewById(R.id.idBtnComputeDistance);

        displayDefaultDates();

        //2 - behaviors
        mBtnPickDate1.setOnClickListener(mClickHandler);
        mBtnPickDate2.setOnClickListener(mClickHandler);

    }//init

    void displayDefaultDates(){
        AmDate d = new AmDate();
        mEtDate1.setText(d.toString());
        mEtDate2.setText(d.toString());
    }//displayDefaultDates
}
********************************

<?xml version="1.0" encoding="utf-8"?>
<!-- rl_pick_date.xml -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:id="@+id/idLlLabels"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <TextView
            android:gravity="center_horizontal"
            android:layout_weight="1"
            android:text="@string/strTvYear"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
        <TextView
            android:gravity="center_horizontal"
            android:layout_weight="1"
            android:text="@string/strTvMonth"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
        <TextView
            android:gravity="center_horizontal"
            android:layout_weight="1"
            android:text="@string/strTvDay"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
    </LinearLayout>

    <LinearLayout
        android:id="@+id/idLlInputs"
        android:layout_below="@id/idLlLabels"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <NumberPicker
            android:layout_weight="1"
            android:id="@+id/idNpYear"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
        <NumberPicker
            android:layout_weight="1"
            android:id="@+id/idNpMonth"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
        <NumberPicker
            android:layout_weight="1"
            android:id="@+id/idNpDay"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>
    </LinearLayout>

    <Button
        android:layout_below="@id/idLlInputs"
        android:id="@+id/idBtnConfirm"
        android:text="@string/strBtnConfirm"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <Button
        android:layout_below="@id/idBtnConfirm"
        android:id="@+id/idBtnCancel"
        android:text="@string/strBtnCancel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</RelativeLayout>

****************************************************************
//DateInput.java
package com.joythis.android.datesdistance;

import androidx.appcompat.app.AppCompatActivity;

import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.NumberPicker;

import java.util.Calendar;

public class DateInput extends AppCompatActivity {

    Activity mA;
    NumberPicker mNpYear, mNpMonth, mNpDay;
    Button mBtnConfirm, mBtnCancel;

    NumberPicker.OnValueChangeListener mNpValueHandler =
    new NumberPicker.OnValueChangeListener() {
        @Override
        public void onValueChange(NumberPicker picker, int oldVal, int newVal) {
            int y = mNpYear.getValue();
            int m = mNpMonth.getValue();
            int maxDay = AmDate.iHowManyDaysIn(y, m);
            mNpDay.setMaxValue(maxDay);
        }//onValueChange
    };//mNpValueHandler

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rl_pick_date);

        init();
    }//onCreate

    void initNpDate(){
        int iCurrentYear = Calendar.getInstance().get(Calendar.YEAR);
        mNpYear.setMinValue(iCurrentYear-400);
        mNpYear.setMaxValue(iCurrentYear+100);
        mNpYear.setValue(iCurrentYear);

        int iCurrentMonth = Calendar.getInstance().get(Calendar.MONTH)+1;
        mNpMonth.setMinValue(1);
        mNpMonth.setMaxValue(12);
        mNpMonth.setValue(iCurrentMonth);

        int iCurrentDay = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
        mNpDay.setMinValue(1);
        mNpDay.setMaxValue(AmDate.iHowManyDaysIn(iCurrentYear, iCurrentMonth));
        mNpDay.setValue(iCurrentDay);
    }//initNpDate

    void init(){
        //1 - assocs
        mNpYear = findViewById(R.id.idNpYear);
        mNpMonth = findViewById(R.id.idNpMonth);
        mNpDay = findViewById(R.id.idNpDay);

        NumberPicker[] nps = {mNpYear, mNpMonth, mNpDay};
        for (NumberPicker np : nps){
            np.setOnValueChangedListener(mNpValueHandler);
        }//for

        initNpDate();
        //2 - behaviors
    }//init
}