DDM 2022-11-02

//AmUtil.java
package com.joythis.android.motivator;

import android.app.Activity;
import android.util.Log;
import android.widget.Toast;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.util.Random;

public class AmUtil {
    Activity mA;
    public AmUtil(Activity pA){
        this.mA = pA;
    }//AmUtil

    public void fb(String pStrMsg){
        Toast t = Toast.makeText(
            this.mA,
            pStrMsg,
            Toast.LENGTH_LONG
        );
        t.show();
    }//fb

    public static int randomInt(
        int pMin,
        int pMax
    ){
        Random r = new Random();
        int iAmplitude =
                Math.max(pMin, pMax) -
                Math.min(pMin, pMax) + 1;
        int iJump = r.nextInt(iAmplitude);
        int iDestination = Math.min(pMin, pMax)+iJump;
        return iDestination;
    }//randomInt

    public boolean writeToTextFile(
        String pFileName,
        String pContent
    ){
        try {
            FileOutputStream fos =
                this.mA.openFileOutput(
                    pFileName,
                    this.mA.MODE_PRIVATE
                );
            if (fos!=null){
                OutputStreamWriter osw =
                    new OutputStreamWriter(
                        fos,
                        StandardCharsets.UTF_8
                    );
                if (osw!=null){
                    osw.write(pContent);
                    osw.close();
                    fos.close();
                    return true;
                }
            }//if
        }
        catch (Exception e){
            Log.e(
                "@AmUtil",
                e.toString()
            );
        }
        return false;
    }//writeToTextFile

    public String readTextFromFile(
        String pFileName
    ){
        try{
            FileInputStream fis =
                this.mA.openFileInput(pFileName);
            if (fis!=null){
                InputStreamReader isr =
                    new InputStreamReader(
                        fis,
                        StandardCharsets.UTF_8
                    );
                if (isr!=null){
                    String strAll="";
                    int i;
                    char c;
                    while((i=isr.read())!=-1){
                        c = (char)i;
                        strAll+=c;
                    }//while
                    isr.close();
                    fis.close();
                    return strAll;
                }//if
            }//if
        }//try
        catch (Exception e){
            Log.e(
                "@AmUtil",
                e.toString()
            );
        }//catch
        return "";
    }//readTextFromFile
}//AmUtil


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

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Button;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    //data members
    Context mContext;

    AmUtil mUtil;

    // for correspondence with whatever relevant in the layout
    TextView mTvAbout, mTvMsgs;
    SeekBar mSbProb; // the user picked probability (of a positive message)
    Button mBtnGetMsg;

    // trio for respecting MVC for ListView
    ListView mLvMsgs;
    //the data
    ArrayList<String> mAlMsgs;
    //the broker
    ArrayAdapter<String> mAd;

    String[] maPositive, maNegative;

    //behavior (click) handler
    View.OnClickListener mClickHandler =
    new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch(v.getId()){
                case R.id.idBtnGetMsg:
                    if(mTvMsgs!=null) {
                        displayMsgInTextView();
                        //boolean bOK = writeMessagesToFile();
                        boolean bOK = mUtil.writeToTextFile(
                            MESSAGES_FILE,
                            mTvMsgs.getText().toString()
                        );
                        String strMsg = "";
                        if (bOK)
                            strMsg = mContext.getResources().getString(
                                R.string.strFileWriteOK
                            );
                        else
                            strMsg = mContext.getResources().getString(
                                R.string.strFileWriteFAIL
                            );
                        mUtil.fb(strMsg);
                    }

                    if(mLvMsgs!=null)
                        displayMessageInListView();
                    break;


            }//switch
        }//onClick
    };//mClickHandler

    void displayMessageInListView(){
        int iUserPickedProbabilityOfPositiveMsg =
                mSbProb.getProgress(); //0..100

        int iRandom = AmUtil.randomInt(
                0,
                mSbProb.getMax()
        );

        boolean bDecidePositive =
                iRandom<iUserPickedProbabilityOfPositiveMsg;

        String strMsg = "";
        if (bDecidePositive) {
            strMsg = maPositive[
                    AmUtil.randomInt(
                            0,
                            maPositive.length - 1
                    )
                    ];
        }
        else
        {
            strMsg = maNegative[
                    AmUtil.randomInt(
                            0,
                            maNegative.length-1
                    )
                    ];
        }

        //???? add strMsg to the ListView
        //mAlMsgs.add(strMsg); // inserts at the end
        mAlMsgs.add(0, strMsg);
        mAd.notifyDataSetChanged();
    }//displayMessageInListView

    void displayMsgInTextView(){
        //String strP1 = maPositive[0];
        //String strN3 = maNegative[2];
        int iUserPickedProbabilityOfPositiveMsg =
            mSbProb.getProgress(); //0..100

        int iRandom = AmUtil.randomInt(
            0,
            mSbProb.getMax()
        );

        boolean bDecidePositive =
            iRandom<iUserPickedProbabilityOfPositiveMsg;

        String strMsg = "";
        if (bDecidePositive) {
            strMsg = maPositive[
                AmUtil.randomInt(
                    0,
                    maPositive.length - 1
                )
            ];
        }
        else
        {
            strMsg = maNegative[
                AmUtil.randomInt(
                    0,
                    maNegative.length-1
                )
            ];
        }

        String strPast = mTvMsgs.getText().toString();
        mTvMsgs.setText(strMsg+"\n"+strPast);
    }//displayMsg

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_main);
        setContentView(R.layout.rl_motivator_v1);
        //setContentView(R.layout.cl_motivator_v1);
        //setContentView(R.layout.rl_motivator_v2);

        init();
    }//onCreate

    void init(){
        //inits
        mContext = this;
        mTvAbout = findViewById(R.id.idTvAbout);
        mSbProb = findViewById(R.id.idSbProb);
        mBtnGetMsg = findViewById(R.id.idBtnGetMsg);

        mUtil = new AmUtil(this);
        //caution!
        mTvMsgs = findViewById(R.id.idTvMsgs);

        mLvMsgs = findViewById(R.id.idLvMsgs);

        if (mLvMsgs!=null) {
            mAlMsgs = new ArrayList<>();
            mAd = new ArrayAdapter<>(
                    mContext,
                    android.R.layout.simple_list_item_1,
                    mAlMsgs
            );
            mLvMsgs.setAdapter(mAd);
        }//if

        maPositive = this.getResources().
            getStringArray(R.array.saPositiveMsgs);
        maNegative = this.getResources().
            getStringArray(R.array.saNegativeMsgs);

        //quality control

        //set behavior
        //associate mBtnGetMsg to some behavior handler
        mBtnGetMsg.setOnClickListener(
            mClickHandler
        );

        /*
        testing randomInt
         */
        /*
        for(int idx=0; idx<100; idx+=1){
            int iRandom = AmUtil.randomInt(555, 777);
            mTvMsgs.setText(
                String.valueOf(iRandom)
                +"\n"+
                mTvMsgs.getText().toString()
            );
        }
         */

        //serviu para vermos a path da Private Internal Storage desta app
        //writeMessagesToFile();

        if (mTvMsgs!=null){
            //String strMsgs = readMessagesFromFile();
            String strMsgs = mUtil.readTextFromFile(
                MESSAGES_FILE
            );
            mTvMsgs.setText(strMsgs);
        }
    }//init

    //2022-11-02
    public final static String MESSAGES_FILE =
            "MESSAGES3.TXT";

    boolean writeMessagesToFile(){
        /*
        todas as apps têm um espaço de storage
        dedicado a si, no dispositivo
        só a própria app (as suas Activity(ies))
        pode ler e escrever nesse espaço privado dedicado
        O nome desse espaço de storage é "Private Internal Storage"
         */
        File thePrivateInternalStorage = this.getFilesDir();
        String strCuriousAboutWhere =
            thePrivateInternalStorage.toString();
        //mUtil.fb(strCuriousAboutWhere); //comment

        if(thePrivateInternalStorage!=null){
            try {
                FileOutputStream fos =
                    this.openFileOutput(
                            MESSAGES_FILE,
                            Context.MODE_PRIVATE
                    );

                if (fos!=null){
                    OutputStreamWriter osw =
                        new OutputStreamWriter(
                            fos,
                            StandardCharsets.UTF_8
                        );

                    if (osw!=null){
                        String strContent =
                            mTvMsgs.getText().toString();
                        osw.write(
                            strContent
                        );
                        osw.close();
                        fos.close();
                        return true;
                    }//if
                }//if
            }//try
            catch (Exception e){
                String strMsg = e.toString();
                Log.e(
                    "@MainActivity",
                    strMsg
                );
            }//catch
        }//
        return false;
    }//writeMessagesToFile

    String readMessagesFromFile(){
        try {
            FileInputStream fis =
                    this.openFileInput(
                        MESSAGES_FILE
                    );
            if (fis!=null){
                InputStreamReader isr =
                    new InputStreamReader(
                        fis,
                        StandardCharsets.UTF_8
                    );
                if (isr!=null){
                    String strAll = "";
                    int i;
                    char c;
                    while((i=isr.read())!=-1){
                        c=(char)i;
                        strAll+=c;
                    }//while
                    isr.close();
                    fis.close();
                    return strAll;
                }//if
            }//if
        }//try
        catch (Exception e){
            String strMsg = e.toString();
            Log.e(
                "@MainActivity",
                strMsg
            );
        }
        return "";
    }//readMessagesFromFile
}//class MainActivity