DDM 20211103

package com.joythis.android.passwordgenerator;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SeekBar;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    //data members
    CheckBox mCbAZ, mCbaz, mCbDigits;
    EditText mEtSS; //for the Special Symbols
    SeekBar mSbLength; //for the password length / size
    Button mBtnGenPass;
    ListView mLvPasswords;
    ArrayList<String> mAlPasswords;
    ArrayAdapter<String> mAd;

    Context mContext;
    AmUtil mUtil;

    SeekBar.OnSeekBarChangeListener mSbHandler =
        new SeekBar.OnSeekBarChangeListener() {
            //auto-called whenever the progress value changes
            //idea: put a new TextView in the layout to display this value
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                //TODO
            }

            //auto-called when the "progress drag" starts
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            //auto-called when the user frees the progress handler
            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                int iProgress = mSbLength.getProgress();
                String strProgress = String.valueOf(iProgress);
                String strMsg =
                    "Length "+strProgress+" picked.";
                mUtil.fb(strMsg);
            }
        };//mSbHandler

    View.OnClickListener mClickHandler = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String[] aParts={};
            switch(v.getId()){
                case R.id.idBtnGenPass:
                    String strUser = mEtSS.getText().toString().trim();
                    if (!strUser.isEmpty()){
                       aParts = strUser.split(" ");
                    }//if
                    String strPassword = AmUtil.genPassword(
                        mSbLength.getProgress(),
                        mCbaz.isChecked(),
                        mCbAZ.isChecked(),
                        mCbDigits.isChecked(),
                        aParts
                    );
                    mAlPasswords.add(0, strPassword);
                    mAd.notifyDataSetChanged();
                    break;
            }//switch
        }//onClick
    };//mClickHandler

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rl_pass_gen_v1);

        init(savedInstanceState);
    }//onCreate

    void init (Bundle pB){
        //bindings
        mContext = this;
        //mContext = MainActivity.this;
        mUtil = new AmUtil(this);

        mCbaz = findViewById(R.id.idCbaz);
        mCbAZ = findViewById(R.id.idCbAZ);
        mCbDigits = findViewById(R.id.idCbDigits);
        mEtSS = findViewById(R.id.idEtSS);
        mSbLength = findViewById(R.id.idSbLength);
        mBtnGenPass = findViewById(R.id.idBtnGenPass);
        mLvPasswords = findViewById(R.id.idLvPasswords);

        if (mLvPasswords!=null){
            //data source + adapter
            mAlPasswords = new ArrayList<>();
            mAd = new ArrayAdapter<>(
                mContext,
                android.R.layout.simple_list_item_1,
                mAlPasswords
            );
            mLvPasswords.setAdapter(mAd);
        }//if (ListView pattern)

        //behaviors
        mBtnGenPass.setOnClickListener(mClickHandler);
        //testing();
        mSbLength.setOnSeekBarChangeListener(mSbHandler);
    }//init

    void testing(){
        String strTest_az = "";
        String strTest_AZ = "";
        String strTest_Digits = "";
        String strTest_SS = "";
        //" exemplo ".trim() --> "exemplo"
        String strUserSS = mEtSS.getText().toString().trim();
        //"A B C".split(" ") ---> ["A", "B", "C"]
        String[] aUserSS = strUserSS.split(" ");
        for(int idx=0; idx<30; idx++) {
            strTest_az += AmUtil.random_az() + " ";
            strTest_AZ += AmUtil.random_AZ() + " ";
            strTest_Digits += AmUtil.random_09() + " ";
            strTest_SS += AmUtil.randomSpecialSymbol(
                aUserSS
            ) + " ";
        }//for
        mAlPasswords.add(strTest_az);
        mAlPasswords.add(strTest_AZ);
        mAlPasswords.add(strTest_Digits);
        mAlPasswords.add(strTest_SS);

        mAd.notifyDataSetChanged();
    }//testing


}

******

package com.joythis.android.passwordgenerator;

import android.app.Activity;
import android.view.Gravity;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.Random;

public class AmUtil {
    private Activity mA;

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

    public void fb  (String pStrMsg){
        Toast t = Toast.makeText(
        this.mA,
            pStrMsg,
            Toast.LENGTH_SHORT
        );

        t.setGravity(Gravity.CENTER, 0, 0);

        t.show();
    }//fb

    //tools related to randomness
    public static int randomInt(int pMin, int pMax){
        Random r = new Random();
        int iAmplitude = pMax-pMin+1;
        int iJump = r.nextInt(iAmplitude);
        int iDestination = pMin + iJump;
        return iDestination;
    }//randomInt

    public static char random_az(){
        int code_a = (int)'a';
        int code_z = (int)'z';
        int codeRandom = randomInt(code_a, code_z);
        char letterRandom = (char)codeRandom;
        return letterRandom;
    }//random_az

    public static char random_AZ(){
        int code_A = (int)'A';
        int code_Z = (int)'Z';
        int codeRandom = randomInt(code_A, code_Z);
        char letterRandom = (char)codeRandom;
        return letterRandom;
    }//random_AZ

    public static char random_09(){
        int code_0 = (int)'0';
        int code_9 = (int)'9';
        int codeRandom = randomInt(code_0, code_9);
        char letterRandom = (char)codeRandom;
        return letterRandom;
    }//random_09

    public static char randomSymbol(char pS1, char pS2){
        int code_s1 = (int)pS1;
        int code_s2 = (int)pS2;
        int codeRandom = randomInt(code_s1, code_s2);
        char letterRandom = (char)codeRandom;
        return letterRandom;
    }//randomSymbol

    public static char rAZ(){return randomSymbol('A', 'Z');}
    public static char raz(){return randomSymbol('a', 'z');}
    public static char r09(){return randomSymbol('0', '9');}

    /*
    ["*", "?", ":"]
     */
    public static char randomSpecialSymbol(
        ArrayList<String> pAlAcceptableSpecialSymbols
    ){
        int iHowMany = pAlAcceptableSpecialSymbols.size();
        int iRandomAddress = randomInt(0, iHowMany-1);
        String strRandomSymbol =
                pAlAcceptableSpecialSymbols.get(iRandomAddress);
        return strRandomSymbol.charAt(0);
    }//randomSpecialSymbol

    public static char randomSpecialSymbol(
        String[] paAcceptableSymbols
    ){
        int iHowMany = paAcceptableSymbols.length;
        int iRandomAddress = randomInt(0, iHowMany-1);
        String strRandomSymbol =
            paAcceptableSymbols[iRandomAddress];
        return strRandomSymbol.charAt(0);
    }//randomSpecialSymbol

    public static String genPassword(
        int pPassLength,
        boolean pb_az,
        boolean pb_AZ,
        boolean pb_09,
        String[] paSS //array of special symbols
    ){
        String strPassword = "";
        boolean bPasswordReady = false;
        char cRandomSymbol;
        boolean bAllTypesRejected =
            !pb_az && !pb_AZ && !pb_09 && paSS.length==0;
        if (!bAllTypesRejected){
            while(!bPasswordReady){
                int iType = randomInt(1, 4);
                cRandomSymbol = 'x';
                switch(iType){
                    case 1: //az
                        cRandomSymbol = random_az();
                        break;
                    case 2: //AZ
                        cRandomSymbol = random_AZ();
                        break;
                    case 3: //09
                        cRandomSymbol = random_09();
                        break;
                    case 4: //SS
                        if (paSS.length>0) {
                            int index = randomInt(0, paSS.length - 1);
                            cRandomSymbol = paSS[index].charAt(0);
                        }//if
                        break;
                }//switch
                //cRandomSymbol
                if (pb_az && iType==1) strPassword+=cRandomSymbol;
                if (pb_AZ && iType==2) strPassword+=cRandomSymbol;
                if (pb_09 && iType==3) strPassword+=cRandomSymbol;
                if (paSS.length>0 && iType==4) strPassword+=cRandomSymbol;

                if (strPassword.length()==pPassLength)
                    bPasswordReady=true;
            }//while
        }//if not everything rejected
        else{
            return "empty password";
        }

        return strPassword;
    }//genPassword
}//AmUtil