Develop Reference

How to delete all RecyclerView items from SQLite Database?

I am a beginner at coding in Java. I am creating a notes app with lots of other features. And one of the features are, storing the user's bank card details in a RecyclerView. I did this by making an SQLite CRUD. All of the Create, Read, Update and Delete works. And I protected this page with a Pattern lock.
And when we are in the Input Pattern page, we can see a clickable text called Click HERE if you forgot your pattern, That works. And when you click on that clickable text, the app shows an Alert Dialog, titled are you sure? and the message is If you change your pattern, all your data will be deleted then there are two buttons Yes and No. No does nothing, it just cancel the forgot pattern thing. But the problem is with the Yes button.
When we click it, It should delete all bank cards or delete all data. Please suggest a way to delete all data from the SQLite Database. I tried lots of ways to do this.
HERE IS MY INPUT PATTERN ACTIVITY
package com.ixidev.simplenotepad;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebChromeClient;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import com.ixidev.simplenotepad.model.Note;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;
public class ProgramActivity extends AppCompatActivity {
FloatingActionButton fab, fabChangePattern, fabexit;
RecyclerView mRecyclerViewBC;
CardsDatabaseHelper cardsDatabaseHelper;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_program);
mRecyclerViewBC = findViewById(R.id.recyclerViewBC);
cardsDatabaseHelper = new CardsDatabaseHelper(this);
showRecord();
fabexit = findViewById(R.id.exitProgram);
fab = findViewById(R.id.addFabButtonBC);
fabChangePattern = findViewById(R.id.ChangePattern);
fabexit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(ProgramActivity.this, MainActivity.class);
startActivity(intent);
}
});
fabChangePattern.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(ProgramActivity.this, CreatePasswordActivity.class);
startActivity(intent);
}
});
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(ProgramActivity.this, AddBankCardActivity.class);
intent.putExtra("BCeditMode", false);
startActivity(intent);
}
});
}
private void showRecord() {
CardAdapter cardAdapter = new CardAdapter(ProgramActivity.this, cardsDatabaseHelper.getAllBCdata(ConstantsCard.BC_C_ADD_TIMESTAMP + " DESC"));
mRecyclerViewBC.setAdapter(cardAdapter);
}
#Override
protected void onResume() {
super.onResume();
showRecord();
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == event.KEYCODE_BACK) {
moveTaskToBack(true);
}
return super.onKeyDown(keyCode, event);
}
}
HERE IS MY DATABASE HELPER CLASS
package com.ixidev.simplenotepad;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;
import androidx.annotation.Nullable;
import java.util.ArrayList;
public class CardsDatabaseHelper extends SQLiteOpenHelper {
public CardsDatabaseHelper(#Nullable Context context) {
super(context, ConstantsCard.BC_DB_NAME, null, ConstantsCard.BC_DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(ConstantsCard.BC_CREATE_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + ConstantsCard.BC_TABLE_NAME);
onCreate(db);
}
public long insertInfo(String number, String cvv, String expiry, String image, String addTimestamp, String updateTimestamp) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(ConstantsCard.BC_C_NUMBER, number);
values.put(ConstantsCard.BC_C_CVV, cvv);
values.put(ConstantsCard.BC_C_EXPIRY, expiry);
values.put(ConstantsCard.BC_C_IMAGE, image);
values.put(ConstantsCard.BC_C_ADD_TIMESTAMP, addTimestamp);
values.put(ConstantsCard.BC_C_UPDATE_TIMESTAMP, updateTimestamp);
long id = db.insert(ConstantsCard.BC_TABLE_NAME, null, values);
db.close();
return id;
}
public void updateInfo(String BCid, String number, String cvv, String expiry, String image, String addTimestamp, String updateTimestamp) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(ConstantsCard.BC_C_NUMBER, number);
values.put(ConstantsCard.BC_C_CVV, cvv);
values.put(ConstantsCard.BC_C_EXPIRY, expiry);
values.put(ConstantsCard.BC_C_IMAGE, image);
values.put(ConstantsCard.BC_C_ADD_TIMESTAMP, addTimestamp);
values.put(ConstantsCard.BC_C_UPDATE_TIMESTAMP, updateTimestamp);
db.update(ConstantsCard.BC_TABLE_NAME, values, ConstantsCard.BC_C_ID + " = ?", new String[]{BCid});
db.close();
}
public void deleteInfo(String BCid) {
SQLiteDatabase db = getWritableDatabase();
db.delete(ConstantsCard.BC_TABLE_NAME, ConstantsCard.BC_C_ID + " = ? ", new String[]{BCid});
db.close();
}
public void testDelete() {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(ConstantsCard.BC_TABLE_NAME,null,null);
db.execSQL("delete from "+ ConstantsCard.BC_TABLE_NAME);
db.execSQL("TRUNCATE table " + ConstantsCard.BC_TABLE_NAME);
db.close();
}
public void delete(String BCid)
{
String[] args={BCid};
getWritableDatabase().delete("texts", "_ID=?", args);
}
public ArrayList<CardModel> getAllBCdata(String orderByBC) {
ArrayList<CardModel> ArrayListCard = new ArrayList<>();
String selectQuery = "SELECT * FROM " + ConstantsCard.BC_TABLE_NAME + " ORDER BY " + orderByBC;
SQLiteDatabase BCdb = this.getWritableDatabase();
Cursor CardCursor = BCdb.rawQuery(selectQuery, null);
if (CardCursor.moveToNext()) {
do {
CardModel cardModel = new CardModel(
""+CardCursor.getInt(CardCursor.getColumnIndex(ConstantsCard.BC_C_ID)),
""+CardCursor.getString(CardCursor.getColumnIndex(ConstantsCard.BC_C_IMAGE)),
""+CardCursor.getString(CardCursor.getColumnIndex(ConstantsCard.BC_C_NUMBER)),
""+CardCursor.getString(CardCursor.getColumnIndex(ConstantsCard.BC_C_CVV)),
""+CardCursor.getString(CardCursor.getColumnIndex(ConstantsCard.BC_C_EXPIRY)),
""+CardCursor.getString(CardCursor.getColumnIndex(ConstantsCard.BC_C_ADD_TIMESTAMP)),
""+CardCursor.getString(CardCursor.getColumnIndex(ConstantsCard.BC_C_UPDATE_TIMESTAMP))
);
ArrayListCard.add(cardModel);
} while (CardCursor.moveToNext());
}
BCdb.close();
return ArrayListCard;
}
}
HERE IS MY ADAPTER CLASS
package com.ixidev.simplenotepad;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.arch.core.executor.TaskExecutor;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
public class CardAdapter extends RecyclerView.Adapter<CardAdapter.Holder> {
private Context CardContext;
private ArrayList<CardModel> CardArrayList;
CardsDatabaseHelper cardsDatabaseHelper;
public CardAdapter(Context cardContext, ArrayList<CardModel> cardArrayList) {
CardContext = cardContext;
CardArrayList = cardArrayList;
cardsDatabaseHelper = new CardsDatabaseHelper(CardContext);
}
#NonNull
#Override
public Holder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View viewBC = LayoutInflater.from(CardContext).inflate(R.layout.bc_row, parent, false);
return new Holder(viewBC);
}
#Override
public void onBindViewHolder(#NonNull Holder holder, int position) {
CardModel cardModel = CardArrayList.get(position);
final String BCid = cardModel.getBCid();
final String BCimage = cardModel.getImageBC();
final String BCnumber = cardModel.getNumber();
final String BCcvv = cardModel.getCvv();
final String BCexpiry = cardModel.getExpiryBC();
final String addTimeStampBC = cardModel.getAddTimeStampBC();
final String updateTimeStampBC = cardModel.getUpdateTimeStampBC();
holder.profileIvBC.setImageURI(Uri.parse(BCimage));
holder.number.setText(BCnumber);
holder.cvv.setText(BCcvv);
holder.expiryBC.setText(BCexpiry);
holder.editButtonBC.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
editDialog(
""+position,
""+BCid,
""+BCnumber,
""+BCcvv,
""+BCexpiry,
""+BCimage,
""+addTimeStampBC,
""+updateTimeStampBC
);
}
});
holder.itemView.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
deleteDialog(
""+BCid
);
return false;
}
});
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(CardContext, "Clicked", Toast.LENGTH_SHORT).show();
cardsDatabaseHelper.testDelete();
cardsDatabaseHelper.delete(BCid);
}
});
}
private void deleteDialog(final String BCid) {
AlertDialog.Builder builderBC = new AlertDialog.Builder(CardContext);
builderBC.setTitle("Delete?");
builderBC.setMessage("Are you sure you want to delete this document?");
builderBC.setCancelable(false);
builderBC.setIcon(R.drawable.ic_action_delete);
builderBC.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
cardsDatabaseHelper.deleteInfo(BCid);
((ProgramActivity)CardContext).onResume();
Toast.makeText(CardContext, "Successfully deleted!", Toast.LENGTH_SHORT).show();
}
});
builderBC.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
builderBC.create().show();
}
private void editDialog(String position, String BCid, String BCnumber, String BCcvv, String BCexpiry, String BCimage, String addTimeStampBC, String updateTimeStampBC) {
AlertDialog.Builder BCbuilder = new AlertDialog.Builder(CardContext);
BCbuilder.setTitle("Edit?");
BCbuilder.setMessage("Are you sure you want to edit this Bank Card?");
BCbuilder.setCancelable(false);
BCbuilder.setIcon(R.drawable.ic_action_edit);
BCbuilder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(CardContext, EditBankCardActivity.class);
intent.putExtra("BCID", BCid);
intent.putExtra("NUMBER", BCnumber);
intent.putExtra("CVV", BCcvv);
intent.putExtra("EXPIRYBC", BCexpiry);
intent.putExtra("IMAGE", BCimage);
intent.putExtra("BC_ADD_TIMESTAMP", addTimeStampBC);
intent.putExtra("BC_UPDATE_TIMESTAMP", updateTimeStampBC);
intent.putExtra("BCeditMode", true);
CardContext.startActivity(intent);
}
});
BCbuilder.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
BCbuilder.create().show();
}
#Override
public int getItemCount() {
return CardArrayList.size();
}
class Holder extends RecyclerView.ViewHolder {
ImageView profileIvBC;
TextView number, cvv, expiryBC;
ImageButton editButtonBC;
public Holder(#NonNull View itemView) {
super(itemView);
profileIvBC = itemView.findViewById(R.id.profileIvBC);
number = itemView.findViewById(R.id.number);
cvv = itemView.findViewById(R.id.cvv);
expiryBC = itemView.findViewById(R.id.expiry);
editButtonBC = itemView.findViewById(R.id.editBtnBC);
}
}
}
HERE IS MY MODEL CLASS
package com.ixidev.simplenotepad;
public class CardModel {
String BCid, imageBC, number, cvv, expiryBC, addTimeStampBC, updateTimeStampBC;
public CardModel(String BCid, String imageBC, String number, String cvv, String expiryBC, String addTimeStampBC, String updateTimeStampBC) {
this.BCid = BCid;
this.imageBC = imageBC;
this.number = number;
this.cvv = cvv;
this.expiryBC = expiryBC;
this.addTimeStampBC = addTimeStampBC;
this.updateTimeStampBC = updateTimeStampBC;
}
public String getBCid() {
return BCid;
}
public void setBCid(String BCid) {
this.BCid = BCid;
}
public String getImageBC() {
return imageBC;
}
public void setImageBC(String imageBC) {
this.imageBC = imageBC;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public String getCvv() {
return cvv;
}
public void setCvv(String cvv) {
this.cvv = cvv;
}
public String getExpiryBC() {
return expiryBC;
}
public void setExpiryBC(String expiryBC) {
this.expiryBC = expiryBC;
}
public String getAddTimeStampBC() {
return addTimeStampBC;
}
public void setAddTimeStampBC(String addTimeStampBC) {
this.addTimeStampBC = addTimeStampBC;
}
public String getUpdateTimeStampBC() {
return updateTimeStampBC;
}
public void setUpdateTimeStampBC(String updateTimeStampBC) {
this.updateTimeStampBC = updateTimeStampBC;
}
}
And here is my CONSTANTS class
package com.ixidev.simplenotepad;
public class ConstantsCard {
public static final String BC_DB_NAME = "MY_BANK_CARDS";
public static final int BC_DB_VERSION = 1;
public static final String BC_TABLE_NAME = "MY_BANK_CARDS_TABLE";
public static final String BC_C_ID = "BC_ID";
public static final String BC_C_NUMBER = "BC_NUMBER";
public static final String BC_C_CVV = "BC_CVV";
public static final String BC_C_EXPIRY = "BC_EXPIRY";
public static final String BC_C_IMAGE = "BC_IMAGE";
public static final String BC_C_ADD_TIMESTAMP = "BC_ADD_TIMESTAMP";
public static final String BC_C_UPDATE_TIMESTAMP = "BC_UPDATE_TIMESTAMP";
public static final String BC_CREATE_TABLE = "CREATE TABLE " + BC_TABLE_NAME + "("
+ BC_C_ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ BC_C_NUMBER + " TEXT,"
+ BC_C_CVV + " TEXT,"
+ BC_C_EXPIRY + " TEXT,"
+ BC_C_IMAGE + " TEXT,"
+ BC_C_ADD_TIMESTAMP + " TEXT,"
+ BC_C_UPDATE_TIMESTAMP + " TEXT"
+ ");";
}

android edittext (Number validation) cannot return value from a method with void result type

package com.example.crazywriteup.getbmi;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MaleActivity extends AppCompatActivity
{
EditText enm,ehgf,ehgi,ewg;
Button btnmale;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_male);
enm = (EditText)findViewById(R.id.mleditText);
ehgf = (EditText)findViewById(R.id.mleditText2);
ehgi = (EditText)findViewById(R.id.mleditText3);
ewg = (EditText)findViewById(R.id.mleditText4);
btnmale = (Button)findViewById(R.id.btnmlsubmit);
btnmale.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
if(enm.getText().toString().isEmpty())
{
Toast toast = Toast.makeText(getApplicationContext(), "PLS FILL NAME",Toast.LENGTH_SHORT);
toast.setGravity(Gravity.TOP|Gravity.CENTER, 0, 0);
toast.show();
}
else
{
// Nothing
ehgf.requestFocus();
}
}
});
public boolean isNum(String val)
{
boolean check = false;
String no = "\\d*\\.?\\d+";
CharSequence inputstr = val;
Pattern pte = Pattern.compile(no,Pattern.CASE_INSENSITIVE);
Matcher matcher = pte.matcher(inputstr);
if(matcher.matches())
{
check = true;
}
return check;
}
}
}
I am working on android number textbox () I want to set the range 1 to 7 but I am facing difficulty in programming code. It always shows the error cannot return a value from a method with void result type. I am a beginner & don't have much knowledge about programming.

The onCreate() method return void and you are trying to return boolean
You need to create your isNum() method outside the onCreate()
SAMPLE CODE
public class MaleActivity extends AppCompatActivity
{
EditText enm,ehgf,ehgi,ewg;
Button btnmale;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_male);
enm = (EditText)findViewById(R.id.mleditText);
ehgf = (EditText)findViewById(R.id.mleditText2);
ehgi = (EditText)findViewById(R.id.mleditText3);
ewg = (EditText)findViewById(R.id.mleditText4);
btnmale = (Button)findViewById(R.id.btnmlsubmit);
btnmale.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v)
{
if(enm.getText().toString().isEmpty())
{
Toast toast = Toast.makeText(getApplicationContext(), "PLS FILL NAME",Toast.LENGTH_SHORT);
toast.setGravity(Gravity.TOP|Gravity.CENTER, 0, 0);
toast.show();
}
else
{
// Nothing
ehgf.requestFocus();
}
}
});
}
public boolean isNum(String val)
{
boolean check = false;
String no = "\\d*\\.?\\d+";
CharSequence inputstr = val;
Pattern pte = Pattern.compile(no,Pattern.CASE_INSENSITIVE);
Matcher matcher = pte.matcher(inputstr);
if(matcher.matches())
{
check = true;
}
return check;
}
}

TextWatcher implementation with RadioButtons

Please see attached image and code snippet to aid in explanation.
From the attached image I would like the user to enter a cost, quantity and select either Include Tax or Exclude tax and a new cost is automatically generated where indicated without pressing a Button, but to no avail I am unable to do this. Someone please help. Thanks
See Image Here
After implementing the Changes that were suggested and trying to enter an input in the cost field I was met with the error seen below. Please provide additional feedback. Thanks
Error image
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;
public class Calculator extends Fragment {
private static EditText itemText, editCost, editQuantity, calCost, rTax;
private static RadioGroup rGroup;
private static RadioButton rb;
View gView;
private double bTotal = 0, aTotal = 0, trueCost = 0, taxValue = 16.5, cost = 0, newCost = 0;
private int quantity = 1;
DecimalFormatSymbols symbols = DecimalFormatSymbols.getInstance(Locale.US);
DecimalFormat decimalFormat = new DecimalFormat("###,###.##", symbols);
CalculatorListener activityCommander;
public interface CalculatorListener {
void addtoCart(String itemName, int qty, double beforeTax, double afterTax, double bTotal, double aTotal);
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
try {
activityCommander = (CalculatorListener) context;
} catch (ClassCastException e) {
throw new ClassCastException(context.toString());
}
}
public Calculator() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
gView = inflater.inflate(R.layout.fragment_calculator, container, false);
editCost = (EditText) gView.findViewById(R.id.editcost);
itemText = (EditText) gView.findViewById(R.id.itemText);
editQuantity = (EditText) gView.findViewById(R.id.editquantity);
calCost = (EditText) gView.findViewById(R.id.calcost);
rTax = (EditText) gView.findViewById(R.id.rtax);
rGroup = (RadioGroup) gView.findViewById(R.id.rgroup);
final ImageButton FieldButton = (ImageButton) gView.findViewById(R.id.FieldButton);
final ImageButton TaxButton = (ImageButton) gView.findViewById(R.id.TaxButton);
final ImageButton CalButton = (ImageButton) gView.findViewById(R.id.CalButton);
rTax.setEnabled(false);
calCost.setEnabled(false);
rGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
rb = (RadioButton)gView.findViewById(checkedId);
}
});
editCost.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
try{
update();
}catch (NumberFormatException e)
{
e.printStackTrace();
}
}
});
editQuantity.addTextChangedListener(new TextWatcher() {
#Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
}
#Override
public void afterTextChanged(Editable s) {
try{
update();
}catch (NumberFormatException e)
{
e.printStackTrace();
}
}
});
FieldButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
clearfield();
}
}
);
TaxButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
adjtax();
}
}
);
CalButton.setOnClickListener(
new View.OnClickListener() {
public void onClick(View v) {
//toCart();
}
}
);
return gView;
}
public void clearfield() {
editCost.setText("");
editCost.setBackgroundResource(R.drawable.edittxt);
editQuantity.setText("");
editQuantity.setBackgroundResource(R.drawable.edittxt);
calCost.setText("");
calCost.setBackgroundResource(R.drawable.edittxt);
itemText.setText("");
itemText.setBackgroundResource(R.drawable.edittxt);
rGroup.clearCheck();
}
public void adjtax() {
editCost.setBackgroundResource(R.drawable.edittxt);
editQuantity.setBackgroundResource(R.drawable.edittxt);
calCost.setBackgroundResource(R.drawable.edittxt);
itemText.setBackgroundResource(R.drawable.edittxt);
rTax.setEnabled(true);
rTax.setText("");
rTax.setBackgroundResource(R.drawable.edittxtfocus);
rTax.setOnFocusChangeListener(new View.OnFocusChangeListener() {
#Override
public void onFocusChange(View v, boolean hasFocus) {
if (hasFocus) {
rTax.setEnabled(true);
} else {
rTax.setEnabled(false);
v.setBackgroundResource(R.drawable.edittxt);
}
}
});
}
public void update(){
if (rTax.getText().toString().isEmpty()) {
taxValue = 16.5;
} else if (!rTax.getText().toString().isEmpty()) {
taxValue = Double.parseDouble(rTax.getText().toString());
}
//CHECKS THE TAX VALUE IF IT NEEDS TO BE CONVERTED
if (taxValue > 1) {
taxValue = taxValue / 100;
} else {
taxValue = taxValue * 1;
}
//CUSTOM VALIDATOR FOR QUANTITY FIELD
if (editQuantity.getText().toString().isEmpty()) {
quantity = 1;
} else if (!editQuantity.getText().toString().isEmpty()) {
quantity = Integer.parseInt(editQuantity.getText().toString());
}
if(rb.getText() == "Include Tax"){
newCost = (((cost = Double.parseDouble(editCost.getText().toString())) * taxValue) + cost) * quantity;
calCost.setText(decimalFormat.format(newCost).toString());
}
else if(rb.getText() == "Exclude Tax"){
newCost = ((cost = Double.parseDouble(editCost.getText().toString())) * quantity);
calCost.setText(decimalFormat.format(newCost).toString());
}
trueCost = cost * quantity;
bTotal = trueCost;
aTotal = newCost;
}
}

Move the rgroup.setOnCheckedChangeListener out of the update() method and into the onCreateView(). You should not have to set the listener every time the text has been updated.
The update method called after text entry can probably just update the tax value if a valid value has been entered and either the check boxes have been selected.
Update with another suggestion
I would lookup the radio button by comparing text as you are doing, some time in the future you may want to change the text in the resource file or apply another locale and this code will stop working.
if(rb.getText() == "Include Tax")
I would suggest comparing against the id itself:
if (checkedId == R.id.radio1 )
Another Suggestion:
Consider changing your variable names to lead with a lower case character. Leading with an upper case letter makes it look like either class name or a constant and make the code a bit more difficult to read.
private EditText itemText;
private EditText editCost;
private EditText editQuantity;
private EditText calcost;
private EdtiText rTax;
You can also remove all(some) the focus change listeners you have and set those attributes in the android drawable resources. Take a look here.
Update 9/9/2016 22:22
A bit better, but as you've found out calls to update can throw a null pointer if rb had never been initialized. You should check for a null rb in the update method and give the user a notice to select an option. You could also assign rb to either of the two values from the start in the onCreateView, so it is never null.
You should probably also add a call to update() after setting rb in the radio group callback. This will allow the screen to update as soon as they choose an option.

Checkboxes and if-else statements

This is the source for a small app I'm making in Android Studio. When I call this function its suppose to compare dog,cat, and parrot to each other and then increment int dogCounter by 5. When I run the function however, It does not update the score.
dogCounter= 0;
catCounter = 0;
//check boxes
cutestCheckBoxDog = (CheckBox)findViewById(R.id.CheckboxCutestDog);
cutestCheckBoxCat = (CheckBox)findViewById(R.id.CheckboxCutestCat);
cutestCheckBoxParrot =(CheckBox)findViewById(R.id.CheckboxCutestParrot);
//call methods
processCutest(cutestCheckBoxDog, cutestCheckBoxCat, cutestCheckBoxParrot);
showResultButton= (Button)findViewById(R.id.showResults);
showResultButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(),catCounter + " " + dogCounter, Toast.LENGTH_LONG).show();
public void processCutest(CheckBox dog, CheckBox cat, CheckBox parrot){
if (dog.isChecked() && !cat.isChecked() && !parrot.isChecked()){
dogCounter += 5;
}else if (cat.isChecked() && !dog.isChecked() && !parrot.isChecked()){
catCounter += 5;
} else{
//nobody gets points
}
}
edit: Sorry for poor organization. Still pretty new, pointers on that would be nice as well.
package dogorcatperson.ivellapplication.com.dogorcatperson;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private RadioGroup canineRadioGroup;
private RadioButton canineRadioButton;
private SeekBar seekBar;
private TextView seekBarTextView;
private CheckBox cutestCheckBoxDog;
private CheckBox cutestCheckBoxCat;
private CheckBox cutestCheckBoxParrot;
private RadioGroup droolRadioGroup;
private RadioButton droolRadioButton;
private Button showResultButton;
private int dogCounter;
private int catCounter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//call setup()
setUp();
//seekbar
seekBar = (SeekBar) findViewById(R.id.seekBarFeline);
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
seekBarTextView.setText("comfortableness: " + progress + "/" + seekBar.getMax());
}
#Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
}
});
}
public void setUp(){
dogCounter= 0;
catCounter = 0;
canineRadioGroup =(RadioGroup)findViewById(R.id.radioGroupCanine);
droolRadioGroup = (RadioGroup)findViewById(R.id.RadioGroupDrool);
seekBarTextView = (TextView)findViewById(R.id.seekBarProgressTextView);
//check boxes
cutestCheckBoxDog = (CheckBox)findViewById(R.id.CheckboxCutestDog);
cutestCheckBoxCat = (CheckBox)findViewById(R.id.CheckboxCutestCat);
cutestCheckBoxParrot = (CheckBox)findViewById(R.id.CheckboxCutestParrot);
//call methods
processCutest(cutestCheckBoxDog, cutestCheckBoxCat, cutestCheckBoxParrot);
processDrool(droolRadioGroup);
processCanine(canineRadioGroup);
showResultButton= (Button)findViewById(R.id.showResults);
showResultButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getApplicationContext(),catCounter + " " + dogCounter, Toast.LENGTH_LONG).show();
// Intent i = new Intent(MainActivity.this, ResultActivity.class);
// i.putExtra("catCounter", catCounter);
// i.putExtra("dogCounter", dogCounter);
// startActivity(i);
}
});
}
public void processCutest(CheckBox dog, CheckBox cat, CheckBox parrot){
if (dog.isChecked() && !cat.isChecked() && !parrot.isChecked()){
dogCounter += 5;
}else if (cat.isChecked() && !dog.isChecked() && !parrot.isChecked()){
catCounter += 5;
} else{
//nobody gets points
}
}
public void processDrool(final RadioGroup radioGroup){
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
int radioId= radioGroup.getCheckedRadioButtonId();
droolRadioButton = (RadioButton)findViewById(radioId);
if (droolRadioButton.getText().equals("yes")){
dogCounter+= 5;
}else if (droolRadioButton.getText().equals("no")){
catCounter+= 5;
}
}
});
}
public void processCanine(final RadioGroup radioGroup){
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
int radioId= canineRadioGroup.getCheckedRadioButtonId();
canineRadioButton = (RadioButton)findViewById(radioId);
if (canineRadioButton.getText().equals("yes")){
catCounter+= 5;
}else if (canineRadioButton.getText().equals("no")){
dogCounter+= 5;
}
}
});
}
}

I think you just need to change your processCutest call so that it goes inside the onClick method, but before the toast.makeText call. Like this:
showResultButton= (Button)findViewById(R.id.showResults);
showResultButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
processCutest(cutestCheckBoxDog, cutestCheckBoxCat, cutestCheckBoxParrot);
Toast.makeText(getApplicationContext(),catCounter + " " + dogCounter, Toast.LENGTH_LONG).show();
I'm assuming that the actual checkboxes are defined elsewhere. Are your checkboxes showing up? If so you might want to put the processDrool and processCanine calls right there as well.

Null Pointer Exception after some code moved to a custom Application class

Getting NullPointerException after I moved some of the code to a separate, custom application class called YambaApplication. This application posts to a Twitter enabled service. I checked the code 3 times, and cleaned the project 5 times:
Exception:
06-16 14:08:22.723: E/AndroidRuntime(392): Caused by:
java.lang.NullPointerException 06-16 14:08:22.723:
E/AndroidRuntime(392): at
com.user.yamba.StatusActivity$PostToTwitter.doInBackground(StatusActivity.java:70)
YambaApplication.java (here we initialize and return a twitter object):
package com.user.yamba;
import winterwell.jtwitter.Twitter;
import android.app.Application;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.preference.PreferenceManager;
import android.text.TextUtils;
import android.util.Log;
public class YambaApplication extends Application implements
OnSharedPreferenceChangeListener {
private static final String TAG = YambaApplication.class.getSimpleName();
public Twitter twitter;
private SharedPreferences prefs;
#Override
public void onCreate() {
super.onCreate();
this.prefs = PreferenceManager.getDefaultSharedPreferences(this);
this.prefs.registerOnSharedPreferenceChangeListener(this);
Log.i(TAG, "onCreated");
}
#Override
public void onTerminate() {
super.onTerminate();
Log.i(TAG, "onTerminated");
}
#Override
public synchronized void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key) {
this.twitter = null;
}
public synchronized Twitter getTwitter() {
if (this.twitter == null) {
String username, password, apiRoot;
username = this.prefs.getString("username", "");
password = this.prefs.getString("password", "");
apiRoot = this.prefs.getString("apiRoot",
"http://yamba.marakana.com/api");
if (!TextUtils.isEmpty(username) && !TextUtils.isEmpty(password)
&& !TextUtils.isEmpty(apiRoot)) {
this.twitter = new Twitter(username, password);
this.twitter.setAPIRootUrl(apiRoot);
}
}
return this.twitter;
}
}
StatusActivity.java (the first activity user sees with an EditText and an update button. Most of the code from YambaApplication class was inside this class.):
package com.user.yamba;
import winterwell.jtwitter.Twitter;
import winterwell.jtwitter.TwitterException;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class StatusActivity extends Activity implements OnClickListener,
TextWatcher {
private static final String TAG = "StatusActivity";
EditText editTextStatusUpdate;
Button buttonStatusUpdate;
TextView textViewCharacterCounter;
//SharedPreferences prefs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_status);
// Find views
editTextStatusUpdate = (EditText) findViewById(R.id.editStatus);
buttonStatusUpdate = (Button) findViewById(R.id.buttonUpdate);
buttonStatusUpdate.setOnClickListener(this);
textViewCharacterCounter = (TextView) findViewById(R.id.editTextUpdateStatusCounter);
textViewCharacterCounter.setText(Integer.toString(140));
textViewCharacterCounter.setTextColor(Color.GREEN);
editTextStatusUpdate.addTextChangedListener(this);
//prefs = PreferenceManager.getDefaultSharedPreferences(this);
//prefs.registerOnSharedPreferenceChangeListener(this);
// Initialize twitter
// twitter = new Twitter("student", "password");
// twitter.setAPIRootUrl("http://yamba.marakana.com/api");
}
#Override
public void onClick(View v) {
String statusUpdate = editTextStatusUpdate.getText().toString();
new PostToTwitter().execute(statusUpdate);
Log.d(TAG, "onClicked");
}
// Async class to post of twitter
class PostToTwitter extends AsyncTask<String, Integer, String> {
// Async post status to twitter
#Override
protected String doInBackground(String... params) {
try {
YambaApplication yamba = ((YambaApplication) getApplication());
Twitter.Status status = yamba.getTwitter().updateStatus(params[0]); // EXCEPTION FIRED HERE
return status.text;
} catch (TwitterException e) {
Log.e(TAG, "Failed to connect to twitter service");
return "Failed to post";
}
}
// Called when there's status to be updated
#Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
// Not used
}
// Called once async task completed
#Override
protected void onPostExecute(String result) {
Toast.makeText(StatusActivity.this, result, Toast.LENGTH_LONG)
.show();
}
}
#Override
public void beforeTextChanged(CharSequence s, int start, int count,
int after) {
// Not in use
}
#Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
// Not in use
}
// Update characters counter after text
// is changed(entered or deleted)
#Override
public void afterTextChanged(Editable statusText) {
int count = 140 - statusText.length();
textViewCharacterCounter.setText(Integer.toString(count));
textViewCharacterCounter.setTextColor(Color.GREEN);
if (count < 10) {
textViewCharacterCounter.setTextColor(Color.YELLOW);
}
if (count < 0) {
textViewCharacterCounter.setTextColor(Color.RED);
}
}
// When user taps on the menu hardware button inflate
// the menu resource
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
// Determine what item user tapped on the menu
// and start the item's activity
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.itemPrefs:
startActivity(new Intent(this, PrefsActivity.class));
break;
}
return true;
}
// private Twitter getTwitter() {
// if (twitter == null) {
// String username, password, apiRoot;
// username = prefs.getString("username", "");
// password = prefs.getString("password", "");
// apiRoot = prefs.getString("apiRoot",
// "http://yamba.marakana.com/api");
//
// // Connect to twitter
// twitter = new Twitter(username, password);
// twitter.setAPIRootUrl(apiRoot);
// }
// return twitter;
// }
// #Override
// public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
// String key) {
// // invalidate twitter
// twitter = null;
//
// }
}
Manifest (added this line to the application tag in the manifest):
android:name=".YambaApplication"

The first thing I saw were the new checks for the username and password to contain text.
Maybe try to debug if they both are set correctly and if a Twitter Object is returned from the Application, or simply null, because of those checks.

Null is because in YambaApplication you check:
if (!TextUtils.isEmpty(username) && !TextUtils.isEmpty(password)
&& !TextUtils.isEmpty(apiRoot)) {
...
}
If any field is empty you get twiter == null.