Develop Reference

Crashing whenever any buttons are clicked

The app executed just fine, and the interface loads just fine as well, but when I try to press any of the buttons, nothing that should happen happens. The point is fairly simple: press the '+' button, the quantity increases, and the price immediately updates to match said quantity, vice versa for the '-' button. I don't know what I've done wrong, but any button interaction with the app crashes it.
Here's my Java:
package com.t99sdevelopment.mobile.eyy;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
import java.text.NumberFormat;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public int quantityValue = 1;
public void increaseQuantity (View view) {
quantityValue = quantityValue + 1;
updateQuantityValue(view);
}
public void decreaseQuantity (View view) {
quantityValue = quantityValue - 1;
updateQuantityValue(view);
}
public void updateQuantityValue(View view) {
updateQuantity(quantityValue);
updatePrice(quantityValue);
}
private void updateQuantity(int number) {
TextView quantity = (TextView) findViewById(
R.id.quantityValue);
quantity.setText(number);
}
private void updatePrice(int number) {
TextView price = (TextView) findViewById(R.id.priceValue);
price.setText(NumberFormat.getCurrencyInstance().format(number * 5));
}
}
Here's my XML:
<TextView
android:text="Quantity"
android:id="#+id/quantityText"
android:textAllCaps="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="16sp"
android:textColor="#000000"
android:autoText="false"
android:paddingBottom="20dp" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="center_horizontal">
<TextView
android:text="0"
android:id="#+id/quantityValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="16dp"
android:paddingBottom="16dp" />
<Button
android:layout_width="48dp"
android:layout_height="48dp"
android:text="-"
android:id="#+id/button"
android:layout_alignParentTop="true"
android:layout_toLeftOf="#+id/quantityValue"
android:layout_toStartOf="#+id/quantityValue"
android:layout_marginRight="15dp"
android:layout_marginEnd="15dp"
android:onClick="decreaseQuantity" />
<Button
android:layout_width="48dp"
android:layout_height="48dp"
android:text="+"
android:id="#+id/button2"
android:layout_alignParentTop="true"
android:layout_toRightOf="#+id/quantityValue"
android:layout_toEndOf="#+id/quantityValue"
android:layout_marginLeft="15dp"
android:layout_marginStart="15dp"
android:onClick="increaseQuantity" />
</RelativeLayout>
<TextView
android:text="Price"
android:id="#+id/priceText"
android:textAllCaps="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="16sp"
android:textColor="#000000"
android:autoText="false"
android:paddingTop="20dp" />
<TextView
android:text="$0"
android:id="#+id/priceValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingTop="20dp"
android:paddingBottom="20dp" />
<Button
android:text="Order"
android:textAllCaps="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
The formatting of the actual code is just fine, but it got screwy when I pasted in into stack, so I know that's not the problem.

Change you updateQuantity and updatePrice method like :
private void updateQuantity(int number) {
TextView quantity = (TextView) findViewById(
R.id.quantityValue);
quantity.setText(String.valueOf(number));
}
private void updatePrice(int number) {
TextView price = (TextView) findViewById(R.id.priceValue);
price.setText(String.valueOf(NumberFormat.getCurrencyInstance().format(number * 5)));
}
}

Android Simple Calculator App Crashing and Logic

I'm making an android app for a simple calculator. The most important part is that it uses a "rolling" textView, so for example if you did 1+1, then if you pressed another arithmetic operator, "+" for example, the textView would then turn into 2+(enter new number, 3 for example) and then if you clicked multiply, it would then show 5* etc etc.
Right now the error is at line34 showing a null pointer error when I click the number 1 on the calculator. Wondering if anybody can assist me on this / other logic errors if you see them.
Basically if you click to use an arithmetic operator on the calculator, and if there's already an operator in the textView on the calculator, then it calculates the current textView and spits that new arithmetic operator beside it. Otherwise if there are no arithmetic operators on the calculator, it just puts the operator beside the first number.
What I'm trying to do is:
if the user clicks a number, then set rollingBar to that number
if the user clicks an operator
if it is the first operator then there must be only 1 string inside of
the rollingBar, so assign that string to leftNum, and assign the first
operator type to the text of the button eg. "1".
get text in rolling bar, assign it to text1, make text2 and assign
it to text1 + stringButton(which would be 1,2,3,4 etc.. name of btn.
set the first operator to false
if it's not the first operator, then you need to calculate by splitting
the function at the first arithmetic operator, assign the last number
from the split into rightNum
switch to the first operator type
do the math
assign this second operator to the next rollingBar
Right now I'm getting some problems... I'll show a picture and the java file...
Picture:
http://imgur.com/35hy4Ze
Java File:
package com.example.w0273754.calcfinal;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.lang.String;
public class MainActivity extends AppCompatActivity {
//declarations
TextView rollingBar;//where all of the text goes when the user clicks a button
String leftNum;
String rightNum;
boolean firstOptr;
String firstOptrType;
String number;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rollingBar = (TextView) findViewById(R.id.rollingBar);
leftNum = "";
rightNum = "";
firstOptr = true;
number = "";
}
public void number(View v){
Button button = (Button) v;
number += button.getText().toString();
rollingBar.setText(number);
}
//i can click 1 and it outputs 1
// i can click + and it outputs +
// when I click next number it just outputs the number, nothing else
public void operater(View v) {
Button button = (Button) v;
String stringButton = button.getText().toString();
//if it's the first operator being done, then set the rollbar text to text1,
// then add the operator string to text1 and store it in text 2.
if (firstOptr) {
leftNum = rollingBar.getText().toString();
firstOptrType = stringButton;
number += stringButton;
rollingBar.setText(number);
firstOptr = false;
}
//if it's not the first operator, then you need to calculate leftnum and the right num
else {
String fullString = (String) rollingBar.getText().toString();
String[] bits = fullString.split("[-+*/]");
rightNum = bits[bits.length - 1];
switch (firstOptrType) {
case "+":
add(leftNum, rightNum);
break;
case "-":
break;
case "*":
break;
case "/":
break;
default:
rollingBar.setText("OPERATOR METHOD PROBLEM");
}
}
}
public void add(String leftNum, String rightNum){
int parsedLeftNum = Integer.parseInt(leftNum);
int parsedRightNum = Integer.parseInt(rightNum);
rollingBar.setText(parsedLeftNum + parsedRightNum);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
XML file:
<TableLayout android:id="#+id/TableLayout"
tools:context=".MainActivity"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:layout_height="match_parent"
android:layout_width="match_parent"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android">
<TableRow android:paddingBottom="10dp" android:layout_height="match_parent" android:layout_width="match_parent">
<TextView android:id="#+id/rollingBar" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_column="1" android:layout_span="4" android:text="#string/rollingBar"/>
</TableRow>
<TableRow android:layout_height="match_parent"
android:layout_width="match_parent">
<Button android:id="#+id/buttonClear" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/buttonClear" />
<Button android:id="#+id/buttonPlusMinus" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/buttonPlusMinus" android:onClick="onClick1"/>
<Button android:id="#+id/buttonDelete" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/buttonDelete" />
<Button android:id="#+id/buttonDivide" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_column="3" android:text="#string/buttonDivide" android:onClick="operater"/>
</TableRow>
<TableRow android:paddingBottom="10dp" android:layout_height="match_parent" android:layout_width="match_parent">
<Button android:id="#+id/button7" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/button7" android:onClick="number" android:nestedScrollingEnabled="false"/>
<Button android:id="#+id/button8" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/button8" android:onClick="number"/>
<Button android:id="#+id/button9" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/button9" android:onClick="number"/>
<Button android:id="#+id/buttonMultiply" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_column="3" android:text="#string/buttonMultiply" android:onClick="operater"/>
</TableRow>
<TableRow android:paddingBottom="10dp" android:layout_height="match_parent" android:layout_width="match_parent">
<Button android:id="#+id/button4" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/button4" android:onClick="number"/>
<Button android:id="#+id/button5" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/button5" android:onClick="number"/>
<Button android:id="#+id/button6" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="#string/button6" android:onClick="number"/>
<Button android:id="#+id/buttonSubtract" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_column="3" android:text="#string/buttonSubtract" android:onClick="operater"/>
</TableRow>
<TableRow android:paddingBottom="10dp" android:layout_height="wrap_content" android:layout_width="match_parent">
<Button android:id="#+id/button1" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/button1" android:onClick="number"/>
<Button android:id="#+id/button2" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/button2" android:onClick="number"/>
<Button android:id="#+id/button3" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/button3" android:onClick="number"/>
<Button android:id="#+id/buttonAdd" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_column="3" android:text="#string/buttonAdd" android:onClick="operater"/>
</TableRow>
<TableRow android:paddingBottom="10dp" android:layout_height="match_parent" android:layout_width="match_parent">
<Button android:id="#+id/button0" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="2" android:text="#string/button0" android:onClick="number"/>
<Button android:id="#+id/buttonDecimal" android:layout_height="wrap_content" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/buttonDecimal"/>
<Button android:id="#+id/buttonEqual" android:layout_height="match_parent" android:layout_width="wrap_content" android:layout_span="1" android:text="#string/buttonEqual" android:onClick="operater"/>
</TableRow>
<TableRow android:layout_height="match_parent" android:layout_width="match_parent">
<TextView android:id="#+id/textView" android:layout_height="wrap_content" android:layout_width="wrap_content" android:text="0"/>
</TableRow>
<TableRow android:layout_height="match_parent" android:layout_width="match_parent">
<TextView android:id="#+id/errorMessage" android:layout_height="wrap_content" android:layout_width="wrap_content"/>
</TableRow>
</TableLayout>
Thank you very much,for the help!

#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView rollingBar = (TextView) findViewById(R.id.rollingBar); // <-- HERE
String leftNum = "";
String rightNum = "";
boolean firstOptr = true;
String firstOptrType;
}
You declare a local variable rollingBar in onCreate which shadow the member variable of your Activity, so the member variable rollingBar always null, delete the TextView:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rollingBar = (TextView) findViewById(R.id.rollingBar);
String leftNum = "";
String rightNum = "";
boolean firstOptr = true;
String firstOptrType;
}

Button becomes blank(text) when Onclick method executed

This is the xml code:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context=".MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="20dp"
android:text="eBay Search"
android:textSize="13pt"
android:textStyle="bold"
android:textColor="#000099"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true">
</TextView>
<TableLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="80dp"
android:id="#+id/tableLayout">
<TableRow
android:layout_marginTop="15dp">
<TextView
android:layout_height="wrap_content"
android:layout_width="0dp"
android:text="Keyword:"
android:textSize="10pt"
android:layout_weight="2">
</TextView>
<EditText
android:id="#+id/keyword"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="3"
>
</EditText>
</TableRow>
<TableRow
android:layout_marginTop="15dp">
<TextView
android:layout_height="wrap_content"
android:layout_width="0dp"
android:text="Price From:"
android:textSize="10pt"
android:layout_weight="2">
</TextView>
<EditText
android:id="#+id/from"
android:layout_width="0dp"
android:inputType="numberDecimal"
android:layout_height="wrap_content"
android:layout_weight="3"
>
</EditText>
</TableRow>
<TableRow
android:layout_marginTop="15dp">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Price To:"
android:textSize="10pt"
android:layout_weight="2">
</TextView>
<EditText
android:id="#+id/to"
android:layout_height="wrap_content"
android:layout_gravity="right"
android:layout_weight="3"
android:inputType="numberDecimal"
android:layout_width="0dp"
>
</EditText>
</TableRow>
<TableRow
android:layout_marginTop="15dp">
<TextView
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="Sort By:"
android:textSize="10pt"
android:layout_weight="2">
</TextView>
<Spinner
android:id="#+id/sortby"
android:layout_height="wrap_content"
android:prompt="#string/op1"
android:layout_width="fill_parent"
android:entries="#array/sortlist">
</Spinner>
</TableRow>
<TableRow
android:layout_marginTop="15dp"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Clear"
android:id="#+id/Clear"
android:onClick="clearForm"
android:layout_marginLeft="50dp"
/>
<Button
android:layout_width="90dp"
android:layout_height="wrap_content"
android:text="Search"
android:textColor="#color/black"
android:id="#+id/search"
android:layout_marginLeft="50dp"
/>
</TableRow>
</TableLayout>
<TextView
android:id="#+id/keyerror"
android:layout_marginTop="420dp"
android:layout_centerHorizontal="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:textSize="7pt"
android:textColor="#color/red"
>
</TextView>
<TextView
android:id="#+id/priceerror"
android:layout_marginTop="445dp"
android:layout_centerHorizontal="true"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:textSize="7pt"
android:textColor="#color/red"
>
</TextView>
This is the mainactivity code which has onclicklistener method for the search button:
package com.example.hrishikesh.hw9;
import android.app.AlertDialog;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import java.net.URLEncoder;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Button search = (Button)findViewById(R.id.search);
search.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int error=0;
EditText text1 = (EditText) findViewById(R.id.keyword);
EditText text2 = (EditText) findViewById(R.id.from);
EditText text3 = (EditText) findViewById(R.id.to);
TextView keyerror = (TextView) findViewById(R.id.keyerror);
TextView priceerror = (TextView) findViewById(R.id.priceerror);
String keyword = text1.getText().toString();
String from = text2.getText().toString();
String to = text3.getText().toString();
String reg = "^[0-9]+$";
if (keyword == null || keyword.length() < 1 || keyword.trim().length() < 1) {
keyerror.setText("Enter a valid keyword");
error=1;
}
else
{
keyerror.setText("");
error=0;
}
if(to.matches(reg) || to.length()==0)
{
}
else
{
priceerror.setText("Enter a valid positive number for maximum price");
error=1;
}
if(from.matches(reg) || from.length()==0)
{
}
else
{
priceerror.setText("Enter a valid positive number for minimum price");
error=1;
}
if(from.length()>0 && to.length()>0)
if(Integer.parseInt(from) - Integer.parseInt(to)>=0){
priceerror.setText("Minimum price has to be less than maximum price");
error=1;
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
public void clearForm(View v){
EditText text1 = (EditText)this.findViewById(R.id.keyword);
EditText text2 = (EditText)this.findViewById(R.id.from);
EditText text3 = (EditText)this.findViewById(R.id.to);
if (text1 != null) text1.setText("");
if (text2 != null) text2.setText("");
if (text3 != null) text3.setText("");
Spinner spin1 = (Spinner)this.findViewById(R.id.sortby);
spin1.setSelection(0);
}
public void validate(View v){
}
public void search(String keywords,int from,int to,String sortorder){
String url;
int i=0;
url = "http://hrishisaraf-env.elasticbeanstalk.com/";
}
}
Whenever the onclick method gets executed and an error is detected like the keyword being blank. The error text is set and the Search button becomes blank.

No idea why but Setting the width to wrap_content solved the problem.

If Else statement in Android not working

Here I am creating a simple Droid LoginApp, which simply tells login successfull or not. But the if statement is not giving me the desired result.
Following is the code : MainActivity.java
package com.example.login1;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends Activity implements OnClickListener
{
public EditText t1,t2;
public Button b1;
String user,pass;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
t1=(EditText)findViewById(R.id.editText1);
t2=(EditText) findViewById(R.id.editText2);
b1= (Button) findViewById(R.id.button1);
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
public void onClick(View arg0)
{
user = t1.getText().toString();
pass = t2.getText().toString();
if (((user.equals("user")) && (pass.equals("user"))))
{
Toast.makeText(this, "Login Sucessful", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(this, "Sorry", Toast.LENGTH_SHORT).show();
t1.setText("");
t2.setText("");
}
}
}
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="fill_vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="29dp"
android:layout_marginTop="28dp"
android:text="Username"
android:textAppearance="?android:attr/textAppearanceLarge" />
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView1"
android:layout_centerHorizontal="true"
android:ems="10"
android:inputType="text" >
<requestFocus />
</EditText>
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignRight="#+id/textView1"
android:layout_below="#+id/editText1"
android:layout_marginTop="53dp"
android:text="Password"
android:textAppearance="?android:attr/textAppearanceLarge" />
<EditText
android:id="#+id/editText2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/editText1"
android:layout_centerVertical="true"
android:ems="10"
android:inputType="textPassword" />
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/textView2"
android:layout_centerHorizontal="true"
android:layout_marginTop="86dp"
android:clickable="true"
android:onClick="onClick"
android:text="Login" />
</RelativeLayout>
While I run the App, on clicking the Login button, the if statement does not give a correct result.. I simply don't know where is the error.

Well, you should compare strings with "equals()" and not with "==".
Replace:
user == "user"
With:
user.equals("user")
And also, I think there's no need for this extra line you have:
if (arg0.findViewById(R.id.button1)==b1)
^ Why are you checking this?

use this code, for click command
b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
user = t1.getText().toString();
if (user.equals("user")){
Toast.makeText(this, "Login Sucessful", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Sorry", Toast.LENGTH_SHORT).show();
}
}
}

Android Launcher Shows Calculator activity layout but does nothing

Hi i'm working on a Android Launcher that Shows Calculator activity. It shows the layout fine but does nothing when you click on any of the buttons I need help I have tried everything I can and i'm getting upset! any help would be amazing!!
Calculator.java:
package com.dva.schooltoolshome;
import java.text.DecimalFormat;
import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class Calculator extends FragmentActivity implements OnClickListener {
private TextView calculatorDisplay;
private static final String DIGITS = "0123456789.";
private Boolean userIsInTheMiddleOfTypingANumber = false;
DecimalFormat df = new DecimalFormat("############");
CalculatorBrain brain;
#SuppressLint("NewApi")
#Override
protected void onCreate(Bundle savedInstanceState) {
// hide the window title.
requestWindowFeature(Window.FEATURE_NO_TITLE);
// hide the status bar and other OS-level chrome
getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_calculator);
brain = new CalculatorBrain();
calculatorDisplay = (TextView) findViewById(R.id.textView1);
df.setMinimumFractionDigits(0);
df.setMinimumIntegerDigits(1);
df.setMaximumIntegerDigits(8);
findViewById(R.id.button0).setOnClickListener(this);
findViewById(R.id.button1).setOnClickListener(this);
findViewById(R.id.button2).setOnClickListener(this);
findViewById(R.id.button3).setOnClickListener(this);
findViewById(R.id.button4).setOnClickListener(this);
findViewById(R.id.button5).setOnClickListener(this);
findViewById(R.id.button6).setOnClickListener(this);
findViewById(R.id.button7).setOnClickListener(this);
findViewById(R.id.button8).setOnClickListener(this);
findViewById(R.id.button9).setOnClickListener(this);
findViewById(R.id.buttonAdd).setOnClickListener(this);
findViewById(R.id.buttonSubtract).setOnClickListener(this);
findViewById(R.id.buttonMultiply).setOnClickListener(this);
findViewById(R.id.buttonDivide).setOnClickListener(this);
findViewById(R.id.buttonToggleSign).setOnClickListener(this);
findViewById(R.id.buttonDecimalPoint).setOnClickListener(this);
findViewById(R.id.buttonEquals).setOnClickListener(this);
findViewById(R.id.buttonClear).setOnClickListener(this);
findViewById(R.id.buttonClearMemory).setOnClickListener(this);
findViewById(R.id.buttonAddToMemory).setOnClickListener(this);
findViewById(R.id.buttonSubtractFromMemory).setOnClickListener(this);
findViewById(R.id.buttonRecallMemory).setOnClickListener(this);
// The following buttons only exist in layout-land (Landscape mode) and require extra attention.
// The messier option is to place the buttons in the regular layout too and set android:visibility="invisible".
if (findViewById(R.id.buttonSquareRoot) != null) {
findViewById(R.id.buttonSquareRoot).setOnClickListener(this);
}
if (findViewById(R.id.buttonInvert) != null) {
findViewById(R.id.buttonInvert).setOnClickListener(this);
}
if (findViewById(R.id.buttonCos) != null) {
findViewById(R.id.buttonCos).setOnClickListener(this);
}
if (findViewById(R.id.buttonSin) != null) {
findViewById(R.id.buttonSin).setOnClickListener(this);
}
// Another way to hide the window title and actionbar, but only in newer sdk's
// if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
// ActionBar actionBar = getActionBar();
// actionBar.setDisplayShowHomeEnabled(false);
// actionBar.setDisplayShowTitleEnabled(false);
// actionBar.hide();
// }
}
// #Override
public void onClick(View view) {
String buttonPressed = ((Button) view).getText().toString();
// String digits = "0123456789.";
if (DIGITS.contains(buttonPressed)) {
// digit was pressed
if (userIsInTheMiddleOfTypingANumber) {
calculatorDisplay.append(buttonPressed);
} else {
calculatorDisplay.setText(buttonPressed);
userIsInTheMiddleOfTypingANumber = true;
}
} else {
// operation was pressed
if (userIsInTheMiddleOfTypingANumber) {
brain.setOperand(Double.parseDouble(calculatorDisplay.getText().toString()));
userIsInTheMiddleOfTypingANumber = false;
}
brain.performOperation(buttonPressed);
calculatorDisplay.setText(df.format(brain.getResult()));
}
}
#Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// Save variables on screen orientation change
outState.putDouble("OPERAND", brain.getResult());
outState.putDouble("MEMORY", brain.getMemory());
}
#Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// Restore variables on screen orientation change
brain.setOperand(savedInstanceState.getDouble("OPERAND"));
brain.setMemory(savedInstanceState.getDouble("MEMORY"));
calculatorDisplay.setText(df.format(brain.getResult()));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
}
CalculatorBrain.java:
package com.dva.schooltoolshome;
public class CalculatorBrain {
// 3 + 6 = 9
// 3 & 6 are called the operand.
// The + is called the operator.
// 9 is the result of the operation.
private double operand = 0;
private double waitingOperand = 0;
private String waitingOperator = "";
private double calculatorMemory = 0;
public void setOperand(double operand) {
this.operand = operand;
}
public double getResult() {
return operand;
}
// used on screen orientation change
public void setMemory(double calculatorMemory) {
this.calculatorMemory = calculatorMemory;
}
// used on screen orientation change
public double getMemory() {
return calculatorMemory;
}
public String toString() {
return Double.toString(operand);
}
protected double performOperation(String operator) {
/*
* If you are using Java 7, then you can use switch in place of if statements
*
* switch (operator) {
* case "MC":
* calculatorMemory = 0;
* break;
* case "M+":
* calculatorMemory = calculatorMemory + operand;
* break;
* }
*/
if (operator.equals("MC")) {
calculatorMemory = 0;
} else if (operator.equals("M+")) {
calculatorMemory = calculatorMemory + operand;
} else if (operator.equals("M-")) {
calculatorMemory = calculatorMemory - operand;
} else if (operator.equals("MR")) {
operand = calculatorMemory;
} else if (operator.equals("C")) {
operand = 0;
waitingOperator = "";
waitingOperand = 0;
calculatorMemory = 0;
} else if (operator.equals("Sqrt")) {
operand = Math.sqrt(operand);
} else if (operator.equals("1/x")) {
if (operand != 0) {
operand = 1 / operand;
}
} else if (operator.equals("+/-")) {
operand = -operand;
} else if (operator.equals("sin")) {
operand = Math.sin(operand);
} else if (operator.equals("cos")) {
operand = Math.cos(operand);
} else {
performWaitingOperation();
waitingOperator = operator;
waitingOperand = operand;
}
return operand;
}
protected void performWaitingOperation() {
if (waitingOperator.equals("+")) {
operand = waitingOperand + operand;
} else if (waitingOperator.equals("*")) {
operand = waitingOperand * operand;
} else if (waitingOperator.equals("-")) {
operand = waitingOperand - operand;
} else if (waitingOperator.equals("/")) {
if (operand != 0) {
operand = waitingOperand / operand;
}
}
}
}
activity_calculator.xml:
<RelativeLayout xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/bg" >
<LinearLayout
android:id="#+id/linearLayout1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true" >
<TextView
android:id="#+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:maxLines="1"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:text="0"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="40sp" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/linearLayout1" >
<Button
android:id="#+id/buttonAddToMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="M+" />
<Button
android:id="#+id/buttonSubtractFromMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="M-" />
<Button
android:id="#+id/buttonRecallMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="MR" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/linearLayout2" >
<Button
android:id="#+id/buttonClear"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="C" />
<Button
android:id="#+id/buttonToggleSign"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="+/-" />
<Button
android:id="#+id/buttonDivide"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="/" />
<Button
android:id="#+id/buttonMultiply"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="*" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout4"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/linearLayout3" >
<Button
android:id="#+id/button7"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="#string/button7" />
<Button
android:id="#+id/button8"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="#string/button8" />
<Button
android:id="#+id/button9"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="#string/button9" />
<Button
android:id="#+id/buttonSubtract"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="-" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout5"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/linearLayout4" >
<Button
android:id="#+id/button4"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="#string/button4" />
<Button
android:id="#+id/button5"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="#string/button5" />
<Button
android:id="#+id/button6"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="#string/button6" />
<Button
android:id="#+id/buttonAdd"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".25"
android:text="+" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout6"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/linearLayout5"
android:baselineAligned="false" >
<LinearLayout
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".75"
android:orientation="vertical" >
<LinearLayout
android:id="#+id/linearLayout7"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="#+id/button1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".33"
android:text="#string/button1" />
<Button
android:id="#+id/button2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".33"
android:text="#string/button2" />
<Button
android:id="#+id/button3"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".34"
android:text="#string/button3" />
</LinearLayout>
<LinearLayout
android:id="#+id/linearLayout8"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<Button
android:id="#+id/button0"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".66"
android:text="#string/button0" />
<Button
android:id="#+id/buttonDecimalPoint"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight=".34"
android:text="." />
</LinearLayout>
</LinearLayout>
<Button
android:id="#+id/buttonEquals"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".25"
android:text="=" />
</LinearLayout>
<ImageButton
android:id="#+id/apps"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/wbrowser"
android:background="#drawable/appdrawer"
android:src="#drawable/appdrawer" />
<ImageButton
android:id="#+id/wbrowser"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:src="#drawable/browser" />
<ImageButton
android:id="#+id/ImageButton01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignTop="#+id/wbrowser"
android:background="#drawable/appdrawer"
android:src="#drawable/appdrawer" />
<Button
android:id="#+id/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/ImageButton01"
android:layout_centerHorizontal="true"
android:text="Tools" />
<Button
android:id="#+id/buttonClearMemory"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_above="#+id/ImageButton01"
android:layout_alignLeft="#+id/tools"
android:layout_marginBottom="163dp"
android:layout_weight=".25"
android:text="MC" />
</RelativeLayout>
I'm still new to android development so please don't judge
Regards
Rapsong11

First of all use switch statement in OnClick(View v) function for every button.
like this.
public void onClick(View v)
{
case R.Id.button1
// the functionality code goes here
break;
case R.id.button2
break;
}