Android - Simple Interest Calculation

Screen

Layout

<?xml version="1.0" encoding="utf-8"?>

<AbsoluteLayout

android:id="@+id/widget0"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

xmlns:android="http://schemas.android.com/apk/res/android"

>

<EditText

android:id="@+id/pAmount"

android:layout_width="141px"

android:layout_height="35px"

android:textSize="18sp"

android:layout_x="150px"

android:layout_y="42px"

android:inputType="numberDecimal"

>

</EditText>

<EditText

android:id="@+id/pRateofInterest"

android:layout_width="142px"

android:layout_height="37px"

android:textSize="18sp"

android:layout_x="150px"

android:layout_y="112px"

android:inputType="numberDecimal"

>

</EditText>

<EditText

android:id="@+id/pPeriod"

android:layout_width="142px"

android:layout_height="38px"

android:textSize="18sp"

android:layout_x="150px"

android:layout_y="182px"

android:inputType="numberDecimal"

>

</EditText>

<Button

android:id="@+id/bCalculate"

android:layout_width="107px"

android:layout_height="43px"

android:text="Calculate"

android:layout_x="100px"

android:layout_y="252px"

>

</Button>

<TextView

android:id="@+id/widget31"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Principal Amount:"

android:layout_x="27px"

android:layout_y="47px"

>

</TextView>

<TextView

android:id="@+id/widget38"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Rate of Interest:"

android:layout_x="37px"

android:layout_y="119px"

>

</TextView>

<TextView

android:id="@+id/widget67"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Period:"

android:layout_x="94px"

android:layout_y="188px"

>

</TextView>

<EditText

android:id="@+id/pSimpleInterest"

android:layout_width="130px"

android:layout_height="37px"

android:text=""

android:textSize="18sp"

android:layout_x="160px"

android:layout_y="342px"

>

</EditText>

<TextView

android:id="@+id/widget93"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Simple Interest:"

android:layout_x="50px"

android:layout_y="352px"

>

</TextView>

</AbsoluteLayout>

Java Code

package com.simple;

import android.app.Activity;

import android.app.AlertDialog;

import android.content.Context;

import android.content.DialogInterface;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuInflater;

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 simpleinterest extends Activity {

/** Called when the activity is first created. */

Button calculate;

Button messageBox;

EditText principal;

EditText rate;

EditText period;

EditText simpleinterest;

TextView simpleIntrest;

TextView siText;

Context context;

@Override

public boolean onCreateOptionsMenu(Menu menu) {

MenuInflater inflater = getMenuInflater();

inflater.inflate(R.menu.mymenu, menu);

return true;

}

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

context = this.getApplicationContext();

// Get all the UI components

siText = (TextView) findViewById(R.id.pSimpleInterest);

simpleIntrest = (TextView) findViewById(R.id.pSimpleInterest);

messageBox = (Button) findViewById(R.id.bCalculate);

messageBox.setOnClickListener((OnClickListener) new clicker()); 

}

class clicker implements Button.OnClickListener {

public void onClick(View v) {

principal = (EditText) findViewById(R.id.pAmount);

rate = (EditText) findViewById(R.id.pRateofInterest);

period = (EditText) findViewById(R.id.pPeriod);

simpleinterest = (EditText) findViewById(R.id.pSimpleInterest);

try {

if (principal.getText().toString().equals("")) {

Toast.makeText(context, "Principal Missing",

Toast.LENGTH_SHORT).show();

} else if (rate.getText().toString().equals("")) {

Toast.makeText(context, "Rate Of Intrest Missing",

Toast.LENGTH_SHORT).show();

} else if (period.getText().toString().equals("")) {

Toast.makeText(context, "Period Missing",

Toast.LENGTH_SHORT).show();

} else {

Double p = Double.parseDouble(principal.getText()

.toString());

Double r = Double

.parseDouble(rate.getText().toString());

Double t = Double.parseDouble(period.getText()

.toString());

Double si;

System.out.println("P = " + p + "\nR = " + r + "\nT = "

+ t);

si = (p * r * t) / 100;

// prepare the alert box

AlertDialog.Builder alertbox = new AlertDialog.Builder(

v.getContext());

System.out.println("Alert builder");

// set the message to display

alertbox.setMessage("Simple Interest = "

+ si.toString());

simpleinterest.setText(si.toString());

simpleinterest.setVisibility(TextView.VISIBLE);

// add a neutral button to the alert box and assign a

// click listener

alertbox.setNeutralButton("Ok",

new DialogInterface.OnClickListener() {

// click listener on the alert box

public void onClick(DialogInterface arg0,

int arg1) {

// the button was clicked

Toast.makeText(getApplicationContext(),

"Thank You !!!!",

Toast.LENGTH_LONG).show();

}

});

// show it

alertbox.show();

System.out.println("Alert show");

// simpleIntrest.setText(si.toString());

// simpleIntrest.setVisibility(TextView.VISIBLE);

// siText.setVisibility(TextView.VISIBLE);

}

} catch (Exception e) {

System.out.println("In catch block");

e.printStackTrace();

}

}

}

@Override

protected void onStart() {

super.onStart();

System.out.println("In OnStart");

}

}