Developing Complex UI Part 1(Contd...)

Functional Logic for Calculator App..

package com.findandroidhub.democalculator;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity
{
 private EditText t1,t2;
 private Button b1,b2,b3,b4;
 private TextView tv;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  // TODO Auto-generated method stub
  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);
  b2=(Button)findViewById(R.id.button2);
  b3=(Button)findViewById(R.id.button3);
  b4=(Button)findViewById(R.id.button4);
  tv=(TextView)findViewById(R.id.disp);

  b1.setOnClickListener(new View.OnClickListener() {
 
   @Override
   public void onClick(View v) {
    float a,b;
    a=Float.parseFloat(t1.getText().toString());
    b=Float.parseFloat(t2.getText().toString());
    float add=a+b;
    tv.setText("Your total is:"+add);
  
  
   }
  });
  b2.setOnClickListener(new View.OnClickListener() {
 
   @Override
   public void onClick(View v) {
    float a,b;
    a=Float.parseFloat(t1.getText().toString());
    b=Float.parseFloat(t2.getText().toString());
    float sub=a-b;
    tv.setText("Your total is:"+sub);
  
  
   }
  });
  b3.setOnClickListener(new View.OnClickListener() {
 
   @Override
   public void onClick(View v) {
    float a,b;
    a=Float.parseFloat(t1.getText().toString());
    b=Float.parseFloat(t2.getText().toString());
    float multi=a*b;
    tv.setText("Your total is:"+multi);
  
  
   }
  });
  b4.setOnClickListener(new View.OnClickListener() {
 
   @Override
   public void onClick(View v) {
    float a,b;
    a=Float.parseFloat(t1.getText().toString());
    b=Float.parseFloat(t2.getText().toString());
    float div=a/b;
    tv.setText("Your total is:"+div);
  
  
   }
  });


 }


}