Calcolatrice versione quasi defintiva

----------------Calcolatrice.java----------------

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

package org.me.calcolatrice;

import android.app.Activity;
import android.os.Bundle;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.content.Context;
import android.widget.*;
import android.view.View;
import android.content.Intent;

/**
*
* @author 4ALE
*/
public class Calcolatrice extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        // ToDo add your GUI initialization code here       
    }
    public double leggiV1(){
        EditText numero1=(EditText)findViewById(R.id.num1);
        double num1=0;
        try{
                    num1=Double.parseDouble(numero1.getText().toString());
                    }catch(Exception e){
                        numero1.setError("Il dato immesso non è valido");
                    }
        return num1;
    }
    public double leggiV2(){
        EditText numero2=(EditText)findViewById(R.id.num2);
        double num2=0;
        try{
                    num2=Double.parseDouble(numero2.getText().toString());
                    }catch(Exception e){
                        numero2.setError("Il dato immesso non è valido");
                    }
        return num2;
    }
    public void somma(View view) {
           double a=leggiV1();
           double b=leggiV2();
           double c=a+b;
           setRisp(a+"+"+b+"="+c);
    }

    public void cos (View view){
        double num1=leggiV1();
        double ang=Math.toRadians(num1);
        double cos=Math.cos(ang);
        setRisp("cos"+num1+"="+cos);
    }
    public void sen (View view){
        double num1=leggiV1();
        double ang=Math.toRadians(num1);
        double sin=Math.sin(ang);
        setRisp("sin"+num1+"="+sin);
    }
    public void setRisp(String risp){
        TextView ris1=(TextView)findViewById(R.id.ris);
        ris1.setText(risp);
    }

    public void diff(View view){
        double a=leggiV1();
        double b=leggiV2();
        double c=a-b;
        setRisp(a+"-"+b+"="+c);
    }
    public void per(View view){
        double a=leggiV1();
        double b=leggiV2();
        double c=a*b;
        setRisp(a+"x"+b+"="+c);
    }
    public void divi(View view){
        double a=leggiV1();
        double b=leggiV2();
        double c=a/b;
        setRisp(a+"/"+b+"="+c);
    }
    public void tan(View view){
        double a=leggiV1();
        double tan=Math.tan(Math.toRadians(a));
        setRisp("tan"+a+"="+tan);
    }
    public void log(View view){
        double a=leggiV1();
        double l=Math.log(a);
        setRisp("log"+a+"="+l);
    }
}

----------------main.xml----------------

<?xml version="1.0" encoding="UTF-8"?>
<TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:stretchColumns="5"
>
    <TableRow>
        <TextView android:text="numero:"
                  android:layout_width="100px"
                  />
    <EditText
        android:layout_width="200px"
        android:layout_height="wrap_content"
        android:id="@+id/num1"
    />
    </TableRow>
        <TableRow>
        <TextView android:text="numero:"
                  android:layout_width="100px"
                  />
    <EditText
        android:layout_width="200px"
        android:layout_height="wrap_content"
        android:id="@+id/num2"
    />
    </TableRow>
    <TableRow>
        <TextView android:text="Risultato:"
                  android:layout_width="100px"
                  />
    <TextView
        android:layout_width="200px"
        android:layout_height="30px"
        android:id="@+id/ris"
    />
    </TableRow>

    <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:stretchColumns="4"
>
    <TableRow>
        <Button android:id="@+id/somma"
                android:layout_width="50px"
                android:layout_height="50px"
                android:text="+"
                android:onClick="somma"
          />
        <Button android:id="@+id/diff"
                android:layout_width="50px"
                android:layout_height="50px"
                android:text="-"
                android:onClick="diff"
          />
      <Button android:id="@+id/prodotto"
                android:layout_width="50px"
                android:layout_height="50px"
                android:text="x"
                android:onClick="per"
          />
      <Button android:id="@+id/rapporto"
                android:layout_width="50px"
                android:layout_height="50px"
                android:text=":"
                android:onClick="divi"
          />
          </TableRow>
          <TableRow>
        <Button android:id="@+id/cos"
                android:layout_width="70px"
                android:layout_height="50px"
                android:text="cos(x)"
                android:onClick="cos"
          />
        <Button android:id="@+id/sin"
                android:layout_width="70px"
                android:layout_height="50px"
                android:text="sin(x)"
                android:onClick="sen"
          />
        <Button android:id="@+id/tan"
                android:layout_width="70px"
                android:layout_height="50px"
                android:text="tan(x)"
                android:onClick="tan"
          />
      <Button android:id="@+id/log"
                android:layout_width="70px"
                android:layout_height="50px"
                android:text="log(x)"
                android:onClick="log"
          />
</TableRow>
</TableLayout>
</TableLayout>