CircleTimeActivity from mobile apps club

CircleTimeActivity.java

package org.cmu.mobileappsclub.circletime;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class CircleTimeActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        Button areaButton = (Button) this.findViewById(R.id.areaButton);
        areaButton.setOnClickListener(new AreaListener());
        
        Button clearButton = (Button) this.findViewById(R.id.clearButton);
        clearButton.setOnClickListener(new OnClickListener() {

			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				EditText input = (EditText) CircleTimeActivity.this.findViewById(R.id.textbox);
				input.setText("");
				Log.d("clear", "We pressed the clear button");
			}
        	
        });
    }
    
    private class AreaListener implements OnClickListener {

		public void onClick(View arg0) {
			// TODO Auto-generated method stub
			EditText input = (EditText) CircleTimeActivity.this.findViewById(R.id.textbox);
			double radius = Double.parseDouble(input.getEditableText().toString());
			
			double area = radius*radius*Math.PI;
			
			Toast.makeText(CircleTimeActivity.this, "The area of the circle is " + area, Toast.LENGTH_LONG).show();
		}
    	
    }
}