package appdibujarcirculocalculararea;

public class Principal extends javax.swing.JFrame {

    public Principal() {
        initComponents();
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                         
    private void initComponents() {}                      

    private void btngraficarActionPerformed(java.awt.event.ActionEvent evt) {                                           
       int Xo = Integer.parseInt(this.textX0.getText());
       int Yo = Integer.parseInt(this.texty0.getText());
       int X1 = Integer.parseInt(this.textX1.getText());
       int Y1 = Integer.parseInt(this.texty1.getText());

       panel1.setXo(Xo);
       panel1.setYo(Yo);
       panel1.setX1(X1);
       panel1.setY1(Y1);

       panel1.DibujarCirculo();

    }                                          

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Principal().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                    
    private javax.swing.JButton btncalcular;
    private javax.swing.JButton btngraficar;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JPanel jPanel1;
    private appdibujarcirculocalculararea.Panel panel1;
    private javax.swing.JTextField textX0;
    private javax.swing.JTextField textX1;
    private javax.swing.JTextField texty0;
    private javax.swing.JTextField texty1;
    // End of variables declaration                  

}


package appdibujarcirculocalculararea;

import java.awt.Graphics;
import java.awt.*;


public class Panel extends javax.swing.JPanel {

    private int Xo,Yo;
    private int X1,Y1;

    public void setX1(int X1) {
        this.X1 = X1;
    }

    public void setXo(int Xo) {
        this.Xo = Xo;
    }

    public void setY1(int Y1) {
        this.Y1 = Y1;
    }

    public void setYo(int Yo) {
        this.Yo = Yo;
    }


    public Panel() {
        initComponents();
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                         
    private void initComponents() {

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
        this.setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );
    }// </editor-fold>                       

    @Override
    public void paint(Graphics g) {
        super.paint(g);
        g.setColor(Color.red);
        g.drawOval(this.Xo, this.Yo, this.X1, this.Y1);
    }
    public void DibujarCirculo()
    {
      repaint();
    }

    // Variables declaration - do not modify                    
    // End of variables declaration                  

}