Demo_Java2D.java

// Author Thitipong Samranvanich  
// Since 2017-05-28
// For:   Demo Java 2D Painting + Swing GUI  
// STILL ERROR , CAN NOT MOUSE MOVE , By Mouse Click is OK 

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

// for Graphics 2D 
import java.awt.* ; 
import java.awt.geom.*; 	// <== for Line2D 

// for MouseEvent
import java.awt.event.*; 


public class Form1 extends JFrame implements MouseMotionListener{
	JLabel lb ; 
	JPanel pan ;
        int x2 = 200, y2 = 200;	
	public Form1(){
		//=====================
		pan = new JPanel();
		pan.setBackground(new Color(170,180,170));
		//this.add(pan);
		getContentPane().add(pan);
		
		this.addComp(pan);
		//=== add event ==
		
	
		this.addMouseListener( new MouseAdapter(){
			public void mouseEnter(MouseEvent e){
				System.out.println("MouseENTER");
			}
			public void mouseClicked(MouseEvent e){
				x2 = e.getX();
				y2 = e.getY();
				repaint();
				System.out.println(" mouse clicked");
			}
			public void mouseMoved(MouseEvent e){
				lb.setText(" mouse x,y = "+ e.getX() 
							+ "," + e.getY()
					);
				x2 = e.getX();
				y2 = e.getY();
				repaint();
				System.out.println(" mouse moved");				
			}
		});

		//===== set property ==
		this.setSize(300,400);
		this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		this.setVisible(true);

	}
	public void mouseDragged(MouseEvent e){
		System.out.println(" mouse draged , Implemented ");
	}	

	public void mouseMoved(MouseEvent e){
		System.out.println(" mouse moved , Implemented ");
	}

	private void addComp(JPanel pan){
		pan.setLayout(null);
		
		lb = new JLabel("Demo Label");
		lb.setBounds(10,10,200,30);
		pan.add(lb);

		JTextField tx = new JTextField(40);
		tx.setText("Demo Text");
		tx.setBounds( 20 ,30 , 200, 20 );
		pan.add(tx);

		pan.invalidate();

	}
	
	public void paint(Graphics g){
		super.paint(g);  	// must do 
		Graphics2D g2 = (Graphics2D)g ;
		Line2D lin = new Line2D.Float(100,100,x2,y2 );
		g2.draw(lin);

		//this.invalidate();
		getContentPane().invalidate();
		
	}

	public static void main(String[] args){
		System.out.println("Form1 Started ");
		Form1 f1 = new Form1();
		System.out.println("Form1 Created ");
	}
}