GrowWire.java

import java.io.*;
import java.util.ArrayList;
import javax.swing.*;

import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;


public class GrowWire extends GridPanel  implements MouseMotionListener  {
    Wire path = null;
    ArrayList<Wire> wlist = new ArrayList<Wire>();
    JLabel status = new JLabel(" ");
    JButton save = new JButton("Save");
    //Point2D loc = null;

    int nc = 0;
    Point base, current;
    boolean in_progress = false;
    boolean starting = false;

GrowWire()
    {
	status.setBackground(Color.WHITE);
	status.setOpaque(true);
	status.setBorder(BorderFactory.createEmptyBorder(4, 4, 4, 4));	

	save.addActionListener(actionEvent -> showPath("wires.txt"));

	addMouseMotionListener(this);
	addMouseListener(new MouseHandler());
    }

 public void read(File file)
     {
	String delims = "[\\s]+";		
	try (BufferedReader br = new BufferedReader(new FileReader(file));) 
	{
	   String CurrentLine;

	   while ((CurrentLine = br.readLine()) != null) 
	   {
		// debug: System.out.println(CurrentLine);
		//Split each line of text file
 		String[] tokens = (CurrentLine.trim().split(delims));
		if (tokens[0].equals("W")) {
			Wire w = new Wire(tokens);
			wlist.add(w);
		}
	   }
	   br.close(); 
      } 		
      catch (IOException e) {
	   JOptionPane.showMessageDialog(null, e);
	   System.err.println(e);
      }
    }

   public void drawContent(Graphics g) {
	for (Wire w: wlist) w.draw(g);
	if (path!=null) path.draw(g);
 }

 private class MouseHandler extends MouseAdapter
    {

	public void mousePressed(MouseEvent e)
	{
	    Point2D src;
	    Point2D grid = new Point2D.Double();
	    if (in_progress) {
		if (e.getClickCount()>1) {
			in_progress = false;
			wlist.add(path);
			path = null;
		}
		else {
		     src = new Point2D.Double(current.getX(),current.getY());
		     tf.transform(src,grid);
		     path.add(grid.getX(),-grid.getY());
		     base = current;
		     repaint();
		   //System.out.println("LineTo " + x + "  " + y);
		   //to = new LineTo(x,y);
		   //path.getElements().add(to);
		}
	    }
	    else {
		in_progress = true;
		starting = true;
		base = e.getPoint();
		current = base;
		path = new Wire();
		src = new Point2D.Double(base.getX(),base.getY());
	   	 tf.transform(src,grid);
		path.add(grid.getX(),-grid.getY());
	    }
	}

	public void mouseReleased(MouseEvent e)
	{
	}
    }


    public void mouseMoved(MouseEvent event)
    {
	if (!in_progress) return;
	Graphics g = getGraphics();
	Graphics2D g2 = (Graphics2D) g;
	int bx = base.x;
	int by = base.y;
	g.setXORMode(Color.WHITE);
	g2.setStroke(new BasicStroke(2.5f,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND));
	// clear old line
	if (!starting) g.drawLine(bx,by,current.x,current.y);
	else starting = false;
	current = event.getPoint();
	// xor new line
	g.drawLine(bx,by,current.x,current.y);
	g.setPaintMode();
	g.setColor(Color.BLACK);
    }

    public void mouseDragged(MouseEvent event)
    {
    }

    public void showPath(String filename) {
	double x, y;
	double xr, yr;
        try (
         BufferedWriter bw = new BufferedWriter(new FileWriter(filename));
        ) {
	 for (Wire w: wlist) {
		bw.write(w.toString());
		bw.newLine();
	 }
	 bw.close();
      } catch (IOException e) {
         System.err.println("I/O Exception: " + e);
      }

    }


   static public void main(String[] args) {
	GrowWire panel = new GrowWire();
	if (args.length>0) { 
	   File file = new File(args[0]);
	   panel.read(file);
                  }
	//for (Wire w: app.wlist) System.out.println(w);

       	 EventQueue.invokeLater(() -> {
		JFrame application = new JFrame("WireDemo");
		application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		application.add(panel);
		application.add(panel.status,BorderLayout.SOUTH);
	      	 JPanel buttons = new JPanel();
		buttons.setBackground(new Color(245,245,245));
	       	buttons.add(panel.save);
	       	application.add(buttons,BorderLayout.NORTH);
		application.setSize(496,480);
		application.setVisible(true);
	});
   }
}