praktikum-holons/src/ui/view/MyCanvas.java

package ui.view;

import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.LinkedList;

import javax.swing.ImageIcon;
import javax.swing.JPanel;

import classes.CpsObject;
import classes.HolonObject;

class MyCanvas extends JPanel implements MouseListener, MouseMotionListener 
{
	private Image img = null;      // Contains the image to draw on MyCanvas
	private int x = 0;
	private int y = 0;
	LinkedList<CpsObject> choords = new LinkedList<>();
	boolean dragging = false;
	CpsObject tempCPS = null;
	
    public MyCanvas()
    {
    	
    	img = new ImageIcon(this.getClass().getResource("/Images/Dummy_House.png")).getImage().getScaledInstance(30, 30, java.awt.Image.SCALE_SMOOTH);
    	
        this.addMouseListener(this);
        this.addMouseMotionListener(this);
    }

    public void paintComponent(Graphics g)
    {
        // Draws the image to the canvas
    	super.paintComponent(g);
    	for (CpsObject cps : choords){
    		g.drawImage(img, cps.getPos().x, cps.getPos().y, null);
    	}
    }

	@Override
	public void mouseClicked(MouseEvent e) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void mouseEntered(MouseEvent e) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void mouseExited(MouseEvent e) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void mousePressed(MouseEvent e) {
		// TODO Auto-generated method stub
		x = e.getX();
        y = e.getY();
        
		for (CpsObject cps : choords){
    		int cx = cps.getPos().x;
    		int cy = cps.getPos().y;
    		if (x-img.getWidth(null)<=cx && y-img.getHeight(null) <=cy&& x+img.getWidth(null)>=cx && y+img.getHeight(null)>= cy) {
				tempCPS = cps;
				dragging = true;
			}
    	}
		
	}

	@Override
	public void mouseReleased(MouseEvent e) {        
        if(dragging){
        	x = e.getX();
            y = e.getY();
        	dragging = false;
        	tempCPS.setPos(e.getX()-15, e.getY()-15);
        	tempCPS = null;
        	repaint();
        }
	}

	@Override
	public void mouseDragged(MouseEvent e) {
		// TODO Auto-generated method stub
		if(dragging){
			tempCPS.setPos(e.getX()-15, e.getY()-15);
			repaint();
			System.out.println("drag: "+e.getX()+" "+e.getY());
		}
	}

	@Override
	public void mouseMoved(MouseEvent e) {
		// TODO Auto-generated method stub
		
	}
}