TileListener.java

// This class responds to mouse events on a tile.

import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;

public class TileListener extends MouseInputAdapter {
    private TileList tiles;
    private TilePanel parent;
    private Point firstSpot;
    private Point lastSpot;
    private Tile current;

    public TileListener(TileList tiles, TilePanel parent) {
        this.tiles = tiles;
        this.parent = parent;
    }
                        
    public void mouseClicked(MouseEvent e) {
        parent.repaint();
    }
                        
    public void mousePressed(MouseEvent e) {
        firstSpot = lastSpot = e.getPoint();
        current = tiles.moveToBack(e.getX(), e.getY());
    }
                        
    public void mouseReleased(MouseEvent e) {
        int deltaX = lastSpot.x - firstSpot.x;
        int deltaY = lastSpot.y - firstSpot.y;
        Point newSpot = e.getPoint();
        if (current == null) {
            if (deltaX != 0 && deltaY != 0) {
                Tile nextTile = new Tile(firstSpot.x, firstSpot.y, deltaX, 
                                         deltaY, parent.getColor());
                tiles.insertBack(nextTile);
            }
        } else {
            current.translate(newSpot.x - firstSpot.x,
                              newSpot.y - firstSpot.y);
        }
        parent.repaint();
    }
                        
    private void drawBorder(Graphics g) {
        int deltaX = lastSpot.x - firstSpot.x;
        int deltaY = lastSpot.y - firstSpot.y;
        if (current != null) {
            g.drawRect(current.getX() + deltaX, current.getY() + deltaY, 
                       current.getWidth(), current.getHeight());
        } else {
            int cornerX, cornerY;
            if (deltaX < 0) {
                cornerX = firstSpot.x + deltaX;
            } else {
                cornerX = firstSpot.x;
            }
            if (deltaY < 0) {
                cornerY = firstSpot.y + deltaY;
            } else {
                cornerY = firstSpot.y;
            }
            g.drawRect(cornerX, cornerY, Math.abs(deltaX), Math.abs(deltaY));
        }
    }
        
    public void mouseDragged(MouseEvent e) {
        Graphics g = parent.getGraphics();
        g.setXORMode(parent.getBackground());
        drawBorder(g);
        lastSpot = e.getPoint();
        drawBorder(g);
        g.dispose();
    }
}