public void mouseDragged(MouseEvent e) {
int x = e.getX(), y = e.getY(), dx = lastX - x, dy = lastY - y;
lastX = x;
lastY = y;
if (first == null) {
Line line = addLine(point1, new Point(x, y));
if (line != null) {
canvas.add(line.getP2());
first = line.getP2();
canvas.add(line);
}
} else {
first.move(-dx, -dy);
}
repaint();
}
private Line addLine(Point p1, Point p2) {
if (Math.abs(p1.getX() - p2.getX()) < 5 || Math.abs(p1.getY() - p2.getY()) < 5) {
return null;
}
Line line = null;
if (p1 != null && p2 != null) {
line = new Line(p1, p2);
canvas.add(line);
}
repaint();
return line;
}
private Point addPoint(int x, int y) {
Point p = new Point(x, y);
canvas.add(p);
repaint();
return p;
}