java - how to get mouselistener notice clicks inside an imaginary triangle?

Question

I have three points on a grid. I want my mouselistener to give me a heads up, when a point on the area within this imaginary triangle of three points has been clicked. how to do that??I dont wanna use a shape class or anything, since it is an imaginary triangle. any ideas ? thx!

Answer 1

以下代码应该完成您正在尝试做的事情。

private static final Polygon POLY = new Polygon();

static {
    POLY.addPoint(x1, y1); // first point
    POLY.addPoint(x2, y2); // second point
    POLY.addPoint(x3, y3); // third point
}

@Override
public void mouseClicked(final MouseEvent e) {
    if (POLY.contains(e.getX(), e.getY())) {
        // notify user
    }
}

请注意，即使您拥有的三角形是“虚构的”，您也需要定义某种多边形。这样 Java 就知道形状内可能有什么样的点。