As the title states, I am trying to detect a mouse hover over an object that is not a JComponent. Right now I have a window with a green JPanel. When you left-click on this JPanel you create a point.
What I am trying to do is to have extra information displayed when I hover over these points. However, I have no idea how to even begin detecting if I am hovering my mouse over a point. I tried looking into the MouseListener interface but I could not find any examples of people using MouseListener with an object. I have only seen people use MouseListener with JComponents. I would preferably like to have this mouse hover detection code in my Point class if possible to keep my code clean.
JPanel Code
class Map extends JPanel implements MouseListener {
public static ArrayList<Point> points = new ArrayList<Point>(); //array for the points
public Map() {
this.setBackground(Color.green);
this.setPreferredSize(new Dimension(1280, 720));
this.addMouseListener(this);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D graphics = (Graphics2D) g;
drawPoints(graphics);
}
private void drawPoints(Graphics2D graphics) {
for(int i = 0; i < points.size(); i++) {
points.get(i).drawPoint(graphics);
}
}
@Override
public void mouseClicked(MouseEvent e) {
}
@Override
public void mousePressed(MouseEvent e) {
if(e.getButton() == MouseEvent.BUTTON1) { //Left Click
points.add(new Point(e.getX(), e.getY()));
repaint();
}
else if(e.getButton() == MouseEvent.BUTTON3) { //right click
for(int i = points.size() - 1; i >= 0; i--) { //loop backwards so if points overlap remove the one on top first
Point current = points.get(i);
if( Math.abs( e.getX() - current.x ) < current.size/2 && Math.abs( e.getY() - current.y ) < current.size/2 ) {
points.remove(i);
repaint();
break;
}
}
}
}
@Override
public void mouseReleased(MouseEvent e) {
}
@Override
public void mouseEntered(MouseEvent e) {
}
@Override
public void mouseExited(MouseEvent e) {
}
}
Point Code
public class Point {
public int x, y;
public int size = 10;
public Point(int x, int y) {
this.x = x;
this.y = y;
}
public Point() {
this.x = 0;
this.y = 0;
}
public void drawPoint(Graphics2D graphics) {
graphics.setPaint(Color.black);
graphics.setStroke(new BasicStroke(5));
graphics.drawOval(x - (size/2), y - (size/2), size, size);
graphics.setPaint(Color.red);
graphics.fillOval(x - (size/2), y - (size/2), size, size);
}
public void drawInfo(Graphics2D graphics) {
graphics.drawString("test", x, y);
}
}
I had the same issue with a Packet-Tracer-Like program, where I drew rects.
If they are just points, I would check if the mouse cords are the same as the point cords when the mouse is moved.
@Override
public void mouseMoved(MouseEvent e) {
entered = false;
if(point.x == e.getX() && point.y == e.getY()){
entered = true;
}
}
If although, like in my case, the drawn object has a width and a height, it gets messier.
@Override
public void mouseMoved(MouseEvent e) {
entered = false;
if((e.getX() <= point.x+width) && (e.getX() >= point.x)){
if((e.getY() <= point.y+height) && (e.getY() >= point.y)){
entered = true;
}
}
}