// ToolTip mechanism with custom Swing content.

// Note: Doesn't make a border by itself, just shows the raw component

// returned by makeContent.

sclass CustomToolTip is AutoCloseable {

  JComponent target;

  JWindow window;

  bool debug;

  MouseAdapter mouseAdapter;

  swappable JComponent makeContent() { null; }

  *(IF0<JComponent> *makeContent) {}

  // run in Swing thread

  void move {

    if (window == null) ret;

    if (debug) print("CustomToolTip move");

    var mouse = mouseLocationOnScreen();

    window.setLocation(mouse.x+10, mouse.y+10);

  }

  // run in Swing thread

  void showOrMove {

    if (window != null)

      ret with move();

    window = new JWindow;

    window.pack();

    thread "Make tool tip content" {

      var content = makeContent();

      if (content == null) ret;

      swing {

        setWindowContents(window, content);

        move();

        window.pack();

        if (isAlwaysOnTop(getWindow(target)))

          window.setAlwaysOnTop(true);

        showWindow(window);

      }

    }

  }

  void hide swing {

    disposeWindow(window);

    window = null;

  }

  void installOn(JComponent target) {

    this.target = target;

    if (target == null) ret;

    addMouseAdapter(target, mouseAdapter = new MouseAdapter {

      @Override public void mouseEntered aka mouseMoved(MouseEvent e) { showOrMove(); }

      @Override public void mouseExited aka mousePressed(MouseEvent e) { hide(); }

    });

    target.setToolTipText(null);

  }

  public void close swing {

    hide();

    removeMouseAdapter(target, mouseAdapter);

    target = null;

  }

}