!7

module FontPlusMinus > DynPrintLog {
  transient volatile bool active, enlarging;
  double scale = 1.25;

  visualize {
    ret centerAndSouthWithMargins(super.visualize(), jhgrid(
      jbutton("Font +", r { doIt(true) }),
      jbutton("Font -", r { doIt(false) })));
  }
  
  start {
    dm_requireMouseLogger();
    ownResource(vmBus_onMessage('mouseDown, voidfunc(int x, int y, int button) {
      if (!active) ret;
      active = false;
      final JComponent c = optCast(JComponent, componentAtScreenLocation(x, y));
      print("Have component: " + c);
      if (c == null) ret;
      swing {
        Font font = scaleFont(c.getFont(), enlarging ? scale : 1/scale);
        c.setFont(font);
        print((enlarging ? "Enlarged" : "Shrunk") + " font to " + formatDouble(font.getSize2D(), 1));
      }
    }));
  }
  
  void doIt(bool enlarge) {
    enlarging = enlarge;
    print("Please click on a component to " + (enlarge ? "enlarge" : "shrink") + " its font");
    set active;
  }
}