How can I detect whether a Mac has a Retina display from Java?

Question

I've found a Swing image rendering bug which afflicts only Macs with Retina displays (TYPE_INT_ARGB_PRE BufferedImages fail to draw). I have an effective workaround (use TYPE_INT_ARGB images instead), but in order to apply it, I need to be able to detect whether the host machine is a Mac with a Retina display. Detecting whether the machine is a Mac is no problem, but how can I determine the display type?

Answer 1

Toolkit.getDefaultToolkit().getDesktopProperty("apple.awt.contentScaleFactor")

The above line should return 2.0 on retina displays. On more recent non-retina macs it returns 1.0 and on all other platforms you get back null. I can't find any official documentation, but I ran across it in this mailing list post while trying to solve a similar problem.

Answer 2

I found this solution which uses:

Graphics2D g = (Graphics2D) this.getGraphics ();
boolean retinaTest = g.getFontRenderContext ().getTransform ()
    .equals (AffineTransform.getScaleInstance (2.0, 2.0));