How to know, whether HiDPI is supported?

[Robert Krüger]

I tested this with OpenJDK 8 on my MBP and in all retina modes the
scale factor is exactly 2.0 so your initial suggestion will work
there.

On Sun, Dec 1, 2013 at 7:45 PM, Eirik Bakke <ebakke at mit.edu> wrote:
> Ah, I see.
>
>> I would probably just treat anything thats > 1.0 as HiDPI.
>
> Good call, at least for the purposes of selecting icons/bitmap graphics.
> (In my case I have an app that generates some graphics which it tries to
> align to pixel boundaries. So in retina mode it aligns to "half-pixels"
> instead of pixels. I'll have to see if it's worth trying to align to
> pixels on more general scale factors, or whether I should just not try to
> do any alignment at all on the odd HiDPI modes...)
>
>
> -- Eirik
>
> On 12/1/13, 8:54 AM, "Robert Krüger" <krueger at lesspain.de> wrote:
>
>>Yes, that's what I mean. On my Macbook Pro I can choose out of five
>>settings if I choose "scaled" rather than "best for retina display"
>>and I, for example, use the "more space" setting to have a maximum
>>resolution in terms of pixels and I doubt this is 2.0, so your check
>>would probably fail although it would make sense to use the
>>higher-resolution graphics on my Macbook with that setting. I would
>>probably just treat anything thats > 1.0 as HiDPI.
>>
>>Robert
>>
>>On Sat, Nov 30, 2013 at 8:09 PM, Eirik Bakke <ebakke at mit.edu> wrote:
>>> Quite possible--do you mean if the scale factor is not exactly 1.0 or
>>>2.0?
>>> In that case, yes, you should need to get the actual scale factor from
>>>the
>>> AffineTransform. But I'm unsure how often scale factors other than 1.0
>>>or
>>> 2.0 are encountered (surely there can't be more than two sets of icons
>>>for
>>> every app... unless everyone provides bitmap for the low resolution and
>>> SVG for the higher ones).
>>>
>>> I should add that I have only tested the Retina mode using the "Enable
>>> HiDPI display modes" option from the Graphics Tools for XCode [1]. And
>>> that one only lets me try 2x scale factors.
>>>
>>> -- Eirik
>>>
>>> [1]
>>>
>>>http://stackoverflow.com/questions/12124576/how-to-simulate-a-retina-disp
>>>la
>>> y-hidpi-mode-in-mac-os-x-10-8-mountain-lion-on
>>>
>>> -- Eirik
>>>
>>> On 11/30/13, 7:04 AM, "Robert Krüger" <krueger at lesspain.de> wrote:
>>>
>>>>Don't the scale factors depend on the individual user's retina
>>>>settings? Of course, your approach will also work if that is the case,
>>>>it will just require some more checks.
>>>>
>>>>On Fri, Nov 29, 2013 at 11:26 PM, Eirik Bakke <ebakke at mit.edu> wrote:
>>>>> This did the trick for me:
>>>>>
>>>>> // g is the Graphics2D object fed to the paint() or paintComponent()
>>>>> method of your Swing component.
>>>>>
>>>>>g.getFontRenderContext().getTransform().equals(AffineTransform.getScale
>>>>>In
>>>>>st
>>>>> ance(2.0, 2.0))
>>>>>
>>>>>
>>>>> It uses no private APIs, and has the advantage that it lets you make
>>>>>the
>>>>> retina-or-not decision on a component-to-component basis (or in
>>>>>practice,
>>>>> on a window-to-window basis, as all components in the same window have
>>>>>the
>>>>> same FontRenderContext). This means if your user has one window on
>>>>>their
>>>>> retina laptop screen and another on their non-retina external monitor,
>>>>> both will render appropriately for their respective devices (I've
>>>>> confirmed this to work on Java 1.7.0_45 for MacOS X 10.8.5).
>>>>>
>>>>> -- Eirik
>>>>>
>>>>> On 11/29/13, 7:36 AM, "Hendrik Schreiber" <hs at tagtraum.com> wrote:
>>>>>
>>>>>>Hey..
>>>>>>
>>>>>>with some of the Retina work appearing in 1.7.0_60, what is the
>>>>>>recommended way for the developer to find out, whether images are/can
>>>>>>be
>>>>>>scaled, i.e., whether we are dealing with a HiDPI display.
>>>>>>
>>>>>>In the past, on the Apple JVM, we used:
>>>>>>
>>>>>>       final Float scaleFactor = (Float)
>>>>>>Toolkit.getDefaultToolkit().getDesktopProperty("apple.awt.contentScale
>>>>>>Fa
>>>>>>ct
>>>>>>or");
>>>>>>
>>>>>>Is there an equivalent?
>>>>>>
>>>>>>I very much appreciate that you are pushing some of the work down to
>>>>>>1.7.0_60. Can you say what parts should now/soon work and how to use
>>>>>>them?
>>>>>>
>>>>>>Thank you,
>>>>>>
>>>>>>-hendrik
>>>>>
>>>
>