<Swing Dev> [9] Review request for 8058742: Text size is twice bigger under GTK L&F on Gnome with HiDPI enabled

[Semyon Sadetsky]

On 22.08.2016 18:52, Sergey Bylokhov wrote:
> On 22.08.16 16:43, Semyon Sadetsky wrote:
>>
>>
>> On 8/22/2016 2:14 PM, Sergey Bylokhov wrote:
>>> On 22.08.16 10:56, Semyon Sadetsky wrote:
>>>>> But I don't suggest to use it as a global scale, use it only if other
>>>>> scales were not set(default transform is 1).
>>>> That also means that it will go to the global UI scale on Linuxes 
>>>> which
>>>> are not gnome/unity based. And the only difference with the current
>>>> solution that on such Linux DEs Java apps will receive some 
>>>> uncontrolled
>>>> scale because testing of unsupported OSes is out of the scope. If this
>>>> topic bothers you I suggest to create a separate bug to investigate 
>>>> how
>>>> the native scale may be supported on different Linux flavors using the
>>>> Xft.dpi env var.  Without that we may get complains that the scale
>>>> becomes wrong on unsupported Linuxes and DEs even when hidpi is not 
>>>> used
>>>> in the native desktop at all.
>>>
>>> I do not get it how it can affect the non-dpi systems,
>> we are talking about the method that receive the desktop scale, right?
>
> Am talking about GraphicsConfiguration.getDefaultTransform() which 
> returns non-identity value only on HiDPI screens.
It simply returns a transform to the detected scale. The transform is 
wrong if the native scale is incorrectly detected.
>
> =======
>>> since only in jdk9 on HiDPI screens default scale can have some
>>> transform. The difference from the current solution is that the shared
>>> code will used the public/shared java2d api, instead of platform
>>> specific.
>>>
>>>>>>>>  - Take debug scale into account if it was set and skip all 
>>>>>>>> others.
>>>>>>>>  - Check J2D_UISCALE
>>>>>>>>  - Check scale-factor, text-scale-factor, text-scaling-factor.
>>>>>>>>  - Check Xft.dpi.
>>>>>>>>  - If non of them was set then scale=1 should be used.
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>