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

[Semyon Sadetsky]

On 7/26/2016 1:50 PM, Sergey Bylokhov wrote:
> On 26.07.16 13:32, Semyon Sadetsky wrote:
>>> The question was why the native scale is taken into account, but debug
>>> scale not. In this case we will get a different results if the native
>>> scale=2 was read from J2D_UISCALE/scale-factor/GDK_SCALE/Xft.dpi or
>>> was set for debugging by the user.
>> I have answered you already the GTK font size will be unexpectedly small
>> if divided on debug scale.
>
> Debug scale should always be taken into account, if the text will be 
> small in this case then Xft.dpi should be ignored as I described 
> below. We should use only one property at a time.
I did not get, why in case of debug the GTK font size should be 
decreased by scale times while size of all other fonts and interface 
elements is being increased by scale times?
>
>>> I think the logic should be:
>>>  - 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.
>> Did you try to use scale from Xft.dpi? Its value is not a scale usually.
>
> What is the difference between text-scale-factor and Xft.dpi? Both of 
> them text related. But one of them is used as a general/default scale 
> of GC and another one affects the text only.
>
>> Anyway, the above is about a global scale, so it is unrelated to the
>> original issue which sounds like "Text size is twice bigger under GTK 
>> L&F".
>
> It is related since we should decide how and when to use Xft.dpi.
>