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

[Semyon Sadetsky]

On 21.07.2016 18:33, Alexandr Scherbatiy wrote:
> On 7/21/2016 1:40 PM, Semyon Sadetsky wrote:
>> On 7/21/2016 1:24 PM, Sergey Bylokhov wrote:
>>
>>> On 21.07.16 13:18, Semyon Sadetsky wrote:
>>>> We do not support non-integer scale on Linux.
>>>
>>> If it is unsupported then why it is validated in the pango fonts and 
>>> not in X11GraphicsDevice? I am not sure how scale less than 1 
>>> prevent us from usage of 1.5 for example.
>> getNativeScale() returns int. int cannot be 1.5.
>
>   The fix JDK-8149115 "[hidpi] Linux: display-wise scaling factor 
> should probably be taken into account" allows to read the UI scale 
> factor from some system properties like J2D_UISCALE and 
> com.ubuntu.user-interface scale-factor. Could they have floating point 
> values?
On the native side they are floating point. But since we do not support 
floating point scale on linux they are rounded to integer.
>   How do they relate to the "gnome.Xft/DPI" property from the 
> PangoFonts? Is it possible that the  "gnome.Xft/DPI" value is 192 
> which corresponds to 2x HiDPI display and the J2D_UISCALE is set to 3?
gnome.Xft/DPI is set by desktop env. Usually it corresponds the system 
scale from gsettings db. But I cannot guarantee this for any WM/desktop 
combinations.
J2D_UISCALE variable is only for java, it may be set to any value and it 
is unrelated to the native scale.

--Semyon
>
>   Thanks,
>   Alexandr.
>
>>>
>>>> On 21.07.2016 13:13, Sergey Bylokhov wrote:
>>>>> Is it intended to skip scales less than 1?
>>>>>
>>>>> On 07.07.16 10:01, Alexandr Scherbatiy wrote:
>>>>>>
>>>>>> The fix looks good to me.
>>>>>>
>>>>>> Thanks,
>>>>>> Alexandr.
>>>>>>
>>>>>> On 7/6/2016 10:03 PM, Semyon Sadetsky wrote:
>>>>>>> On 7/6/2016 6:03 PM, Alexandr Scherbatiy wrote:
>>>>>>>
>>>>>>>> On 7/6/2016 4:13 PM, Semyon Sadetsky wrote:
>>>>>>>>> Hello,
>>>>>>>>>
>>>>>>>>> Please review fix for JDK9:
>>>>>>>>>
>>>>>>>>> bug: https://bugs.openjdk.java.net/browse/JDK-8058742
>>>>>>>>>
>>>>>>>>> webrev: http://cr.openjdk.java.net/~ssadetsky/8058742/webrev.00/
>>>>>>>>
>>>>>>>>    - PangoFonts class is placed in the shared space and it uses 
>>>>>>>> the
>>>>>>>> X11GraphicsDevice from the unix space. Could there be problems 
>>>>>>>> with
>>>>>>>> build compilation on platforms differ from Unix?
>>>>>>> no it doesn't cause compilations problems. PangoFonts is used on 
>>>>>>> Linux
>>>>>>> platform only.
>>>>>>>>   - It is better to rename the scale field to nativeScale just 
>>>>>>>> to not
>>>>>>>> mix it with other scale types
>>>>>>> ok.  webrev is updated:
>>>>>>> http://cr.openjdk.java.net/~ssadetsky/8058742/webrev.01/
>>>>>>>>   - Does the test
>>>>>>>> test/java/awt/font/FontScaling/FontScalingTest.java fails without
>>>>>>>> the proposed fix on Linux?
>>>>>>> Yes it fails before and passes after the fix.
>>>>>>>
>>>>>>> --Semyon
>>>>>>>>
>>>>>>>>   Thanks,
>>>>>>>>   Alexandr.
>>>>>>>>
>>>>>>>>>
>>>>>>>>> After adding hdpi support to JDK the GTK LnF fonts are scaled 
>>>>>>>>> twice
>>>>>>>>> using the JDK UI scale factor and the native scale factor derived
>>>>>>>>> from the screen dpi setting.  The fix removes the native scale 
>>>>>>>>> if it
>>>>>>>>> is already taken into account in the JDK UI scale.
>>>>>>>>>
>>>>>>>>> --Semyon
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>