[PyQt] PYQt defaults to fonts looking bold on macOS but C++ Qt does not

[Phil Thompson]

On 26 Jul 2016, at 5:45 pm, Barry Scott <barry at barrys-emacs.org> wrote:
> 
> On Tuesday, 26 July 2016 17:43:44 BST Phil Thompson wrote:
>> On 26 Jul 2016, at 5:20 pm, Barry Scott <barry at barrys-emacs.org> wrote:
>>> On Tuesday, 26 July 2016 13:10:36 BST Barry Scott wrote:
>>>>> On 6 Jul 2016, at 11:50, Phil Thompson <phil at riverbankcomputing.com>
>>>>> wrote:
>>>>> 
>>>>> On 6 Jul 2016, at 11:26 am, Barry Scott <barry at barrys-emacs.org> wrote:
>>>>>> Compare the windows snapshots taken for a PyQt5 app and a C++ Qt5 app
>>>>>> that use a QLabel control.
>>>>>> 
>>>>>> http://www.barrys-emacs.org/export/Qt5.png
>>>>>> 
>>>>>> http://www.barrys-emacs.org/export/PyQt5.png
>>>>>> 
>>>>>> You can see that the text in PyQt5 looks like it is bold compared to
>>>>>> the
>>>>>> Qt5 version.
>>>>>> 
>>>>>> On Fedora I see that same text for Qt5 and PyQT5.
>>>>>> 
>>>>>> Please fix this problem in PyQt5.
>>>>>> 
>>>>>> The source code I used is in:
>>>>>> 
>>>>>> http://barrys-emacs.org/export/font-example.tar.gz
>>>>>> 
>>>>>> Note: This bug affects all text, list, tables, line edit everything.
>>>>> 
>>>>> ...on your system. It works fine for me. PyQt does nothing with fonts.
>>>> 
>>>> Phil,
>>>> 
>>>> I know what macOS preference changes this behaviour.
>>>> 
>>>> In "System Preferences…”, “General” there is a property,
>>>> “Use LCD font smoothing when available” (bottom of the dialog).
>>>> If this is ticked PyQt5 text is bold in appearance.
>>>> When it is not ticked it looks normal.
>>>> 
>>>> But this setting does not change the output of a Qt5 C++ app.
>>>> 
>>>> Can you reproduce this problem now?
>>> 
>>> Now I can show command line PyQt5 program shows bold text but
>>> command line C++ app does not.
>>> 
>>> Have I done enough to show that this is a problem with PyQt5 responding
>>> in an undesirable way to LCD smoothing option? And that its not a quirk of
>>> my Mac.
>>> 
>>> I am assuming that you can reproduce the problem I'm reporting with the
>>> LCD smoothing option enabled.
>> 
>> No I can't. My Mac defaults to that option being set anyway.
> 
> Do you see any difference in appreance if you turn that option off?

None.

Phil