[PyQt] Issue with touch panel and QWebEngineView since upgrading PyQt5.8 -> 5.10

[Phil Thompson]

On 14 Aug 2018, at 11:31 pm, Brian Knudson <brian.knudson at cxcsimulations.com> wrote:
> 
> 
> 
> On Tue, Aug 14, 2018 at 2:12 PM, Phil Thompson <phil at riverbankcomputing.com> wrote:
> On 14 Aug 2018, at 7:09 pm, Brian Knudson <brian.knudson at cxcsimulations.com> wrote:
> > 
> > Ooops.  I somehow sent that last message while trying to type "PyQt".  Not quite sure how that even happened.  Let's try that again.
> > 
> > 
> > 
> > Hello all,
> > 
> > I have an application that uses QWebEngineView to render its main UI. The html page rendered by QWebEngineView relies on a lot of Javascript and CSS, and has been working well for a year or so while using PyQt5.8.1.  I recently moved to PyQt 5.10.1 and am now having problems when using a consumer grade touch panel (Planar or Viewsonic or the like) to control the application.
> > 
> > In the html UI, there is a '+' and a '-' on which the user can tap to change a number.  With PyQt5.8.1, the user can tap as fast as they'd like.  With 5.10.1, if they tap too fast (not impossibly fast, but just quick tapping), they loose the ability to tap. Occasionally, the number will continue to increment after the ability to tap is lost.
> > 
> > I can get the ability to tap back if I click the '+' or '-' with the mouse.  I suspect doing so is giving the "mouse up" that seems to have gotten lost with fast tapping.
> > 
> > Because I don't have both versions of Qt and PyQt installed on the same machine, to test this, I compiled my app with PyInstaller 3.2.1 on each machine, then copied the executables around to several other machines (running both Windows 7 and 10). On every machine, the one compiled with PyQt 5.10.1 showed the "lost ability to tap" issue, while the one compiled with PyQt 5.8.1 worked as expected. 
> > 
> > I should note that this is commercial PyQt, so it's compiled from source.  I used Visual Studio 2015 on Windows 7 to compile PyQt 5.8.1, and Visual Studio 2017 on Windows 10 to compile PyQt 5.10.1.
> > 
> > This issue is on Windows.  This app isn't cross platform, so I haven't tested on other OSs.
> > 
> > I wonder if anyone has seen this or has a suggestion as to where to start looking for a solution.
> 
> You haven't mentioned the version(s) of Qt involved.
> 
> working as expected:
> PyQt 5.8.1 / Qt 5.8.0 / SIP 4.19.1 on Windows 7. PyQt compiled with Visual Studio 2015
> 
> loses tap ability after tapping too quickly:
> PyQt 5.10.1 / Qt 5.10.1 / SIP 4.19.8 on Windows 10. PyQt compiled with Visual Studuio 2017

So the most likely cause is the different Qt version.

Phil