[vtk-developers] Delayed mouse interaction due to event-loop bug in Qt5
david.gobbi at gmail.com
Mon Apr 10 16:07:40 EDT 2017
My strong preference is only call Render() within Qt's paintEvent(),
and to disable Render() everywhere else. Then, when I want VTK
to render, I call update() on my QWidget to let Qt know that it has
This keeps things nicely synchronized between VTK and Qt, which
is especially important for things like resizing the window.
Another thing that I do differently from QVTKWidget is that I install
a dummy QPaintEngine so that Qt never executes any drawing
commands within the widget, but that's a separate issue from the
event loop bug.
On Mon, Apr 10, 2017 at 1:13 PM, Elvis Stansvik <
elvis.stansvik at orexplore.com> wrote:
> 2017-04-10 21:10 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
> > 2017-04-10 20:07 GMT+02:00 Pat Marion <james.patrick.marion at gmail.com>:
> >> Hi Elvis,
> >> In prior emails you mentioned that you use a QVTKWidget subclass (or
> >> QVTKWidget2?) that contains a workaround for this event issue. Is this
> >> class something that you can share? Do you recommend using this
> >> or is the patched qt5.5 preferable?
> > Sure, I'm attaching VTKWidget.h/cpp, which contains the QVTKWidget
> > subclass I'm currently using.
> > If I remember correctly, it was David Gobbi who led me to this
> > workaround, so he should have the credit.
> My bad, it was Clint and David together who helped me out. This was
> the original thread:
> > It's of course preferable to use a fixed Qt (5.6 or higher, or patched
> > 5.5.1), but I'll use this workaround until the patched package is in
> > the xenial-updates repo (the upload to xenial-proposed seems to take
> > some time, I guess the approvers are busy).
> > Elvis
> >> Pat
> >> On Mon, Mar 20, 2017 at 4:55 PM, Elvis Stansvik
> >> <elvis.stansvik at orexplore.com> wrote:
> >>> > On Mon, Jul 13, 2015 at 16:51:34 -0400, Ben Boeckel wrote:
> >>> >> On Mon, Jul 13, 2015 at 15:00:56 -0400, Ben Boeckel wrote:
> >>> >>> https://codereview.qt-project.org/#/c/115531/
> >>> >>
> >>> >> Applying this patch (with one conflicting hunk) to 5.5.0 fixes the
> >>> >> problem for me. I'll poke the review to see if some movement can't
> >>> >> made.
> >>> >
> >>> > It looks like the patch has been merged for 5.6.0 (due at the end of
> >>> > October).
> >>> Just in case anyone is in the same boat like me, hitting this bug on
> >>> Ubuntu 16.04 LTS (which has Qt 5.5.1), just FYI I'm trying to get an
> >>> SRU (Stable Release Update) going with this fix:
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