Word completion does not work in KDE application (okular)

Word completion needs at-spi2 to get information about the environment it is typing into. Thus, the following packages needs to be installed:

libatk-adaptor # for mozilla applications (XUL based)
qt-at-spi
libreoffice-gtk
libreoffice-gtk3
libatk-wrapper-java # for java applications

However, I just tried okular on my system, and prediction only works partly in okular. I have to continuously change context (ior example by clicking on the desktop) to re-initiate prediction. Does it behave the same way on your system after installing the above packages?

OK I installed all of these packages (except libreoffice-gtk3 because that was not found in the repo). Does not seem to have any effect on the problem though... not even clicking on the desktop and back seems to help.

Installing qt-at-spi is the right thing to do, but it will go only so far. The best you can hope for is getting auto-show to work. Word suggestions and auto-capitalization will still do (almost) nothing.

I believe the problem is with qt-at-spi or QAccessible. Onboard expects to be notified when text is edited, and word suggestions are updated in response to those notifications. For that we're listening to "object:text-changed" events. While this work great with gtk2/3 widgets, no events are ever received from Qt widgets.

I think a lot of AT-SPI functionality, including "object:text-changed", is simply not yet implemented on the Qt side, even though the relevant interfaces are listed as supported. I think the best we can do is file upstream bug reports.

Just for the record, this also affects Chrome/Chromium browser. The way to workaround this limitation is to use the GNOME Swipe plugin, after you are in Qt/Chrome's text input field. Of course, you lose onboard's text completion feature.