no OSK in Plasma Mobile

[Martin Flöser]

Am 2018-03-19 21:25, schrieb Heather Ellsworth:
> On 03/17/2018 02:41 PM, Martin Flöser wrote:
>> 
>> 
>> Am 17. März 2018 02:01:24 MEZ schrieb Heather Ellsworth 
>> <heather.ellsworth at puri.sm>:
>>> On 03/15/2018 09:10 PM, Bhushan Shah wrote:
>>>> Hello Heather,
>>>> 
>>>> On Thu, Mar 15, 2018 at 06:57:27PM -0600, Heather Ellsworth wrote:
>>>>> I've been running Plasma Mobile on my iMX6 dev board (precursor to
>>> the
>>>>> dev kit for the Librem 5) and I've notices there's no onscreen
>>> keyboard.
>>>>> Is it there and I'm just not initializing it? Or what is the story
>>> with
>>>>> the OSK in Plasma Mobile?
>>>> 
>>>> For OSK, you just need to install qtvirtualkeyboard-plugin package,
>>> it
>>>> should give you working on-screen-keyboard for the Qt applications.
>>> It
>>>> is however possible that QtVirtualKeyboard is disabled by default if
>>> you
>>>> have keyboard attached. In that case you can enable it by clicking 
>>>> on
>>>> virtualkeyboard icon in top drawer.
>>>> 
>>>> You can also "export QT_VIRTUALKEYBOARD_STYLE=Plasma" for better
>>> theming
>>>> integration with Plasma Mobile.
>>> 
>>> After installing qtvirtualkeyboard-plugin and exporting
>>> QT_VIRTUALKEYBOARD_STYLE, we still do not see a keyboard icon in the
>>> top
>>> left of the Plasma Mobile desktop.
>>> 
>>> Similarly, we do not see the icon after manually enabling the 
>>> keyboard
>>> with:
>>> 
>>> $ qdbus org.kde.KWin /VirtualKeyboard
>>> org.kde.kwin.VirtualKeyboard.enable
>>> 
>>> However, after enabling the keyboard with the above qdbus command, we
>>> see the keyboard pop up when a text field is clicked (like the search
>>> bar, kwrite, konsole) but then the keyboard immediately goes away.
>>> 
>>> Also in the lock screen, I see the virtual keyboard icon in the 
>>> bottom
>>> left. When I click it, the virtual keyboard appears and does not
>>> disappear. Then I can type in the password (using Ctrl+Super to guide
>>> my
>>> mouse) to log back in.
>>> 
>>> So the virtual keyboard works, but when in the desktop session the
>>> keyboard goes away right after it appears. Any troubleshooting advice
>>> you have would be helpful.
>>> 
>> 
>> It might sound stupid, but just unplug the physical keyboard. Then it 
>> should work best. If the keyboard still hides, run the apps with 
>> WAYLAND_DEBUG=1 then we can see what's going on and why it hides. It 
>> should only hide if the application requests it and that's something 
>> we can see in the debug output.
>> 
> 
> Thank you for the suggestion. It turns out that the issue was actually
> setting the QT_IM_MODULE:
> 
> $ export QT_IM_MODULE=qtvirtualkeyboard
> 
> With this variable set, I see the keyboard come up and then disappear
> when a text field is clicked. I was testing with this variable on
> Friday. However with this variable unset, the keyboard seems to _stay
> around_ and be usable when a text field is clicked. So the trick is to
> not set this :)

Yes, that makes sense. If the env variable is set, Qt creates a window 
in the process. If the env variable is not set the wayland protocol is 
used and KWin can provide the virtual keyboard.

I think I also understand why it closed directly: when the window opens 
KWin passes it keyboard focus. Thus the text field which triggered the 
keyboard loses keyboard focus and closes the keyboard again.

Cheers
Martin