Need help to code VirtualKeyboard using QQuickWidget on Widget-based app

IMAN4K

yes, if you want to use it with QtWidgets.
An InputPanel QML element can also show a virtualkeyboard using EGLFS.

So far so good!
I have managed to cross compile Qt v5.12.3 on Raspbian stretch@Raspberry Pi3B+ without EGLFS and with EGL on X11 and all Virtual Keyboard plugins are deployed correctly based on Deployment Guide BUT VK won't run and if we set QT_DEBUG_PLUGINS to true only $$[QT_INSTALL_PLUGINS]/platforminputcontexts/libqtvirtualkeyboardplugin.so is loaded(full log).
So do you have any clue about what's wrong?
Regards.

Hope to get to a solution on this topic for anyone else

raven-worx

@iman4k
did you set QT_IM_MODULE=qtvirtualkeyboard env variable?
How do you start your application? With what parameters and or platform plugin?
Do you see your application in your X11 display?

IMAN4K

@raven-worx said in Need help to code VirtualKeyboard using QQuickWidget on Widget-based app:

@iman4k
did you set QT_IM_MODULE=qtvirtualkeyboard env variable?
How do you start your application? With what parameters and or platform plugin?
Do you see your application in your X11 display?

Yes, before QApplication creation in the main function:
- qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
./<my-app> -platform xcb
Not sure about seeing application on X11 display but yes my app running normally(windowed) just like the desktop-x86 one.

IMAN4K

@raven-worx

Also for more debugging when I set qputenv("QT_LOGGING_RULES", QByteArray("qt.virtualkeyboard=true"));, the VK's logs
for raspberry is like this :

qt.virtualkeyboard: Loading extension "japanese"
qt.virtualkeyboard: Loading extension "traditional_chinese"
qt.virtualkeyboard: Loading extension "pinyin"
qt.virtualkeyboard: Loading extension "thai"
qt.virtualkeyboard: Loading extension "hangul"
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QLineEdit(0x7ec96790)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImInputItemClipRectangle)
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QLineEdit(0x7ec96790)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::showInputPanel()
qt.virtualkeyboard: PlatformInputContext::commit()
qt.virtualkeyboard: PlatformInputContext::commit()
qt.virtualkeyboard: PlatformInputContext::hideInputPanel()
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QObject(0x0)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)

So showInputPanel() is called but actually is not shown! and couldn't find the reason.
And these logs are for running on Desktop:

qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImInputItemClipRectangle)
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QLineEdit(0x7ffe8952fa60)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: InputContext::setFocus(): true
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QLineEdit(0x7ffe8952fa60)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: InputContext::setLocale(): "en_GB"
qt.virtualkeyboard: PlatformInputContext::setLocale(): QLocale(English, Latin, UnitedKingdom)
qt.virtualkeyboard: InputEngine::setInputMethod(): QtVirtualKeyboard::PlainInputMethod(0x1110b60)
qt.virtualkeyboard: InputEngine::setInputMode(): 0
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::showInputPanel()
qt.virtualkeyboard: DesktopInputPanel::repositionView(): QRect(55,24 1865x1056)
qt.virtualkeyboard: PlatformInputContext::hideInputPanel()
qt.virtualkeyboard: PlatformInputContext::commit()
qt.virtualkeyboard: PlatformInputContext::commit()
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QObject(0x0)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: InputContext::setFocus(): false
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImInputItemClipRectangle)
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QLineEdit(0x7ffe8952fa60)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: InputContext::setFocus(): true
qt.virtualkeyboard: PlatformInputContext::setFocusObject(): QLineEdit(0x7ffe8952fa60)
qt.virtualkeyboard: PlatformInputContext::update(): QFlags<Qt::InputMethodQuery>(ImQueryAll)
qt.virtualkeyboard: PlatformInputContext::commit()
qt.virtualkeyboard: PlatformInputContext::commit()
qt.virtualkeyboard: InputContext::setFocus(): false

IMAN4K

@raven-worx
Any idea or hint would be appreciated.
Regards.

raven-worx

@iman4k
seems you somehow loosing input-focus in your non-working case?
are you running the exact same application on desktop and on your pi?
any other output in the console?

IMAN4K

@raven-worx said in Need help to code VirtualKeyboard using QQuickWidget on Widget-based app:

@iman4k
seems you somehow loosing input-focus in your non-working case?
are you running the exact same application on desktop and on your pi?
any other output in the console?

No, input focus is just fine and the lineedit will get focus as expected(the last 3 line of logs in the non-working case is because I clicked on the outside of widget area at the end)
Yes, the exact same application is running on Desktop and also on Embedded(raspberry) kit
Nothing more than those logs I mentioned!

This is somehow strange, it took 1 week struggling on this :(

raven-worx

@iman4k
then i guess either something in your application or your used Qt installation.
Just to amke sure: I assume - becasue of the log output - the qtvirtualkeyboard plugin is available on your Pi?
are you also using QML in your application or is it a pure QtWidget application?

IMAN4K

@raven-worx said in Need help to code VirtualKeyboard using QQuickWidget on Widget-based app:

@iman4k
then i guess either something in your application or your used Qt installation.
Just to amke sure: I assume - becasue of the log output - the qtvirtualkeyboard plugin is available on your Pi?
are you also using QML in your application or is it a pure QtWidget application?

Yes, these are deployed on the pi side in install step of cross-compile:
- /usr/local/qt5pi/plugins/platforminputcontexts/libqtvirtualkeyboardplugin.so
- /usr/local/qt5pi/qml/QtQuick/VirtualKeyboard/libqtquickvirtualkeyboardplugin.so
- /usr/local/qt5pi/qml/QtQuick/Layouts/libqquicklayoutsplugin.so
- /usr/local/qt5pi/lib/libQt5VirtualKeyboard.so
So I assume the plugin is available.
It's a simple QtWidgets application:

#include <QtWidgets>

int main(int argc, char *argv[]) {
    qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
    qputenv("QT_LOGGING_RULES", QByteArray("qt.virtualkeyboard=true"));
    QApplication a(argc, argv);
    QMainWindow w;
    QLineEdit edit(&w);
    edit.move(50, 50);
    w.show();
    return a.exec();
}

Is this problem related to Openbox WindowManager?
I'm also curious to know why DesktopInputPanel::repositionView(): QRect(55,24 1865x1056) is not called after PlatformInputContext::showInputPanel() in raspberry?

MarKus12

@IMAN4K

Hi,
similar problem exists here.
Did you eventually found a solution for the problem, that you remember?

I run into it on a buildroot issue without desktop manager.
Currently I suspect a problem with the interpreting system input events by QApplication.
Seems that QGuiApplication does something different.