QtVirtualKeyboard is shown on desktop but not on Raspberry pi 3 ?

IMAN4K

Hi everyone.
I just want to use the qtvirtualkeyboard on my widget-based application in raspberry pi 3b+ it will show nicely on desktop(ubuntu16.04) but not on my embedded Linux ?!
Because qtvirtualkeyboard is a dedicated top-level window, I'm using xcb platform plugin on the embedded side.
So what do you suggest?

Configuration

OS: Raspbian stretch
Qt: 5.8.0 cross-compiled
Plugin: xcb (without eglfs)

Qt configure summary:

Building on: linux-g++ (x86_64, CPU features: mmx sse sse2)
Building for: devices/linux-rpi3-g++ (arm, CPU features: neon)
Configuration: cross_compile compile_examples enable_new_dtags largefile neon precompile_header shared rpath accessibility release c++11 concurrent dbus mremap reduce_exports stl
Build options:
  Mode ................................... release
  Building shared libraries .............. yes
  Using C++ standard ..................... C++11
  Using gold linker ...................... no
  Using new DTAGS ........................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. yes
  Build parts ............................ libs
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... yes
  Qt D-Bus directly linked to libdbus .... no
  Qt Gui ................................. yes
  Qt Network ............................. yes
  Qt Sql ................................. yes
  Qt Testlib ............................. yes
  Qt Widgets ............................. yes
  Qt Xml ................................. yes
Support enabled for:
  Accessibility .......................... yes
  Using pkg-config ....................... yes
  QML debugging .......................... yes
  udev ................................... yes
  Using system zlib ...................... yes
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ yes
  GLib ................................... no
  iconv .................................. yes
  ICU .................................... no
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  Using system PCRE ...................... yes
Qt Network:
  getaddrinfo() .......................... yes
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ no
  SCTP ................................... no
  Use system proxies ..................... yes
Qt Sql:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... no
  PostgreSQL ............................. no
  SQLite2 ................................ yes
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no
Qt Gui:
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ yes
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... yes
    PNG .................................. yes
      Using system libpng ................ yes
  OpenGL:
    EGL .................................. yes
    Desktop OpenGL ....................... yes
    OpenGL ES 2.0 ........................ no
    OpenGL ES 3.0 ........................ no
    OpenGL ES 3.1 ........................ no
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... yes
  mtdev .................................. yes
  tslib .................................. yes
  xkbcommon-evdev ........................ yes
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. no
  LinuxFB ................................ yes
  Mir client ............................. no
  X11:
    Using system-provided XCB libraries .. yes
    EGL on X11 ........................... yes
    Xinput2 .............................. yes
    XCB XKB .............................. yes
    XLib ................................. yes
    XCB render ........................... yes
    XCB GLX .............................. yes
    XCB Xlib ............................. yes
    Using system-provided xkbcommon ...... no
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... yes
Qt QML:
  QML interpreter ........................ yes
  QML network support .................... yes
Qt Quick:
  Direct3D 12 ............................ no
  AnimatedImage item ..................... yes
  Canvas item ............................ yes
  Support for Quick Designer ............. yes
  Flipable item .......................... yes
  GridView item .......................... yes
  ListView item .......................... yes
  Path support ........................... yes
  PathView item .......................... yes
  Positioner items ....................... yes
  ShaderEffect item ...................... yes
  Sprite item ............................ yes
Qt Multimedia:
  ALSA ................................... yes
  GStreamer 1.0 .......................... no
  GStreamer 0.10 ......................... no
  Video for Linux ........................ yes
  OpenAL ................................. no
  PulseAudio ............................. no
  Resource Policy (libresourceqt5) ....... no
  DirectShow ............................. no
  Windows Media Foundation ............... no

Note: I also set `QT_DEBUG_PLUGINS` to 1 and confirm that `libqtvirtualkeyboardplugin.so` successfully loaded.

IMAN4K

Nobody to help me?
It's critical:(

J.Hilk

@iman4k
looking at your configure summary I would say you did not cross compile the qtvirtualkeyboard module

IMAN4K

Hi @j-hilk
Why is that?
I cross compile whole Qt with the device option.

If you say for EGLFS, I reconfigured Qt to just enable EGLFS and OpenGL ES 2.0 alongside the xcb plugin:

Building on: linux-g++ (x86_64, CPU features: mmx sse sse2)
Building for: devices/linux-rpi3-g++ (arm, CPU features: neon)
Configuration: cross_compile compile_examples enable_new_dtags largefile neon precompile_header shared rpath accessibility release c++11 concurrent dbus mremap reduce_exports stl
Build options:
  Mode ................................... release
  Building shared libraries .............. yes
  Using C++ standard ..................... C++11
  Using gold linker ...................... no
  Using new DTAGS ........................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. yes
  Build parts ............................ libs
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... yes
  Qt D-Bus directly linked to libdbus .... no
  Qt Gui ................................. yes
  Qt Network ............................. yes
  Qt Sql ................................. yes
  Qt Testlib ............................. yes
  Qt Widgets ............................. yes
  Qt Xml ................................. yes
Support enabled for:
  Accessibility .......................... yes
  Using pkg-config ....................... yes
  QML debugging .......................... yes
  udev ................................... yes
  Using system zlib ...................... yes
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ yes
  GLib ................................... no
  iconv .................................. yes
  ICU .................................... no
  Logging backends:
    journald ............................. no
    syslog ............................... no
    slog2 ................................ no
  Using system PCRE ...................... yes
Qt Network:
  getaddrinfo() .......................... yes
  getifaddrs() ........................... yes
  IPv6 ifname ............................ yes
  libproxy ............................... no
  OpenSSL ................................ yes
    Qt directly linked to OpenSSL ........ no
  SCTP ................................... no
  Use system proxies ..................... yes
Qt Sql:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. yes
  SQLite2 ................................ yes
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... yes
Qt Gui:
  FreeType ............................... yes
    Using system FreeType ................ yes
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ yes
  Fontconfig ............................. yes
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... yes
    PNG .................................. yes
      Using system libpng ................ yes
  OpenGL:
    EGL .................................. yes
    Desktop OpenGL ....................... no
    OpenGL ES 2.0 ........................ yes
    OpenGL ES 3.0 ........................ yes
    OpenGL ES 3.1 ........................ yes
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. yes
  libinput ............................... yes
  mtdev .................................. yes
  tslib .................................. yes
  xkbcommon-evdev ........................ yes
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. yes
  EGLFS details:
    EGLFS i.Mx6 .......................... no
    EGLFS i.Mx6 Wayland .................. no
    EGLFS EGLDevice ...................... yes
    EGLFS GBM ............................ yes
    EGLFS Mali ........................... no
    EGLFS Raspberry Pi ................... no
    EGL on X11 ........................... yes
  LinuxFB ................................ yes
  Mir client ............................. no
  X11:
    Using system-provided XCB libraries .. yes
    EGL on X11 ........................... yes
    Xinput2 .............................. yes
    XCB XKB .............................. yes
    XLib ................................. yes
    XCB render ........................... yes
    XCB GLX .............................. yes
    XCB Xlib ............................. yes
    Using system-provided xkbcommon ...... no
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... yes
Qt QML:
  QML interpreter ........................ yes
  QML network support .................... yes
Qt Quick:
  Direct3D 12 ............................ no
  AnimatedImage item ..................... yes
  Canvas item ............................ yes
  Support for Quick Designer ............. yes
  Flipable item .......................... yes
  GridView item .......................... yes
  ListView item .......................... yes
  Path support ........................... yes
  PathView item .......................... yes
  Positioner items ....................... yes
  ShaderEffect item ...................... yes
  Sprite item ............................ yes
Qt Multimedia:
  ALSA ................................... yes
  GStreamer 1.0 .......................... no
  GStreamer 0.10 ......................... no
  Video for Linux ........................ yes
  OpenAL ................................. no
  PulseAudio ............................. no
  Resource Policy (libresourceqt5) ....... no
  DirectShow ............................. no
  Windows Media Foundation ............... no

J.Hilk

@iman4k
I don't know, I'm not a cross compile expert by any means.
I'm just telling you want I can see from the configure you posted.

Anyway, should be easy enough to add
according to this
https://doc.qt.io/qt-5/qtvirtualkeyboard-build.html

you can simply open the qtvirtualkeyboard source project with QtCreator and compile it, using your cross compile kit

QtVirtualKeyboard is shown on desktop but not on Raspberry pi 3 ?

Configuration

Note: I also set QT_DEBUG_PLUGINS to 1 and confirm that libqtvirtualkeyboardplugin.so successfully loaded.

Note: I also set `QT_DEBUG_PLUGINS` to 1 and confirm that `libqtvirtualkeyboardplugin.so` successfully loaded.