5.0.1 - "Cannot create accessible interface for object" warnings



  • Just finished a custom Qt5.0.1 build and noticed an *extensive *amount of what I assume are warnings, coinciding with a significant performance loss of about 25% compared to Qt5.0 and none of those warnings. Here is a short snapshot of what the warnings look like:

    @...
    Cannot create accessible interface for object: QProgressBar(0x35fb30, name = "prog")
    Cannot create accessible interface for object: QProgressBar(0x35fb30, name = "prog")
    Cannot create accessible interface for object: QProgressBar(0x35fb30, name = "prog")
    Cannot create accessible interface for object: QProgressBar(0x35fb30, name = "prog")
    Cannot create accessible interface for object: QLabel(0x3888d0, name = "uniqueWordsLbl")
    Cannot create accessible interface for object: QLabel(0x388850, name = "totalWordsLbl")
    Cannot create accessible interface for object: QLabel(0x3889d0, name = "textCharLbl")
    Cannot create accessible interface for object: QLabel(0x388a50, name = "sepCharLbl")
    Cannot create accessible interface for object: QLabel(0x388950, name = "totalCharLbl")
    Cannot create accessible interface for object: QLabel(0x388ad0, name = "timeLbl")
    Cannot create accessible interface for object: QLabel(0x388b50, name = "mcpiLbl")
    Cannot create accessible interface for object: QHeaderView(0x23de3c0)
    Cannot create accessible interface for object: QHeaderView(0x23de680)
    Cannot create accessible interface for object: QTableView(0x23de0c0, name = "tableView")
    Cannot create accessible interface for object: QHeaderView(0x23de3c0)
    Cannot create accessible interface for object: QHeaderView(0x23de680)
    Cannot create accessible interface for object: QScrollBar(0x23de280)
    Cannot create accessible interface for object: QTableView(0x23de0c0, name = "tableView")
    Cannot create accessible interface for object: QTabBar(0x23781b0, name = "qt_tabwidget_tabbar")
    Cannot create accessible interface for object: QWidget(0x2378470, name = "qt_scrollarea_viewport")
    Cannot create accessible interface for object: QPlainTextEdit(0x2378430, name = "plainTextEdit")
    Cannot create accessible interface for object: QPushButton(0x2378bf0, name = "editBtn")
    ...@

    Also worth nothing I am getting those not only in debug but also in release mode. I assume the performance drop has to do with all that extra output I am getting.

    Ideas?



  • Also, just noticed I get the warnings only on Windows 7 and Windows 7 Basic UI themes, switching to windows classic there removes the warnings and the performance drop.



  • I have the same problem, why?


  • Moderators

    Is there a "bug report":https://bugreports.qt-project.org/ about this? I am sure the developer working on accessibility would like to know about your experience.





  • Hi there,

    the Bug is still not resolved. It says "Need More Info", which I hope I can provide because I ran into the same issue. In case I am just missing something trivial, I would be grateful for hints. Here is how I reproduce the behaviour:

    I built Qt5 from the GIT repository (checked out yesterday) on Windows XP as described "here":http://qt-project.org/wiki/Building_Qt_5_from_Git using the MinGW 4.7 compiler included with the "Qt binary download":http://download.qt-project.org/official_releases/qt/5.0/5.0.2/qt-windows-opensource-5.0.2-mingw47_32-x86-offline.exe.

    For the build I used ActivePerl 5.16.3.1603 and Python-3.3.1.

    My configure options were:

    @configure
    -prefix D:/qt5-build
    -opensource
    -opengl desktop
    -no-icu
    -no-angle
    -no-native-gestures
    -no-audio-backend@

    "make install" ran through without interruption.

    Then, I build the Qt example
    \examples\widgets\dialogs\findfiles

    I add the following line to the findfiles.pro file:
    @CONFIG += console@

    Otherwise the "Cannot create accessible interface for object" warnings will not show at runtime.

    After "qmake" followed by "make release" the program findfiles.exe runs fine under my Windows XP.

    Now, I want to deploy it for a Windows 7 machine. So I copy the following files from the MinGW 4.7 compiler and from my Qt5 build bin directories into my deploy directory:

    • platforms/qwindows.dll
    • libgcc_s_sjlj-1.dll
    • libstdc++-6.dll
    • libwinpthread-1.dll
    • Qt5Core.dll
    • Qt5Gui.dll
    • Qt5Widgets.dll
    • findfiles.exe

    I run findfiles.exe on Windows 7 (with the "Windows Classic" UI theme), and everything works fine.

    When I change the UI theme to "Windows 7", however, I get the "Cannot create accessible interface for object" warnings in the console.

    As suggested in the "bug report":https://bugreports.qt-project.org/browse/QTBUG-29720 I set the environment variable QT_DEBUG_PLUGINS=1. Here is what output I get while just starting findfiles.exe and closing the window immediately after it appeared:

    @QFactoryLoader::QFactoryLoader() looking at "C:/mydeploy/platforms/qwindows.dll"
    Got keys from plugin meta data ("windows")
    loaded library "C:/mydeploy/platforms/qwindows.dll"
    Cannot create accessible interface for object: QLabel(0x45e4a8)
    Cannot create accessible interface for object: QLineEdit(0x438d68)
    Cannot create accessible interface for object: QComboBox(0x349900)
    Cannot create accessible interface for object: QLabel(0x45e5e8)
    Cannot create accessible interface for object: QLineEdit(0x45df88)
    Cannot create accessible interface for object: QComboBox(0x438d88)
    Cannot create accessible interface for object: QLabel(0x45e628)
    Cannot create accessible interface for object: QLineEdit(0x45e488)
    Cannot create accessible interface for object: QComboBox(0x45e0c8)
    Cannot create accessible interface for object: QPushButton(0x3497a0)
    Cannot create accessible interface for object: QWidget(0x48d998, name = "qt_scr
    ollarea_viewport")
    Cannot create accessible interface for object: QWidget(0x48ded8, name = "qt_scr
    ollarea_viewport")
    Cannot create accessible interface for object: QHeaderView(0x48deb8)
    Cannot create accessible interface for object: QTableWidget(0x48d958)
    Cannot create accessible interface for object: QLabel(0x45e668)
    Cannot create accessible interface for object: QPushButton(0x349840)
    Cannot create accessible interface for object: Window(0x28fe6c)
    Cannot create accessible interface for object: Window(0x28fe6c)
    QLibraryPrivate::unload succeeded on "C:/mydeploy/platforms/qwindows.dll"@

    Clicking any buttons in the findfiles program produces a lot more of these warnings. I hope that somebody can shed some light onto this. For findfiles there is no noticable performace loss, but with my actual application there is...

    Thanks a lot in Advance,
    Ludwick


  • Moderators

    Please provide the information to the bug report, not the forum:-)



  • Adding the file

    accessible/qtaccessiblewidgets.dll

    into the folder of my executable file, actually solved the problem!



  • I have same problem with this warning bug under VS2010 with using static build.

    Solved by:

    1. importing plugin to my main.cpp:

    #include <QtPlugin>
    Q_IMPORT_PLUGIN(AccessibleFactory)

    1. adding to project options > Linker>Input>Additional Library Directories->$(QTDIR)\plugins\accessible

    2. adding to project options >Linker>Input>Additional Dependencies->qtaccessiblewidgets(d).lib (d -> depending on debug or release version)



  • I have same problem.
    the Qt version 5.0.2


  • Moderators

    @LuYong

    Please provide a detailed of your actual problem.
    Simply stating that you have the same problem does not get you anywhere.
    Version 5.0.2 is completely outdated.

    BTW you are necroposting.


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