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Qwidget shows transparent background on linux machine.

  • Hi ,

    i have created the window using base class as Qwidget.
    TopWindow::Topwindow(const char* name):Qwidget(0, name)


    the created window launch fine on windows machine but on Linux machine it shows the desktop background while launching application.
    i have created the child widget on this window.
    on Linux it shows the opened document background while launching application but once it is launched it shows proper background.

    how to prevent the displaying the desktop background while launching application on Linux machine.?


  • plz anybody know this problem?

  • Moderators


    Is your Linux machine a physical machine or a virtual machine?

    What graphics card does your Linux machine have?

    What happens if your application launches a plain QWidget, instead of your TopWindow?

    @TopWindow::Topwindow(const char* name):Qwidget(0, name)@
    [/quote]That won't compile. Please show us some of your actual code.

    Also, please be patient. Wait a few days before posting again.

  • Hi,

    yes, my Linux machine is physical machine. Linux machine has NVDIA graphics driver.

    here TopWindow is derived class from QWidget.

    Thanks for your reply

  • Moderators

    [quote author="yhodage" date="1391593710"]here TopWindow is derived class from QWidget.[/quote]I meant this:

    QWidget w;

  • Hello ,

    actually we have graphics widget on mainwindow. main window is inherited from QWidget and graphics widget inherited from QGLWidget.
    on Linux(red hat 5.4) when we launch main application it shows desktop background while launching. it seems that the the graphics widget does not clear previous content.
    I have attached the two snapshot of the same.
    Please help me to resolve this issue

  • can you please let me know how to add the attachment to current thread?

  • Moderators


    You have to upload your images to an external host (like Google Drive, or Microsoft OneDrive, or Imgur) and post the links here.


    What version of Qt are you using?

    Do other OpenGL applications work properly on your machine?

  • Thanks for reply

    i am using qt 4.8 version. we are using two types of graphics library i.e. OpenGL and Hoops. this problem is occurred on linux machine with graphics library OpenGL

  • Moderators

    That's why I asked you: Do other OpenGL applications work properly on your machine?

    Maybe you need to fix your graphics drivers.

  • yes the other OpenGl application works on linux machine

  • Moderators


    Are you able to try Qt 5.2.1 (or even Qt 5.3.0 beta)? There have been many improvements in graphics since Qt 4.8.

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