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Thread: Unable to access members of same class, giving seg fault

  1. #1
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    Default Unable to access members of same class, giving seg fault

    I am trying to create a slot from object to other
    frame to log , but both belongs to same class

    when trying to access objects placed on log , they are becoming invalid.

    how to solve the problem?

    Qt Code:
    1. QWidget* ApplicationLog::createLogWindow()
    2. {
    3. m_pCmdLogHL = new QHBoxLayout(this);
    4. m_pLogTE = new QTextEdit(this);
    5. m_pCmdLogHL->addWidget(m_pLogTE);
    6. }
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    Qt Code:
    1. QWidget* ApplicationLog::createFrameWindow()
    2. {
    3. m_pButtonsHL = new QHBoxLayout(this);
    4. m_pMinMaxBut = new Button(this,"Minimize");
    5. connect(m_pMinMaxBut,SIGNAL(clicked()),this,SLOT(logWindowMinMax()));
    6. m_bIsMaximize = 1;
    7. }
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    Qt Code:
    1. void ApplicationLog::logWindowMinMax()
    2. {
    3. qDebug()<<"slot invoked" ;
    4. if(m_bIsMaximize)
    5. {
    6. m_pLogTE->setVisible(false);
    7. m_pMinMaxBut->setTooltip("Maximize");
    8. m_bIsMaximize = 0;
    9. }
    10. else
    11. {
    12. m_pLogTE->setVisible(true);
    13. m_bIsMaximize = 1;
    14. m_pMinMaxBut->setTooltip("Minimize");
    15. }
    16. }
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    in the main window i am calling
    Qt Code:
    1. QWidget* frame = framewindow->createFrameWindow();
    2. QWidget* log = logwindow->createLogWindow();
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    this particular line is giving problem (segmentation)
    Qt Code:
    1. m_pLogTE->setVisible(false);
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    why is it wrong to access that object,how to access the object?

  2. #2
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    Default Re: Unable to access members of same class, giving seg fault

    No return statements in functions returning non-void:
    Qt Code:
    1. QWidget* ApplicationLog::createLogWindow()
    2. {
    3. m_pCmdLogHL = new QHBoxLayout(this);
    4. m_pLogTE = new QTextEdit(this);
    5. m_pCmdLogHL->addWidget(m_pLogTE);
    6. // return !
    7. }
    8.  
    9. QWidget* ApplicationLog::createFrameWindow()
    10. {
    11. m_pButtonsHL = new QHBoxLayout(this);
    12. m_pMinMaxBut = new Button(this,"Minimize");
    13. connect(m_pMinMaxBut,SIGNAL(clicked()),this,SLOT(logWindowMinMax()));
    14. m_bIsMaximize = 1;
    15. // return !
    16. }
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    Another thing, check if createLogWindow() is called before trying to access m_pLogTE object.
    Last edited by stampede; 25th October 2013 at 13:29. Reason: updated contents

  3. #3
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    Default Re: Unable to access members of same class, giving seg fault

    The OP's code won't even compile, much less execute, so obviously we are not seeing the whole story. As amleto says in every post:

    If you have a problem, CUT and PASTE your code. Do not retype or simplify it. Give a COMPLETE and COMPILABLE example of your problem. Otherwise we are all guessing the problem from a fabrication where relevant details are often missing.

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