QTabWidget not appearing when findChildren is called.

mar0029

Hello!

I am trying to find all of the children of a layout. One of these children is a QTabWidget. It does not appear when called. Code is as follows:

 MainWindow::buildFunction()
 {
      configTabArea = new QTabWidget;
      configMainVbox = new QVBoxLayout;
      myHbox = new QHBoxLayout;
      button = new QPushButton;
      ...work...
      myHbox->addWidget(button);
      configMainVbox->addWidget(configTabArea);
      configMainVbox->addLayout(myHbox);
 }

 MainWindow::actionFunction()
 {
      QList<QLayout*> layoutList = configMainVbox->findChildren<QLayout *>();
      // line above finds one layout, the QHBoxLayout

      QList<QTabWidget*> tabList = configMainVbox->findChildren<QTabWidget *>():
      //this line finds nothing. Same when using QWidget instead of QTabWidget
 }

Any help would be greatly appreciated

VRonin

Try

MainWindow::buildFunction()
 {
      configTabArea = new QTabWidget(this);
configTabArea->setObjectName("configTabArea"); //Set the name
      configMainVbox = new QVBoxLayout;
      myHbox = new QHBoxLayout;
      button = new QPushButton;
      ...work...
      myHbox->addWidget(button);
      configMainVbox->addWidget(configTabArea);
      configMainVbox->addLayout(myHbox);
 }

 MainWindow::actionFunction()
 {
      QList<QLayout*> layoutList = configMainVbox->findChildren<QLayout *>();
      // line above finds one layout, the QHBoxLayout

      QTabWidget* tabList = findChild<QTabWidget *>("configTabArea"):
      //Check that tabList is not null
 }

mar0029

Thank you for your reply!

So I tried your suggestion and it returns a null QObject.

I noticed you set the parent of QTabWidget to this. This is all taking place in a non-modal dialog configScreen so I tried explicitly setting that as the parent but it didn't seem to have any effect.

mrjj

@mar0029 said:

This is all taking place in a non-modal dialog configScreen

But you seems to try to find the QTabWidget* in the context of MainWindow ?
If QTabWidget lives in dialog ,
you cannot find it from context of mainwindow unless
its dialog->findChild

mar0029

Thank you for your response!

One correction on my part, everything takes place within a modal dialog and not a non-modal one.

I think I may have miss spoke. I'm posting a more complete version of my code below, minus details on what happens in the window.

 void MainWindow::configApply()
 {
     QList<QLayout*> layoutList = configMainVbox->findChildren<QLayout*>();

qDebug() << "layoutList size " << layoutList.size();

QTabWidget* tabWidget = configScreen->layout()->layout()->findChild<QTabWidget*>("configTabArea");

if(tabWidget != NULL)
{
    qDebug() << "is OK ";
}
else
    qDebug() << "NULL";
 }

 void MainWindow::configFunction()
 {
configScreen = new QDialog;
configScreen->setFixedSize(575,500);

myHbox = new QHBoxLayout;

tab0 = new QWidget;
tab1 = new QWidget;
tab2 = new QWidget;
tab3 = new QWidget;

sa0 = new QScrollArea;
sa1 = new QScrollArea;
sa2 = new QScrollArea;
sa3 = new QScrollArea;

vbox0 = new QVBoxLayout;
vbox1 = new QVBoxLayout;
vbox2 = new QVBoxLayout;
vbox3 = new QVBoxLayout;

configTabArea = new QTabWidget;
configMainVbox = new QVBoxLayout;
configTabArea->setObjectName("configTabArea");
 //
 //stuff is added to the QVBoxLayouts
 //
   vbox0->setSizeConstraint(QLayout::SetFixedSize); //important to keep scrolling active
vbox1->setSizeConstraint(QLayout::SetFixedSize);
vbox2->setSizeConstraint(QLayout::SetFixedSize);
vbox3->setSizeConstraint(QLayout::SetFixedSize);

tab0->setLayout(vbox0);
sa0->setWidget(tab0);

tab1->setLayout(vbox1);
sa1->setWidget(tab1);

tab2->setLayout(vbox2);
sa2->setWidget(tab2);

tab3->setLayout(vbox3);
sa3->setWidget(tab3);

QPushButton *configApplyButton = new QPushButton("Apply");
QPushButton *configCancelButton = new QPushButton("Cancel");

myHbox->addWidget(configApplyButton);
myHbox->addWidget(configCancelButton);

configTabArea->addTab(sa0, tr("file1"));
configTabArea->addTab(sa1, tr("file2"));
configTabArea->addTab(sa2, tr("file3"));
configTabArea->addTab(sa3, tr("file4"));

configMainVbox->addWidget(configTabArea);
configMainVbox->addLayout(myHbox);

connect(configApplyButton, SIGNAL(clicked(bool)), this, SLOT(configApply()));
connect(configCancelButton, SIGNAL(clicked(bool)), configScreen, SLOT(accept()));

configScreen->setLayout(configMainVbox);
configScreen->setWindowTitle("Set your file's configurations");

configScreen->setAttribute(Qt::WA_DeleteOnClose);
configScreen->exec();
}

let me know what you think.

mrjj

@mar0029 said:

Hi
Normally this is very easy so I wonder if something odd is going on :)

can u try

QList<QTabWidget*> AlltabWidgetslist = configScreen->findChildren<QTabWidget*>();

qDebug << "num of tabs:" << AlltabWidgetslist.count();

and see if it say 1

mar0029

@mrjj
Thank you very much. This started me on the right path.