Access the widget of a tab in a QTabWidget

Question

I have a QTabWidget, where each tab has a QPlainTextEdit as its widget. So, how do I access each tab widget? How do I edit that widget?

Intermittent

Answer 1

You can use the widget function of QTabWidget in order to get the widget at the specified tab index.

If the QPlainTextEdit is the only widget of every tab page then the returned widget will be that. Otherwise you need to get the children of the widget and find the QPlainTextEdit in them.

QPlainTextEdit* pTextEdit = NULL;
QWidget* pWidget= ui->tabWidget->widget(1); // for the second tab
// You can use metaobject to get widget type or qobject_cast
if (pWidget->metaObject()->className() == "QPlainTextEdit")
    pTextEdit = (QPlainTextEdit*)pWidget;
else
{
    QList<QPlainTextEdit *> allTextEdits = pWidget->findChildren<QPlainTextEdit *>();
    if (allTextEdits.count() != 1)
    { 
        qError() << "Error";
        return;
    }  
    pTextEdit = allTextEdits[0];
}

// Do whatever you want with it...
ptextEdit->setPlainText("Updated Plain Text Edit);

Imperishable

Advice: avoid using QWidget* pWidget= ui->tabWidget->widget(1); and instead use QWidget* pWidget= ui->tabWidget->findChild<QWidget *>("your_tab_object_name");. This will ensure that even when movable your code will work as intended. The moment you rearrange your tabs (through code or by making them movable) the first piece of code will fail to return the tab you actually want. – Dipsomaniac

Furthermore you should be using qobject_cast<QPlainTextEdit*> and then test the result for nullptr instead of checking the meta object's classname. – Distinction