QPalette doesn't apply correctly with QHBoxLayout

vijaychsk

Hi,
I have a custom widget that gets added to my main window. This custom widget simply contains a QHBoxLayout with two radio buttons and QLineEdit. However, the color palette doesn't seem to be working as expected on this custom widget.

Header:

class myWidget : public QGroupBox {
  QHBoxLayout* _hbox = nullptr;
  QRadioButton* _rb1 = nullptr;
  QRadioButton* _rb2 = nullptr;
  QLineEdit* _lineEdit = nullptr;
}

Implementation:

   _hbox = new QHBoxLayout();
   _hbox->setContentsMargins(0, 0, 0, 0);
   _hbox->setSpacing(5);
   _rb1    = new QRadioButton("RB1", _parent);
   _rb1->setChecked(true);
   _rb2 = new QRadioButton("RB2", _parent);
   _lineEdit = new QLineEdit();
   _lineEdit->setText(tr("0"));
   _hbox->addWidget(_rb1);
   _hbox->addWidget(_rb2);
   _hbox->addWidget(_lineEdit);
   setLayout(_hbox);
}

The layout is perfect. Now, I'm trying to highlight/change the color on the lineEdit in case it is found empty. I tried to use QPalette, it is working but the color is getting applied to the entire HBox layout including the radio buttons. I only want the color for the QLineEdit which is what I specified in the code below. It is straight forward code:

QPalette pal = _lineEdit->style()->standardPalette(); // also tried _lineEdit->palette();
pal.setColor(QPalette::Base, Qt::red);
setPalette(pal);

What can possibly be wrong?

Christian Ehrlicher

@vijaychsk said in QPalette doesn't apply correctly with QHBoxLayout:

What can possibly be wrong?

You set the palette to the whole widget, not only to the lineedit.

vijaychsk

@Christian-Ehrlicher Good catch. I missed it. Thank you.