title: How to set precise size of QPushButton?
body: <p>I have SignatureEditorForm class, which inherits QDialog class:</p>
  
  <pre><code>SignatureEditorForm(QWidget* parent_widget) : QDialog(parent_widget)
  {
      resize(SIGNATURE_EDITOR_SIZE);
      setWindowTitle(QString("Signature Editor"));
      setWindowFlags(Qt::Window | Qt::MSWindowsFixedSizeDialogHint | Qt::WindowCloseButtonHint);
      setModal(true);
      {
          QPushButton* const button = new QPushButton(QString("&lt;"), this);
          const QSize BUTTON_SIZE = QSize(22, 22);
          button-&gt;resize(BUTTON_SIZE);
      }
  }
  </code></pre>
  
  <p>It contains QPushButton which has size (width: 22, height: 22) and "&lt;" caption.
  I have such picture of this widget (SignatureEditorForm). QPushButton has size (width: 20, height: 20). How can I set precise size of button?</p>
  
  <p>P.S. I tried to use setMinimumSize, but it has not effects.</p>
  
  <p><a href="https://i.stack.imgur.com/QPhwj.png" rel="noreferrer"><img src="https://i.stack.imgur.com/QPhwj.png" alt="enter image description here"></a></p>
  
  <p>P.P.S. this line button->setStyleSheet("border: 1px solid black; background: white"); gives such effect (precise size)</p>
  
  <p><a href="https://i.stack.imgur.com/IRUyr.png" rel="noreferrer"><img src="https://i.stack.imgur.com/IRUyr.png" alt="enter image description here"></a></p>