title: How to add a hover transition to QPushButton?
body: <p>I try to make a custom <code>QPushButton</code> with a stylesheet. I want to custom color of button when we mouse over it. It works, but I want to put a transition duration.
  But in Qt this option is not available.</p>
  
  <p>Here is my custom button:</p>
  
  <pre><code>#include "bouton.h"
  
  Bouton::Bouton(QString title, QWidget *parent) : QPushButton()
  {
    setGeometry(50,50,120,40);
    setText(title);
    setMinimumHeight(30);
    setParent(parent);
    setStyleSheet(" QPushButton {"
                "border-radius: 5px; "
                "border: 1.5px solid rgb(91,231,255); "
                "background-color: white; }"
                "QPushButton:pressed {"
                "border: 1.4px solid rgb(73,186,205); }"
                "QPushButton:hover {"
                "font-size: 16px;"
                "transition: 0.9s; }");
  }
  </code></pre>
  
  <p>The argument "transition 0.9s" doesn't work.</p>
  
  <p>Here is an <a href="https://www.w3schools.com/howto/tryit.asp?filename=tryhow_css_buttons_fade1" rel="nofollow noreferrer">example in CSS</a>.</p>
  
  <p>Are there other ways to do this?</p>