Все-таки QSS это не совсем CSS.
Как мне узнать, например, какие атрибуты я могу применять к QToolButton?
Вот что мне дает ассистент:
Supports the box model.
If the QToolButton has a menu, is ::menu-indicator subcontrol can be used to style the indicator. By default, the menu-indicator is positioned at the bottom right of the Padding rectangle of the widget.
If the QToolButton is in QToolButton::MenuButtonPopup mode, the ::menu-button subcontrol is used to draw the menu button. ::menu-arrow subcontrol is used to draw the menu arrow inside the menu-button. By default, it is positioned in the center of the Contents rectangle of the menu-button subcontrol.
When the QToolButton displays arrows, the ::up-arrow, ::down-arrow, ::left-arrow and ::right-arrow subcontrols are used.
Warning: If you only set a background-color on a QToolButton, the background will not appear unless you set the border property to some value. This is because, by default, the QToolButton draws a native border which completely overlaps the background-color. For example,
QToolButton { background-color: red; border: none; }
See Customizing QToolButton for an example.
Плюс экзамплы. Этого мало.
Вот где я мог найти свое решение?