You can change the textElideMode
property by adding a rule QComboBox QAbstractItemView { qproperty-textElideMode: ElideNone }
(See Style Sheet Syntax - Setting QObject properties) but it will only clip the text on the right without extending the drop-down box.
According to the code source, the list view adjust its size to its content when it is displayed as a popup which is done by adding this in the stylesheet:
QComboBox {
combobox-popup: true;
// To make room for the possible scrollbar
// (the value has to match the scrollbar width of the current style/platform)
padding-right: 20px;
}
Outside that popup mode, the width of the drop-down box is taken from the list view minimum size (or from the min-width
css property of the QAbstractItemView
), but there doesn't seem to be a way, with css only, to automatically adjust the size of the drop-down box to the content of the list.