How to get current theme name from linux desktop environment using Qt C++

Question

I am going to develop an app using Qt, and I want to use the icons in /usr/share/icons directory, however, I don't know how to make the icons change automatically when the desktop evironment theme changed.

I use QIcon and declaring the icon path by absolute path, for example, I want to use Numix-Circle icon theme, so I did this:

QPushButton *button = new QPushButton ;
QIcon icon ( '/usr/share/icons/Numix-Circle/48/apps/gnome-do.svg' ) ;
button -> setText ( "" ) ;
button -> setIcon ( icon );

But the icon will not change with the DE theme change, furthermore , if the user doesn't install the theme, the icon in app will not show.

Is there any way to get the icons from desktop environment?or the other way to make the icons in app responsive?

Answer 1

QIcon::fromTheme("gnome-do") will return a QIcon from the current theme. In KDE, if you change the icon theme, the icons should also update to match the new theme.