Don't assume every tab has the same width
use the complete Listview contentwidth as implicit width, just like qqc2-desktop-style, allowing for tabs to have different widths, otherwise some can have elided text (activitybar plasmoid had this problem)
use the complete Listview contentwidth as implicit width, just like qqc2-desktop-style, allowing for tabs to have different widths, otherwise some can have elided text (activitybar plasmoid had this problem)