Previously, I would have installed the xfce4-taskbar-plugin to get pinnable window buttons by dropping in a taskbar, but https://goodies.xfce.org/projects/panel-plugins/xfce4-taskbar-plugin says "Since the 4.4 version of the Xfce, the taskbar plugin is shipped with the panel. So there is no need to install any other stuff". I don't see a taskbar plugin in the Add New Items dialog, and none of the other built-in plugins seem to have the same function (I thought maybe the functionality was rolled into another plugin). Window Buttons is close, but doesn't allow me to pin the buttons.
I think you are looking for https://git.xfce.org/panel-plugins/xfce4-taskbar-plugin/ , not the old -now integrated- taskbar :) (yes, they have the same name). This plugin does not seems to be very active/compilable through.
(In reply to Skunnyk from comment #1) > I think you are looking for > https://git.xfce.org/panel-plugins/xfce4-taskbar-plugin/ , not the old -now > integrated- taskbar :) (yes, they have the same name). > This plugin does not seems to be very active/compilable through. Slightly confusing :P That does seem to compile and work. Thanks for pointing to it (and updating the goodies page).