Plasma/libplasma2/fullyqualifiedtype
< Plasma | libplasma2
Discussion
Applet has a signal void messageButtonPressed(const MessageButton button). Since moc does a string comparison in connect, trying to connect it to a slot that takes "Plasma::MessageButton" will not work because "MessageButton" != "Plasma::MessageButton"
Proposed Solution
Change it to messageButtonPressed(const Plasma::MessageButton button);