current_mixer_strip->Hiding.connect (sigc::mem_fun(*this, &Editor::current_mixer_strip_hidden));
current_mixer_strip->WidthChanged.connect (sigc::mem_fun (*this, &Editor::mixer_strip_width_changed));
current_mixer_strip->Hiding.connect (sigc::mem_fun(*this, &Editor::current_mixer_strip_hidden));
current_mixer_strip->WidthChanged.connect (sigc::mem_fun (*this, &Editor::mixer_strip_width_changed));