{
App::signal_instance_deleted().connect(sigc::mem_fun(*this,&studio::Dock_History::delete_instance));
App::signal_instance_selected().connect(sigc::mem_fun(*this,&studio::Dock_History::set_selected_instance_signal));
{
App::signal_instance_deleted().connect(sigc::mem_fun(*this,&studio::Dock_History::delete_instance));
App::signal_instance_selected().connect(sigc::mem_fun(*this,&studio::Dock_History::set_selected_instance_signal));