# The main window of the applicationclass MainWindow < KDE::XmlGuiWindow def initialize super # The main tabWidget, which is also the central widget @tabWidget = KDE::TabWidget.new(self) @tabWidget.addTab(KDE::TextEdit.new, "Placeholder") setCentralWidget( @tabWidget ) # The MultiTabBar is those bottons around the central widget, think sidebar @multiTabBar = KDE::MultiTabBar.new(KDE::MultiTabBar::Bottom, self) @multiTabBar.appendTab(KDE::IconLoader.new.loadIcon("cookies", KDE::IconLoader::Toolbar),-1,"Cookies") setupActions end...