void (@NotNull JRootPane rootPane) { Component glassPane = rootPane.getGlassPane(); if (glassPane instanceof IdeGlassPane) { assert disposable == null : "Disposable is not null"; disposable = Disposer.newDisposable("Ruler Guide"); Disposer.register(this, disposable); ((IdeGlassPane) glassPane).addPainter(glassPane, this, disposable); } else { ThiefGlassPane glass = new ThiefGlassPane(glassPane); rootPane.setGlassPane(glass); glass.setVisible(true); glass.revalidate(); } }