void showPreview( boolean show ) {
		if( show ) {
			if( preview != null )
				return;

			preview = new FlatThemePreview( textArea );
			add( preview, BorderLayout.LINE_END );
		} else {
			if( preview == null )
				return;

			remove( preview );
			preview = null;
		}

		revalidate();
	}
A pane that supports editing FlatLaf themes.

@author Karl Tauber
flatlaf-theme-editor/src/main/java/com/formdev/flatlaf/themeeditor/FlatThemeEditorPane.java