Case: I have 5 containers inside vbox layout in a parent container. I attach listeners for tap event on each of the 5 child containers. Another way proposed is to add one event listener on the parent container, because apparently it lightens the DOM.
Questions:
Do Event Listeners take space in DOM?
If I put the event listener on the parent container only, how do I know which child container was clicked?
Event listeners do not take up space in the DOM. They will take up some space in memory. If you can use just 1 listener then you will get a small performance increase over using 5 listeners.