How to know if the composer being used for editing topic,creating topic or replying a topic

When I try to inspect the ember component, I find the action to be null.

In the above screenshot, I inspected the properties for the editor composer. The action is null.

I surely might be doing something wrong, or looking in wrong component. Can you please tell me which component did u inspect?

Why do I need to know if the composer is for create topic or replying?
Because I want to add a custom field in composer, which will be used only when creating topic, not for replying..