Show rendered status from a layer in a specific instant

[marcmelchor]

Objective:

As a user of this library, I will like to know when a specific layer is completely rendered.
Knowing in advance that this is available on the map event listener rendercomplete or by a specific layer (e.g. TileLayer or ImageLayer) with the event listener sourceready. Nevertheless, both options don't fulfill the scenario where you'd like to see the status in a specific instant, rather that continuing listening until the event occurs.

Functional Scenario:

By implementing this new feature, developers could capture, as a picture, the current status in a specific moment of a process.
This feature is not expecting to change the current state of art for this library but, to increase its functionalities.

[ahocevar]

I'm not entirely sure what you're trying to achieve:

developers could capture, as a picture, the current status in a specific moment of a process.

Could you elaborate? Before reading this, I thought what you're looking for is either a rendercomplete event on the layer, or a completelyRendered() method on the layer. But now I'm not sure.

Also note that the sourceready event is fired when source metadata has been processed, not when any data fetched by the source is ready for rendering.

[marcmelchor]

@ahocevar probably I wasn't clear enough.
You were right on your first assumption about a method like completelyRendered() which the response is a boolean.