View.post(), And When Runnables Are Executed

My original problem was needing to know the height and width of my root View so that I could make programmatic layout changes. For my purposes, I don't necessarily need to determin

Solution 1:

I had a look at the View.post(Runnable) method and it seems to me that by calling that method you are just adding a message to the UI thread queue. The only thing that is going to be 'guaranteed' is that the Runnable will be executed sometime AFTER the method which has called post(Runnable) has completed. This assumes you are calling post(Runnable) from the UI thread but as the docs say:

This method can be invoked from outside of the UI thread only when this View is attached to a window.

I think to be sure that both your Root view and Child view both have size, you would need to call post(Runnable) from the child onSizeChanged() method because if the child has size I think it follows that the Parent i.e. Root view therefore must have size too.

Apologies if this is a bit of a rambling answer. I kind of understand what you're wanting to achieve but not 100% sure. Let me know if you want me to clarify anything.

Personally whenever I've needed the size of a View I do everything in onSizeChanged() which I do believe is the 'correct' way of doing it and it has always worked.