A delegate to be called for every active node. Disabled nodes should be included. If the delegate returns a non-zero value, it should immediately break out of the loop and return this value.
If yield returned a non-zero value, it should be returned; if yield wasn't called, or has only returned zeroes, a zero is returned.
List all active hover pointer, namely all pointers that have been loaded since the last resize.
Pointers do not need to be sorted.