Hovered = Decode and Show as Tooltip
When hovering mouse on a very long string, I saw the tooltip keep flickering (and CPU usage high), till I pressed Esc key (not always working). But would happen again after mouse moving.
So I thought of it that way.
Hope you will find the real reason and fix it.

Hovered = Open URL
I don’t think one would use it this way.
But surely it would be best if such uses can be optimized.