I'm using Drupal's theme table function to build a custom table.
All of the columns on my table are sortable. I would like to visually indicate that they are sortable by putting both an ascending and descending sort icon in the column header.
To indicate which sort is active, I would like to show only one icon, corresponding to the current sort (ascending or descending).
Here's what I have:
Here's what I want:
How can I accomplish this?
So far, the closest I've gotten is overriding
theme_tablesort_indicator(), but this will only let me override the icon for the active sort. (Docs here)