Here are few suggestions:
1. Use 2-state icons.
Clicking the button once would highlight the button (blue color), clicking it again would change the icon and sorting order.
E.g:
Code: Select all
ascending / descending
A. ... Z. ...
Z. ... A. ...
In other words, clicking "AZ..." icon would sort by Name ascending only and clicking "ZA..." icon by Name descending. Disadvantage is that we'd need 2x more buttons/icons in toolbar.
3. Use multiple-state Sort by icon.
This would change the main "Sort by" icon by sorting, so we could select any option from the drop down menu and the icon will be changed by this option.
E.g:
Code: Select all
sort by name ascending
A. ...
Z. ...
sort by name descending
Z. ...
A. ...
sort by date ascending
1. ...
2. ...
sort by date descending
9. ...
8. ...