On a desktop and touch devices, I'd like to know is there is a way to tell the user that some control could be clicked (one action) and long pressed (another action)?
Real-world example:
- We have column chart
- Tap performed on column 2007 (single selection)
- Tap performed on column 2009 (single selection)
- Long press performed on column 2010 (single selection)
Current situation is that user doesn't know that chart has possibility to multi-select columns (perform long press). How to indicate that it is possible?