Checking a Win32 Tree View Item Automatically Checks all Child Items

Question

I am using the Win32 API and MS Visual C++ 6 to build a tree view of a directory structure, with check boxes associated with each tree view item. My goal is to be able to check a parent folder, and have that automatically check all of its associated children.

However, after digging through MSDN, I have not been able to find a control notification message for an item being checked, only when an item is selected. I have considered using a selection notification message to prompt the program to poll the item and see if its current 'check state' is true, but I am not sure that checked and selected can be tied together in such a way, and am also concerned about the overhead associated with constantly polling items as a user moves through a very large directory.

Has anyone had experience setting up this scenario? Are my concerns about the overhead of polling a GUI element justified?

Answer 1

There isn't any notification. You can write your own, though. Just handle mouse click and use hittest to see if the mouse cursor is on the state image. For completeness handle the space key and send the same notification for the selected item too.