Control selection in Igor 9 vs earlier versions

In Igor versions prior to 9 an empty listbox, i.e. one that is not displaying any rows, cannot be selected. In Igor 9 it can, and a focus ring is drawn.

Is that behaviour cross platform, and can it be expected to remain as it is now?

I'm using Mac OS 11.3.


I suspect this entry in the What's New in Igor Pro 9 help file is relevant:

Prior to Igor Pro 9, a ListBox control did not respond to mouse clicks if the control was empty. Now an action procedure for an empty ListBox control will receive a mouse down event (event code 1, see WMListboxAction). Along with this change, we fixed a bug: an empty ListBox control with header cells and the userColumnResize keyword set to non-zero will now allow you to drag the cell divider to resize the columns.

Both of these require allowing the mouse-down to propagate further into the code. No doubt it is also causing focus to move to the listbox. Unless it's a real problem, I'm inclined to say this is intended, permanent, and cross-platform.

Ah, I missed that.

It's not a problem. It's an improvement.

In the Spidergram project I allow users to 'paste' data into a listbox control. Previously I simply intercepted the paste in a window hook, but for Igor 9 I check that the listbox that will display the imported data is selected. I think it's more intuitive in the Igor 9 version.