Why do labels and frame have a "Tab Index" property in VB6?

Question

Does anyone know why Labels and Frames (and possibly other controls) have a TabIndex property in VB6? Is there some use for it; some feature of GUI programming I ought to be incorporating in my applications (that I am blissfully unaware of)?

Moisesmoishe

Answer 1

To confirm what Cody said in the comments. The VB6 manual entry for TabIndex says:

Controls that can't receive the focus (Frame and Label controls) remain in the tab order but are skipped during tabbing.

but

If you press the access key for a Frame or Label control, the focus moves to the next control in the tab order that can receive the focus.

Denigrate

Answer 2

TabIndex is the property used to determine the sequence of focused controls when user presses TAB key.
If control with TabIndex=5 is focused and user presses TAB, control with TabIndex=6 will take focus.

Monitorial

Well, yes, but Labels and Frames don't get focus (or do they under some circumstances?); that's the mystery. – Moisesmoishe

@Brian Hooper: for what I remember about VB6, labels take focus, but you can tell them to move focus to another control (for example a TextBox or a ListView) – Monitorial

Ah. Is that so? Thanks, I'll try some experiments. – Moisesmoishe

@Brian: Labels and frames do not get focus. They pass the focus to the control immediately following them in the tab order. That's useful for setting focus to a textbox or combobox, for example, using an ALT+letter combination, since they don't have any text of their own to display a mnemonic. – Nolen

Windows does this all over the place, and it's very important for accessibility with keyboard-only users. Check some of the control panels while holding down the ALT key to make the mnemonics appear. – Nolen

@Cody Gray: thanks, it's a long time I don't use VB6 and my memory was faulty ;) – Monitorial

@Marco: No problem. It's exactly the same deal in every other Windows GUI app, from straight Win32 API to VB 6 to .NET WinForms and beyond. Tab order is extremely important to get right. – Nolen

@Cody Gray: yes, I know the problem of tab order, above all for people using only keyboard (I can use mouse, but I prefer using keyboard if I can, it's faster), but I forgot the fact about labels and frames. Anyway I'm quite sure (but I wait for your advice) that in VB6 you could set a focused control in a Label, overriding taborder... am I right? Thanks again Cody – Monitorial

@Cody @marco Cody is right. I've postd an answer with some supporting quotes from the VB6 manual. – Denigrate

@Cody @marco @Denigrate thank you for that. I think I see the point now; just a bit of work needed on my code... – Moisesmoishe