Question

I have some simple code for popping up a “dialog”-like thing over part of my application window. The idea is, the user must dismiss the dialog before continuing to work with that part of the page.

This works by hovering a large semi-transparent rectangle over the part of the page that is supposed to be disabled – which does a nice enough job of blocking clicks to the region. You see this sort of thing a lot in WPF and Web apps, I think.

The problem I have is, the user can still reach all those juicy blocked controls by tabbing to them using the keyboard. “No problem”, I hear you say, “just set the IsEnabled on the panel to false, thereby blocking keyboard access”.

Unfortunately, disabling the controls:

• Doesn’t look very nice
• Tends to have unintended consequences with custom styles and bindings further down the tree

So, is there a better way to disable a part of the page, without setting the “IsEnabled” property, such that it doesn’t change the visual appearance of any of the controls?

Thanks,
Mark

Answer 1

I solved this by subscribing to the PreviewGotKeyboardFocus event, from the parent element in the tree, and then handling the event such that focus never gets passed to the children.

Also, I had to explicitly remove focus from the “disabled” controls as well, of course.