Impossible to search for apps using onboard virtual keyboard

[aleksandar-todorovic]

It is impossible to search for apps using the `onboard` package and its virtual keyboard. Because it's... well, a keyboard on a screen, as soon as the first key is pressed, Slingshot registers it as the key outside of the window and closes itself.

Unfortunately, this means that the search functionality is completely useless on any sort of touchscreen devices.

I've tried (and succeeding) in replicating this by opening the Slingshot both through Wingpanel and through a Meta + Space keyboard shortcut and then doing the following:

1. Touching on a button on a screen.
2. Using the touchpad to navigate to some key on the keyboard and touching it (which means that this issue is easily reproducible on non-touchscreen devices).

In both of these cases, Slingshot closed.

Now, I have absolutely no proposal for the fix, but I think that this is a non-expected feature for a touchscreen device niche.