The focus issue of the search box after checked the Search as you type option
Steps to reproduce:
1. Launch the latest version of calibre.
2. Click Preferences -> Interface -> Searching and check the Search as type option.
3. Apply the change and go back to the calibre.
4. Type something into the search box and wait for a while.
The cursor doesn't focus on the search box any longer and calibre changes the focus to the list view.
The cursor should be still focused on the search box for easy typing.
That's quite annoying as you are typing the stuff you are gonna search. Let's see if you are thinking what you are gonna type and stop typing for a while (you haven't finished search phrase yet at this moment). The cursor doesn't focus on the search box any more and you have to click the mouse to re-focus it to search box.
1. Window 7 Ultimate 64bit.
2. calibre version: 2.30 64bit.