When widgets overlap, clicks register on both widgets

[gregkatz]

Steps to reproduce:

1. Run widgets example
2. Click Multi-Line Text widget to focus on it
3. Open menu and click "Reset Label" while mouse cursor is also over the text box

Expected behavior:
Label resets, but focus remains on the Multi-Line Widget.

Actual behavior:
Label resets, but focus moves to the text box

This was tested on Ubuntu. I'm not sure if this behavior is intentional, but it can make using drop down menus difficult because menu clicks will also affect what's underneath them.