madjid/MMPickerView — pull request #5 by rickerbh (2013-09-24 06:20:31+00:00)
Title: Don't show the picker if it's already showing.

If the picker is already displayed, and a user taps a control to show it again (e.g., in a space that isn't covered by the overlay like a `UINavigationBar`), the picker and associated views will be added again. This code avoids that.