When a hardware keyboard is attached to an iOS device (iPad), there is still a smaller part of the software keyboard visible: the toolbar with the word suggestions and the undo and redo buttons.
Originally I expected that the documented method for inferring the keyboard height (see https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html ) would - in this case - just give the height of this bar. However, instead the reported height is still the height of the full software keyboard (although only a part is visible).
How can we get the height of the visible software keyboard, when a hardware keyboard is attached?