Problem:
In Mouse preferences, the list of bindings has a dummy empty column, which is a workaround for getting the Tool column to be right aligned. As a result, Narrator reads the list as having 5 columns which is confusing. In addtion, when arrowing down such a list, Narrator initially just reads the contents of the first column, which is unfortunately an empty string.
Fix:
After all the columns have been inserted, the dummy column can be deleted. This workaround was suggested by some Microsoft documentation.
Problem: a user can tab to the list, and no list item is the focus, and there is no visual indication of focus.
Fix: set the first item to be selected and focused
Commit 75e44df made controls in a wxStaticBox children rather than siblings. Three of the controls in KeyConfigPrefs are not handled by ShuttleGui, so needed manual changes of parent.
In addition, on Windows tabbing out of the text box for setting the shortcut resulted in the wrong control getting the focus. Changing to using Navigate() rather than NavigateIn() fixed this, though I don't know why. This needs testing on other platforms.
... except Audacity.h
This forces us to make each header contain all forward declarations or nested
headers that it requires, rather than depend on context.
... except Audacity.h; and in no others.
Do so even if Experimental.h gets multiply included, as in both the .h and
.cpp files.
This makes it easier to do a text scan to be sure there are no unintended quiet
changes of meaning because of omission of Experimental.h when the flag is
an enabled one.
Also move inclusions of Experimental.h earlier.
Also don't require Experimental.h to be preceded by Audacity.h to define
EXPERIMENTAL_MIDI_OUT correctly.
... for wxString and wxArrayStringEx, holding file paths (absolute or relative,
directory or plain file); to be replaced later with different types
(not yet using std::vector, becase of some uses of wxArrayString::Index with
two arguments)
... Remove all uses of the three-valued Cmp comparison member function, which
returns 0 for equality, except in one place. Use operators == and != instead.
(C++20's spaceship operator hasn't landed here yet!)
