guest_ime_modal_dialog checks that another owner polls Idle, that its reset and
close leave the dialog showing, drawable and answerable, that it cannot erase
the answer, and that the owner can answer, reset and close its own dialog.
guest_ime_modal_dialog opens a dialog with a 40 ms bound and never reads its
view: it captures input until the bound, then becomes Unshown, stops capturing,
ignores answers and lets the next dialog open. A dialog whose view was read
keeps capturing and can be answered long after the bound.
A guest test drives the session through its exported functions: refusal
without a presenter, with no buttons, with four buttons and with a focus or
cancel button out of range; focus clamping; confirm and cancel; close and
reset; the D-pad, the left stick and the Cross and Circle presses that only
count after the buttons were seen released; and the IME keyboard taking back
the view and the input until it releases them.
MarcZX10