User jcotton42 suggested copying a D2X-XL feature: preserving the
directory structure of the user's missions area when showing a New Game
dialog. This was substantially more trouble than it should have been,
but the result is good.
Previously, the dialog presented all missions at any depth below the
starting point, and sorted them as if they were all in the root
directory.
Now:
- Empty directories are hidden entirely. There is nothing for the user
to do in them, so there is no point showing them.
- A directory with exactly one entry has that entry promoted into the
parent, since there is no ambiguity about what the user would want.
If the parent in turn has only that one promoted element when the scan
of the parent finishes, then the element can be promoted up again.
This continues until the root is reached or until a level has more
than one entry. For this purpose, both missions and directories count
as entries.
- Directory entries are decorated to inform the user how many
immediate subdirectories are present, how many missions are present
immediately in the directory, and how many missions total are present,
counting all subdirectories. If there are zero immediate
subdirectories, then the directory count is not shown. For this
purpose, directories that were hidden due to a lack of missions are
not counted.
- Sub-dialog boxes for inner directories use a title that reminds the
user of the path so far, and recaps the directory/mission statistics.
- On entry to the New Game dialog, if the last played mission is in a
sub-dialog, appropriate sub-dialogs are opened so that the last played
mission can be pre-selected.
Currently, there is no in-game override to return to the prior rollup
rules.
Requested-by: jcotton42 <https://github.com/dxx-rebirth/dxx-rebirth/issues/392>
Make the listbox handlers and all sub-handlers (when_selected callbacks) return a window_event_result. Makes code more readable and removes one use of window_close, making it easier to inform event system if a window closes in future.
