I implemented something similar in my OpenVMS file manager. It's a grouping cycle
that will, for example, reduce this list of files in several ways:
index.html
proj1.c
proj1.h
proj1.obj
proj1.exe
proj1.zip
proj2.c
proj2.h
proj2.obj
proj2.exe
proj2.zip
proj3.c
proj3.h
proj3.obj
proj3.exe
proj3.zip
readme.txt
Collapse file names:
index.html
*.c
*.h
*.obj
*.exe
*.zip
readme.txt
Collapse file types:
index.html
proj1.*
proj2.*
proj3.*
readme.txt
The first result lets you know instantly that you have exactly 7 file types in your
list of, potentially, millions of files. The second lets you know that you have
exactly 5 different file names.
In these collapsed views, the '*' is actually displayed in the collapsed file list,
which is normally not the case in file managers, as this is not a valid character.
It's a hint, like the [+] we see in front of collapsed directories, but it's also
a valid Filter already prepared for some decision or action...
It's telling you that there are 2 on more matching files in a name or type category.
It's a fast, predefined filter that gives you a quick report and may be implemented
without allowing the user to perform any action other than just view/scroll the
collapsed list. No risk involved; an ESC may be required to exist this view and
restore the original list.
However, the way I implemented this, I allowed the user to act on a category
(collapsed item) like proj1.* or *.obj. For example, hitting Delete on *.obj would
(tag *.obj behind the scenes and) delete the category. One could also Rename proj2.*
to projX.* instantly. This saves a lot of work but is more risky.
I'd love to see this in ZTree and even ZEP for collapsing by color, size, and other categories...