I had an idea for deleting several files at once from a folder.
At the moment, rockbox doesn't have a way to select multiple files at once for deleting from a folder. At the moment, your only options if the player isn't connected to a computer are either to delete one file at a time, or to hook the player to a computer and then delete multiple files.
so this is my idea, what about an option to create to markers, one at the starting point for deleting files, and then one at the end, and any files including and between those two files designated as start and end markers would be deleted, so similar to highlighting on the computer.
I thought this idea could be particularly useful if you have a folder full of a lot of files, which you have listened to a lot of, but not all, and you want to clear the ones you have listened To, without deleting the hole directory. after all, rockbox has several clipboard funcions, for example copy, cut and paste, so why not some kind of select feature for interacting with multiple files and folders at once, as I guess you might want to delete several folders at once as well.