IssueTracker

The Android file management app (DocumentsUI) uses androidx.recyclerview:recyclerview-selection for picking multiple files. And in cases when an app requests user to pick several files, it would be nice if we can (mostly) preserve users' selection order, an improvement over the current random order.

For example, an app that can concatenate images may allow user to pick multiple image files at a time (e.g. a web app https://join-screenshots.zhanghai.me/ opened in chrome), and since the images are sequentially concatenated, the user will probably want some kind of order (instead of random order) in such a scenario.

Currently the androidx.recyclerview.selection.Selection class keeps track of user selection with two HashSets, so changing them to use LinkedHashSet (and modifying setProvisionalSelection() a bit) should be doable to keep user selection order in most cases.