I have confirmed some existing issues.

In the list view mode, it reads like:
"New Folder, dashes, Folder Today 1:23 PM, List item 1 of 2 Selected".
- "Selected" is read last. I guess this is done by the same way as for a normal list like https://www.w3schools.com/tags/tryit.asp?filename=tryhtml_select_multiple , but it is inconvenient here.
- File Size field is blank for folders. It's denoted as "--" and read as "dashes".

In the thumbnail view mode, it reads like:
"List item New Folder, List item".
- Selection status is not read at all.

But I could not reproduce #2.
> we can't hear "selected" state for folders, only image files. 

I haven't came up with the final solution yet, but if we want to read it as
"Selected, New Folder, dashes, Folder Today 1:23 PM, List item 1 of 2",
it is likely to be a large change or require tricky hack.
If we can accept it read like
"Selected, New Folder, dashes, Folder Today 1:23 PM, List item 1 of 2 Selected",
it would be a bit easier.

In either case I think we would also want to fix  Issue 762748 , which reads the same row twice.

+lpalmaro@ FYI. On (2), can you provide some more detail on how to reproduce?

I have found that currently the checkbox in the list view (either thumbnail or an icon) can be focused by touch or accessibility keyboard navigation, but has no aria-text. So it reads nothing.

So I think we should make it recognized as checkbox and labeled by the filename, so that user can know that the file is selected or not by touch or focusing.
For example, "abc.txt checkbox checked".
Using this way user will be able know if a file is selected or not quickly, without waiting for the entire row read.

(Though we's still want better reader output after selecting a file as well.)

I think reading it as "Checkbox checked" is not a good alternative for "Selected".
aria-multiselectable and aria-selected might work with Chromebox? (I haven't checked it, sorry!)

aria-multiselectable looks more suitable for the file list, but it'd only change the way to read the outer list box (but not the items) AFAIK.
https://cs.chromium.org/chromium/src/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js?q=aria_multiselectable_true&sq=package:chromium&l=224

I'll consider a different way for reading the whole row even if we go with annotating the checkboxes. (It will not be read with current rule when focusing the whole row.)

To summarize, here is what I am thinking (and trying to do partially):

- When touching or focusing on the checkbox (= thumbnail / file type icon),
"checkbox, checked" or "checkbox, not checked"
- When focusing the entire row (by using keyboard or Seachr+arrow key)
"1.txt 200 bytes Plain text January 1, 2017, list item 3 of 10 [selected]"
- Right after (un)selecting a file (either by long-tap or checkbox click),
"[un]Selected 1.txt"

The last one is a new type of announcement, which is like "alert of an event" which is distinct from just reading the UI elements being focused. I will see if this is feasible in the app.

Deleted: files-screenreader.png 88.7 KB

	files-screenreader.png 88.7 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4ada703cc2eff3c7de3a832b42a9d4805aca62d3

commit 4ada703cc2eff3c7de3a832b42a9d4805aca62d3
Author: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Date: Tue Oct 17 06:13:11 2017

ChromeVox: Output selection status of listbox option items first.

Bug:  762746 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I77f2279247ffdf33790946f623ff4115b2752e0b
Reviewed-on: https://chromium-review.googlesource.com/715837
Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Tatsuhisa Yamaguchi <yamaguchi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509288}
[modify] https://crrev.com/4ada703cc2eff3c7de3a832b42a9d4805aca62d3/chrome/browser/resources/chromeos/chromevox/cvox2/background/output.js

Now it reads like [[Selected, a.txt, 128 bytes, plain text, Oct.1, list item 2 of 10]] in the list view mode.

The only remaining concern is that it sounds a bit strange in some languages.
For example in Japanese it says "選択されています" in the place of "Selected" status. It sounds a bit strange to me as it means like "is selected." used isolatedly from the sentence.
However I think those can be fixed by modifying the translation strings. Feel free to file a separate issue entry when needed.

Since we got this solution, I'd like to withhold the 3rd item in Comment #9.
> - Right after (un)selecting a file (either by long-tap or checkbox click),
"[un]Selected 1.txt"

Finally, we could not reproduce this issue in the original report.
> 2) Right now, we can't hear "selected" state for folders, only image files. 

So I think all the issues has been addressed now.