Shelf focusing does not work properly when the bubble is open even without ChromeVox right now. Let me investigate that.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4682f12f040444273c1996e9b4a4b2985dc973ef

commit 4682f12f040444273c1996e9b4a4b2985dc973ef
Author: Sammie Quon <sammiequon@google.com>
Date: Fri Jul 13 17:34:19 2018

shelf: Allow focus items in the overflow bubble.

Currently if the bubble is open, you cannot focus the items in the bubble
using the keyboard. Also, if there are for example 4 items in the bubble
and the bubble is closed, you have to tab 4 times to get from the last
item on the main shelf to the first item.

This cl makes the overflow bubble activatable, and focuses it when the
index is out of visible bounds on the main shelf. The main shelf regains
focus when the index is out of visible bounds on the overflow shelf.
This cl also fixes when the overflow bubble is closed, there will not
be need to press tab extra to loop back to the beginning.

Test: add tests
Bug: 854313
Change-Id: Ib36939952488ae23300062300bdc43a7b2a1e5fc
Reviewed-on: https://chromium-review.googlesource.com/1125317
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574964}
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/public/cpp/shell_window_ids.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/overflow_bubble.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/overflow_bubble.h
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/overflow_bubble_view.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/overflow_bubble_view.h
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/overflow_bubble_view_test_api.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/shelf_view.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/shelf_view.h
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/shelf_view_unittest.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/shelf_widget.cc
[modify] https://crrev.com/4682f12f040444273c1996e9b4a4b2985dc973ef/ash/shelf/shelf_widget.h

Note that we also have an issue here with unlabeled images in the status area, e.g. for battery, wifi and more. if using linear navigation with ChromeVox (Search + Right or using one finger to swipe left to right) you don't access these, as when you get to that area you hear "status tray, time is X, battery is X% full, button". But if you use the other mode of navigation -- touch exploration -- to hear whatever is under your finger, you hear "image, image, image" in that area. We need to make sure that those individual items have labels and are marked up properly. 

Ok so this issue really describes several issues that can be fixed independently (in the future, if possible please file one bug per problem, so that it's easy to independently route them, prioritize them -- some are more serious than others -- and fix them).

1) Overflow button is in the wrong visual order

2) Cannot focus items in the overflow bubble with linear swiping.

3) Images in the system tray (battery, wifi, etc.) are not labelled.

1 and 2 belong to the shelf, 3 belongs to the system tray.

If my understanding is correct 2 has already been fixed (comment #3). 1 and 3 remain.

Could someone educate me on how to test these out in the sandbox/emulator ?

I enable Chromebox with Ctrl-Alt-Z. Then I can use Tab to move the focus, but I can never get to the shelf.

If I emulate a touch pointer (instead of mouse), then I can tap on a shelf icon and get the focus there, but then I can't move it around either with Tab (does nothing) or by swiping (that just focuses the thing I'm swiping on instead).

manucornet - You can focus shelf using accelerator Ctrl + alt + L [1]. Then Chromevox should speak out back button or app list button IIRC.

[1] https://cs.chromium.org/chromium/src/ash/public/cpp/accelerators.cc?rcl=9969da5569521f95c9bef9950adb661f795d443a&l=112

Thanks Sammie! It's actually Alt-Shift-L ;-) Thanks for the pointer to the list!

So currently if I use Alt-Shift-L to focus the first shelf button (app list if not in tablet mode) and then use Tab to cycle, I go through all shelf items, but I never get to the overflow button. I get directly from the last app in the list to Launcher. Maybe there's another regression in there.

If the overflow bubble is open, then the shelf items within are part of the focus cycle (I assume that's thanks to Sammie's changes), but the overflow button itself isn't, so it doesn't look like I can open/close the bubble like that.

Oopsies :P. The overflow button was not part of the cycle list when i uploaded the patch in c#3, FWIW.

Ok I think I need a little more advice before I start messing things up :-D The code for this seems to be mostly in

https://cs.chromium.org/chromium/src/ash/shelf/shelf_view.cc?q=FindNextFocusableView+f:shelf_view&sq=package:chromium&g=0&l=158

What is the expected/desirable behavior with regards to the overflow button itself?

I don't see a keyboard shortcut to focus the overflow button (unless I missed it?), so I assume it would be desirable to make it focusable as part of the focus cycle for all shelf items? So that it can opened when it's closed, and closed when it's open? If so, what should be the order when the overflow bubble is closed? [Main shelf items] -> [Overflow shelf items] -> Overflow button? Or [Main shelf items] -> Overflow button -> [Overflow shelf items]?

Now that you mention it my fix doesnt work that well, perhaps i meant to follow it up with a follow up patch but forgot.

I think [Main shelf] -> button -> [overflow] sounds good. Maybe add a ux to be sure.

But i think we can just add the overflow button into the focus cycle in the link.

Specific bug for navigating to the overflow button:  issue 890894 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/65594253ffebb0fd364da090856b6f195895eab8

commit 65594253ffebb0fd364da090856b6f195895eab8
Author: Manu Cornet <manucornet@chromium.org>
Date: Sat Jan 19 11:12:13 2019

CrOS shelf: Simplify focus cycling code and add overflow button

Bug:  890894 , 854313
Change-Id: I734714f3e6457852d038a00c481cc5425b8bf89c
Reviewed-on: https://chromium-review.googlesource.com/c/1420920
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Auto-Submit: Manu Cornet <manucornet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624462}
[modify] https://crrev.com/65594253ffebb0fd364da090856b6f195895eab8/ash/shelf/shelf_view.cc
[modify] https://crrev.com/65594253ffebb0fd364da090856b6f195895eab8/ash/shelf/shelf_view.h
[modify] https://crrev.com/65594253ffebb0fd364da090856b6f195895eab8/ash/shelf/shelf_view_unittest.cc

From comment #10, number 1 and 2 are now fixed. Switching component to Status Area for number 3.