309704 - Keyboard-only users get stuck in plugins ( applet/embed should only be focusable, not tabbable)

Status: VERIFIED FIXED

(Core :: DOM: UI Events & Focus Handling, defect)

Description

[Aaron Leventhal]

Right now keyboard only-users can get themselves in trouble by tabbing into a
plugin. For example, on http://www.macromedia.com you can tab in and then you go
keydead in Firefox. At that point you can't even close the app with the keyboard.

Eventually we want the tabbable contents of plugins to be in the tab order, but
not the <embed> or <applet> object itself. That is how things work in IE, where
the tab navigation story with plugins is working correctly.

So there are 2 reasons to remove them from the tab order:
1. It will keep keyboard-only useres from going into a keydead state
2. There is no reason to have the plugin itself be in the tab order -- just the
contents in it may need to be able to take focus or be tabbable.

Comment 1

[Aaron Leventhal]

At one point this is how we acted but we weren't allowing focus even via click.
When that was fixed via bug 257488 it also caused the keydead problem to appear
(or reappear I'm not sure anymore).

Comment 2

[Aaron Leventhal]

Attachment: Use tabindex = -1 for default value of applet/embed

Comment 3

[Aaron Leventhal]

Attachment: Default tabindex of -1 for applet, object, sharedobjectelement and sharedelement. Makes them focusable but not tabbable.

Not sure if all of them even need tabindex = -1 ...

Do the sharedobjectelement and sharedelement only get instantiated by the
plugin? Are they inner objects within the object/applet? I'm not sure how that
code works. If my guess is correct, I would think only the inner ones would
need tabindex -1 so that they're focusable. Please advise.

Comment 4

[Aaron Leventhal]

Regression -- this wasn't a problem in Firefox 1.0.x

Comment 5

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 197135 [details] [diff] [review]
Default tabindex of -1 for applet, object, sharedobjectelement and sharedelement. Makes them focusable but not tabbable.

Why not just use NS_IMPL_INT_ATTR then?

Comment 6

[Aaron Leventhal]

Attachment: NS_IMPL_INT_ATTR_DEFAULT_VALUE -> NS_IMPL_INT_ATTR (either way uses -1 for default value)

Bz, here you go, but in a way I like explicitly specifying what the default
value is because it's just as good as a comment. It compiles to the same
machine code.

Comment 7

[Mike Schroepfer]

Can we get trunk verification on this?

Comment 8

[Tracy Walker [:tracy]]

As of 0930 Firefox builds this is working on Linux but still broken on Mac and
Windows.  As tested on Linux 1.4, Windows 1.4 and Mac trunk. 

Comment 9

[Asa Dotzler [:asa]]

Aaron, this bug is seriously at risk for not making 1.5. 

Comment 10

[Scott MacGregor]

QA: has this gotten any better in todays build given the fix from 310626? 

If this is still broken on Windows and Linux, we may back it out to fix Bug 311111

Comment 11

[Marcia Knous [:marcia]]

Using today's branch build, Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US;
rv:1.8b5) Gecko/20051004 Firefox/1.4.1, this doesn' seem to work in better. On
the Macromedia site, I still get stuck in the plugin and am unable to tab out of
it. On to check Mac next - Tracy indicated that this did work in Linux but was
broken on Windows and Mac.

Comment 12

[Samuel Sidler (old account; do not CC)]

This WFM as expected on OS X 10.4 with Mozilla/5.0 (Macintosh; U; PPC Mac OS X
Mach-O; en-US; rv:1.8b5) Gecko/20051004 Firefox/1.4.1.

I have full keyboard access on and used weather.com as a test. We do get stuck
in the Flash if the user has clicked their first, but I'm told that's the
expected behavior.

Comment 13

[Scott MacGregor]

Samuel, what do you mean by this works as exepected? If you use a 9/23 build and
compare it todays build, you see the same behavior, that is getting stuck in the
plugin?

Comment 14

[Samuel Sidler (old account; do not CC)]

(In reply to comment #13)
> Samuel, what do you mean by this works as exepected? If you use a 9/23 build and
> compare it todays build, you see the same behavior, that is getting stuck in the
> plugin?

No, I see two different behaviors. In the Mac branch build from 9/23, we tab
into the plugin and get stuck. In the 10/4 branch build, we ignore the plugin
and tab around it, never getting stuck in it. The only time we get stuck in the
plugin is if a user click (with their mouse) in the plugin and tabs back and forth.

Comment 15

[Scott MacGregor]

On Windows, using the 09/23 and a 10/04 build, I see the same behavior when
going to macromedia. In both builds, I can tab around the plugin on the front
page but can't tab out of the plugin. And I'm key dead, I can't do alt-f to
bring up the file menu, etc. As such, I don't think backing out this patch is
going to make this issue any worse for Windows and Mac, and it would fix the
regression.

Comment 16

[Mark Mentovai]

This patch wasn't intended to allow you to tab out of a plugin that's already
gotten focus, it was intended to prevent keyboard-only users from tabbing into a
plugin in the first place.  If you manage to focus the plugin by other means
(mouse click), you'll go key-dead.

Comment 17

[Samuel Sidler (old account; do not CC)]

I see the same behavior on Windows using the 10/4 branch build as I do on Mac.
This is the desired behavior of this bug/patch.

This bug should be re-closed as FIXED.

Comment 18

[Scott MacGregor]

(In reply to comment #17)
> I see the same behavior on Windows using the 10/4 branch build as I do on Mac.
> This is the desired behavior of this bug/patch.
> 
> This bug should be re-closed as FIXED.

Hmmm, using a 9/23 build I can't tab into a plugin using just the keyboard. Same
with the 10/04 (i.e with or without this patch). I'm clicking in the content
window (not the plugin) and then hitting tab and it starts tabbing through the
HTML elements but not the plugin. 

Comment 19

[Samuel Sidler (old account; do not CC)]

(In reply to comment #18)
> Hmmm, using a 9/23 build I can't tab into a plugin using just the keyboard. Same
> with the 10/04 (i.e with or without this patch). I'm clicking in the content
> window (not the plugin) and then hitting tab and it starts tabbing through the
> HTML elements but not the plugin. 
> 
> 

Using the 9/23 branch build of FF/Win, I do the following to reproduce the bad
behavior:

1. Surf to weather.com
2. Place the cursor in the location bar (if it wasn't already)
3. Tab ~25 times

On about the 25th time (depending on if you got a pop-up or not), my cursor is
in the Flash animation which is titled "Play Ball!". I am unable to get the
cursor out of it.

Following the same steps with the 10/4 build results in me being past the Flash
and still tabbing on content.

Comment 20

[Marcia Knous [:marcia]]

I am seeing what Scott sees on the mac, using the 9/23 build I can't tab
directly into the plugin (Macromedia site) and get in the stuck state.  It would
be helpful to understand exactly what the expected behavior is here so we can
test this on all three platforms using various plugins just to verify that it is
in fact fixed.  Thanks.

Comment 21

[Samuel Sidler (old account; do not CC)]

For the record, I get stuck in Flash on macromedia.com within 4-5 tabs from the
location bar in FF/Win/Branch from 9/23.

Also: I'm testing on weather.com mainly because macromedia.com is broken in the
10/4 official nightlies.

Comment 22

[Marcia Knous [:marcia]]

Samuel and I spent some time on IRC and I can confirm that the behavior now
differs between the 092305 build and today's branch build on the weather.com
site. I was testing on Mac 10.4.2 and see that in today's build I don't get hung
up in that one area.

(In reply to comment #19)
> (In reply to comment #18)
> > Hmmm, using a 9/23 build I can't tab into a plugin using just the keyboard. Same
> > with the 10/04 (i.e with or without this patch). I'm clicking in the content
> > window (not the plugin) and then hitting tab and it starts tabbing through the
> > HTML elements but not the plugin. 
> > 
> > 
> 
> Using the 9/23 branch build of FF/Win, I do the following to reproduce the bad
> behavior:
> 
> 1. Surf to weather.com
> 2. Place the cursor in the location bar (if it wasn't already)
> 3. Tab ~25 times
> 
> On about the 25th time (depending on if you got a pop-up or not), my cursor is
> in the Flash animation which is titled "Play Ball!". I am unable to get the
> cursor out of it.
> 
> Following the same steps with the 10/4 build results in me being past the Flash
> and still tabbing on content.

Comment 23

[Samuel Sidler (old account; do not CC)]

Resolving FIXED per comment 22.

Comment 24

[Tracy Walker [:tracy]]

comment 16 clarifies this bug to me.  
Tested with the 1.4.1 builds of 2005-10-04-18-mozilla1.8 on Win, Mac and Linux

able to tab around flash plugin.  VERIFIED FIXED

Is there a bug open for not being able to tab out of the flash plugin content?

Comment 25

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1527381