1016283 - [Keyboard][V2.0] Flash of black happens on keyboard when you quickly switch built-in keyboard

Status: VERIFIED FIXED

(Firefox OS Graveyard :: Gaia::System::Input Mgmt, defect)

Description

[William Hsu [:whsu]]

Attachment: WP_20140527_016.mp4

* Description:
  This is a regression bug. V1.4 build doesn't have this problem.
  Quickly switch built-in keyboard, you will see the twinkle on keyboard.
  Attach the demo video.(WP_20140527_016.mp4)

* Reproduction steps:
  1. Enable many built-in keyboard layouts
  2. Launch the message app
  3. Tap "Pencil" icon to edit a message
  4. Tap message field
  5. After keyboard pops up, quickly tap the "Globe" key to switch keyboard layout

* Expected result:
  You can smoothly switch to the other keyboard layouts

* Actual result:
  Twinkle happens on keyboard

* Reproduction build: V2.0 (Buri)
 - Gaia      f3b5d74dd3428c89cab06db734c62f3c9dbb8c4d
 - Gecko     https://hg.mozilla.org/mozilla-central/rev/e86a0d92d174
 - BuildID   20140525160203
 - Version   32.0a1

Comment 1

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I assume "Twinkle" means flash of black.

Comment 3

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I am having trouble identifying the regression window of this. I thought this was due to my recent keyboard app change but it does to be the case.

Comment 4

[Jason Smith [:jsmith]]

This needs to be a blocker in order to get a window on it, but I'm not sure I would block on this issue.

Comment 5

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I am now suspect this is due to the fact we setVisible(false) and setVisible(true) in the same function loop in the input management code, so, switching components.

Comment 6

[Tim Guan-tin Chien [:timdream] (please needinfo)]

I can now verify this is because we setVisible(false) and setVisible(true) the same frame in the same function loop, when we switch between layouts of the same app.

Removing this line 
https://github.com/mozilla-b2g/gaia/blob/f60210825f0840f95819f47a878b165019f232e9/apps/system/js/keyboard_manager.js#L678

will get rid of the flash. This also means this bug is not a "regression" as the symptom only visible on mid-end phones.

To properly fix this I think we need a better keyboard frame life cycle management. John, I asked you to study input management; do you think you understand this part of code well enough to address this? If not I can continuing working on this.

Comment 7

[John Lu [:mnjul][Please NI or I'll miss]]

Nope, I was distracted by several new lockscreen visual refresh bugs and haven't had time to well study the codes yet.

Comment 8

[Mozilla Shepherd (This account is used for automation and doesn't receive bugmail)]

Attachment: mozilla-b2g:master PR#20353

Comment 9

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Comment on attachment 8438324 [details] [review]
mozilla-b2g:master PR#20353

I decide to do a quick fix first before working on something else because this is annoying enough. Sadly this make keyboard_manager.js a little bigger than before. I also didn't add any tests because that function has no tests at first place.

Comment 10

[Rudy Lu [:rudyl] (inactive after 2015/7/3)]

Comment on attachment 8438324 [details] [review]
mozilla-b2g:master PR#20353

r=me.
Thanks.

Comment 11

[Tim Guan-tin Chien [:timdream] (please needinfo)]

master: https://github.com/mozilla-b2g/gaia/commit/c0d1670ba57666210a7e7fd021ca4d9b47ab990c

Comment 12

[William Hsu [:whsu]]

Thanks Tim!
I cannot reproduce this bug on the latest V2.1(Master) build.

* Build information:
 - Gaia      83392cae2c964fa6f8a97ac3fc515c3f94ef3c1c
 - Gecko     https://hg.mozilla.org/mozilla-central/rev/c4cf1181993e
 - BuildID   20140617160234
 - Version   33.0a1

Comment 13

[Rachel Pribble [:rpribble]]

This issue is still occurring on the Flame v2.0 MOZ ril since the fix was only uplifted to the v2.1 master.

Environmental Variables:
Device: Flame 2.0 MOZ ril
Build ID: 20140623000201
Gaia: 729f214b887ce8efe7d870145d31acb2c6427817
Gecko: 117ba3eda4d2
Version: 32.0a2 (2.0) 
Firmware Version: v121-2
User Agent: Mozilla/5.0 (Mobile; rv:32.0) Gecko/32.0 Firefox/32.0

Tapping the language layout button to change the language of the keyboard results in the keyboard rapidly flashing in and out of view. User is able to see the background momentarily, rather than the keyboard remaining visible and transitioning smoothly.

Comment 14

[John Lu [:mnjul][Please NI or I'll miss]]

Backed-out on master: https://github.com/mozilla-b2g/gaia/commit/6ba0bc68738f70edc42d496cfede5ea09af334d4 due to causing 2.0+ bug 1031505

Comment 15

[Rudy Lu [:rudyl] (inactive after 2015/7/3)]

Let's change the status to re-opened to reflect that fact that the patch has been backed out.

Comment 16

[Tim Guan-tin Chien [:timdream] (please needinfo)]

We decide to keep the patch in master and address regression in bug 1031505.

master: https://github.com/mozilla-b2g/gaia/commit/d5b9c54acdd948f39e8db714db174d90ff2d7b9e

Comment 18

[xiupinglong]

[Blocking Requested - why for this release]:

Dear Tim Guan-tin Chien,

When will be fixed on v2.0?

Comment 19

[Yeojin Chung [:YeojinC]]

This issue is verified on Flame 2.1.

Result: The keyboard changes smoothly without showing the background.

Device: Flame 2.1 (319mb)(Kitkat Base)(Full Flash)
BuildID: 20141029001202
Gaia: eb0aab0f13c78c7ac378ad860e865c4b6eaf669f
Gecko: 318019f80a8e
Gonk: 48835395daa6a49b281db62c50805bd6ca24077e
Version: 34.0 (2.1)
Firmware: V188
User Agent: Mozilla/5.0 (Mobile; rv:34.0) Gecko/34.0 Firefox/34.0
==================================
2.0 is marked as wontfix.

Comment 20

[Jack Liu]

Hi Wesly,

From product point of view, this bug must be fixed in 2.0. 
It's not good that end users suffer it continuously because 2.1/2.2 is a long way to go.

Thanks to push patch uplift.

Comment 21

[Wesly Huang (EPM)]

[Triage] after discussion, pls partner to take patch, but Triage only nom. to 2.2 instead of 2.0.

Comment 22

[Jack Liu]

(In reply to Wesly Huang from comment #21)
> [Triage] after discussion, pls partner to take patch, but Triage only nom.
> to 2.2 instead of 2.0.

Thanks, will take and verify the patch then feedback.

Comment 23

[Yeojin Chung [:YeojinC]]

This issue is verified on Flame 2.2.

Result: The keyboard changes smoothly without showing the background.

Device: Flame 2.2 (319mb, KK, Full Flash)
BuildID: 20141107040206
Gaia: 779f05fead3d009f6e7fe713ad0fea16b6f2fb31
Gecko: 64f4392d0bdc
Gonk: 48835395daa6a49b281db62c50805bd6ca24077e
Version: 36.0a1 (2.2 Master)
Firmware: V188
User Agent: Mozilla/5.0 (Mobile; rv:36.0) Gecko/36.0 Firefox/36.0

Comment 25

[Tim Guan-tin Chien [:timdream] (please needinfo)]

(In reply to Wesly Huang from comment #21)
> [Triage] after discussion, pls partner to take patch, but Triage only nom.
> to 2.2 instead of 2.0.

Not a 2.2 blocker since the regression happens on 2.0.