1009729 - [B2G][Homescreen] Inconsistent flashing/non-flashing edit mode behavior when moving icons around the homescreen

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::Homescreen, defect)

Description

[Natalya Kot [:nkot]]

Description:
Edit mode behavior seems to be inconsistent - sometimes icons are flashing when longpress and move them around, sometimes aren't. 

Repro Steps:
1) Updated Open_C BuildID: 20140512040203
2) Long-press any icon on the grid and move it around the screen
3) Long-press any icon on the Dock and move it to the grid page
4) Long-press any icon on the grid and move it to the Dock
5) Observe icons behavior while in Edit mode

Actual:
Icons are flashing when moving them from the grid to the Docs, and aren't flashing when moving them around the screen or from the Dock to a grid page

Expected:
Edit mode behavior is consistent when moving icons from/to the Dock or around the screen 

Environmental Variables:
Device: Open_C master m-c
BuildID: 20140513040202
Gaia: de1c755411949b50ae395b42e124af215ed9b702
Gecko: 7f5a8526b55a
Version: 32.0a1
P821A10V1.0.0B06_LOG_DL

Notes: on 1.4 icons are flashing in Edit mode

Repro frequency: 100%
See video at http://youtu.be/65rbx7c8Ipc

Comment 1

[Natalya Kot [:nkot]]

happens on Buri trunk too

Comment 2

[Natalya Kot [:nkot]]

correct video link http://youtu.be/Ucv7dzYIiHA

Comment 3

[Cristian Rodriguez (:crdlc)]

Basically the problem is:

1. Press and hold an icon
2. Move it around
3. Release the icon and unexpectedly a 'click' event is dispatched and we exit from edit mode

https://github.com/mozilla-b2g/gaia/blob/master/apps/homescreen/js/homescreen.js#L78
https://github.com/mozilla-b2g/gaia/blob/master/apps/homescreen/js/homescreen.js#L107

Comment 4

[Cristian Rodriguez (:crdlc)]

Attachment: Patch v1

This patch prevents the behavior explained in comment 3. I mean, the issue disappears because we are doing more robust the handler. Although it seems a bug on Gecko, if users press&hold in some place and they move the finger across screen. Then a 'click' event shouldn't be dispatched thought. Thanks Vivien for the review

Comment 5

[Jason Smith [:jsmith]]

This is potentially bad because it becomes not clear that the homescreen is in edit mode or not, which is confusing UX.

Comment 6

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

(In reply to Cristian Rodriguez (:crdlc) from comment #4)
> Created attachment 8422245 [details]
> Patch v1
> 
> This patch prevents the behavior explained in comment 3. I mean, the issue
> disappears because we are doing more robust the handler. Although it seems a
> bug on Gecko, if users press&hold in some place and they move the finger
> across screen. Then a 'click' event shouldn't be dispatched thought. Thanks
> Vivien for the review

That sounds correct. A click should not fired if you move your finger on the screen, even after a long press. Can you file a platform bug against the product: Core, and Component: Panning and zooming. Then in the title you can add set "[APZ] Click events are fired after a long press, even if the user has moved the finger".

Comment 7

[Vivien Nicolas (:vingtetun) (:21) - (NOT reading bugmails, needinfo? please)]

Comment on attachment 8422245 [details]
Patch v1

R+ if you open a bug on the platform side, and add a comment containing "Bug XXXXXX" in your patch, next to the code, explaining why you need this workaround.

Comment 8

[Cristian Rodriguez (:crdlc)]

See bug 1011389

Comment 9

[Cristian Rodriguez (:crdlc)]

Merged in master:

https://github.com/mozilla-b2g/gaia/commit/50dc6a7b5332b3a67dc9fafb938d2336de0a21df