561809 - Double click related bug

Status: RESOLVED INVALID

(Firefox for Android Graveyard :: Panning/Zooming, defect)

Description

[Benjamin Stover (:stechz)]

I'm not sure what bad things this bug could cause, but it is clearly the wrong check:

http://mxr.mozilla.org/mobile-browser/source/chrome/content/InputHandler.js#634

It is checking to see that the time elapsed between first mousedown and mouseup is less than the double click threshold.  Since the timer expires and cleans upanyways, I'm not sure this if is needed.

Comment 1

[Benjamin Stover (:stechz)]

Vivien did this here: https://bugzilla.mozilla.org/show_bug.cgi?id=547722

Is this so that the single clicks happen as fast as possible?

Comment 2

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

(In reply to comment #1)
> Vivien did this here: https://bugzilla.mozilla.org/show_bug.cgi?id=547722
> 
> Is this so that the single clicks happen as fast as possible?

Exact! I've tried to avoid waiting 400ms when it is unnecessary.

I'm a bit confused, have you found a bug with this code or you just think this code can create bugs? 

(In reply to comment #0)
> I'm not sure what bad things this bug could cause, but it is clearly the wrong
> check:
> 
> http://mxr.mozilla.org/mobile-browser/source/chrome/content/InputHandler.js#634
> 
> It is checking to see that the time elapsed between first mousedown and mouseup
> is less than the double click threshold.  Since the timer expires and cleans
> upanyways, I'm not sure this if is needed.

Do you mean the timer of duration kDoubleClickInterval?
The constant here is kDoubleClickThreshold (maybe the name is confusing)

Comment 3

[Benjamin Stover (:stechz)]

Yes that is confusing to me--could you explain this a little?

Comment 4

[Matt Brubeck (:mbrubeck)]

kDoubleClickInterval is the maximum delay *between* two clicks for them to be a double click.

kDoubleClickThreshold is the maximum *duration* of a single click for it to be part of a double click.  If a click lasts longer than this threshold, it becomes a single click immediately without waiting for the double-click interval.

I think the code for this is correct, and the patch in bug 593499 adds comments to clarify the meanings.