896017 - Defect - Errant mousemove event fires after a touchstart, triggering mouse input scrollbars on content

Status: VERIFIED FIXED

(Firefox for Metro Graveyard :: Input, defect, P2)

Description

[Jim Mathies [:jimm]]

STR:

1) open a scrollable page
2) move the mouse to bring up scrollbars
3) drag the page using touch

result: sometimes mouse scrollbars will reappear after you touch the screen. The cuase is a mysterious mousemove that shows up after the first touchstart, triggering InputSourceHelper's precise input events.

Comment 1

[Brian R. Bondy [:bbondy]]

possibly bug 841228?

Comment 2

[Jim Mathies [:jimm]]

(In reply to Brian R. Bondy [:bbondy] from comment #1)
> possibly bug 841228?

Thought of that too, but it isn't the cause. That triggers in OnTapped, and this event show up while you're still dragging the page around.

I think this is a fairly recent regression, it wasn't doing this when I worked on bug 888329. Working up a debug build so I can trap the event and get a good stack.

Comment 3

[Jim Mathies [:jimm]]

Weird, even in a debug build the stack here is completely hosed - 

 	xul.dll!NS_InvokeByIndex(nsISupports * that=0x0927fc00, unsigned int methodIndex=15, unsigned int paramCount=0, nsXPTCVariant * params=0x02c9de60) Line 71	C++
 	xul.dll!CallMethodHelper::Invoke() Line 2795	C++
 	xul.dll!CallMethodHelper::Call() Line 2133	C++
 	xul.dll!XPCWrappedNative::CallMethod(XPCCallContext & ccx={...}, XPCWrappedNative::CallMode mode=CALL_METHOD) Line 2099	C++
 	xul.dll!XPC_WN_CallMethod(JSContext * cx=0x04840070, unsigned int argc=0, JS::Value * vp=0x02c9e2b8) Line 1315	C++
 	mozjs.dll!js::CallJSNative(JSContext * cx=0x04840070, int (JSContext *, unsigned int, JS::Value *) * native=0x6bfb15e0, const JS::CallArgs & args={...}) Line 225	C++
 	mozjs.dll!js::Invoke(JSContext * cx=0x04840070, JS::CallArgs args={...}, js::MaybeConstruct construct=NO_CONSTRUCT) Line 477	C++
 	mozjs.dll!js::Invoke(JSContext * cx=0x04840070, const JS::Value & thisv={...}, const JS::Value & fval={...}, unsigned int argc=0, JS::Value * argv=0x02c9e42c, JS::MutableHandle<JS::Value> rval={...}) Line 527	C++
>	mozjs.dll!js::ion::DoCallFallback(JSContext * cx=0x04840070, js::ion::BaselineFrame * frame=0x02c9e454, js::ion::ICCall_Fallback * stub=0x09827688, unsigned int argc=0, JS::Value * vp=0x02c9e41c, JS::MutableHandle<JS::Value> res={...}) Line 6996	C++
 	03cc5af5()	Unknown
 	[Frames below may be incorrect and/or missing]	
 	09827688()	Unknown
 	04571180()	Unknown
 	04570b25()	Unknown

Comment 4

[Jim Mathies [:jimm]]

Ah, nm, that was due to the funky way I was trapping this. I have a better stack now.

Comment 5

[Jim Mathies [:jimm]]

Attachment: stack.txt

Odd, this is coming from winrt.

Comment 6

[Jim Mathies [:jimm]]

Attachment: strange.txt

Odd Win8 bug which must have come down in an update, this wasn't happening a few weeks ago. We can work around this in the front end. In fact there's another corner case (touch input while moving the mouse) that we can address at the same time. One concern I have is how this might impact content which also receives this weird mousemove event. If we need to we can filter this down in widget pretty easily.

Comment 7

[Jim Mathies [:jimm]]

My guess is ms will pick up on this bug and eventually fix it.

Comment 8

[Jim Mathies [:jimm]]

Attachment: patch

Comment 9

[Matt Brubeck (:mbrubeck)]

Comment on attachment 778845 [details] [diff] [review]
patch

Review of attachment 778845 [details] [diff] [review]:
-----------------------------------------------------------------

::: browser/metro/base/content/input.js
@@ +1155,5 @@
>   * Helper to track when the user is using a precise pointing device (pen/mouse)
>   * versus an imprecise one (touch).
>   */
>  var InputSourceHelper = {
>    isPrecise: false,

You might want to add "touchisActive: false," here just to avoid possible undefined property warnings.

@@ +1186,5 @@
> +      this.touchIsActive = true;
> +      break;
> +      case "touchend":
> +      this.touchIsActive = false;
> +      break;

nit: please add an extra indentation level to these lines (except the "case" statements), for readability.

Comment 10

[Jim Mathies [:jimm]]

Attachment: export

Comment 11

[Jim Mathies [:jimm]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/c0ae4eae38eb

Comment 12

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/c0ae4eae38eb

Comment 13

[Samvedana (:Samvedana)]

User Agent: Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:25.0) Gecko/20100101 Firefox/25.0
Build ID: 20130805030205

WFM
Tested on Windows 8 for iteration-11 using latest nightly built from http://hg.mozilla.org/mozilla-central/rev/482b9d04974a

I followed steps provided in comment0 and got expected result.
I didn't see mouse scroll-bars reappeared after touching the screen.

Comment 14

[Samvedana (:Samvedana)]

Mozilla/5.0 (Windows NT 6.2; WOW64; rv:26.0) Gecko/20100101 Firefox/26.0
Build ID: 20130815030203
Built from http://hg.mozilla.org/mozilla-central/rev/a8daa428ccbc

WFM
Tested on windows 8 using latest nightly for iteration-12. Followed steps provided in comment0 and got expected result.