1504210 - PointerEvents for the left mouse button do not work correctly on MacOS when Control is pressed

Status: NEW

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Description

[Patrick Dähne]

Attachment: controlClickBug.html

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:63.0) Gecko/20100101 Firefox/63.0

Steps to reproduce:

Open the attached test file "controlClickBug.html" with Firefox on MacOS. Press&hold the control button and click the left mouse button when the mouse pointer is over the page.


Actual results:

I get "mousedown" printed on the web page when pressing the left mouse button, and "pointerup" followed by "mouseup" when releasing the left mouse button.


Expected results:

I expect to get "pointerdown" printed on the web page when pressing the left mouse button, and "pointerup" when releasing the left mouse button. I do not expect to get any mouse events.

Comment 1

[Daniel_A[:daschilean] [Please contact - [e-mail]]]

User Agent:  Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:65.0) Gecko/20100101 Firefox/65.0 
Build ID: 20181106100114     
I manage to reproduce this on Macbook 10.14 with Firefox Nightly 65.0a1 (2018-11-06).

Comment 2

[Marcos Caceres [:marcosc]]

Also able to reproduce in Nightly. Tim, any thoughts what might be causing this?

Comment 3

[Tim Huang[:timhuang]]

Sorry for my late response. My speculation is that holding the Control button changes the order of events. In other words, the mousedown event sends before the pointer down event in this case. But how? I am not really an expert of events, so I might be wrong here.

Masayuki, do you happen to know the reason?

Comment 4

[Hsin-Yi Tsai (she/her) [:hsinyi]]

We'll need to have someone own this (pointer events). Working towards a plan.

Comment 6

[Edgar Chen [:edgar]]

We probably doesn't handle the mouse event with modifiers well.

Comment 7

[Edgar Chen [:edgar]]

For Control + left mouse button case, it seems there is a bug in https://searchfox.org/mozilla-central/rev/a4be2fbe9bd4f405c91cc16e4e3a80400f5a9301/dom/events/PointerEventHandler.cpp#512-517 which init a pointermove event instead.

Comment 8

[adrian]

(In reply to Edgar Chen [:edgar] (OOO from 2/19 to 3/6) from comment #7)

For Control + left mouse button case, it seems there is a bug in https://searchfox.org/mozilla-central/rev/a4be2fbe9bd4f405c91cc16e4e3a80400f5a9301/dom/events/PointerEventHandler.cpp#512-517 which init a pointermove event instead.

I too just noticed that, there always seems to be a pointermove event instead of the pointerdown. This issue is really important to us because our product is a datavis toolkit and so this breaks our right click interactions

Comment 9

[Edgar Chen [:edgar]]

This should be fix on Nightly now (bug 1615732), but we still need to fix bug 1630959 first before enabling it on all channel (bug 1630962).

Comment 10

[John Leary]

I don't think this is fixed on Nightly. Control-click generates pointerdown→mousedown→contextmenu on Chrome 95 and Safari 14.1, but still only mousedown→contextmenu (i.e. it omits "pointerdown") on FF 95 and Nightly. [See https://jsfiddle.net/y8ot42pa/]

Setting “dom.event.treat_ctrl_click_as_right_click.disabled” to true does seem to fix the issue, but I'm not sure what the side effects are.

Using a 2012 MacBook Pro running Mojave 10.14.6.