1647711 - mousedown/mouseup preventDefault() doesn't block click

Status: UNCONFIRMED

(Core :: DOM: Events, defect, P5)

Description

[Pierre Ossman]

Attachment: contextmenu.html

User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0

Steps to reproduce:

1. Add event listener for mouseup and mousedown
2. Call preventDefault() in event handler

Actual results:

Got a click event after the mousedown and mouseup events.

Expected results:

Should only have gotten the mousedown and mouseup events.

Comment 1

[Pierre Ossman]

See also bug 186356. Attached test case covers both issues.

Also buggy on Chrome:

https://bugs.chromium.org/p/chromium/issues/detail?id=1098275

Comment 2

[Gyula Palko[:gpalko]]

Setting the component in order to involve the development team.

Comment 3

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

How is the defined in the spec?

Considering the behavior is consistent with other browsers, we shouldn't rush to do this, no matter what the spec definition is.

Comment 4

[Edgar Chen [:edgar]]

Dispatching click event isn't the default action of a mousedown event, nor mouseup event. And spec doesn't define that we should suppress click event if preventDefault() is called in mousedown/mouseup event handler. This is a legacy behavior, all browser behave the same, change this would cause massive compatibility problems.

Comment 5

[Pierre Ossman]

That's a shame, but understandable.

So I guess we as web page developers will have to continue adding handlers just to do preventDefault() on click? Or is there something else that is recommended to state that we want to handle the mouse events fully ourselves?