1808965 - Stop calling _mouseleave and _mouseenter from _setPositionalAttributes

Status: RESOLVED FIXED

(Firefox :: Tabbed Browser, task)

Description

[Oriol Brufau [:Oriol]]

The main reason for calling _mouseleave and _mouseenter from _setPositionalAttributes was to update the beforehovered and afterhovered attributes, as the tabs these attributes were set on might change.

However, bug 1808661 is removing these attributes, so mouseenter and mouseleave events should be sufficient for updating _hoveredTab itself.

_setPositionalAttributes is a hot code-path, so avoiding the expensive querySelector("tab:hover") will improve performance.

Comment 1

[Oriol Brufau [:Oriol]]

Attachment: Bug 1808965 - Stop calling _mouseleave and _mouseenter from _setPositionalAttributes. r?Dao

Calling _mouseleave and _mouseenter from _setPositionalAttributes used
to be needed to update the beforehovered and afterhovered attributes,
as the tabs these attributes were set on might have changed.

However, bug 1808661 removed these attributes, so mouseenter/mouseleave
events should be sufficient for updating _hoveredTab itself.

_setPositionalAttributes is a hot code-path, so avoiding the expensive
querySelector("tab:hover") will improve performance when having lots of
tabs.

Depends on D166094

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/4be513bf4ccb
Stop calling _mouseleave and _mouseenter from _setPositionalAttributes. r=dao

Comment 3

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/4be513bf4ccb