1962592 - Too many tabs.onMoved event fired when a tab group is moved to a new window

Status: RESOLVED FIXED

(WebExtensions :: General, defect)

Description

[Rob Wu [:robwu]]

While working on extra test coverage for the tabGroups.move API, I discovered that the tabs.onMoved event fires too frequently when a tab group is moved to a new window. There are multiple reasons for that:

• TabMove is fired whenever the tab group changes. adoptTabGroup adopts tabs by first moving tabs from another window, then adopting tabs in the tab group. Consequently, there is always a transition between tab groups, and tabs.onMoved is fired for each tab in the group.

• When adoptTabGroup adopts tabs, it puts all tabs at the front of the specified destination. Consequently, tabs appear in reverse order before finally being moved to its destination. This final move may trigger additional TabMove events, and therefore also tabs.move.

• The implementation of tabGroups.move first adopts tab groups at the end of a window, and then moves it to its destination. This all will trigger tabs.onMoved events.

Comment 1

[Rob Wu [:robwu]]

Attachment: Bug 1962592 - Avoid unnecessary tabs.onMoved when moving tab groups

This patch covers multiple cases:

• Pre-existing issue: adoptTabGroup adopts tabs by first moving the tabs
  elsewhere, then moving it into a group. When moved into a group,
  TabMove is fired, which previously translated to tabs.onMoved. That
  would result in too much event noise.

• When tabGroups.move is called, it first adopted the tab group in
  another window, and then moved the tab group as a whole. This
  results in unnecessary tabs.onMoved events too. The fix is to specify
  the desired position at once to adoptTabGroup.

Comment 2

[Rob Wu [:robwu]]

Attachment: Bug 1962592 - Reduce tab moves in adoptTabGroup

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/18acdfacc01b
Avoid unnecessary tabs.onMoved when moving tab groups r=zombie
https://hg.mozilla.org/integration/autoland/rev/52abc36a8c48
Reduce tab moves in adoptTabGroup r=tabbrowser-reviewers,dao

Comment 4

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/18acdfacc01b
https://hg.mozilla.org/mozilla-central/rev/52abc36a8c48