459203 - Calendar/task tab switching might be slowed without cause by mode logic

Status: RESOLVED DUPLICATE of bug 516802

(Calendar :: Lightning Only, defect)

Description

[Andrew Sutherland [:asuth] (he/him)]

My changes to lightning for the initial tab implementation on bug 402365 still rely on the preexisting mode mechanism so that switching between calendar and tasks works properly.  (This is required because they share a single tab panel, so configuration changes are required.)  Because I also left the 'Go' mode menu options intact, we also still use the "mail" mode.

In the case when we are switching from a calendar tab to a mail tab back to the calendar tab, there should be no need for layout changes, but I suspect they are happening as a result of the spurious mode changes and perhaps the should-be-idempotent DOM attribute changes (for deck change and some collapsing).

Important: I do not know for sure that this is causing unneeded layout, but if it's not happening, it's sure slow, and we have bigger problems.  I am marking this dependent on 402365 so it doesn't get lost, as slow tab switching sucks.