982809 - CustomizableUI offers competing APIs for specifying where a widget should be placed

Status: NEW

(Firefox :: Toolbars and Customization, defect)

Description

[Jared Wein [:jaws] (please needinfo? me)]

Customizable areas can specify defaultPlacements, an array of ordered widget IDs that should be placed in an area by default.
Customizable widgets can specify a defaultArea, an ID of an area that the widget should be placed in by default.

These two properties compete with each other, and it isn't clear which one takes preferences. Through practice, it appears that the outcome of these is different depending on if the widget is created before the area or vice-versa.

One way we could fix this is by moving this placement tracking to an individual component that customizable areas and widgets communicate with. An area could specify what the defaultPlacements are, and a widget could request to be placed in an area.

The nice benefit of this is that we would have one true source of information as to how an area should be built. We still would have an issue based on what registered/requested first.

(Marking as Australis:P- due to the nature of this change and it being super late in the release cycle.)