[SLING-4685] Introduce generic discovery.commons.ViewStateManager sharable for impls

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Discovery Commons 1.0.0
• Component/s: Extensions
• Assignee: Stefan Egli
• Reporter: Stefan Egli
• Created: 30/Apr/15 13:12
• Updated: 26/Sep/19 12:40
• Resolved: 04/May/15 10:12

Description

With multiple discovery implementations existing/upcoming it starts to become valuable to share code that can be shared. And with the introduction of discovery.commons we have a nice place for this.

As a first thing, I propose to introduce a discovery.commons.ViewStateManager (the name can be changed if wished of course): this one is capable of managing a number of TopologyChangeListeners, can be in deactivated/activated state and can react on handleChanging and handleNewView events and translates all of those to correct events that it sends to the registered listeners accordingly.

This also takes into account the fact that the TOPOLOGY_INIT should be sent only when the first valid view is available - which is flagged to ViewStateManager via handleNewView.

Issue Links

• relates to: SLING-5094 refactor discovery.impl to use discovery.commons (esp ViewStateManager)