Steps to Reproduce

http://zkfiddle.org/sample/1s71k57/1-ZK-3166-SlideEvent-not-triggered-when-setSlide-true
Click "west toggle slide" or "east toggle slide" (Both are the same)

When clicking the collapsed region bar (not button) / anywhere on the page, it would trigger an onSlide event.
Using server side setSlide(false), it triggered an onSlide event.

Current Result

An onSlide (slide = false) event triggered

Expected Result

Both true and false events are not triggered. Since they are not user's interaction.
https://www.zkoss.org/javadoc/latest/zk/org/zkoss/zk/ui/event/SlideEvent.html

Represents an event cause by user's slidedown or slideup something at the client.

Debug Info

Root Cause

ZK-3166

Workaround