onUpdate called twice in Widget

In my widget app, every time I switch between views (WatchUi.switchToView, WatchUi.pushView), the View.onUpdate of the new view is called twice. This happens after View.onShow, which is called only once.

Is there any reason/logic for that? My onUpdate is pretty intense, so I do not want to waste resources.

Also, it happens before any other user input is processed. So, if I push the up/down key multiple times, then the view change of the first key press is completed including the second call to onUpdate, before then the next key press is processed.

I have tested this in the simulator only, not yet sure if it happens on the device as well.

There was similar question, but not really a conclusion for it: forums.garmin.com/.../onupdate-is-called-twice

0 jim_m_58 20 days ago

What are you using for transition when you switch or push? I've seen where something other than SWITCH_IMMEDIATE result in onUpdate being called more than once

0 the-ninth 20 days ago in reply to jim_m_58

I am using SLIDE_UP and SLIDE_DOWN, but it also happens with SLIDE_IMMEDIATE, I just tried it.

Also I tested it on the real device and it happens there as well.

0 the-ninth 20 days ago in reply to the-ninth

So I found one difference that the second onUpdate seems to make. When starting the app in widget mode on my physical Epix2Pro, after the screen pops up, it briefly shows in dimmed brightness before it shows in full brightness. It seems the dimmed brightness is the first onUpdate, the full brightness the second onUpdate.

If I do not redraw in the second onUpdate, then the view STAYS in the dimmed brightness.

But that affects only the first view shown when the app starts. When after that I switch between views they show fine, even if I suppress the second onUpdate.

0 flocsy🤠 20 days ago in reply to the-ninth

I wouldn't start to add hacks that are based on what you see on one physical device you own. It is possible your hack will cause your app not to work on other devices.

0 the-ninth 20 days ago in reply to flocsy🤠

Yes, that is my conclusion as well, I removed the code that skips the second onUpdate.