PDFx Docs should explain that controller must be rebuilt when rebuilding UI

[gisborne]

Describe the bug I spent far too long to work out why my pdf would draw but not redraw. Looks like it was because my controller was final. The docs should say not to do this (and ideally explain why; which I still don't know)

To Reproduce Steps to reproduce the behavior:

1. Set up final controller for pdfx widget. Cause it to draw and then redraw. Wonder why it doesn't redraw. Try to find out why.

Expected behavior Documentation should explain how to do it properly. Ideally, the controller would tell me what I'm doing wrong with a warning.

[nandakista]

I got same problem, i need to redraw the pdf controller but doesnt work

[NachoPorrasLGFM]

Hi all, got anyone solve this bugs? i can try redraw a pdf document but dont work

[mgcarofano]

I got the same problem when moving from dark theme to light theme while viewing pdf document Here's how I reproduced the bug: https://user-images.githubusercontent.com/75757472/204158074-40420d65-9a6f-459f-b887-aab9a055bef6.mp4