This helps with creation and getting values and should be safe since it still keeps lvgl on one thread at a time.
Add OnLvglEvent to UIElement that allows foreasy place for UI Elements to respond to LVGL events .
Add button class that can react to being presssed via a callback function.
Add GetBottom() api to allow easy grabbing of bottom Y coordinate.
use some new stuff in the settings page to sort test it all out.
Create a mutex for UI that will help make it possible to run handlers that update UI elements on seprate threads.
its far from perfect but should hold up for now.
