Change transparency/opacity based on position of other object

How-to
1

Description

What MCU/Processor/Board and compiler are you using?

x86

What LVGL version are you using?

8.3.3

What do you want to achieve?

I want to change an object’s transparency based on the position of another object. The other object can be dragged but is also animated.

What have you tried so far?

I tried to change the transparency when the other object receives a LV_EVENT_SIZE_CHANGED but that is not triggered on position changes.

Is there an event for “position changed”?

Thanks!

2

Got this kind of working with using references to the transparent object both in drag and animation callback: Demo