ChenWen

Hi @liamHowatt, I've made some adjustments based on our previous discussion and have verified them on a virtual machine. PTAL. The previous [PR](https://github.com/lvgl/lvgl/pull/8564) was closed, so I've resubmitted it.

> destructor > Hi, > > Thank you for the new PR. I see that the `ext_data` can be different for every `lv_timer`, but can the destructor be also different?...

> > the destructor is typically the same, but theoretically, it can also be different, depending on whether you bind different destructor functions when creating the timer. > > I...

> Nice work! Even though it LGTM, this addition touches in multiple points of the LVGL modules, so I would like to see some tests cases here. > > Thank...

Hi @kisvegabor > 1. Can we use a common data type, e.g. `lv_ext_data_t`? Yes, but the object data structure differs slightly from the others, which is why a common data...

Hi @kisvegabor > It seems LV_EXT_DATA_MAX_NUM is used only for lv_obj. For consistency I suggest managing arrays externally. So just set the array as ext data. Regarding `lv_obj` consistency, I've...

> > Nice work! Even though it LGTM, this addition touches in multiple points of the LVGL modules, so I would like to see some tests cases here. > >...

> Thank you for the updates! I've just approved it to move it forward. In general it looks good and we can add a new PR if needed. Hi @kisvegabor...

Hi @kisvegabor, do you have any concerns about this PR ? For easier use when pulling, could it be backport to the release/v9.4 branch ?

> Just merged. I think it should be good, but who knows what comes up. 🙂 > > Sure I can backport it to v9.4 but I wonder how it's...