Event triggers

[nagyrobi]

A thought on events from:
https://docs.lvgl.io/8.3/overview/event.html

A universal on_event trigger could be implemented with a parameter type which can be chosen from an enum of LVGL events.
A few shorthands could be implemented for most popular events:

on_press-> LV_EVENT_PRESSED
on_release-> LV_EVENT_RELEASED
on_click-> LV_EVENT_SHORT_CLICKED
on_long_press-> LV_EVENT_LONG_PRESSED
on_value-> LV_EVENT_VALUE_CHANGED, returning the value in x (slider has been moved to value x, switch/btn toggled)
on_gesture-> LV_EVENT_GESTURE, returning the gesture (eg. swipe direction)

[nagyrobi]

Fyi OpenHASP chose these: https://www.openhasp.com/0.7.0/design/objects/#events

[nagyrobi]

We need on_value trigger because btnmatrix control flag CLICK_TRIG offers us this in a configurable way; and that seems the only way to know which button was pressed.

[nagyrobi]

Also something like on_draw_end (perhaps LV_EVENT_DRAW_POST_END). Use case: after displaying a bootlogo on the top_layer, start a delay of a few seconds, and ditch the logo widget...

[clydebarrow]

On gesture and on_draw_end to be done at a later date maybe.