lv_observer_private.h

API reference for lv_observer_private.h

Summary

Functions

void lv_subject_global_init(void)

void lv_subject_global_deinit(void)

struct

The observer object: a descriptor returned when subscribing LVGL widgets to subjects

Member	Type	Description
`subject`	`lv_subject_t *`	Observed subject
`cb`	`lv_observer_cb_t`	Callback that notifies when value changes
`target`	`void *`	A target for the observer, e.g. a widget or any pointer
`user_data`	`void *`	Additional parameter, can be used freely by user
`user_cb`	`void(*)(void)`	Additional function pointer, can be used freely by user
`auto_free_user_data`	`uint32_t`	Automatically free user data when observer is removed
`notified`	`uint32_t`	Was observer already notified?
`for_obj`	`uint32_t`	Is `target` a pointer to a Widget (`lv_obj_t *`)?

struct

Member	Type	Description
`subject`	`lv_subject_t *`	The subject to adjust
`step`	`int32_t`	The step add to the subject
`rollover`	`bool`	Where to start over from the other end when one end is exceeded
`min_value`	`int32_t`	Don't set a value smaller than this
`max_value`	`int32_t`	Don't set a value larger than this