lv_obj_tree.h

Typedefs

typedef lv_obj_tree_walk_res_t (*lv_obj_tree_walk_cb_t)(lv_obj_t*, void*)

Enums

enum lv_obj_tree_walk_res_t

Values:

enumerator LV_OBJ_TREE_WALK_NEXT

enumerator LV_OBJ_TREE_WALK_SKIP_CHILDREN

enumerator LV_OBJ_TREE_WALK_END

Functions

void lv_obj_delete(lv_obj_t *obj)

Delete an object and all of its children. Also remove the objects from their group and remove all animations (if any). Send LV_EVENT_DELETED to deleted objects.

Parameters:: obj – pointer to an object

void lv_obj_clean(lv_obj_t *obj)

Delete all children of an object. Also remove the objects from their group and remove all animations (if any). Send LV_EVENT_DELETED to deleted objects.

Parameters:: obj – pointer to an object

void lv_obj_delete_delayed(lv_obj_t *obj, uint32_t delay_ms)

Delete an object after some delay

Parameters:

obj – pointer to an object
delay_ms – time to wait before delete in milliseconds

void lv_obj_delete_anim_completed_cb(lv_anim_t *a)

A function to be easily used in animation ready callback to delete an object when the animation is ready

Parameters:: a – pointer to the animation

void lv_obj_delete_async(lv_obj_t *obj)

Helper function for asynchronously deleting objects. Useful for cases where you can't delete an object directly in an LV_EVENT_DELETE handler (i.e. parent).

See also

lv_async_call

Parameters:: obj – object to delete

void lv_obj_set_parent(lv_obj_t *obj, lv_obj_t *parent)

Move the parent of an object. The relative coordinates will be kept.

Parameters:

obj – pointer to an object whose parent needs to be changed
parent – pointer to the new parent

void lv_obj_swap(lv_obj_t *obj1, lv_obj_t *obj2)

Swap the positions of two objects. When used in listboxes, it can be used to sort the listbox items.

Parameters:

obj1 – pointer to the first object
obj2 – pointer to the second object

void lv_obj_move_to_index(lv_obj_t *obj, int32_t index)

moves the object to the given index in its parent. When used in listboxes, it can be used to sort the listbox items.

Note

to move to the background: lv_obj_move_to_index(obj, 0)

Note

to move forward (up): lv_obj_move_to_index(obj, lv_obj_get_index(obj) - 1)

Parameters:

obj – pointer to the object to be moved.
index – new index in parent. -1 to count from the back

lv_obj_t *lv_obj_get_screen(const lv_obj_t *obj)

Get the screen of an object

Parameters:: obj – pointer to an object
Returns:: pointer to the object's screen

lv_display_t *lv_obj_get_display(const lv_obj_t *obj)

Get the display of the object

Parameters:: obj – pointer to an object
Returns:: pointer to the object's display

lv_obj_t *lv_obj_get_parent(const lv_obj_t *obj)

Get the parent of an object

Parameters:: obj – pointer to an object
Returns:: the parent of the object. (NULL if obj was a screen)

lv_obj_t *lv_obj_get_child(const lv_obj_t *obj, int32_t idx)

Get the child of an object by the child's index.

Parameters:

obj – pointer to an object whose child should be get
idx – the index of the child. 0: the oldest (firstly created) child 1: the second oldest child count-1: the youngest -1: the youngest -2: the second youngest

Returns:

pointer to the child or NULL if the index was invalid

lv_obj_t *lv_obj_get_child_by_type(const lv_obj_t *obj, int32_t idx, const lv_obj_class_t *class_p)

Get the child of an object by the child's index. Consider the children only with a given type.

Parameters:

obj – pointer to an object whose child should be get
idx – the index of the child. 0: the oldest (firstly created) child 1: the second oldest child count-1: the youngest -1: the youngest -2: the second youngest
class_p – the type of the children to check

Returns:

pointer to the child or NULL if the index was invalid

lv_obj_t *lv_obj_get_sibling(const lv_obj_t *obj, int32_t idx)

Return a sibling of an object

Parameters:

obj – pointer to an object whose sibling should be get
idx – 0: obj itself -1: the first older sibling -2: the next older sibling 1: the first younger sibling 2: the next younger sibling etc

Returns:

pointer to the requested sibling or NULL if there is no such sibling

lv_obj_t *lv_obj_get_sibling_by_type(const lv_obj_t *obj, int32_t idx, const lv_obj_class_t *class_p)

Return a sibling of an object. Consider the siblings only with a given type.

Parameters:

obj – pointer to an object whose sibling should be get
idx – 0: obj itself -1: the first older sibling -2: the next older sibling 1: the first younger sibling 2: the next younger sibling etc
class_p – the type of the children to check

Returns:

pointer to the requested sibling or NULL if there is no such sibling

uint32_t lv_obj_get_child_count(const lv_obj_t *obj)

Get the number of children

Parameters:: obj – pointer to an object
Returns:: the number of children

uint32_t lv_obj_get_child_count_by_type(const lv_obj_t *obj, const lv_obj_class_t *class_p)

Get the number of children having a given type.

Parameters:

obj – pointer to an object
class_p – the type of the children to check

Returns:

the number of children

int32_t lv_obj_get_index(const lv_obj_t *obj)

Get the index of a child.

Parameters:: obj – pointer to an object
Returns:: the child index of the object. E.g. 0: the oldest (firstly created child). (-1 if child could not be found or no parent exists)

int32_t lv_obj_get_index_by_type(const lv_obj_t *obj, const lv_obj_class_t *class_p)

Get the index of a child. Consider the children only with a given type.

Parameters:

obj – pointer to an object
class_p – the type of the children to check

Returns:

the child index of the object. E.g. 0: the oldest (firstly created child with the given class). (-1 if child could not be found or no parent exists)

void lv_obj_tree_walk(lv_obj_t *start_obj, lv_obj_tree_walk_cb_t cb, void *user_data)

Iterate through all children of any object.

Parameters:

start_obj – start integrating from this object
cb – call this callback on the objects
user_data – pointer to any user related data (will be passed to cb)

void lv_obj_dump_tree(lv_obj_t *start_obj)

Iterate through all children of any object and print their ID.

Parameters:: start_obj – start integrating from this object