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.

参数:

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.

参数:

obj -- pointer to an object

void lv_obj_delete_delayed(lv_obj_t *obj, uint32_t delay_ms)

Delete an object after some delay

参数:

  • 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

参数:

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).

参见

lv_async_call

参数:

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.

参数:

  • 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.

参数:

  • 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.

备注

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

备注

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

参数:

  • 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

参数:

obj -- pointer to an object

返回:

pointer to the object's screen

lv_display_t *lv_obj_get_display(const lv_obj_t *obj)

Get the display of the object

参数:

obj -- pointer to an object

返回:

pointer to the object's display

lv_obj_t *lv_obj_get_parent(const lv_obj_t *obj)

Get the parent of an object

参数:

obj -- pointer to an object

返回:

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.

参数:

  • 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

返回:

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.

参数:

  • 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

返回:

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

参数:

  • 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

返回:

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.

参数:

  • 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

返回:

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

参数:

obj -- pointer to an object

返回:

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.

参数:

  • obj -- pointer to an object

  • class_p -- the type of the children to check

返回:

the number of children

int32_t lv_obj_get_index(const lv_obj_t *obj)

Get the index of a child.

参数:

obj -- pointer to an object

返回:

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.

参数:

  • obj -- pointer to an object

  • class_p -- the type of the children to check

返回:

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.

参数:

  • 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_ob)

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

参数:

start_obj -- start integrating from this object