lv_obj.h

Defines

LV_ASSERT_OBJ(obj_p, obj_class)

LV_TRACE_OBJ_CREATE(...)

Enums

enum [anonymous]

Possible states of a widget. OR-ed values are possible

Values:

enumerator LV_STATE_DEFAULT

enumerator LV_STATE_CHECKED

enumerator LV_STATE_FOCUSED

enumerator LV_STATE_FOCUS_KEY

enumerator LV_STATE_EDITED

enumerator LV_STATE_HOVERED

enumerator LV_STATE_PRESSED

enumerator LV_STATE_SCROLLED

enumerator LV_STATE_DISABLED

enumerator LV_STATE_USER_1

enumerator LV_STATE_USER_2

enumerator LV_STATE_USER_3

enumerator LV_STATE_USER_4

enumerator LV_STATE_ANY: Special value can be used in some functions to target all states

enum [anonymous]

The possible parts of widgets. The parts can be considered as the internal building block of the widgets. E.g. slider = background + indicator + knob Not all parts are used by every widget

Values:

enumerator LV_PART_MAIN: A background like rectangle

enumerator LV_PART_SCROLLBAR: The scrollbar(s)

enumerator LV_PART_INDICATOR: Indicator, e.g. for slider, bar, switch, or the tick box of the checkbox

enumerator LV_PART_KNOB: Like handle to grab to adjust the value

enumerator LV_PART_SELECTED: Indicate the currently selected option or section

enumerator LV_PART_ITEMS: Used if the widget has multiple similar elements (e.g. table cells)

enumerator LV_PART_CURSOR: Mark a specific place e.g. for text area's cursor or on a chart

enumerator LV_PART_CUSTOM_FIRST: Extension point for custom widgets

enumerator LV_PART_ANY: Special value can be used in some functions to target all parts

enum lv_obj_flag_t

On/Off features controlling the object's behavior. OR-ed values are possible

Note: update obj flags corresponding properties below whenever add/remove flags or change bit definition of flags.

Values:

enumerator LV_OBJ_FLAG_HIDDEN: Make the object hidden. (Like it wasn't there at all)

enumerator LV_OBJ_FLAG_CLICKABLE: Make the object clickable by the input devices

enumerator LV_OBJ_FLAG_CLICK_FOCUSABLE: Add focused state to the object when clicked

enumerator LV_OBJ_FLAG_CHECKABLE: Toggle checked state when the object is clicked

enumerator LV_OBJ_FLAG_SCROLLABLE: Make the object scrollable

enumerator LV_OBJ_FLAG_SCROLL_ELASTIC: Allow scrolling inside but with slower speed

enumerator LV_OBJ_FLAG_SCROLL_MOMENTUM: Make the object scroll further when "thrown"

enumerator LV_OBJ_FLAG_SCROLL_ONE: Allow scrolling only one snappable children

enumerator LV_OBJ_FLAG_SCROLL_CHAIN_HOR: Allow propagating the horizontal scroll to a parent

enumerator LV_OBJ_FLAG_SCROLL_CHAIN_VER: Allow propagating the vertical scroll to a parent

enumerator LV_OBJ_FLAG_SCROLL_CHAIN

enumerator LV_OBJ_FLAG_SCROLL_ON_FOCUS: Automatically scroll object to make it visible when focused

enumerator LV_OBJ_FLAG_SCROLL_WITH_ARROW: Allow scrolling the focused object with arrow keys

enumerator LV_OBJ_FLAG_SNAPPABLE: If scroll snap is enabled on the parent it can snap to this object

enumerator LV_OBJ_FLAG_PRESS_LOCK: Keep the object pressed even if the press slid from the object

enumerator LV_OBJ_FLAG_EVENT_BUBBLE: Propagate the events to the parent too

enumerator LV_OBJ_FLAG_GESTURE_BUBBLE: Propagate the gestures to the parent

enumerator LV_OBJ_FLAG_ADV_HITTEST: Allow performing more accurate hit (click) test. E.g. consider rounded corners.

enumerator LV_OBJ_FLAG_IGNORE_LAYOUT: Make the object not positioned by the layouts

enumerator LV_OBJ_FLAG_FLOATING: Do not scroll the object when the parent scrolls and ignore layout

enumerator LV_OBJ_FLAG_SEND_DRAW_TASK_EVENTS: Send LV_EVENT_DRAW_TASK_ADDED events

enumerator LV_OBJ_FLAG_OVERFLOW_VISIBLE: Do not clip the children to the parent's ext draw size

enumerator LV_OBJ_FLAG_FLEX_IN_NEW_TRACK: Start a new flex track on this item

enumerator LV_OBJ_FLAG_LAYOUT_1: Custom flag, free to use by layouts

enumerator LV_OBJ_FLAG_LAYOUT_2: Custom flag, free to use by layouts

enumerator LV_OBJ_FLAG_WIDGET_1: Custom flag, free to use by widget

enumerator LV_OBJ_FLAG_WIDGET_2: Custom flag, free to use by widget

enumerator LV_OBJ_FLAG_USER_1: Custom flag, free to use by user

enumerator LV_OBJ_FLAG_USER_2: Custom flag, free to use by user

enumerator LV_OBJ_FLAG_USER_3: Custom flag, free to use by user

enumerator LV_OBJ_FLAG_USER_4: Custom flag, free to use by user

enum [anonymous]

Values:

enumerator LV_PROPERTY_OBJ_FLAG_START

enumerator LV_PROPERTY_OBJ_FLAG_HIDDEN

enumerator LV_PROPERTY_OBJ_FLAG_CLICKABLE

enumerator LV_PROPERTY_OBJ_FLAG_CLICK_FOCUSABLE

enumerator LV_PROPERTY_OBJ_FLAG_CHECKABLE

enumerator LV_PROPERTY_OBJ_FLAG_SCROLLABLE

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_ELASTIC

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_MOMENTUM

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_ONE

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_CHAIN_HOR

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_CHAIN_VER

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_ON_FOCUS

enumerator LV_PROPERTY_OBJ_FLAG_SCROLL_WITH_ARROW

enumerator LV_PROPERTY_OBJ_FLAG_SNAPPABLE

enumerator LV_PROPERTY_OBJ_FLAG_PRESS_LOCK

enumerator LV_PROPERTY_OBJ_FLAG_EVENT_BUBBLE

enumerator LV_PROPERTY_OBJ_FLAG_GESTURE_BUBBLE

enumerator LV_PROPERTY_OBJ_FLAG_ADV_HITTEST

enumerator LV_PROPERTY_OBJ_FLAG_IGNORE_LAYOUT

enumerator LV_PROPERTY_OBJ_FLAG_FLOATING

enumerator LV_PROPERTY_OBJ_FLAG_SEND_DRAW_TASK_EVENTS

enumerator LV_PROPERTY_OBJ_FLAG_OVERFLOW_VISIBLE

enumerator LV_PROPERTY_OBJ_FLAG_FLEX_IN_NEW_TRACK

enumerator LV_PROPERTY_OBJ_FLAG_LAYOUT_1

enumerator LV_PROPERTY_OBJ_FLAG_LAYOUT_2

enumerator LV_PROPERTY_OBJ_FLAG_WIDGET_1

enumerator LV_PROPERTY_OBJ_FLAG_WIDGET_2

enumerator LV_PROPERTY_OBJ_FLAG_USER_1

enumerator LV_PROPERTY_OBJ_FLAG_USER_2

enumerator LV_PROPERTY_OBJ_FLAG_USER_3

enumerator LV_PROPERTY_OBJ_FLAG_USER_4

enumerator LV_PROPERTY_OBJ_FLAG_END

enumerator LV_PROPERTY_OBJ_STATE_START

enumerator LV_PROPERTY_OBJ_STATE_CHECKED

enumerator LV_PROPERTY_OBJ_STATE_FOCUSED

enumerator LV_PROPERTY_OBJ_STATE_FOCUS_KEY

enumerator LV_PROPERTY_OBJ_STATE_EDITED

enumerator LV_PROPERTY_OBJ_STATE_HOVERED

enumerator LV_PROPERTY_OBJ_STATE_PRESSED

enumerator LV_PROPERTY_OBJ_STATE_SCROLLED

enumerator LV_PROPERTY_OBJ_STATE_DISABLED

enumerator LV_PROPERTY_OBJ_STATE_USER_1

enumerator LV_PROPERTY_OBJ_STATE_USER_2

enumerator LV_PROPERTY_OBJ_STATE_USER_3

enumerator LV_PROPERTY_OBJ_STATE_USER_4

enumerator LV_PROPERTY_OBJ_STATE_ANY

enumerator LV_PROPERTY_OBJ_STATE_END

enumerator LV_PROPERTY_OBJ_PARENT

enumerator LV_PROPERTY_OBJ_X

enumerator LV_PROPERTY_OBJ_Y

enumerator LV_PROPERTY_OBJ_W

enumerator LV_PROPERTY_OBJ_H

enumerator LV_PROPERTY_OBJ_CONTENT_WIDTH

enumerator LV_PROPERTY_OBJ_CONTENT_HEIGHT

enumerator LV_PROPERTY_OBJ_LAYOUT

enumerator LV_PROPERTY_OBJ_ALIGN

enumerator LV_PROPERTY_OBJ_SCROLLBAR_MODE

enumerator LV_PROPERTY_OBJ_SCROLL_DIR

enumerator LV_PROPERTY_OBJ_SCROLL_SNAP_X

enumerator LV_PROPERTY_OBJ_SCROLL_SNAP_Y

enumerator LV_PROPERTY_OBJ_SCROLL_X

enumerator LV_PROPERTY_OBJ_SCROLL_Y

enumerator LV_PROPERTY_OBJ_SCROLL_TOP

enumerator LV_PROPERTY_OBJ_SCROLL_BOTTOM

enumerator LV_PROPERTY_OBJ_SCROLL_LEFT

enumerator LV_PROPERTY_OBJ_SCROLL_RIGHT

enumerator LV_PROPERTY_OBJ_SCROLL_END

enumerator LV_PROPERTY_OBJ_EXT_DRAW_SIZE

enumerator LV_PROPERTY_OBJ_EVENT_COUNT

enumerator LV_PROPERTY_OBJ_SCREEN

enumerator LV_PROPERTY_OBJ_DISPLAY

enumerator LV_PROPERTY_OBJ_CHILD_COUNT

enumerator LV_PROPERTY_OBJ_INDEX

enumerator LV_PROPERTY_OBJ_END

Functions

lv_obj_t *lv_obj_create(lv_obj_t *parent)

Create a base object (a rectangle)

Parameters:: parent – pointer to a parent object. If NULL then a screen will be created.
Returns:: pointer to the new object

void lv_obj_add_flag(lv_obj_t *obj, lv_obj_flag_t f)

Set one or more flags

Parameters:

obj – pointer to an object
f – OR-ed values from lv_obj_flag_t to set.

void lv_obj_remove_flag(lv_obj_t *obj, lv_obj_flag_t f)

Remove one or more flags

Parameters:

obj – pointer to an object
f – OR-ed values from lv_obj_flag_t to clear.

void lv_obj_update_flag(lv_obj_t *obj, lv_obj_flag_t f, bool v)

Set add or remove one or more flags.

Parameters:

obj – pointer to an object
f – OR-ed values from lv_obj_flag_t to update.
v – true: add the flags; false: remove the flags

void lv_obj_add_state(lv_obj_t *obj, lv_state_t state)

Add one or more states to the object. The other state bits will remain unchanged. If specified in the styles, transition animation will be started from the previous state to the current.

Parameters:

obj – pointer to an object
state – the states to add. E.g LV_STATE_PRESSED | LV_STATE_FOCUSED

void lv_obj_remove_state(lv_obj_t *obj, lv_state_t state)

Remove one or more states to the object. The other state bits will remain unchanged. If specified in the styles, transition animation will be started from the previous state to the current.

Parameters:

obj – pointer to an object
state – the states to add. E.g LV_STATE_PRESSED | LV_STATE_FOCUSED

void lv_obj_set_state(lv_obj_t *obj, lv_state_t state, bool v)

Add or remove one or more states to the object. The other state bits will remain unchanged.

Parameters:

obj – pointer to an object
state – the states to add. E.g LV_STATE_PRESSED | LV_STATE_FOCUSED
v – true: add the states; false: remove the states

void lv_obj_set_user_data(lv_obj_t *obj, void *user_data)

Set the user_data field of the object

Parameters:

obj – pointer to an object
user_data – pointer to the new user_data.

bool lv_obj_has_flag(const lv_obj_t *obj, lv_obj_flag_t f)

Check if a given flag or all the given flags are set on an object.

Parameters:

obj – pointer to an object
f – the flag(s) to check (OR-ed values can be used)

Returns:

true: all flags are set; false: not all flags are set

bool lv_obj_has_flag_any(const lv_obj_t *obj, lv_obj_flag_t f)

Check if a given flag or any of the flags are set on an object.

Parameters:

obj – pointer to an object
f – the flag(s) to check (OR-ed values can be used)

Returns:

true: at least one flag is set; false: none of the flags are set

lv_state_t lv_obj_get_state(const lv_obj_t *obj)

Get the state of an object

Parameters:: obj – pointer to an object
Returns:: the state (OR-ed values from lv_state_t)

bool lv_obj_has_state(const lv_obj_t *obj, lv_state_t state)

Check if the object is in a given state or not.

Parameters:

obj – pointer to an object
state – a state or combination of states to check

Returns:

true: obj is in state; false: obj is not in state

lv_group_t *lv_obj_get_group(const lv_obj_t *obj)

Get the group of the object

Parameters:: obj – pointer to an object
Returns:: the pointer to group of the object

void *lv_obj_get_user_data(lv_obj_t *obj)

Get the user_data field of the object

Parameters:: obj – pointer to an object
Returns:: the pointer to the user_data of the object

void lv_obj_allocate_spec_attr(lv_obj_t *obj)

Allocate special data for an object if not allocated yet.

Parameters:: obj – pointer to an object

bool lv_obj_check_type(const lv_obj_t *obj, const lv_obj_class_t *class_p)

Check the type of obj.

Parameters:

obj – pointer to an object
class_p – a class to check (e.g. lv_slider_class)

Returns:

true: class_p is the obj class.

bool lv_obj_has_class(const lv_obj_t *obj, const lv_obj_class_t *class_p)

Check if any object has a given class (type). It checks the ancestor classes too.

Parameters:

obj – pointer to an object
class_p – a class to check (e.g. lv_slider_class)

Returns:

true: obj has the given class

const lv_obj_class_t *lv_obj_get_class(const lv_obj_t *obj)

Get the class (type) of the object

Parameters:: obj – pointer to an object
Returns:: the class (type) of the object

bool lv_obj_is_valid(const lv_obj_t *obj)

Check if any object is still "alive".

Parameters:: obj – pointer to an object
Returns:: true: valid

void lv_obj_null_on_delete(lv_obj_t **obj_ptr)

Utility to set an object reference to NULL when it gets deleted. The reference should be in a location that will not become invalid during the object's lifetime, i.e. static or allocated.

Parameters:: obj_ptr – a pointer to a pointer to an object

void lv_obj_set_id(lv_obj_t *obj, void *id)

Set an id for an object.

Parameters:

obj – pointer to an object
id – the id of the object

void *lv_obj_get_id(const lv_obj_t *obj)

Get the id of an object.

Parameters:: obj – pointer to an object
Returns:: the id of the object

lv_obj_t *lv_obj_get_child_by_id(const lv_obj_t *obj, const void *id)

Get the child object by its id. It will check children and grandchildren recursively. Function lv_obj_id_compare is used to matched obj id with given id.

Parameters:

obj – pointer to an object
id – the id of the child object

Returns:

pointer to the child object or NULL if not found

void lv_obj_assign_id(const lv_obj_class_t *class_p, lv_obj_t *obj)

Assign id to object if not previously assigned. This function gets called automatically when LV_OBJ_ID_AUTO_ASSIGN is enabled.

Set LV_USE_OBJ_ID_BUILTIN to use the builtin method to generate object ID. Otherwise, these functions including lv_obj_[set|assign|free|stringify]_id and lv_obj_id_compareshould be implemented externally.

Parameters:

class_p – the class this obj belongs to. Note obj->class_p is the class currently being constructed.
obj – pointer to an object

void lv_obj_free_id(lv_obj_t *obj)

Free resources allocated by lv_obj_assign_id or lv_obj_set_id. This function is also called automatically when object is deleted.

Parameters:: obj – pointer to an object

int lv_obj_id_compare(const void *id1, const void *id2)

Compare two obj id, return 0 if they are equal.

Set LV_USE_OBJ_ID_BUILTIN to use the builtin method for compare. Otherwise, it must be implemented externally.

Parameters:

id1 – the first id
id2 – the second id

Returns:

0 if they are equal, non-zero otherwise.

const char *lv_obj_stringify_id(lv_obj_t *obj, char *buf, uint32_t len)

Format an object's id into a string.

Parameters:

obj – pointer to an object
buf – buffer to write the string into
len – length of the buffer

void lv_objid_builtin_destroy(void): Free resources used by builtin ID generator.

Variables

const lv_obj_class_t lv_obj_class: Make the base object's class publicly available.