lv_obj_draw.h

Enums

enum lv_cover_res_t

Cover check results.

Values:

enumerator LV_COVER_RES_COVER
enumerator LV_COVER_RES_NOT_COVER
enumerator LV_COVER_RES_MASKED
enum lv_layer_type_t

Values:

enumerator LV_LAYER_TYPE_NONE
enumerator LV_LAYER_TYPE_SIMPLE
enumerator LV_LAYER_TYPE_TRANSFORM

Functions

void lv_obj_init_draw_rect_dsc(struct _lv_obj_t *obj, uint32_t part, lv_draw_rect_dsc_t *draw_dsc)

Initialize a rectangle draw descriptor from an object's styles in its current state

Note

Only the relevant fields will be set. E.g. if border width == 0 the other border properties won't be evaluated.

Parameters:

  • obj -- pointer to an object

  • part -- part of the object, e.g. LV_PART_MAIN, LV_PART_SCROLLBAR, LV_PART_KNOB, etc

  • draw_dsc -- the descriptor to initialize. If an ..._opa field is set to LV_OPA_TRANSP the related properties won't be initialized. Should be initialized with lv_draw_rect_dsc_init(draw_dsc).

void lv_obj_init_draw_label_dsc(struct _lv_obj_t *obj, uint32_t part, lv_draw_label_dsc_t *draw_dsc)

Initialize a label draw descriptor from an object's styles in its current state

Parameters:

  • obj -- pointer to an object

  • part -- part of the object, e.g. LV_PART_MAIN, LV_PART_SCROLLBAR, LV_PART_KNOB, etc

  • draw_dsc -- the descriptor to initialize. If the opa field is set to or the property is equal to LV_OPA_TRANSP the rest won't be initialized. Should be initialized with lv_draw_label_dsc_init(draw_dsc).

void lv_obj_init_draw_img_dsc(struct _lv_obj_t *obj, uint32_t part, lv_draw_img_dsc_t *draw_dsc)

Initialize an image draw descriptor from an object's styles in its current state

Parameters:

  • obj -- pointer to an object

  • part -- part of the object, e.g. LV_PART_MAIN, LV_PART_SCROLLBAR, LV_PART_KNOB, etc

  • draw_dsc -- the descriptor to initialize. Should be initialized with lv_draw_image_dsc_init(draw_dsc).

void lv_obj_init_draw_line_dsc(struct _lv_obj_t *obj, uint32_t part, lv_draw_line_dsc_t *draw_dsc)

Initialize a line draw descriptor from an object's styles in its current state

Parameters:

  • obj -- pointer to an object

  • part -- part of the object, e.g. LV_PART_MAIN, LV_PART_SCROLLBAR, LV_PART_KNOB, etc

  • draw_dsc -- the descriptor to initialize. Should be initialized with lv_draw_line_dsc_init(draw_dsc).

void lv_obj_init_draw_arc_dsc(struct _lv_obj_t *obj, uint32_t part, lv_draw_arc_dsc_t *draw_dsc)

Initialize an arc draw descriptor from an object's styles in its current state

Parameters:

  • obj -- pointer to an object

  • part -- part of the object, e.g. LV_PART_MAIN, LV_PART_SCROLLBAR, LV_PART_KNOB, etc

  • draw_dsc -- the descriptor to initialize. Should be initialized with lv_draw_arc_dsc_init(draw_dsc).

lv_coord_t lv_obj_calculate_ext_draw_size(struct _lv_obj_t *obj, uint32_t part)

Get the required extra size (around the object's part) to draw shadow, outline, value etc.

Parameters:

  • obj -- pointer to an object

  • part -- part of the object

Returns:

the extra size required around the object

void lv_obj_draw_dsc_init(lv_obj_draw_part_dsc_t *dsc, lv_draw_ctx_t *draw_ctx)

Initialize a draw descriptor used in events.

Parameters:

  • dsc -- pointer to a descriptor. Later it should be passed as parameter to an LV_EVENT_DRAW_PART_BEGIN/END event.

  • draw_ctx -- draw the current draw context. (usually returned by lv_event_get_draw_ctx(e))

bool lv_obj_draw_part_check_type(lv_obj_draw_part_dsc_t *dsc, const struct _lv_obj_class_t *class_p, uint32_t type)

Check the type obj a part draw descriptor

Parameters:

  • dsc -- the descriptor (normally the event parameter)

  • class_p -- pointer to class to which type is related

  • type -- element of lv_<name>_draw_part_type_t

Returns:

true if ::dsc is related to ::class_p and ::type

void lv_obj_refresh_ext_draw_size(struct _lv_obj_t *obj)

Send a 'LV_EVENT_REFR_EXT_DRAW_SIZE' Call the ancestor's event handler to the object to refresh the value of the extended draw size. The result will be saved in obj.

Parameters:

obj -- pointer to an object

lv_coord_t _lv_obj_get_ext_draw_size(const struct _lv_obj_t *obj)

Get the extended draw area of an object.

Parameters:

obj -- pointer to an object

Returns:

the size extended draw area around the real coordinates

lv_layer_type_t _lv_obj_get_layer_type(const struct _lv_obj_t *obj)
struct lv_obj_draw_part_dsc_t

Public Members

lv_draw_ctx_t *draw_ctx

Draw context

const struct _lv_obj_class_t *class_p

The class that sent the event

uint32_t type

The type if part being draw. Element of lv_<name>_draw_part_type_t

lv_area_t *draw_area

The area of the part being drawn

lv_draw_rect_dsc_t *rect_dsc

A draw descriptor that can be modified to changed what LVGL will draw. Set only for rectangle-like parts

lv_draw_label_dsc_t *label_dsc

A draw descriptor that can be modified to changed what LVGL will draw. Set only for text-like parts

lv_draw_line_dsc_t *line_dsc

A draw descriptor that can be modified to changed what LVGL will draw. Set only for line-like parts

lv_draw_img_dsc_t *img_dsc

A draw descriptor that can be modified to changed what LVGL will draw. Set only for image-like parts

lv_draw_arc_dsc_t *arc_dsc

A draw descriptor that can be modified to changed what LVGL will draw. Set only for arc-like parts

const lv_point_t *p1

A point calculated during drawing. E.g. a point of chart or the center of an arc.

const lv_point_t *p2

A point calculated during drawing. E.g. a point of chart.

char *text

A text calculated during drawing. Can be modified. E.g. tick labels on a chart axis.

uint32_t text_length

Size of the text buffer containing null-terminated text string calculated during drawing.

uint32_t part

The current part for which the event is sent

uint32_t id

The index of the part. E.g. a button's index on button matrix or table cell index.

lv_coord_t radius

E.g. the radius of an arc (not the corner radius).

int32_t value

A value calculated during drawing. E.g. Chart's tick line value.

const void *sub_part_ptr

A pointer the identifies something in the part. E.g. chart series.