lv_draw_label.h

Defines

LV_DRAW_LABEL_NO_TXT_SEL

Typedefs

typedef struct _lv_draw_label_hint_t lv_draw_label_hint_t: Store some info to speed up drawing of very large texts It takes a lot of time to get the first visible character because all the previous characters needs to be checked to calculate the positions. This structure stores an earlier (e.g. at -1000 px) coordinate and the index of that line. Therefore the calculations can start from here.

typedef void (*lv_draw_glyph_cb_t)(lv_draw_unit_t *draw_unit, lv_draw_glyph_dsc_t *dsc, lv_draw_fill_dsc_t *fill_dsc, const lv_area_t *fill_area)

Passed as a parameter to lv_draw_label_iterate_characters to draw the characters one by one

Param draw_unit:: pointer to a draw unit
Param dsc:: pointer to lv_draw_glyph_dsc_t to describe the character to draw if NULL don't draw character
Param fill_dsc:: pointer to a fill descriptor to draw a background for the character or underline or strike through if NULL do not fill anything
Param fill_area:: the area to fill if NULL do not fill anything

Functions

void lv_draw_label_dsc_init(lv_draw_label_dsc_t *dsc)

Initialize a label draw descriptor

参数:: dsc -- pointer to a draw descriptor

lv_draw_label_dsc_t *lv_draw_task_get_label_dsc(lv_draw_task_t *task)

Try to get a label draw descriptor from a draw task.

参数:: task -- draw task
返回:: the task's draw descriptor or NULL if the task is not of type LV_DRAW_TASK_TYPE_LABEL

void lv_draw_glyph_dsc_init(lv_draw_glyph_dsc_t *dsc)

Initialize a glyph draw descriptor. Used internally.

参数:: dsc -- pointer to a draw descriptor

void lv_draw_label(lv_layer_t *layer, const lv_draw_label_dsc_t *dsc, const lv_area_t *coords)

Crate a draw task to render a text

参数:

layer -- pointer to a layer
dsc -- pointer to draw descriptor
coords -- coordinates of the character

void lv_draw_character(lv_layer_t *layer, lv_draw_label_dsc_t *dsc, const lv_point_t *point, uint32_t unicode_letter)

Crate a draw task to render a single character

参数:

layer -- pointer to a layer
dsc -- pointer to draw descriptor
point -- position of the label
unicode_letter -- the letter to draw

void lv_draw_label_iterate_characters(lv_draw_unit_t *draw_unit, const lv_draw_label_dsc_t *dsc, const lv_area_t *coords, lv_draw_glyph_cb_t cb)

Should be used during rendering the characters to get the position and other parameters of the characters

参数:

draw_unit -- pointer to a draw unit
dsc -- pointer to draw descriptor
coords -- coordinates of the label
cb -- a callback to call to draw each glyphs one by one

struct _lv_draw_label_hint_t

#include <lv_draw_label.h>

Store some info to speed up drawing of very large texts It takes a lot of time to get the first visible character because all the previous characters needs to be checked to calculate the positions. This structure stores an earlier (e.g. at -1000 px) coordinate and the index of that line. Therefore the calculations can start from here.

Public Members