lv_draw_label.h

Defines

LV_DRAW_LABEL_NO_TXT_SEL

Typedefs

typedef void (*lv_draw_glyph_cb_t)(lv_draw_task_t *t, 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 t:: pointer to a draw task
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_letter_dsc_init(lv_draw_letter_dsc_t *dsc)

void lv_draw_label_dsc_init(lv_draw_label_dsc_t *dsc)

Initialize a label draw descriptor

Parameters:: 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.

Parameters:: task – draw task
Returns:: 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.

Parameters:: 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)

Create a draw task to render a text

Parameters:

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)

Create a draw task to render a single character

Parameters:

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

void lv_draw_letter(lv_layer_t *layer, lv_draw_letter_dsc_t *dsc, const lv_point_t *point)

Draw a single letter

Parameters:

layer – pointer to a layer
dsc – pointer to draw descriptor
point – position of the label

void lv_draw_label_iterate_characters(lv_draw_task_t *t, 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

Parameters:

t – pointer to a draw task
dsc – pointer to draw descriptor
coords – coordinates of the label
cb – a callback to call to draw each glyphs one by one

void lv_draw_unit_draw_letter(lv_draw_task_t *t, lv_draw_glyph_dsc_t *dsc, const lv_point_t *pos, const lv_font_t *font, uint32_t letter, lv_draw_glyph_cb_t cb)

Draw a single letter using the provided draw unit, glyph descriptor, position, font, and callback.

This function is responsible for rendering a single character from a text string, applying the necessary styling described by the glyph descriptor (dsc). It handles the retrieval of the glyph's description, checks its visibility within the clipping area, and invokes the callback (cb) to render the glyph at the specified position (pos) using the given font (font).

Parameters:

t – Pointer to the drawing task.
dsc – Pointer to the descriptor containing styling for the glyph to be drawn.
pos – Pointer to the point coordinates where the letter should be drawn.
font – Pointer to the font containing the glyph.
letter – The Unicode code point of the letter to be drawn.
cb – Callback function to execute the actual rendering of the glyph.