Line (lv_line)

Overview

The Line object is capable of drawing straight lines between a set of points.

Parts and Styles

The Line has only a main part, called LV_LABEL_PART_MAIN. It uses all the line style properties.

Usage

Set points

The points has to be stored in an lv_point_t array and passed to the object by the lv_line_set_points(lines, point_array, point_cnt) function.

Auto-size

It is possible to automatically set the size of the line object according to its points. It can be enable with the lv_line_set_auto_size(line, true) function. If enabled then when the points are set the object's width and height will be changed according to the maximal x and y coordinates among the points. The auto size is enabled by default.

Invert y

By deafult, the y == 0 point is in the top of the object. It might be conter-intuitive in some cases so the y coordinates can be inverted with lv_line_set_y_invert(line, true). In this case, y == 0 will be the bottom of teh obejct. The y invert is disabled by default.

Events

Only the Generic events are sent by the object type.

Learn more about Events.

Keys

No Keys are processed by the object type.

Learn more about Keys.

Example

C

Simple Line

code

#include "../../../lv_examples.h"
#if LV_USE_LINE

void lv_ex_line_1(void)
{
    /*Create an array for the points of the line*/
    static lv_point_t line_points[] = { {5, 5}, {70, 70}, {120, 10}, {180, 60}, {240, 10} };

    /*Create style*/
    static lv_style_t style_line;
    lv_style_init(&style_line);
    lv_style_set_line_width(&style_line, LV_STATE_DEFAULT, 8);
    lv_style_set_line_color(&style_line, LV_STATE_DEFAULT, LV_COLOR_BLUE);
    lv_style_set_line_rounded(&style_line, LV_STATE_DEFAULT, true);

    /*Create a line and apply the new style*/
    lv_obj_t * line1;
    line1 = lv_line_create(lv_scr_act(), NULL);
    lv_line_set_points(line1, line_points, 5);     /*Set the points*/
    lv_obj_add_style(line1, LV_LINE_PART_MAIN, &style_line);     /*Set the points*/
    lv_obj_align(line1, NULL, LV_ALIGN_CENTER, 0, 0);
}

#endif

MicroPython

No examples yet.

API

Typedefs

typedef uint8_t lv_line_style_t

Enums

enum [anonymous]

Values:

enumerator LV_LINE_PART_MAIN

Functions

lv_obj_t *lv_line_create(lv_obj_t *par, const lv_obj_t *copy)

Create a line objects

Return

pointer to the created line

Parameters
  • par: pointer to an object, it will be the parent of the new line

void lv_line_set_points(lv_obj_t *line, const lv_point_t point_a[], uint16_t point_num)

Set an array of points. The line object will connect these points.

Parameters
  • line: pointer to a line object

  • point_a: an array of points. Only the address is saved, so the array can NOT be a local variable which will be destroyed

  • point_num: number of points in 'point_a'

void lv_line_set_auto_size(lv_obj_t *line, bool en)

Enable (or disable) the auto-size option. The size of the object will fit to its points. (set width to x max and height to y max)

Parameters
  • line: pointer to a line object

  • en: true: auto size is enabled, false: auto size is disabled

void lv_line_set_y_invert(lv_obj_t *line, bool en)

Enable (or disable) the y coordinate inversion. If enabled then y will be subtracted from the height of the object, therefore the y=0 coordinate will be on the bottom.

Parameters
  • line: pointer to a line object

  • en: true: enable the y inversion, false:disable the y inversion

bool lv_line_get_auto_size(const lv_obj_t *line)

Get the auto size attribute

Return

true: auto size is enabled, false: disabled

Parameters
  • line: pointer to a line object

bool lv_line_get_y_invert(const lv_obj_t *line)

Get the y inversion attribute

Return

true: y inversion is enabled, false: disabled

Parameters
  • line: pointer to a line object

struct lv_line_ext_t

Public Members

const lv_point_t *point_array
uint16_t point_num
uint8_t auto_size
uint8_t y_inv