Calendar (lv_calendar)¶

From v8.1 the header is added directly into the Calendar widget and the API of the headers has been changed.

Overview¶

The Calendar object is a classic calendar which can:

show the days of any month in a 7x7 matrix
Show the name of the days
highlight the current day (today)
highlight any user-defined dates

The Calendar is added to the default group (if it is set). Calendar is an editable object which allow selecting and clicking the dates with encoder navigation too.

To make the Calendar flexible, by default it doesn't show the current year or month. Instead, there are optional "headers" that can be attached to the calendar.

Parts and Styles¶

The Calendar is composed of 3 widegets

Container: A rectangle which is a container for the Header and the Days. Uses only LV_PART_MAIN where all the background related style properties are working.
Days: It's a Button matrix object under the hood to arrange the days into a matrix. lv_calendar_get_btnmatrix(calendar) can be used to get it.
- LV_PART_MAIN The background of the calendar. Uses all the background related style properties.
- LV_PART_ITEMS Refers to the dates and day names. Button matrix control flags are set to differentiate the buttons and a custom drawer event is added modify the properties of the buttons as follows:
  - day names have no border, no background and drawn with a gray color
  - days of the previous and next month have LV_BTNMATRIX_CTRL_DISABLED flag
  - today has a thicker border with the theme's primary color
  - highlighted days have some opacity with the theme's primary color.
Header: Not created by default, the details are up to the given header.

Usage¶

Some functions use the lv_calendar_date_t type which is a structure with year, month and day fields.

Current date¶

To set the current date (today), use the lv_calendar_set_today_date(calendar, year, month, day) function. month needs to be in 1..12 range and day in 1..31 range.

Shown date¶

To set the shown date, use lv_calendar_set_shown_date(calendar, year, month);

Highlighted days¶

The list of highlighted dates should be stored in a lv_calendar_date_t array loaded by lv_calendar_set_highlighted_dates(calendar, highlighted_dates, date_num). Only the array's pointer will be saved so the array should be a static or global variable.

Name of the days¶

The name of the days can be adjusted with lv_calendar_set_day_names(calendar, day_names) where day_names looks like const char * day_names[7] = {"Su", "Mo", ...}; Only the pointer of the day names is saved so the elements should be static, global or constant variables.

Custom year list¶

Sets a custom year list with lv_calendar_header_dropdown_set_year_list(calendar, years_list) where years_list is a pointer to the custom years list. It can be a constant string like static const char * years = "2023\n2022\n2021\n2020\n2019";, or can be generated dynamically into a buffer as well.

Events¶

LV_EVENT_VALUE_CHANGED Sent if a date is clicked. lv_calendar_get_pressed_date(calendar, &date) set date to the date currently being pressed. Returns LV_RES_OK if there is a valid pressed date, else LV_RES_INV.

Learn more about Events.

Keys¶

LV_KEY_RIGHT/UP/LEFT/RIGHT To navigate among the buttons to dates
LV_KEY_ENTER To press/release the selected date

Learn more about Keys.

Headers¶

Arrow buttons¶

lv_calendar_header_arrow_create(calendar) creates a header that contains a left and right arrow on the sides and a text with the current year and month between them.

Drop-down¶

lv_calendar_header_dropdown_create(calendar) creates a header that contains 2 drop-drown lists: one for the year and another for the month.

Example¶

Calendar with header¶

#include "../../lv_examples.h"
#if LV_USE_CALENDAR && LV_BUILD_EXAMPLES

static void event_handler(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t * obj = lv_event_get_current_target(e);

    if(code == LV_EVENT_VALUE_CHANGED) {
        lv_calendar_date_t date;
        if(lv_calendar_get_pressed_date(obj, &date)) {
            LV_LOG_USER("Clicked date: %02d.%02d.%d", date.day, date.month, date.year);
        }
    }
}

void lv_example_calendar_1(void)
{
    lv_obj_t  * calendar = lv_calendar_create(lv_scr_act());
    lv_obj_set_size(calendar, 185, 185);
    lv_obj_align(calendar, LV_ALIGN_CENTER, 0, 27);
    lv_obj_add_event_cb(calendar, event_handler, LV_EVENT_ALL, NULL);

    lv_calendar_set_today_date(calendar, 2021, 02, 23);
    lv_calendar_set_showed_date(calendar, 2021, 02);

    /*Highlight a few days*/
    static lv_calendar_date_t highlighted_days[3];       /*Only its pointer will be saved so should be static*/
    highlighted_days[0].year = 2021;
    highlighted_days[0].month = 02;
    highlighted_days[0].day = 6;

    highlighted_days[1].year = 2021;
    highlighted_days[1].month = 02;
    highlighted_days[1].day = 11;

    highlighted_days[2].year = 2022;
    highlighted_days[2].month = 02;
    highlighted_days[2].day = 22;

    lv_calendar_set_highlighted_dates(calendar, highlighted_days, 3);

#if LV_USE_CALENDAR_HEADER_DROPDOWN
    lv_calendar_header_dropdown_create(calendar);
#elif LV_USE_CALENDAR_HEADER_ARROW
    lv_calendar_header_arrow_create(calendar);
#endif
    lv_calendar_set_showed_date(calendar, 2021, 10);
}

#endif

def event_handler(evt):
    code = evt.get_code()

    if code == lv.EVENT.VALUE_CHANGED:
        source = evt.get_current_target()
        date = lv.calendar_date_t()
        if source.get_pressed_date(date) == lv.RES.OK:
            calendar.set_today_date(date.year, date.month, date.day)
            print("Clicked date: %02d.%02d.%02d"%(date.day, date.month, date.year))


calendar = lv.calendar(lv.scr_act())
calendar.set_size(200, 200)
calendar.align(lv.ALIGN.CENTER, 0, 20)
calendar.add_event_cb(event_handler, lv.EVENT.ALL, None)

calendar.set_today_date(2021, 02, 23)
calendar.set_showed_date(2021, 02)

# Highlight a few days
highlighted_days=[
    lv.calendar_date_t({'year':2021, 'month':2, 'day':6}),
    lv.calendar_date_t({'year':2021, 'month':2, 'day':11}),
    lv.calendar_date_t({'year':2021, 'month':2, 'day':22})
]

calendar.set_highlighted_dates(highlighted_days, len(highlighted_days))

lv.calendar_header_dropdown(calendar)

API¶

Functions

lv_obj_t *lv_calendar_create(lv_obj_t *parent)¶

void lv_calendar_set_today_date(lv_obj_t *obj, uint32_t year, uint32_t month, uint32_t day)¶

Set the today's date

Parameters

obj -- pointer to a calendar object
year -- today's year
month -- today's month [1..12]
day -- today's day [1..31]

void lv_calendar_set_showed_date(lv_obj_t *obj, uint32_t year, uint32_t month)¶

Set the currently showed

Parameters

obj -- pointer to a calendar object
year -- today's year
month -- today's month [1..12]

void lv_calendar_set_highlighted_dates(lv_obj_t *obj, lv_calendar_date_t highlighted[], uint16_t date_num)¶

Set the highlighted dates

Parameters

obj -- pointer to a calendar object
highlighted -- pointer to an lv_calendar_date_t array containing the dates. Only the pointer will be saved so this variable can't be local which will be destroyed later.
date_num -- number of dates in the array

void lv_calendar_set_day_names(lv_obj_t *obj, const char **day_names)¶

Set the name of the days

Parameters

obj -- pointer to a calendar object
day_names -- pointer to an array with the names. E.g. const char * days[7] = {"Sun", "Mon", ...} Only the pointer will be saved so this variable can't be local which will be destroyed later.

lv_obj_t *lv_calendar_get_btnmatrix(const lv_obj_t *obj)¶

Get the button matrix object of the calendar. It shows the dates and day names.

Parameters: obj -- pointer to a calendar object
Returns: pointer to a the button matrix

const lv_calendar_date_t *lv_calendar_get_today_date(const lv_obj_t *calendar)¶

Get the today's date

Parameters: calendar -- pointer to a calendar object
Returns: return pointer to an lv_calendar_date_t variable containing the date of today.

const lv_calendar_date_t *lv_calendar_get_showed_date(const lv_obj_t *calendar)¶

Get the currently showed

Parameters: calendar -- pointer to a calendar object
Returns: pointer to an lv_calendar_date_t variable containing the date is being shown.

lv_calendar_date_t *lv_calendar_get_highlighted_dates(const lv_obj_t *calendar)¶

Get the highlighted dates

Parameters: calendar -- pointer to a calendar object
Returns: pointer to an lv_calendar_date_t array containing the dates.

uint16_t lv_calendar_get_highlighted_dates_num(const lv_obj_t *calendar)¶

Get the number of the highlighted dates

Parameters: calendar -- pointer to a calendar object
Returns: number of highlighted days

lv_res_t lv_calendar_get_pressed_date(const lv_obj_t *calendar, lv_calendar_date_t *date)¶

Get the currently pressed day

Parameters

calendar -- pointer to a calendar object
date -- store the pressed date here

Returns

LV_RES_OK: there is a valid pressed date; LV_RES_INV: there is no pressed data

Variables

const lv_obj_class_t lv_calendar_class¶

struct lv_calendar_date_t¶

#include <lv_calendar.h>

Represents a date on the calendar object (platform-agnostic).

Public Members

uint16_t year¶

int8_t month¶

int8_t day¶: 1..12

struct lv_calendar_t¶

Public Members

lv_obj_t obj¶

lv_obj_t *btnm¶

lv_calendar_date_t today¶

lv_calendar_date_t showed_date¶

lv_calendar_date_t *highlighted_dates¶

uint16_t highlighted_dates_num¶

const char *map[8 * 7]¶

char nums[7 * 6][4]¶