1# Calendar (lv_calendar)
2
3## Overview
4
5The Calendar object is a classic calendar which can:
6- show the days of any month in a 7x7 matrix
7- Show the name of the days
8- highlight the current day (today)
9- highlight any user-defined dates
10
11The 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.
12
13To 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.
14
15## Parts and Styles
16The calendar object uses the [Button matrix](/widgets/core/btnmatrix) object under the hood to arrange the days into a matrix.
17- `LV_PART_MAIN` The background of the calendar. Uses all the background related style properties.
18- `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:
19   - day names have no border, no background and drawn with a gray color
20   - days of the previous and next month have `LV_BTNMATRIX_CTRL_DISABLED` flag
21   - today has a thicker border with the theme's primary color
22   - highlighted days have some opacity with the theme's primary color.
23
24## Usage
25
26Some functions use the `lv_calendar_date_t` type which is a structure with `year`, `month` and `day` fields.
27
28### Current date
29To 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.
30
31### Shown date
32To set the shown date, use `lv_calendar_set_shown_date(calendar, year, month)`;
33
34### Highlighted days
35
36The 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)`.
37Only the array's pointer will be saved so the array should be a static or global variable.
38
39### Name of the days
40The 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", ...};`
41Only the pointer of the day names is saved so the elements should be static, global or constant variables.
42
43## Events
44- `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`.
45
46Learn more about [Events](/overview/event).
47
48## Keys
49- `LV_KEY_RIGHT/UP/LEFT/RIGHT` To navigate among the buttons to dates
50- `LV_KEY_ENTER` To press/release the selected date
51
52Learn more about [Keys](/overview/indev).
53
54## Headers
55
56**From v8.1 the header is added directly into the Calendar widget and the API of the headers has been changed.**
57
58### Arrow buttons
59
60`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.
61
62
63### Drop-down
64`lv_calendar_header_dropdown_create(calendar)` creates a header that contains 2 drop-drown lists: one for the year and another for the month.
65
66
67## Example
68
69```eval_rst
70
71.. include:: ../../../examples/widgets/calendar/index.rst
72
73```
74
75## API
76
77```eval_rst
78
79.. doxygenfile:: lv_calendar.h
80  :project: lvgl
81
82```
83