text: /**
   * @file lv_chart.h
   *
   */
  
  #ifndef LV_CHART_H
  #define LV_CHART_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /*********************
   *      INCLUDES
   *********************/
  #include "../lv_conf_internal.h"
  
  #if LV_USE_CHART != 0
  
  #include "../lv_core/lv_obj.h"
  #include "lv_line.h"
  
  /*********************
   *      DEFINES
   *********************/
  
  /**Default value of points. Can be used to not draw a point*/
  #define LV_CHART_POINT_DEF (LV_COORD_MIN)
  
  /**Automatically calculate the tick length*/
  #define LV_CHART_TICK_LENGTH_AUTO 255
  
  LV_EXPORT_CONST_INT(LV_CHART_POINT_DEF);
  LV_EXPORT_CONST_INT(LV_CHART_TICK_LENGTH_AUTO);
  
  /**********************
   *      TYPEDEFS
   **********************/
  
  /** Chart types*/
  enum {
      LV_CHART_TYPE_NONE     = 0x00, /**< Don't draw the series*/
      LV_CHART_TYPE_LINE     = 0x01, /**< Connect the points with lines*/
      LV_CHART_TYPE_COLUMN   = 0x02, /**< Draw columns*/
  };
  typedef uint8_t lv_chart_type_t;
  
  /** Chart update mode for `lv_chart_set_next`*/
  enum {
      LV_CHART_UPDATE_MODE_SHIFT,     /**< Shift old data to the left and add the new one o the right*/
      LV_CHART_UPDATE_MODE_CIRCULAR,  /**< Add the new data in a circular way*/
  };
  typedef uint8_t lv_chart_update_mode_t;
  
  typedef struct {
      lv_coord_t * points;
      lv_color_t color;
      uint16_t start_point;
  } lv_chart_series_t;
  
  /** Data of axis */
  enum {
      LV_CHART_AXIS_SKIP_LAST_TICK = 0x00,            /**< don't draw the last tick */
      LV_CHART_AXIS_DRAW_LAST_TICK = 0x01,            /**< draw the last tick */
      LV_CHART_AXIS_INVERSE_LABELS_ORDER = 0x02       /**< draw tick labels in an inversed order*/
  };
  typedef uint8_t lv_chart_axis_options_t;
  
  typedef struct {
      const char * list_of_values;
      lv_chart_axis_options_t options;
      uint8_t num_tick_marks;
      uint8_t major_tick_len;
      uint8_t minor_tick_len;
  } lv_chart_axis_cfg_t;
  
  /*Data of chart */
  typedef struct {
      /*No inherited ext*/ /*Ext. of ancestor*/
      /*New data for this type */
      lv_ll_t series_ll;    /*Linked list for the data line pointers (stores lv_chart_series_t)*/
      lv_coord_t ymin;      /*y min value (used to scale the data)*/
      lv_coord_t ymax;      /*y max value (used to scale the data)*/
      uint8_t hdiv_cnt;     /*Number of horizontal division lines*/
      uint8_t vdiv_cnt;     /*Number of vertical division lines*/
      uint16_t point_cnt;   /*Point number in a data line*/
      lv_style_list_t style_series_bg;
      lv_style_list_t style_series;
      lv_chart_type_t type; /*Line, column or point chart (from 'lv_chart_type_t')*/
      lv_chart_axis_cfg_t y_axis;
      lv_chart_axis_cfg_t x_axis;
      lv_chart_axis_cfg_t secondary_y_axis;
      uint8_t update_mode : 1;
  } lv_chart_ext_t;
  
  /*Parts of the chart*/
  enum {
      LV_CHART_PART_BG = LV_OBJ_PART_MAIN,
      LV_CHART_PART_SERIES_BG = _LV_OBJ_PART_VIRTUAL_LAST,
      LV_CHART_PART_SERIES
  };
  
  /**********************
   * GLOBAL PROTOTYPES
   **********************/
  
  /**
   * Create a chart background objects
   * @param par pointer to an object, it will be the parent of the new chart background
   * @param copy pointer to a chart background object, if not NULL then the new object will be copied
   * from it
   * @return pointer to the created chart background
   */
  lv_obj_t * lv_chart_create(lv_obj_t * par, const lv_obj_t * copy);
  
  /*======================
   * Add/remove functions
   *=====================*/
  
  /**
   * Allocate and add a data series to the chart
   * @param chart pointer to a chart object
   * @param color color of the data series
   * @return pointer to the allocated data series
   */
  lv_chart_series_t * lv_chart_add_series(lv_obj_t * chart, lv_color_t color);
  
  /**
   * Clear the point of a series
   * @param chart pointer to a chart object
   * @param serie pointer to the chart's series to clear
   */
  void lv_chart_clear_serie(lv_obj_t * chart, lv_chart_series_t * serie);
  
  /*=====================
   * Setter functions
   *====================*/
  
  /**
   * Set the number of horizontal and vertical division lines
   * @param chart pointer to a graph background object
   * @param hdiv number of horizontal division lines
   * @param vdiv number of vertical division lines
   */
  void lv_chart_set_div_line_count(lv_obj_t * chart, uint8_t hdiv, uint8_t vdiv);
  
  /**
   * Set the minimal and maximal y values
   * @param chart pointer to a graph background object
   * @param ymin y minimum value
   * @param ymax y maximum value
   */
  void lv_chart_set_range(lv_obj_t * chart, lv_coord_t ymin, lv_coord_t ymax);
  
  /**
   * Set a new type for a chart
   * @param chart pointer to a chart object
   * @param type new type of the chart (from 'lv_chart_type_t' enum)
   */
  void lv_chart_set_type(lv_obj_t * chart, lv_chart_type_t type);
  
  /**
   * Set the number of points on a data line on a chart
   * @param chart pointer r to chart object
   * @param point_cnt new number of points on the data lines
   */
  void lv_chart_set_point_count(lv_obj_t * chart, uint16_t point_cnt);
  
  /**
   * Initialize all data points with a value
   * @param chart pointer to chart object
   * @param ser pointer to a data series on 'chart'
   * @param y the new value  for all points
   */
  void lv_chart_init_points(lv_obj_t * chart, lv_chart_series_t * ser, lv_coord_t y);
  
  /**
   * Set the value of points from an array
   * @param chart pointer to chart object
   * @param ser pointer to a data series on 'chart'
   * @param y_array array of 'lv_coord_t' points (with 'points count' elements )
   */
  void lv_chart_set_points(lv_obj_t * chart, lv_chart_series_t * ser, lv_coord_t y_array[]);
  
  /**
   * Shift all data right and set the most right data on a data line
   * @param chart pointer to chart object
   * @param ser pointer to a data series on 'chart'
   * @param y the new value of the most right data
   */
  void lv_chart_set_next(lv_obj_t * chart, lv_chart_series_t * ser, lv_coord_t y);
  
  /**
   * Set update mode of the chart object.
   * @param chart pointer to a chart object
   * @param update mode
   */
  void lv_chart_set_update_mode(lv_obj_t * chart, lv_chart_update_mode_t update_mode);
  
  /**
   * Set the length of the tick marks on the x axis
   * @param chart pointer to the chart
   * @param major_tick_len the length of the major tick or `LV_CHART_TICK_LENGTH_AUTO` to set automatically
   *                       (where labels are added)
   * @param minor_tick_len the length of the minor tick, `LV_CHART_TICK_LENGTH_AUTO` to set automatically
   *                       (where no labels are added)
   */
  void lv_chart_set_x_tick_length(lv_obj_t * chart, uint8_t major_tick_len, uint8_t minor_tick_len);
  
  /**
   * Set the length of the tick marks on the y axis
   * @param chart pointer to the chart
   * @param major_tick_len the length of the major tick or `LV_CHART_TICK_LENGTH_AUTO` to set automatically
   *                       (where labels are added)
   * @param minor_tick_len the length of the minor tick, `LV_CHART_TICK_LENGTH_AUTO` to set automatically
   *                       (where no labels are added)
   */
  void lv_chart_set_y_tick_length(lv_obj_t * chart, uint8_t major_tick_len, uint8_t minor_tick_len);
  
  /**
   * Set the length of the tick marks on the secondary y axis
   * @param chart pointer to the chart
   * @param major_tick_len the length of the major tick or `LV_CHART_TICK_LENGTH_AUTO` to set automatically
   *                       (where labels are added)
   * @param minor_tick_len the length of the minor tick, `LV_CHART_TICK_LENGTH_AUTO` to set automatically
   *                       (where no labels are added)
   */
  void lv_chart_set_secondary_y_tick_length(lv_obj_t * chart, uint8_t major_tick_len, uint8_t minor_tick_len);
  
  /**
   * Set the x-axis tick count and labels of a chart
   * @param chart             pointer to a chart object
   * @param list_of_values    list of string values, terminated with \n, except the last
   * @param num_tick_marks    if list_of_values is NULL: total number of ticks per axis
   *                          else number of ticks between two value labels
   * @param options           extra options
   */
  void lv_chart_set_x_tick_texts(lv_obj_t * chart, const char * list_of_values, uint8_t num_tick_marks,
                                 lv_chart_axis_options_t options);
  
  /**
   * Set the secondary y-axis tick count and labels of a chart
   * @param chart             pointer to a chart object
   * @param list_of_values    list of string values, terminated with \n, except the last
   * @param num_tick_marks    if list_of_values is NULL: total number of ticks per axis
   *                          else number of ticks between two value labels
   * @param options           extra options
   */
  void lv_chart_set_secondary_y_tick_texts(lv_obj_t * chart, const char * list_of_values, uint8_t num_tick_marks,
                                           lv_chart_axis_options_t options);
  
  /**
   * Set the y-axis tick count and labels of a chart
   * @param chart             pointer to a chart object
   * @param list_of_values    list of string values, terminated with \n, except the last
   * @param num_tick_marks    if list_of_values is NULL: total number of ticks per axis
   *                          else number of ticks between two value labels
   * @param options           extra options
   */
  void lv_chart_set_y_tick_texts(lv_obj_t * chart, const char * list_of_values, uint8_t num_tick_marks,
                                 lv_chart_axis_options_t options);
  
  /*=====================
   * Getter functions
   *====================*/
  
  /**
   * Get the type of a chart
   * @param chart pointer to chart object
   * @return type of the chart (from 'lv_chart_t' enum)
   */
  lv_chart_type_t lv_chart_get_type(const lv_obj_t * chart);
  
  /**
   * Get the data point number per data line on chart
   * @param chart pointer to chart object
   * @return point number on each data line
   */
  uint16_t lv_chart_get_point_count(const lv_obj_t * chart);
  
  /*=====================
   * Other functions
   *====================*/
  
  /**
   * Refresh a chart if its data line has changed
   * @param chart pointer to chart object
   */
  void lv_chart_refresh(lv_obj_t * chart);
  
  /**********************
   *      MACROS
   **********************/
  
  #endif /*LV_USE_CHART*/
  
  #ifdef __cplusplus
  } /* extern "C" */
  #endif
  
  #endif /*LV_CHART_H*/
  