text: /**
   * @file lv_btnm.h
   *
   */
  
  #ifndef LV_BTNMATRIX_H
  #define LV_BTNMATRIX_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  /*********************
   *      INCLUDES
   *********************/
  #include "../lv_conf_internal.h"
  
  #if LV_USE_BTNMATRIX != 0
  
  #include "../core/lv_obj.h"
  
  /*********************
   *      DEFINES
   *********************/
  #define LV_BTNMATRIX_BTN_NONE 0xFFFF
  LV_EXPORT_CONST_INT(LV_BTNMATRIX_BTN_NONE);
  
  /**********************
   *      TYPEDEFS
   **********************/
  
  /** Type to store button control bits (disabled, hidden etc.)
   * The first 3 bits are used to store the width*/
  enum {
      _LV_BTNMATRIX_WIDTH     = 0x0007,      /**< Reserved to stire the size units*/
      LV_BTNMATRIX_CTRL_HIDDEN     = 0x0008, /**< Button hidden*/
      LV_BTNMATRIX_CTRL_NO_REPEAT  = 0x0010, /**< Do not repeat press this button.*/
      LV_BTNMATRIX_CTRL_DISABLED   = 0x0020, /**< Disable this button.*/
      LV_BTNMATRIX_CTRL_CHECKABLE  = 0x0040, /**< The button can be toggled.*/
      LV_BTNMATRIX_CTRL_CHECKED    = 0x0080, /**< Button is currently toggled (e.g. checked).*/
      LV_BTNMATRIX_CTRL_CLICK_TRIG = 0x0100, /**< 1: Send LV_EVENT_VALUE_CHANGE on CLICK, 0: Send LV_EVENT_VALUE_CHANGE on PRESS*/
      LV_BTNMATRIX_CTRL_POPOVER    = 0x0200, /**< Show a popover when pressing this key*/
      LV_BTNMATRIX_CTRL_RECOLOR    = 0x1000, /**< Enable text recoloring with `#color`*/
      _LV_BTNMATRIX_CTRL_RESERVED  = 0x2000, /**< Reserved for later use*/
      LV_BTNMATRIX_CTRL_CUSTOM_1   = 0x4000, /**< Custom free to use flag*/
      LV_BTNMATRIX_CTRL_CUSTOM_2   = 0x8000, /**< Custom free to use flag*/
  };
  
  typedef uint16_t lv_btnmatrix_ctrl_t;
  
  typedef bool (*lv_btnmatrix_btn_draw_cb_t)(lv_obj_t * btnm, uint32_t btn_id, const lv_area_t * draw_area,
                                             const lv_area_t * clip_area);
  
  /*Data of button matrix*/
  typedef struct {
      lv_obj_t obj;
      const char ** map_p;                              /*Pointer to the current map*/
      lv_area_t * button_areas;                         /*Array of areas of buttons*/
      lv_btnmatrix_ctrl_t * ctrl_bits;                       /*Array of control bytes*/
      uint16_t btn_cnt;                                 /*Number of button in 'map_p'(Handled by the library)*/
      uint16_t row_cnt;                                 /*Number of rows in 'map_p'(Handled by the library)*/
      uint16_t btn_id_sel;    /*Index of the active button (being pressed/released etc) or LV_BTNMATRIX_BTN_NONE*/
      uint8_t one_check : 1;  /*Single button toggled at once*/
  } lv_btnmatrix_t;
  
  extern const lv_obj_class_t lv_btnmatrix_class;
  
  /**
   * `type` field in `lv_obj_draw_part_dsc_t` if `class_p = lv_btnmatrix_class`
   * Used in `LV_EVENT_DRAW_PART_BEGIN` and `LV_EVENT_DRAW_PART_END`
   */
  typedef enum {
      LV_BTNMATRIX_DRAW_PART_BTN,    /**< The rectangle and label of buttons*/
  } lv_btnmatrix_draw_part_type_t;
  
  /**********************
   * GLOBAL PROTOTYPES
   **********************/
  
  /**
   * Create a button matrix objects
   * @param parent    pointer to an object, it will be the parent of the new button matrix
   * @return          pointer to the created button matrix
   */
  lv_obj_t * lv_btnmatrix_create(lv_obj_t * parent);
  
  /*=====================
   * Setter functions
   *====================*/
  
  /**
   * Set a new map. Buttons will be created/deleted according to the map. The
   * button matrix keeps a reference to the map and so the string array must not
   * be deallocated during the life of the matrix.
   * @param obj       pointer to a button matrix object
   * @param map       pointer a string array. The last string has to be: "". Use "\n" to make a line break.
   */
  void lv_btnmatrix_set_map(lv_obj_t * obj, const char * map[]);
  
  /**
   * Set the button control map (hidden, disabled etc.) for a button matrix.
   * The control map array will be copied and so may be deallocated after this
   * function returns.
   * @param obj       pointer to a button matrix object
   * @param ctrl_map  pointer to an array of `lv_btn_ctrl_t` control bytes. The
   *                  length of the array and position of the elements must match
   *                  the number and order of the individual buttons (i.e. excludes
   *                  newline entries).
   *                  An element of the map should look like e.g.:
   *                 `ctrl_map[0] = width | LV_BTNMATRIX_CTRL_NO_REPEAT |  LV_BTNMATRIX_CTRL_TGL_ENABLE`
   */
  void lv_btnmatrix_set_ctrl_map(lv_obj_t * obj, const lv_btnmatrix_ctrl_t ctrl_map[]);
  
  /**
   * Set the selected buttons
   * @param obj        pointer to button matrix object
   * @param btn_id         0 based index of the button to modify. (Not counting new lines)
   */
  void lv_btnmatrix_set_selected_btn(lv_obj_t * obj, uint16_t btn_id);
  
  /**
   * Set the attributes of a button of the button matrix
   * @param obj       pointer to button matrix object
   * @param btn_id    0 based index of the button to modify. (Not counting new lines)
   * @param ctrl      OR-ed attributs. E.g. `LV_BTNMATRIX_CTRL_NO_REPEAT | LV_BTNMATRIX_CTRL_CHECKABLE`
   */
  void lv_btnmatrix_set_btn_ctrl(lv_obj_t * obj, uint16_t btn_id, lv_btnmatrix_ctrl_t ctrl);
  
  /**
   * Clear the attributes of a button of the button matrix
   * @param obj       pointer to button matrix object
   * @param btn_id    0 based index of the button to modify. (Not counting new lines)
   * @param ctrl      OR-ed attributs. E.g. `LV_BTNMATRIX_CTRL_NO_REPEAT | LV_BTNMATRIX_CTRL_CHECKABLE`
   */
  void lv_btnmatrix_clear_btn_ctrl(lv_obj_t * obj, uint16_t btn_id, lv_btnmatrix_ctrl_t ctrl);
  
  /**
   * Set attributes of all buttons of a button matrix
   * @param obj       pointer to a button matrix object
   * @param ctrl      attribute(s) to set from `lv_btnmatrix_ctrl_t`. Values can be ORed.
   */
  void lv_btnmatrix_set_btn_ctrl_all(lv_obj_t * obj, lv_btnmatrix_ctrl_t ctrl);
  
  /**
   * Clear the attributes of all buttons of a button matrix
   * @param obj       pointer to a button matrix object
   * @param ctrl      attribute(s) to set from `lv_btnmatrix_ctrl_t`. Values can be ORed.
   * @param en        true: set the attributes; false: clear the attributes
   */
  void lv_btnmatrix_clear_btn_ctrl_all(lv_obj_t * obj, lv_btnmatrix_ctrl_t ctrl);
  
  /**
   * Set a single button's relative width.
   * This method will cause the matrix be regenerated and is a relatively
   * expensive operation. It is recommended that initial width be specified using
   * `lv_btnmatrix_set_ctrl_map` and this method only be used for dynamic changes.
   * @param obj       pointer to button matrix object
   * @param btn_id    0 based index of the button to modify.
   * @param width     relative width compared to the buttons in the same row. [1..7]
   */
  void lv_btnmatrix_set_btn_width(lv_obj_t * obj, uint16_t btn_id, uint8_t width);
  
  /**
   * Make the button matrix like a selector widget (only one button may be checked at a time).
   * `LV_BTNMATRIX_CTRL_CHECKABLE` must be enabled on the buttons to be selected using
   *  `lv_btnmatrix_set_ctrl()` or `lv_btnmatrix_set_btn_ctrl_all()`.
   * @param obj       pointer to a button matrix object
   * @param en        whether "one check" mode is enabled
   */
  void lv_btnmatrix_set_one_checked(lv_obj_t * obj, bool en);
  
  /*=====================
   * Getter functions
   *====================*/
  
  /**
   * Get the current map of a button matrix
   * @param obj       pointer to a button matrix object
   * @return          the current map
   */
  const char ** lv_btnmatrix_get_map(const lv_obj_t * obj);
  
  /**
   * Get the index of the lastly "activated" button by the user (pressed, released, focused etc)
   * Useful in the the `event_cb` to get the text of the button, check if hidden etc.
   * @param obj       pointer to button matrix object
   * @return          index of the last released button (LV_BTNMATRIX_BTN_NONE: if unset)
   */
  uint16_t lv_btnmatrix_get_selected_btn(const lv_obj_t * obj);
  
  /**
   * Get the button's text
   * @param obj       pointer to button matrix object
   * @param btn_id    the index a button not counting new line characters.
   * @return          text of btn_index` button
   */
  const char * lv_btnmatrix_get_btn_text(const lv_obj_t * obj, uint16_t btn_id);
  
  /**
   * Get the whether a control value is enabled or disabled for button of a button matrix
   * @param obj       pointer to a button matrix object
   * @param btn_id    the index of a button not counting new line characters.
   * @param ctrl      control values to check (ORed value can be used)
   * @return          true: the control attribute is enabled false: disabled
   */
  bool lv_btnmatrix_has_btn_ctrl(lv_obj_t * obj, uint16_t btn_id, lv_btnmatrix_ctrl_t ctrl);
  
  /**
   * Tell whether "one check" mode is enabled or not.
   * @param obj       Button matrix object
   * @return          true: "one check" mode is enabled; false: disabled
   */
  bool lv_btnmatrix_get_one_checked(const lv_obj_t * obj);
  
  /**********************
   *      MACROS
   **********************/
  
  #endif /*LV_USE_BTNMATRIX*/
  
  #ifdef __cplusplus
  } /*extern "C"*/
  #endif
  
  #endif /*LV_BTNMATRIX_H*/
  