事件 - lightdong/LVGL_Study GitHub Wiki

typedef void (*lv_event_cb_t)(lv_event_t * e);

回调函数这种操作是非常常见的，重定义一个函数指针的类型lv_event_cb_t，接收什么样的函数？ 无返回值：void 形参：lv_event_t *e

事件有很多不同的类型

typedef enum {
    LV_EVENT_ALL = 0,

    /** Input device events*/
    LV_EVENT_PRESSED,             /*按下就有*/
    LV_EVENT_PRESSING,            /*只要按着就会有*/
    LV_EVENT_PRESS_LOST,          /**< The object is still being pressed but slid cursor/finger off of the object */
    LV_EVENT_SHORT_CLICKED,       /**< The object was pressed for a short period of time, then released it. Not called if scrolled.*/
    LV_EVENT_LONG_PRESSED,        /**< Object has been pressed for at least `long_press_time`.  Not called if scrolled.*/
    LV_EVENT_LONG_PRESSED_REPEAT, /**< Called after `long_press_time` in every `long_press_repeat_time` ms.  Not called if scrolled.*/
    LV_EVENT_CLICKED,             /*按下再松开会有事件*/
    LV_EVENT_RELEASED,            /**< Called in every cases when the object has been released*/
    LV_EVENT_SCROLL_BEGIN,        /**< Scrolling begins. The event parameter is a pointer to the animation of the scroll. Can be modified*/
    LV_EVENT_SCROLL_END,          /**< Scrolling ends*/
    LV_EVENT_SCROLL,              /**< Scrolling*/
    LV_EVENT_GESTURE,             /**< A gesture is detected. Get the gesture with `lv_indev_get_gesture_dir(lv_indev_get_act());` */
    LV_EVENT_KEY,                 /**< A key is sent to the object. Get the key with `lv_indev_get_key(lv_indev_get_act());`*/
    LV_EVENT_FOCUSED,             /**< The object is focused*/
    LV_EVENT_DEFOCUSED,           /**< The object is defocused*/
    LV_EVENT_LEAVE,               /**< The object is defocused but still selected*/
    LV_EVENT_HIT_TEST,            /**< Perform advanced hit-testing*/

    /** Drawing events*/
    LV_EVENT_COVER_CHECK,        /**< Check if the object fully covers an area. The event parameter is `lv_cover_check_info_t *`.*/
    LV_EVENT_REFR_EXT_DRAW_SIZE, /**< Get the required extra draw area around the object (e.g. for shadow). The event parameter is `lv_coord_t *` to store the size.*/
    LV_EVENT_DRAW_MAIN_BEGIN,    /**< Starting the main drawing phase*/
    LV_EVENT_DRAW_MAIN,          /**< Perform the main drawing*/
    LV_EVENT_DRAW_MAIN_END,      /**< Finishing the main drawing phase*/
    LV_EVENT_DRAW_POST_BEGIN,    /**< Starting the post draw phase (when all children are drawn)*/
    LV_EVENT_DRAW_POST,          /**< Perform the post draw phase (when all children are drawn)*/
    LV_EVENT_DRAW_POST_END,      /**< Finishing the post draw phase (when all children are drawn)*/
    LV_EVENT_DRAW_PART_BEGIN,    /**< Starting to draw a part. The event parameter is `lv_obj_draw_dsc_t *`. */
    LV_EVENT_DRAW_PART_END,      /**< Finishing to draw a part. The event parameter is `lv_obj_draw_dsc_t *`. */

    /** Special events*/
    LV_EVENT_VALUE_CHANGED,       /**< The object's value has changed (i.e. slider moved)*/
    LV_EVENT_INSERT,              /**< A text is inserted to the object. The event data is `char *` being inserted.*/
    LV_EVENT_REFRESH,             /**< Notify the object to refresh something on it (for the user)*/
    LV_EVENT_READY,               /**< A process has finished*/
    LV_EVENT_CANCEL,              /**< A process has been cancelled */

    /** Other events*/
    LV_EVENT_DELETE,              /**< Object is being deleted*/
    LV_EVENT_CHILD_CHANGED,       /**< Child was removed, added, or its size, position were changed */
    LV_EVENT_CHILD_CREATED,       /**< Child was created, always bubbles up to all parents*/
    LV_EVENT_CHILD_DELETED,       /**< Child was deleted, always bubbles up to all parents*/
    LV_EVENT_SCREEN_UNLOAD_START, /**< A screen unload started, fired immediately when scr_load is called*/
    LV_EVENT_SCREEN_LOAD_START,   /**< A screen load started, fired when the screen change delay is expired*/
    LV_EVENT_SCREEN_LOADED,       /**< A screen was loaded*/
    LV_EVENT_SCREEN_UNLOADED,     /**< A screen was unloaded*/
    LV_EVENT_SIZE_CHANGED,        /**< Object coordinates/size have changed*/
    LV_EVENT_STYLE_CHANGED,       /**< Object's style has changed*/
    LV_EVENT_LAYOUT_CHANGED,      /**< The children position has changed due to a layout recalculation*/
    LV_EVENT_GET_SELF_SIZE,       /**< Get the internal size of a widget*/

    _LV_EVENT_LAST,               /** Number of default events*/


    LV_EVENT_PREPROCESS = 0x80,   /** This is a flag that can be set with an event so it's processed
                                      before the class default event processing */
} lv_event_code_t;

pointer to the user_data返回指向数据的指针