部件的盒子模型 - lightdong/LVGL_Study GitHub Wiki
可以把下面的每一条边都测试一下
/**
* Selects on which sides border should be drawn
* 'OR'ed values can be used.
*/
enum {
LV_BORDER_SIDE_NONE = 0x00,
LV_BORDER_SIDE_BOTTOM = 0x01,
LV_BORDER_SIDE_TOP = 0x02,
LV_BORDER_SIDE_LEFT = 0x04,
LV_BORDER_SIDE_RIGHT = 0x08,
LV_BORDER_SIDE_FULL = 0x0F,
LV_BORDER_SIDE_INTERNAL = 0x10, /**< FOR matrix-like objects (e.g. Button matrix)*/
};
typedef uint8_t lv_border_side_t;