# API Guide
## 8ms related
List of initialized screens  
void qmsd_screen_list_init(int max);  

Register a screen   
void qmsd_screen_register(lv_obj_t* obj,const char* id);  

Remove registered screens   
void qmsd_screen_remove(const char *id);  

Set ID for the specified obj   
void qmsd_obj_set_id(lv_obj_t* obj,const char *id);  

Print all currently registered screens   
void qmsd_screen_print();  

Search a screen based on registered id  
lv_obj_t* qmsd_search_screen(const char *id);  

Search a widget based on registered id  
lv_obj_t* qmsd_search_widget(const char *id);  

Get image resource corresponding to the name  
lv_img_src_t *qmsd_get_img(const char *w_name);

Get font resource corresponding to the name  
lv_font_t *qmsd_get_font(const char *w_name)；

Send events to all child widgets of the page  
void qmsd_send_event_to_chill(lv_obj_t* obj, lv_obj_t* prev, qmsd_event event)  
## Control protocol related

- Send control protocol to UI thread via text message  
int qmsd_ctrl_str(const char *json_str);

-  Use mutex to wait for UI thread to process interval resolution and perform related operations  
char *qmsd_ctrl_str_sync(const char *json_str);

- Parse and process the control protocol inside the GUI thread, only for use inside the GUI thread  
char *qmsd_ctrl_str_gui(const char *json_str);