Initial commit

include/liblvgl/extra/others/msg/lv_msg.h

@@ -0,0 +1,124 @@
+/**
+ * @file lv_msg.h
+ *
+ */
+
+#ifndef LV_MSG_H
+#define LV_MSG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+#include "liblvgl/core/lv_obj.h"
+#if LV_USE_MSG
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+typedef struct {
+    uint32_t id;            /*Identifier of the message*/
+    void * user_data;       /*Set the the user_data set in `lv_msg_subscribe`*/
+    void * _priv_data;      /*Used internally*/
+    const void * payload;   /*Pointer to the data of the message*/
+} lv_msg_t;
+
+typedef void (*lv_msg_subscribe_cb_t)(void * s, lv_msg_t * msg);
+
+typedef void (*lv_msg_request_cb_t)(void * r, uint32_t msg_id);
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+
+/**
+ * Called internally to initialize the message module
+ */
+void lv_msg_init(void);
+
+/**
+ * Subscribe to an `msg_id`
+ * @param msg_id        the message ID to listen to
+ * @param cb            callback to call if a message with `msg_id` was sent
+ * @param user_data     arbitrary data which will be available in `cb` too
+ * @return              pointer to a "subscribe object". It can be used the unsubscribe.
+ */
+void * lv_msg_subsribe(uint32_t msg_id, lv_msg_subscribe_cb_t cb, void * user_data);
+
+/**
+ * Subscribe an `lv_obj` to a message.
+ * `LV_EVENT_MSG_RECEIVED` will be triggered if a message with matching ID was sent
+ * @param msg_id        the message ID to listen to
+ * @param obj           pointer to an `lv_obj`
+ * @param user_data     arbitrary data which will be available in `cb` too
+ * @return              pointer to a "subscribe object". It can be used the unsubscribe.
+ */
+void * lv_msg_subsribe_obj(uint32_t msg_id, lv_obj_t * obj, void * user_data);
+
+/**
+ * Cancel a previous subscription
+ * @param s             pointer to a "subscibe object".
+ *                      Return value of `lv_msg_subsribe` or `lv_msg_subsribe_obj`
+ */
+void lv_msg_unsubscribe(void * s);
+
+/**
+ * Send a message with a given ID and payload
+ * @param msg_id        ID of the message to send
+ * @param data          pointer to the data to send
+ */
+void lv_msg_send(uint32_t msg_id, const void * payload);
+
+/**
+ * Get the ID of a message object. Typically used in the subscriber callback.
+ * @param m             pointer to a message object
+ * @return              the ID of the message
+ */
+uint32_t lv_msg_get_id(lv_msg_t * m);
+
+/**
+ * Get the payload of a message object. Typically used in the subscriber callback.
+ * @param m             pointer to a message object
+ * @return              the payload of the message
+ */
+const void * lv_msg_get_payload(lv_msg_t * m);
+
+/**
+ * Get the user data of a message object. Typically used in the subscriber callback.
+ * @param m             pointer to a message object
+ * @return              the user data of the message
+ */
+void * lv_msg_get_user_data(lv_msg_t * m);
+
+/**
+ * Get the message object from an event object. Can be used in `LV_EVENT_MSG_RECEIVED` events.
+ * @param e     pointer to an event object
+ * @return      the message object or NULL if called with unrelated event code.
+ */
+lv_msg_t * lv_event_get_msg(lv_event_t * e);
+
+/**********************
+ * GLOBAL VARIABLES
+ **********************/
+
+extern lv_event_code_t LV_EVENT_MSG_RECEIVED;
+
+/**********************
+ *      MACROS
+ **********************/
+
+#endif /*LV_USE_MSG*/
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif /*LV_MSG_H*/