Task #9 - callbacks return a struct with Arduino strings so beginners can avoid using std:: strings.

README.md

@@ -62,8 +62,8 @@ void onBLEStateChanged(BLENotifications::State state) {
 }
 
 // Setup a callback for when a notification arrives
-void onNotificationArrived(const Notification * notification) {
-    Serial.println(notification->title.c_str());
+void onNotificationArrived(const ArduinoNotification * notification, Notification * rawData) {
+    Serial.println(notification->title);
 }
 
 // Register the callback to be informed when a notification arrives

examples/ble_connection/ble_connection.ino

@@ -51,11 +51,16 @@ void onBLEStateChanged(BLENotifications::State state) {
 
 
 // A notification arrived from the mobile device, ie a social media notification or incoming call.
-void onNotificationArrived(const Notification * notification) {
+// parameters:
+//  - notification: an Arduino-friendly structure containing notification information. Do not keep a
+//                  pointer to this data - it will be destroyed after this function.
+//  - rawNotificationData: a pointer to the underlying data. It contains the same information, but is
+//                         not beginner-friendly. For advanced use-cases.
+void onNotificationArrived(const ArduinoNotification * notification, const Notification * rawNotificationData) {
     Serial.print("Got notification: ");   
-    Serial.println(notification->title.c_str()); // The title, ie name of who sent the message
-    Serial.println(notification->message.c_str()); // The detail, ie "be home for dinner at 7".
-    Serial.println(notification->type.c_str());  // Which app sent it
+    Serial.println(notification->title); // The title, ie name of who sent the message
+    Serial.println(notification->message); // The detail, ie "be home for dinner at 7".
+    Serial.println(notification->type);  // Which app sent it
     Serial.println(notifications.getNotificationCategoryDescription(notification->category));  // ie "social media"
     Serial.println(notification->categoryCount); // How may other notifications are there from this app (ie badge number)
     if (notification->category == CategoryIDIncomingCall) {
@@ -70,11 +75,11 @@ void onNotificationArrived(const Notification * notification) {
 
 
 // A notification was cleared
-void onNotificationRemoved(const Notification * notification) {
+void onNotificationRemoved(const ArduinoNotification * notification, const Notification * rawNotificationData) {
      Serial.print("Removed notification: ");   
-     Serial.println(notification->title.c_str());
-     Serial.println(notification->message.c_str());
-     Serial.println(notification->type.c_str());  
+     Serial.println(notification->title);
+     Serial.println(notification->message);
+     Serial.println(notification->type);  
 }
 
 

src/ancs_ble_client.cpp

@@ -204,7 +204,8 @@ void ANCSBLEClient::onDataSourceNotify(
       if (!notification->title.empty() && !notification->message.empty()) {
 		if (notificationCB && notification->isComplete == false) {
 			ESP_LOGI(LOG_TAG, "got a full notification: %s - %s ", notification->title.c_str(), notification->message.c_str());
-			notificationCB(notification);
+			const ArduinoNotification arduinoNotification = ArduinoNotification(*notification);
+			notificationCB(&arduinoNotification, notification);
 		}
 		notification->isComplete = true;
       }
@@ -239,7 +240,8 @@ void ANCSBLEClient::onNotificationSourceNotify(
 	    }
 		
 		if (removedCB) {
-			removedCB(notification);
+			const ArduinoNotification arduinoNotification = ArduinoNotification(*notification);
+			removedCB(&arduinoNotification, notification);
 		}
 	}
 	else if (pData[0] == ANCS::EventIDNotificationAdded) {

src/ble_notification.h

@@ -7,6 +7,7 @@
 #define BLE_NOTIFICATION_H_
 
 #include <string>
+#include <WString.h> // Arduino string
 
 /**
  * Notification category, based on ANCS values, but could also be used for Android.
@@ -91,17 +92,48 @@ struct Notification {
 	uint8_t categoryCount; /**< Number of other notifications in this category (ie badge number count). */
 };
 
+/**
+ * C++ strings might be confusing for beginners, so this is the same struct as Notification, but using
+ * Arduino strings. We still use Notification for the underlying logic, because of the heap fragmentation issues
+ * with Arduino strings.
+ */
+struct ArduinoNotification {
+    String title;
+    String message;
+    String type;
+	uint32_t eventFlags; /**< Bitfield of ANCS::EventFlags flags. */
+    time_t time;
+    uint32_t uuid = 0;
+    bool showed = false;
+    bool isComplete = false;
+	NotificationCategory category; /**< If it is a call, social media, email, etc. */
+	uint8_t categoryCount; /**< Number of other notifications in this category (ie badge number count). */
+	
+	ArduinoNotification(const Notification & src) {
+		title = String(src.title.c_str());
+		message = String(src.message.c_str());
+		type = String(src.type.c_str());
+		eventFlags = src.eventFlags;
+		time = src.time;
+		uuid = src.uuid;
+		showed = src.showed;
+		isComplete = src.isComplete;
+		category = src.category;
+		categoryCount = src.categoryCount;
+	}
+};
+
 /**
  * Callback for when a notification arrives.
  * @param notification The notification that just arrived.
  */
-typedef void (*ble_notification_arrived_t)(const Notification * notification);
+typedef void (*ble_notification_arrived_t)(const ArduinoNotification * notification, const Notification * rawNotificationData);
 
 /**
  * Callback for when a notification was removed.
  * @param notification The notification that was removed.
  */
-typedef void (*ble_notification_removed_t)(const Notification * notification);
+typedef void (*ble_notification_removed_t)(const ArduinoNotification * notification, const Notification * rawNotificationData);