Allow user of GattClient to call write on a discovered characteristic with

the continuation function

ble/DiscoveredCharacteristic.h

@@ -137,6 +137,11 @@ public:
      */
     ble_error_t write(uint16_t length, const uint8_t *value) const;
 
+    /** 
+     * Same as above but register the callback wich will be called once the data has been written
+     */
+    ble_error_t write(uint16_t length, const uint8_t *value, const GattClient::WriteCallback_t& onRead) const;
+
     void setupLongUUID(UUID::LongUUIDBytes_t longUUID) {
         uuid.setupLong(longUUID);
     }

source/DiscoveredCharacteristic.cpp

@@ -31,7 +31,6 @@ DiscoveredCharacteristic::read(uint16_t offset) const
     return gattc->read(connHandle, valueHandle, offset);
 }
 
-
 struct OneShotReadCallback { 
     static void launch(GattClient* client, Gap::Handle_t connHandle, 
                        GattAttribute::Handle_t handle,const GattClient::ReadCallback_t& cb) { 
@@ -45,7 +44,7 @@ private:
                         GattAttribute::Handle_t handle, const GattClient::ReadCallback_t& cb) : 
         _client(client),
         _connHandle(connHandle),
-        _handle(handle),
+        _handle(handle), 
         _callback(cb) { } 
 
     void attach() { 
@@ -54,7 +53,7 @@ private:
 
     void call(const GattReadCallbackParams* params) {
         // verifiy that it is the right characteristic on the right connection
-        if(params->connHandle == _connHandle && params->handle == _handle) { 
+        if (params->connHandle == _connHandle && params->handle == _handle) { 
             _callback(params);
             _client->onDataRead().detach(makeFunctionPointer(this, &OneShotReadCallback::call));
             delete this;
@@ -69,7 +68,7 @@ private:
 
 ble_error_t DiscoveredCharacteristic::read(uint16_t offset, const GattClient::ReadCallback_t& onRead) const {
     ble_error_t error = read(offset);
-    if(error) { 
+    if (error) { 
         return error;
     }
 
@@ -78,9 +77,6 @@ ble_error_t DiscoveredCharacteristic::read(uint16_t offset, const GattClient::Re
     return error;
 }
 
-
-
-
 ble_error_t
 DiscoveredCharacteristic::write(uint16_t length, const uint8_t *value) const
 {
@@ -109,6 +105,52 @@ DiscoveredCharacteristic::writeWoResponse(uint16_t length, const uint8_t *value)
     return gattc->write(GattClient::GATT_OP_WRITE_CMD, connHandle, valueHandle, length, value);
 }
 
+struct OneShotWriteCallback { 
+    static void launch(GattClient* client, Gap::Handle_t connHandle, 
+                       GattAttribute::Handle_t handle,const GattClient::WriteCallback_t& cb) { 
+        OneShotWriteCallback* oneShot = new OneShotWriteCallback(client, connHandle, handle, cb);
+        oneShot->attach();
+        // delete will be made when this callback is called
+    }
+
+private:
+    OneShotWriteCallback(GattClient* client, Gap::Handle_t connHandle, 
+                        GattAttribute::Handle_t handle, const GattClient::WriteCallback_t& cb) : 
+        _client(client),
+        _connHandle(connHandle),
+        _handle(handle), 
+        _callback(cb) { } 
+
+    void attach() { 
+        _client->onDataWritten(makeFunctionPointer(this, &OneShotWriteCallback::call));
+    }
+
+    void call(const GattWriteCallbackParams* params) {
+        // verifiy that it is the right characteristic on the right connection
+        if (params->connHandle == _connHandle && params->handle == _handle) { 
+            _callback(params);
+            _client->onDataWritten().detach(makeFunctionPointer(this, &OneShotWriteCallback::call));
+            delete this;
+        }
+    }
+
+    GattClient* _client;
+    Gap::Handle_t _connHandle;
+    GattAttribute::Handle_t _handle;
+    GattClient::WriteCallback_t _callback;
+};
+
+ble_error_t DiscoveredCharacteristic::write(uint16_t length, const uint8_t *value, const GattClient::WriteCallback_t& onRead) const {
+    ble_error_t error = write(length, value);
+    if (error) { 
+        return error;
+    }
+
+    OneShotWriteCallback::launch(gattc, connHandle, valueHandle, onRead);
+
+    return error;
+}
+
 ble_error_t
 DiscoveredCharacteristic::discoverDescriptors(DescriptorCallback_t callback, const UUID &matchingUUID) const
 {