Implement Gatt Presentation Format Descriptor class

descriptors/GattPresentationFormatDescriptor.h

@@ -0,0 +1,60 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2020-2021 Embedded Planet, Inc
+ * Copyright (c) 2020-2021 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef GATT_PRESENTATION_FORMAT_DESCRIPTOR_H_
+#define GATT_PRESENTATION_FORMAT_DESCRIPTOR_H_
+
+#include "GattCharacteristic.h"
+#include "GattAttribute.h"
+
+/** Length of a presentation format descriptor struct */
+#define GATT_PRESENTATION_FORMAT_DESCRIPTOR_LEN 7
+
+/**
+ * Class encapsulating a GATT Presentation Format Descriptor
+ */
+class GattPresentationFormatDescriptor: public GattAttribute {
+
+public:
+
+    GattPresentationFormatDescriptor(uint8_t format_type, uint16_t unit =
+            GattCharacteristic::BLE_GATT_UNIT_NONE, int8_t exponent = 1,
+            uint8_t namespace_id = 0x01,
+            uint16_t namespace_description = 0x0000) :
+            GattAttribute(
+                    (const UUID&) UUID(
+                            BLE_UUID_DESCRIPTOR_CHAR_PRESENTATION_FORMAT),
+                    (uint8_t*) format, GATT_PRESENTATION_FORMAT_DESCRIPTOR_LEN,
+                    GATT_PRESENTATION_FORMAT_DESCRIPTOR_LEN, false) {
+
+        format[0] = format_type;
+        format[1] = exponent;
+        format[2] = (unit & 0xFF00) >> 8;
+        format[3] = (unit & 0x00FF);
+        format[4] = namespace_id;
+        format[5] = (namespace_description & 0xFF00) >> 8;
+        format[6] = (namespace_description & 0x00FF);
+
+    }
+
+private:
+
+    uint8_t format[7];
+};
+
+#endif /* GATT_PRESENTATION_FORMAT_DESCRIPTOR_H_ */