Add special handling for 0x2902 and 0x2904 descriptors

Author: sandeepmistry

libraries/CurieBle/src/BleCharacteristic.cpp

@@ -32,7 +32,9 @@ BleCharacteristic::BleCharacteristic(const char* uuid,
     _written(false),
     _cccd_value(0),
     _value_handle(0),
-    _cccd_handle(0)
+    _cccd_handle(0),
+    _user_description(NULL),
+    _presentation_format(NULL)
 {
     _max_len = maxLength > BLE_MAX_ATTR_DATA_LEN ? BLE_MAX_ATTR_DATA_LEN : maxLength;
 
@@ -148,6 +150,8 @@ BleCharacteristic::add(uint16_t serviceHandle)
 
     struct ble_gatts_characteristic char_data;
     struct ble_gatts_char_handles handles;
+    struct ble_gatt_char_user_desc user_desc;
+    struct ble_gatt_pf_desc pf_desc;
 
     memset(&char_data, 0, sizeof(char_data));
 
@@ -170,6 +174,19 @@ BleCharacteristic::add(uint16_t serviceHandle)
     char_data.max_len = _max_len;
     char_data.p_value = _data;
 
+    if (_user_description) {
+        user_desc.buffer = (uint8_t*)_user_description->value();
+        user_desc.len = _user_description->valueLength();
+
+        char_data.p_user_desc = &user_desc;
+    }
+
+    if (_presentation_format) {
+        memcpy(&pf_desc, _presentation_format->value(), sizeof(pf_desc));
+
+        char_data.p_char_pf_desc = &pf_desc;
+    }
+
     BleStatus status = ble_client_gatts_add_characteristic(serviceHandle, &char_data, &handles);
     if (BLE_STATUS_SUCCESS == status) {
         _value_handle = handles.value_handle;
@@ -209,6 +226,17 @@ BleCharacteristic::setCccdValue(BleCentral& central, uint16_t value)
     }
 }
 
+void
+BleCharacteristic::setUserDescription(BleDescriptor *descriptor)
+{
+    _user_description = descriptor;
+}
+
+void BleCharacteristic::setPresentationFormat(BleDescriptor *descriptor)
+{
+    _presentation_format = descriptor;
+}
+
 void
 BleCharacteristic::_setValue(const uint8_t value[], uint16_t length)
 {

libraries/CurieBle/src/BleCharacteristic.h

@@ -22,6 +22,7 @@
 
 #include "BleAttribute.h"
 #include "BleCentral.h"
+#include "BleDescriptor.h"
 
 /**
  * BLE Characteristic Events
@@ -153,6 +154,9 @@ class BleCharacteristic : public BleAttribute {
     void setValue(BleCentral& central, const uint8_t value[], uint16_t length);
     void setCccdValue(BleCentral& central, uint16_t value);
 
+    void setUserDescription(BleDescriptor *descriptor);
+    void setPresentationFormat(BleDescriptor *descriptor);
+
     friend class BlePeripheral;
 
 private:
@@ -167,6 +171,9 @@ class BleCharacteristic : public BleAttribute {
     uint16_t _cccd_value;
     uint16_t _value_handle;
     uint16_t _cccd_handle;
+
+    BleDescriptor* _user_description;
+    BleDescriptor* _presentation_format;
 
     BleCharacteristicEventHandler _event_handlers[BleCharacteristicEventLast];
 };

libraries/CurieBle/src/BleDescriptor.cpp

@@ -66,16 +66,12 @@ BleDescriptor::add(uint16_t serviceHandle)
 
     desc.p_uuid = &uuid;
 
+    desc.p_value = _data;
+    desc.length = _data_len;
+
     // this class only supports read-only descriptors
     desc.perms.rd = GAP_SEC_MODE_1 | GAP_SEC_LEVEL_1;
     desc.perms.wr = GAP_SEC_NO_PERMISSION;
 
-    BleStatus status = ble_client_gatts_add_descriptor(serviceHandle, &desc, &handle);
-
-    if (BLE_STATUS_SUCCESS == status) {
-        setHandle(handle);
-        status = ble_client_gatts_set_attribute_value(handle, _data_len, _data, 0);
-    }
-
-    return status; 
+    return ble_client_gatts_add_descriptor(serviceHandle, &desc, &handle); 
 }

libraries/CurieBle/src/BlePeripheral.cpp

@@ -44,13 +44,13 @@ blePeripheralGattsEventHandler(ble_client_gatts_event_t event, struct ble_gatts_
 }
 
 BlePeripheral::BlePeripheral(void) :
+    _state(BLE_PERIPH_STATE_NOT_READY),
+    _appearance(0),
     _central(this),
     _attributes(NULL),
-    _num_attributes(0)
+    _num_attributes(0),
+    _last_added_characteritic(NULL)
 {
-    _appearance = 0;
-    _state = BLE_PERIPH_STATE_NOT_READY;
-
     memset(_event_handlers, 0x00, sizeof(_event_handlers));
 
     ble_client_get_factory_config(&_local_bda, _local_name);
@@ -89,10 +89,15 @@ BleStatus BlePeripheral::begin()
 
             characteristic->add(lastServiceHandle);
         } else if (BleTypeDescriptor == type) {
-            // TODO: handle UUID 0x2901 and 0x2904 in a special way
-
             BleDescriptor *descriptor = (BleDescriptor*)attribute;
 
+            if (strcmp(descriptor->uuid(), "2901") == 0 ||
+                strcmp(descriptor->uuid(), "2902") == 0 ||
+                strcmp(descriptor->uuid(), "2903") == 0 ||
+                strcmp(descriptor->uuid(), "2904") == 0) {
+                continue; // skip
+            }
+
             status = descriptor->add(lastServiceHandle);
         }
 
@@ -189,6 +194,22 @@ BlePeripheral::addAttribute(BleAttribute& attribute)
     _attributes[_num_attributes] = &attribute;
     _num_attributes++;
 
+    BleAttributeType type = attribute.type();
+
+    if (BleTypeCharacteristic == type) {
+        _last_added_characteritic = (BleCharacteristic*)&attribute;
+    } else if (BleTypeDescriptor == type) {
+        if (_last_added_characteritic) {
+            BleDescriptor* descriptor = (BleDescriptor*)&attribute;
+
+            if (strcmp("2901", descriptor->uuid()) == 0) {
+                _last_added_characteritic->setUserDescription(descriptor);
+            } else if (strcmp("2904", descriptor->uuid()) == 0) {
+                _last_added_characteritic->setPresentationFormat(descriptor);
+            }
+        }
+    }
+
     return BLE_STATUS_SUCCESS;
 }
 

libraries/CurieBle/src/BlePeripheral.h

@@ -24,6 +24,7 @@
 
 #include "BleAttribute.h"
 #include "BleCentral.h"
+#include "BleCharacteristic.h"
 #include "BleCommon.h"
 
 /**
@@ -185,6 +186,8 @@ class BlePeripheral {
 
     BleAttribute** _attributes;
     uint16_t _num_attributes;
+
+    BleCharacteristic* _last_added_characteritic;
 };
 
 #endif // _BLE_DEVICE_H_INCLUDED