Diff: features/FEATURE_BLE/ble/services/LinkLossService.h

Revision:

0:5b88d5760320

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/FEATURE_BLE/ble/services/LinkLossService.h	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,109 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * 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 __BLE_LINK_LOSS_SERVICE_H__
+#define __BLE_LINK_LOSS_SERVICE_H__
+
+#include "ble/Gap.h"
+
+#if BLE_FEATURE_GATT_SERVER
+
+/**
+* @class LinkLossService
+* @brief This service defines behavior when a link is lost between two devices.
+* Service:  https://developer.bluetooth.org/gatt/services/Pages/ServiceViewer.aspx?u=org.bluetooth.service.link_loss.xml
+* Alertness Level Char: https://developer.bluetooth.org/gatt/characteristics/Pages/CharacteristicViewer.aspx?u=org.bluetooth.characteristic.alert_level.xml
+*/
+class LinkLossService {
+public:
+    enum AlertLevel_t {
+        NO_ALERT   = 0,
+        MILD_ALERT = 1,
+        HIGH_ALERT = 2
+    };
+
+    typedef void (* callback_t)(AlertLevel_t level);
+
+    /**
+     * @param bleIn
+     *               BLE object for the underlying controller.
+     * @param callbackIn Callback invoked upon disconnection.
+     * @param levelIn Alert level.
+     */
+    LinkLossService(BLE &bleIn, callback_t callbackIn, AlertLevel_t levelIn = NO_ALERT) :
+        ble(bleIn),
+        alertLevel(levelIn),
+        callback(callbackIn),
+        alertLevelChar(GattCharacteristic::UUID_ALERT_LEVEL_CHAR, reinterpret_cast<uint8_t *>(&alertLevel)) {
+        static bool serviceAdded = false; /* We should only ever add one LinkLoss service. */
+        if (serviceAdded) {
+            return;
+        }
+
+        GattCharacteristic *charTable[] = {&alertLevelChar};
+        GattService         linkLossService(GattService::UUID_LINK_LOSS_SERVICE, charTable, sizeof(charTable) / sizeof(GattCharacteristic *));
+
+        ble.gattServer().addService(linkLossService);
+        serviceAdded = true;
+
+        ble.gap().onDisconnection(this, &LinkLossService::onDisconnectionFilter);
+        ble.gattServer().onDataWritten(this, &LinkLossService::onDataWritten);
+    }
+
+    /**
+     * Update the callback.
+     */
+    void setCallback(callback_t newCallback) {
+        callback = newCallback;
+    }
+
+    /**
+     * Update alertness level.
+     */
+    void setAlertLevel(AlertLevel_t newLevel) {
+        alertLevel = newLevel;
+    }
+
+protected:
+    /**
+     * This callback allows receiving updates to the AlertLevel characteristic.
+     *
+     * @param[in] params
+     *     Information about the characteristic being updated.
+     */
+    virtual void onDataWritten(const GattWriteCallbackParams *params) {
+        if (params->handle == alertLevelChar.getValueHandle()) {
+            alertLevel = *reinterpret_cast<const AlertLevel_t *>(params->data);
+        }
+    }
+
+    void onDisconnectionFilter(const Gap::DisconnectionCallbackParams_t *params) {
+        if (alertLevel != NO_ALERT) {
+            callback(alertLevel);
+        }
+    }
+
+protected:
+    BLE          &ble;
+    AlertLevel_t  alertLevel;
+    callback_t    callback;
+
+    ReadWriteGattCharacteristic<uint8_t> alertLevelChar;
+};
+
+#endif // BLE_FEATURE_GATT_SERVER
+
+#endif /* __BLE_LINK_LOSS_SERVICE_H__ */