GattClient.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef __GATT_CLIENT_H__
00018 #define __GATT_CLIENT_H__
00019 
00020 #include "Gap.h"
00021 #include "GattAttribute.h"
00022 #include "ServiceDiscovery.h"
00023 
00024 #include "GattCallbackParamTypes.h"
00025 
00026 class GattClient {
00027 public:
00028     typedef void (*ReadCallback_t)(const GattReadCallbackParams *params);
00029 
00030     enum WriteOp_t {
00031         GATT_OP_WRITE_REQ = 0x01,  /**< Write Request. */
00032         GATT_OP_WRITE_CMD = 0x02,  /**< Write Command. */
00033     };
00034 
00035     typedef void (*WriteCallback_t)(const GattWriteCallbackParams *params);
00036 
00037     typedef void (*HVXCallback_t)(const GattHVXCallbackParams *params);
00038 
00039     /*
00040      * The following functions are meant to be overridden in the platform-specific sub-class.
00041      */
00042 public:
00043     /**
00044      * Launch service discovery. Once launched, application callbacks will be
00045      * invoked for matching services/characteristics. isServiceDiscoveryActive()
00046      * can be used to determine status; and a termination callback (if setup)
00047      * will be invoked at the end. Service discovery can be terminated prematurely
00048      * if needed using terminateServiceDiscovery().
00049      *
00050      * @param  connectionHandle
00051      *           Handle for the connection with the peer.
00052      * @param  sc
00053      *           This is the application callback for matching service. Taken as
00054      *           NULL by default. Note: service discovery may still be active
00055      *           when this callback is issued; calling asynchronous BLE-stack
00056      *           APIs from within this application callback might cause the
00057      *           stack to abort service discovery. If this becomes an issue, it
00058      *           may be better to make local copy of the discoveredService and
00059      *           wait for service discovery to terminate before operating on the
00060      *           service.
00061      * @param  cc
00062      *           This is the application callback for matching characteristic.
00063      *           Taken as NULL by default. Note: service discovery may still be
00064      *           active when this callback is issued; calling asynchronous
00065      *           BLE-stack APIs from within this application callback might cause
00066      *           the stack to abort service discovery. If this becomes an issue,
00067      *           it may be better to make local copy of the discoveredCharacteristic
00068      *           and wait for service discovery to terminate before operating on the
00069      *           characteristic.
00070      * @param  matchingServiceUUID
00071      *           UUID based filter for specifying a service in which the application is
00072      *           interested. By default it is set as the wildcard UUID_UNKNOWN,
00073      *           in which case it matches all services. If characteristic-UUID
00074      *           filter (below) is set to the wildcard value, then a service
00075      *           callback will be invoked for the matching service (or for every
00076      *           service if the service filter is a wildcard).
00077      * @param  matchingCharacteristicUUIDIn
00078      *           UUID based filter for specifying characteristic in which the application
00079      *           is interested. By default it is set as the wildcard UUID_UKNOWN
00080      *           to match against any characteristic. If both service-UUID
00081      *           filter and characteristic-UUID filter are used with non- wildcard
00082      *           values, then only a single characteristic callback is
00083      *           invoked for the matching characteristic.
00084      *
00085      * @note     Using wildcard values for both service-UUID and characteristic-
00086      *           UUID will result in complete service discovery--callbacks being
00087      *           called for every service and characteristic.
00088      *
00089      * @note     Providing NULL for the characteristic callback will result in
00090      *           characteristic discovery being skipped for each matching
00091      *           service. This allows for an inexpensive method to discover only
00092      *           services.
00093      *
00094      * @return
00095      *           BLE_ERROR_NONE if service discovery is launched successfully; else an appropriate error.
00096      */
00097     virtual ble_error_t launchServiceDiscovery(Gap::Handle_t                               connectionHandle,
00098                                                ServiceDiscovery::ServiceCallback_t         sc                           = NULL,
00099                                                ServiceDiscovery::CharacteristicCallback_t  cc                           = NULL,
00100                                                const UUID                                 &matchingServiceUUID          = UUID::ShortUUIDBytes_t(BLE_UUID_UNKNOWN),
00101                                                const UUID                                 &matchingCharacteristicUUIDIn = UUID::ShortUUIDBytes_t(BLE_UUID_UNKNOWN)) {
00102         /* avoid compiler warnings about unused variables */
00103         (void)connectionHandle;
00104         (void)sc;
00105         (void)cc;
00106         (void)matchingServiceUUID;
00107         (void)matchingCharacteristicUUIDIn;
00108 
00109         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porter(s): override this API if this capability is supported. */
00110     }
00111 
00112     /**
00113      * Launch service discovery for services. Once launched, service discovery will remain
00114      * active with service-callbacks being issued back into the application for matching
00115      * services. isServiceDiscoveryActive() can be used to
00116      * determine status; and a termination callback (if setup) will be invoked
00117      * at the end. Service discovery can be terminated prematurely if needed
00118      * using terminateServiceDiscovery().
00119      *
00120      * @param  connectionHandle
00121      *           Handle for the connection with the peer.
00122      * @param  sc
00123      *           This is the application callback for matching service. Note: service discovery may still be active
00124      *           when this callback is issued; calling asynchronous BLE-stack
00125      *           APIs from within this application callback might cause the
00126      *           stack to abort service discovery. If this becomes an issue, it
00127      *           may be better to make local copy of the discoveredService and
00128      *           wait for service discovery to terminate before operating on the
00129      *           service.
00130      * @param  matchingServiceUUID
00131      *           UUID based filter for specifying a service in which the application is
00132      *           interested. By default it is set as the wildcard UUID_UNKNOWN,
00133      *           in which case it matches all services.
00134      *
00135      * @return
00136      *           BLE_ERROR_NONE if service discovery is launched successfully; else an appropriate error.
00137      */
00138     virtual ble_error_t discoverServices(Gap::Handle_t                        connectionHandle,
00139                                          ServiceDiscovery::ServiceCallback_t  callback,
00140                                          const UUID                          &matchingServiceUUID = UUID::ShortUUIDBytes_t(BLE_UUID_UNKNOWN)) {
00141         return launchServiceDiscovery(connectionHandle, callback, NULL, matchingServiceUUID); /* We take advantage of the property
00142                                                                 * that providing NULL for the characteristic callback will result in
00143                                                                 * characteristic discovery being skipped for each matching
00144                                                                 * service. This allows for an inexpensive method to discover only
00145                                                                 * services. Porter(s) are free to override this. */
00146     }
00147 
00148     /**
00149      * Launch service discovery for services. Once launched, service discovery will remain
00150      * active with service-callbacks being issued back into the application for matching
00151      * services. isServiceDiscoveryActive() can be used to
00152      * determine status; and a termination callback (if setup) will be invoked
00153      * at the end. Service discovery can be terminated prematurely if needed
00154      * using terminateServiceDiscovery().
00155      *
00156      * @param  connectionHandle
00157      *           Handle for the connection with the peer.
00158      * @param  sc
00159      *           This is the application callback for matching service. Note: service discovery may still be active
00160      *           when this callback is issued; calling asynchronous BLE-stack
00161      *           APIs from within this application callback might cause the
00162      *           stack to abort service discovery. If this becomes an issue, it
00163      *           may be better to make local copy of the discoveredService and
00164      *           wait for service discovery to terminate before operating on the
00165      *           service.
00166      * @param  startHandle, endHandle
00167      *           Handle range within which to limit the search
00168      *
00169      * @return
00170      *           BLE_ERROR_NONE if service discovery is launched successfully; else an appropriate error.
00171      */
00172     virtual ble_error_t discoverServices(Gap::Handle_t                        connectionHandle,
00173                                          ServiceDiscovery::ServiceCallback_t  callback,
00174                                          GattAttribute::Handle_t              startHandle,
00175                                          GattAttribute::Handle_t              endHandle) {
00176         /* avoid compiler warnings about unused variables */
00177         (void)connectionHandle;
00178         (void)callback;
00179         (void)startHandle;
00180         (void)endHandle;
00181 
00182         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porter(s): override this API if this capability is supported. */
00183     }
00184 
00185     /**
00186      * Is service-discovery currently active?
00187      */
00188     virtual bool isServiceDiscoveryActive(void) const {
00189         return false; /* Requesting action from porter(s): override this API if this capability is supported. */
00190     }
00191 
00192     /**
00193      * Terminate an ongoing service-discovery. This should result in an
00194      * invocation of the TerminationCallback if service-discovery is active.
00195      */
00196     virtual void terminateServiceDiscovery(void) {
00197         /* Requesting action from porter(s): override this API if this capability is supported. */
00198     }
00199 
00200     /* Initiate a Gatt Client read procedure by attribute-handle. */
00201     virtual ble_error_t read(Gap::Handle_t connHandle, GattAttribute::Handle_t attributeHandle, uint16_t offset) const {
00202         /* avoid compiler warnings about unused variables */
00203         (void)connHandle;
00204         (void)attributeHandle;
00205         (void)offset;
00206 
00207         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porter(s): override this API if this capability is supported. */
00208     }
00209 
00210     /**
00211      * Initiate a GATT Client write procedure.
00212      *
00213      * @param[in] cmd
00214      *              Command can be either a write-request (which generates a
00215      *              matching response from the peripheral), or a write-command,
00216      *              which doesn't require the connected peer to respond.
00217      * @param[in] connHandle
00218      *              Connection handle.
00219      * @param[in] attributeHandle
00220      *              handle for the target attribtue on the remote GATT server.
00221      * @param[in] length
00222      *              length of the new value.
00223      * @param[in] value
00224      *              new value being written.
00225      */
00226     virtual ble_error_t write(GattClient::WriteOp_t    cmd,
00227                               Gap::Handle_t            connHandle,
00228                               GattAttribute::Handle_t  attributeHandle,
00229                               size_t                   length,
00230                               const uint8_t           *value) const {
00231         /* avoid compiler warnings about unused variables */
00232         (void)cmd;
00233         (void)connHandle;
00234         (void)attributeHandle;
00235         (void)length;
00236         (void)value;
00237 
00238         return BLE_ERROR_NOT_IMPLEMENTED; /* Requesting action from porter(s): override this API if this capability is supported. */
00239     }
00240 
00241     /* Event callback handlers. */
00242 public:
00243     /**
00244      * Setup a callback for read response events.
00245      */
00246     void onDataRead(ReadCallback_t callback) {
00247         onDataReadCallback = callback;
00248     }
00249 
00250     /**
00251      * Setup a callback for write response events.
00252      * @Note: write commands (issued using writeWoResponse) don't generate a response.
00253      */
00254     void onDataWrite(WriteCallback_t callback) {
00255         onDataWriteCallback = callback;
00256     }
00257 
00258     /**
00259      * Setup callback for when serviceDiscovery terminates.
00260      */
00261     virtual void onServiceDiscoveryTermination(ServiceDiscovery::TerminationCallback_t callback) {
00262         (void)callback; /* avoid compiler warnings about ununsed variables */
00263 
00264         /* Requesting action from porter(s): override this API if this capability is supported. */
00265     }
00266 
00267     /**
00268      * Setup a callback for when GattClient receives an update event
00269      * corresponding to a change in value of a characteristic on the remote
00270      * GattServer.
00271      */
00272     void onHVX(HVXCallback_t callback) {
00273         onHVXCallback = callback;
00274     }
00275 
00276 protected:
00277     GattClient() {
00278         /* empty */
00279     }
00280 
00281     /* Entry points for the underlying stack to report events back to the user. */
00282 public:
00283     void processReadResponse(const GattReadCallbackParams *params) {
00284         if (onDataReadCallback) {
00285             onDataReadCallback(params);
00286         }
00287     }
00288 
00289     void processWriteResponse(const GattWriteCallbackParams *params) {
00290         if (onDataWriteCallback) {
00291             onDataWriteCallback(params);
00292         }
00293     }
00294 
00295     void processHVXEvent(const GattHVXCallbackParams *params) {
00296         if (onHVXCallback) {
00297             onHVXCallback(params);
00298         }
00299     }
00300 
00301 protected:
00302     ReadCallback_t  onDataReadCallback;
00303     WriteCallback_t onDataWriteCallback;
00304     HVXCallback_t   onHVXCallback;
00305 
00306 private:
00307     /* disallow copy and assignment */
00308     GattClient(const GattClient &);
00309     GattClient& operator=(const GattClient &);
00310 };
00311 
00312 #endif // ifndef __GATT_CLIENT_H__