BLE::init() should also be able to take an <object, member> tuple for its callback

ble/BLE.h

@@ -22,6 +22,8 @@
 #include "GattServer.h"
 #include "GattClient.h"
 
+#include "ble/FunctionPointerWithContext.h"
+
 #ifdef YOTTA_CFG_MBED_OS
 #include "mbed-drivers/mbed_error.h"
 #else
@@ -41,16 +43,28 @@ class BLE
     typedef unsigned InstanceID_t; /** The type returned by BLE::getInstanceID(). */
 
     /**
-     * The function signature for callbacks for initialization completion.
+     * The context provided to init-completion-callbacks (see init() below).
+     *
      * @param  ble
      *             A reference to the BLE instance being initialized.
      * @param  error
      *             This captures the result of initialization. It is set to
      *             BLE_ERROR_NONE if initialization completed successfully. Else
      *             the error value is implementation specific.
+     */
+    struct InitializationCompleteCallbackContext {
+        BLE&        ble;   /* Reference to the BLE object which has been initialized */
+        ble_error_t error; /* Error status of the initialization. It is set to BLE_ERROR_NONE initialization completed successfully. */
+    };
+
+    /**
+     * The signature for function-pointer like callbacks for initialization-completion.
      *
+     * @note There are two versions of init(). In addition to the simple
+     *     function-pointer, init() can also take a <Object, member> tuple as its
+     *     callback target. In case of the latter, the following declaration doesn't apply.
      */
-    typedef void (*InitializationCompleteCallback_t)(BLE &ble, ble_error_t error);
+    typedef void (*InitializationCompleteCallback_t)(InitializationCompleteCallbackContext *context);
 
     /**
      * Initialize the BLE controller. This should be called before using
@@ -63,7 +77,7 @@ class BLE
      * context where ordering is compiler specific and can't be guaranteed--it
      * is safe to call BLE::init() from within main().
      *
-     * @param  callback
+     * @param  initCompleteCallback
      *           A callback for when initialization completes for a BLE
      *           instance. This is an optional parameter, if no callback is
      *           setup the application can still determine the status of
@@ -72,17 +86,36 @@ class BLE
      * @return  BLE_ERROR_NONE if the initialization procedure was started
      *     successfully.
      *
-     * @note The underlying stack must invoke the initialization completion
-     *     callback in response to init(). In some cases, initialization is
-     *     instantaneous (or blocking); if so, it is acceptable for the stack-
-     *     specific implementation of init() to invoke the completion callback
-     *     directly--i.e. within its own context.
+     * @note If init() returns BLE_ERROR_NONE, the underlying stack must invoke
+     *     the initialization completion callback at some point.
+     *
+     * @note In some cases, initialization is instantaneous (or blocking); if
+     *     so, it is acceptable for the stack-specific implementation of init()
+     *     to invoke the completion callback directly--i.e. within its own
+     *     context.
      *
      * @note Nearly all BLE APIs would return
      *     BLE_ERROR_INITIALIZATION_INCOMPLETE if used on an instance before the
      *     corresponding transport is initialized.
+     *
+     * @note There are two versions of init(). In addition to the simple
+     *     function-pointer, init() can also take an <Object, member> tuple as its
+     *     callback target.
+     */
+    ble_error_t init(InitializationCompleteCallback_t initCompleteCallback = NULL) {
+        FunctionPointerWithContext<InitializationCompleteCallbackContext *> callback(initCompleteCallback);
+        initImplementation(callback);
+    }
+
+    /**
+     * An alternate declaration for init(). This one takes an <Object, member> tuple as its
+     * callback target.
      */
-    ble_error_t init(InitializationCompleteCallback_t callback = NULL);
+    template<typename T>
+    ble_error_t init(T *object, void (T::*initCompleteCallback)(InitializationCompleteCallbackContext *context)) {
+        FunctionPointerWithContext<InitializationCompleteCallbackContext *> callback(object, initCompleteCallback);
+        initImplementation(callback);
+    }
 
     /**
      * @return true if initialization has completed for the underlying BLE
@@ -1387,6 +1420,15 @@ class BLE
         return securityManager().onPasskeyDisplay(callback);
     }
 
+private:
+    /**
+     * Implementation of init() [internal to BLE_API].
+     *
+     * The implementation is separated into a private method because it isn't
+     * suitable to be included in the header.
+     */
+    ble_error_t initImplementation(FunctionPointerWithContext<InitializationCompleteCallbackContext *> callback);
+
 private:
     BLE(const BLE&);
     BLE &operator=(const BLE &);

ble/BLEInstanceBase.h

@@ -32,7 +32,8 @@ class GattClient;
 class BLEInstanceBase
 {
 public:
-    virtual ble_error_t            init(BLE::InstanceID_t instanceID, BLE::InitializationCompleteCallback_t) = 0;
+    virtual ble_error_t            init(BLE::InstanceID_t instanceID,
+                                        FunctionPointerWithContext<BLE::InitializationCompleteCallbackContext *> initCallback) = 0;
     virtual bool                   hasInitialized(void) const = 0;
     virtual ble_error_t            shutdown(void)             = 0;
     virtual const char *           getVersion(void)           = 0;

ble/FunctionPointerWithContext.h

@@ -19,8 +19,6 @@
 
 #include <string.h>
 
-
-
 /** A class for storing and calling a pointer to a static or member void function
  *  which takes a context.
  */
@@ -107,10 +105,10 @@ class FunctionPointerWithContext {
     template<typename T>
     static void membercaller(pFunctionPointerWithContext_t self, ContextType context) {
         if (self->_memberFunctionAndPointer._object) {
-            T *o = static_cast<T *>(self->_memberFunctionAndPointer._object);        
+            T *o = static_cast<T *>(self->_memberFunctionAndPointer._object);
             void (T::*m)(ContextType);
             memcpy((char*) &m, self->_memberFunctionAndPointer._memberFunction, sizeof(m));
-            (o->*m)(context);            
+            (o->*m)(context);
         }
     }
 
@@ -122,9 +120,9 @@ class FunctionPointerWithContext {
 
     struct MemberFunctionAndPtr {
         /*
-         * forward declaration of a class and a member function to this class. 
-         * Because the compiler doesn't know anything about the forwarded member 
-         * function, it will always use the biggest size and the biggest alignment 
+         * forward declaration of a class and a member function to this class.
+         * Because the compiler doesn't know anything about the forwarded member
+         * function, it will always use the biggest size and the biggest alignment
          * that a member function can take for objects of type UndefinedMemberFunction.
          */
         class UndefinedClass;
@@ -133,17 +131,17 @@ class FunctionPointerWithContext {
         void* _object;
         union {
             char _memberFunction[sizeof(UndefinedMemberFunction)];
-            UndefinedMemberFunction _alignment;            
+            UndefinedMemberFunction _alignment;
         };
     };
 
     union {
         pvoidfcontext_t _function;                      /**< static function pointer - NULL if none attached */
-        /** 
-         * object this pointer and pointer to member - 
-         * _memberFunctionAndPointer._object will be NULL if none attached 
-         */        
-        MemberFunctionAndPtr _memberFunctionAndPointer;      
+        /**
+         * object this pointer and pointer to member -
+         * _memberFunctionAndPointer._object will be NULL if none attached
+         */
+        MemberFunctionAndPtr _memberFunctionAndPointer;
     };
 
     void (*_caller)(FunctionPointerWithContext*, ContextType);

source/BLE.cpp

@@ -22,7 +22,7 @@
 #endif
 
 ble_error_t
-BLE::init(BLE::InitializationCompleteCallback_t callback)
+BLE::initImplementation(FunctionPointerWithContext<InitializationCompleteCallbackContext *> callback)
 {
     ble_error_t err = transport->init(instanceID, callback);
     if (err != BLE_ERROR_NONE) {