text: /******************************************************************************
   *
   *  Copyright (C) 2014 Google, Inc.
   *
   *  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 _L2CAP_CLIENT_H_
  #define _L2CAP_CLIENT_H_
  #if (defined(L2CAP_CLIENT_INCLUDED) && L2CAP_CLIENT_INCLUDED == TRUE)
  
  //#include <hardware/bluetooth.h>
  #include <stdbool.h>
  #include <stdint.h>
  
  typedef struct buffer_t buffer_t;
  typedef struct l2cap_client_t l2cap_client_t;
  
  typedef struct {
      void (*connected)(l2cap_client_t *client, void *context);
      void (*disconnected)(l2cap_client_t *client, void *context);
      void (*read_ready)(l2cap_client_t *client, buffer_t *packet, void *context);
      void (*write_ready)(l2cap_client_t *client, void *context);
  } l2cap_client_callbacks_t;
  
  // Returns a new buffer with enough space for |size| bytes of L2CAP payload.
  // |size| must be greater than zero. This function returns NULL if the buffer
  // could not be allocated. The returned buffer must be freed with |buffer_free|
  // when it is no longer needed.
  buffer_t *l2cap_buffer_new(size_t size);
  
  // Creates and returns a new L2CAP client object. |callbacks| must not be NULL and
  // must specify a set of functions that should be called back when events occur
  // on the L2CAP connection. |context| may be NULL and will be passed as the argument
  // to all callbacks in |l2cap_client_callbacks_t|. The returned object must be freed
  // with |l2cap_client_free|.
  l2cap_client_t *l2cap_client_new(const l2cap_client_callbacks_t *callbacks, void *context);
  
  // Frees the L2CAP client object allocated with |l2cap_client_new|. |client| may be NULL.
  void l2cap_client_free(l2cap_client_t *client);
  
  // Attempts to connect the |client| to a peer device specified by |remote_bdaddr|
  // using the |psm| protocol specifier. This function returns true if the connect
  // operation could be started and will indicate completion with either a 'connected'
  // callback (success) or a 'disconnected' callback (failure).
  //
  // This function must not be called while a connect operation is in progress or
  // while |l2cap_client_is_connected|. |client| and |remote_bdaddr| must not be NULL.
  // |psm| must be greater than zero.
  bool l2cap_client_connect(l2cap_client_t *client, const bt_bdaddr_t *remote_bdaddr, uint16_t psm);
  
  // Disconnects a connected |client|. This function is asynchronous and idempotent. It
  // will indicate completion with a 'disconnected' callback. |client| must not be NULL.
  void l2cap_client_disconnect(l2cap_client_t *client);
  
  // Returns true if |client| is connected and is ready to accept data written to it.
  // |client| must not be NULL.
  bool l2cap_client_is_connected(const l2cap_client_t *client);
  
  // Writes data contained in |packet| to a connected |client|. This function returns
  // true if the packet was successfully queued for delivery, false if the client cannot
  // accept more data at this time. If this function returns false, the caller must wait
  // for the 'write_ready' callback to write additional data to the client. Neither
  // |client| nor |packet| may be NULL.
  bool l2cap_client_write(l2cap_client_t *client, buffer_t *packet);
  
  #endif  ///(defined(L2CAP_CLIENT_INCLUDED) && L2CAP_CLIENT_INCLUDED == TRUE)
  
  #endif /*_L2CAP_CLIENT_H_*/
  