android蓝牙hfp client使用例

1、首先确认配置文件是否开启hfp profile功能。根据设备的角色（hfp client / hfp server）来配置hfp profile.
profile 配置文件路径：
        packages/apps/Bluetooth/res/values/config.xml 

e.g.  设备的角色定义为hfp client,需做如下配置：
    <bool name="profile_supported_hs_hfp">false</bool>
    <bool name="profile_supported_hfpclient">true</bool

接下来看一下hfp client的实现，以accept call为例

2、步获取hfp client service
1) BluetoothAdapter mAdapter = BluetoothAdapter.getDefaultAdapter();
2) mAdapter.getProfileProxy(getApplicationContext(),new MServerListener(), BluetoothProfile.HEADSET_CLIENT);
3) public class MServerListener implements ServiceListener {
@Override
public void onServiceConnected(int profile, BluetoothProfile proxy) {
if (profile == BluetoothProfile.HEADSET_CLIENT ) {
mclient=(BluetoothHeadsetClient)proxy ;
.......   
}

}

3、 app获取hfp client service 的proxy之后，就可以直接调用相应的API进行连接控制与call 控制 。e.g.
mclient.connect ( device) //Connects to remote device.
mclient.connectAudio () //Initiates a connection of audio channel, set up SCO channel
mclient.acceptCall (device,0);
mclient.rejectCall (device);
mclient.terminateCall (device,0);

4、android hfp 对外API:
frameworks/base/core/java/android/bluetooth/
BluetoothHeadsetClientCall.aidl
BluetoothHeadsetClientCall.java
BluetoothHeadsetClient.java
BluetoothHeadset.java
IBluetoothHeadset.aidl
IBluetoothHeadsetClient.aidl
IBluetoothHeadsetPhone.aidl

e.g.

BluetoothHeadsetClient.acceptCall()

5、android hfp client services
packages\apps\bluetooth\src\com\android\bluetooth\hfpclient
HeadsetClientHalConstants.java
HeadsetClientService.java
HeadsetClientStateMachine.java
e.g.  send msg to state machine  and handle these msg
  boolean acceptCall(BluetoothDevice device, int flag) {
        enforceCallingOrSelfPermission(BLUETOOTH_PERM, "Need BLUETOOTH permission");
        int connectionState = mStateMachine.getConnectionState(device);
        if (connectionState != BluetoothProfile.STATE_CONNECTED &&
                connectionState != BluetoothProfile.STATE_CONNECTING) {
            return false;
        }
        Message msg = mStateMachine.obtainMessage(HeadsetClientStateMachine.ACCEPT_CALL);
        msg.arg1 = flag;
        mStateMachine.sendMessage(msg);
        return true;
    }
private void acceptCall(int flag, boolean retry) {
......
        if (handleCallActionNative(action, 0)) {
            addQueuedAction(ACCEPT_CALL, action);
        } else {
            Log.e(TAG, "ERROR: Couldn't accept a call, action:" + action);
        }
}
6、enter native layter
packages/apps/Bluetooth/jni
com_android_bluetooth_hfpclient.cpp
com_android_bluetooth_hfp.cpp
e.g.
static jboolean handleCallActionNative(JNIEnv *env, jobject object, jint action, jint index) {
    bt_status_t status;
    if (!sBluetoothHfpClientInterface) return JNI_FALSE;
    if ( (status = sBluetoothHfpClientInterface->handle_call_action((bthf_client_call_action_t)action, (int)index)) != BT_STATUS_SUCCESS) {
        ALOGE("Failed to enter private mode, status: %d", status);
    }
    return (status == BT_STATUS_SUCCESS) ? JNI_TRUE : JNI_FALSE;
}

//get bt stack profile interface
static void initializeNative(JNIEnv *env, jobject object) {
......
    if ( (btInf = getBluetoothInterface()) == NULL) {
        ALOGE("Bluetooth module is not loaded");
        return;
    }
    sBluetoothHfpClientInterface = (bthf_client_interface_t *)
            btInf->get_profile_interface(BT_PROFILE_HANDSFREE_CLIENT_ID);
    if (sBluetoothHfpClientInterface  == NULL) {
        ALOGE("Failed to get Bluetooth HFP Client Interface");
        return;
    }
}

7、enter bt stack

external/bluetooth/bluedroid/bta/hf_client

bta_hf_client_act.c
bta_hf_client_api.c
bta_hf_client_at.c
bta_hf_client_at.h
bta_hf_client_cmd.c
bta_hf_client_int.h
bta_hf_client_main.c
bta_hf_client_rfc.c
bta_hf_client_sco.c
bta_hf_client_sdp.c

e.g. send AT cmd ATA to accept this call

handle_call_action(bthf_client_call_action_t action, int idx){
......
    case BTHF_CLIENT_CALL_ACTION_ATA:
        BTA_HfClientSendAT(btif_hf_client_cb.handle, BTA_HF_CLIENT_AT_CMD_ATA, 0, 0, NULL);
        break;
}