your bluetooth search model is这个是蓝牙搜索的意思吗
发布网友
发布时间：2023-01-06 17:22
共2个回答
热心网友
时间：2023-10-18 21:11
[cpp] view plaincopy
private void updateContent(int bluetoothState, boolean scanState) {
if (numberOfPairedDevices == 0) {
preferenceScreen.removePreference(mPairedDevicesCategory);
if (scanState == true) {
mActivityStarted = false;
startScanning();
} else<span style="font-family: Arial, Helvetica, sans-serif;"> ........</span>
}
private void startScanning() {
if (!mAvailableDevicesCategoryIsPresent) {
getPreferenceScreen().addPreference(mAvailableDevicesCategory);
}
mLocalAdapter.startScanning(true);
}
其实在这里蓝牙搜索和打开流程是结构上是一致的，利用LocalBluetoothAdapter.java过渡到BluetoothAdapter.java再跳转至AdapterService.java要稍微留意下的是在这个过渡中startScaning()方法变成了startDiscovery()方法，看下代码：packages/apps/Settings/src/com/android/settings/bluetooth/LocalBluetoothAdapter.java
[java] view plaincopy
void startScanning(boolean force) {
if (!mAdapter.isDiscovering()) {
if (!force) {
// Don't scan more than frequently than SCAN_EXPIRATION_MS,
// unless forced
if (mLastScan + SCAN_EXPIRATION_MS > System.currentTimeMillis()) {
return;
}
// If we are playing music, don't scan unless forced.
A2dpProfile a2dp = mProfileManager.getA2dpProfile();
if (a2dp != null && a2dp.isA2dpPlaying()) {
return;
}
}
//这里才是我们最关注的，前面*条件关注一下就行了
if (mAdapter.startDiscovery()) {
mLastScan = System.currentTimeMillis();
}
}
BluetoothAdapter.java的那一段，路径 /frameworks/base/core/java/android/bluetooth/BluetoothAdapter.java
[java] view plaincopy
public boolean startDiscovery() {
.............................
AdapterService service = getService();
if (service == null) return false;
return service.startDiscovery();
}
这个service代码写得很明白AdapterService，转了一圈从framework又回到packages了，
下面的代码路径自然是 :packages/apps/Bluetooth/src/com/android/bluetooth/btservice/AdapterService.java，
[java] view plaincopy
boolean startDiscovery() {
enforceCallingOrSelfPermission(BLUETOOTH_ADMIN_PERM,
"Need BLUETOOTH ADMIN permission");
return startDiscoveryNative();
}
和打开蓝牙根本就是一个套路，上面的流程略过一小步，很简单的不写了，下面要怎么走，估计大家也都猜到了，JNI应该出场了，
路径：/packages/apps/Bluetooth/jni/com_android_bluetooth_btservice_AdapterService.cpp
[cpp] view plaincopy
static jboolean startDiscoveryNative(JNIEnv* env, jobject obj) {
ALOGV("%s:",__FUNCTION__);
jboolean result = JNI_FALSE;
if (!sBluetoothInterface) return result;
int ret = sBluetoothInterface->start_discovery();
result = (ret == BT_STATUS_SUCCESS) ? JNI_TRUE : JNI_FALSE;
return result;
}
在下面要去哪？稍微要动下脑筋，不过我们在上一篇android -- 蓝牙 bluetooth （二） 打开蓝牙已经说过怎么找了，注意android.mk文件，先找头文件，再找对应的实现C文件代码。就是现在回顾下，蓝牙打开和搜索的代码流程我们都看了，跳转都是一个套路，settings界面发起，LocalBluetoothAdapter.java过渡，去framework的转转（BluetoothAdapter.java）后回到packages的AdapterService.java，再走JNI来的external。流程就是这样的，相信类似的功能跳转(比如蓝牙配对，关闭蓝牙，停止扫描这些)大家都应该熟悉了，后面再有类似的功能就写函数名一笔带过了，还有这里要注意的就是这个start_discovery()实现代码的寻找，留意mk文件就是了，不复杂。小结结束，继续看代码 路径：/external/bluetooth/bluedroid/btif/src/bluetooth.c
[cpp] view plaincopy
static int start_discovery(void)
{
/* sanity check */
if (interface_ready() == FALSE)
return BT_STATUS_NOT_READY;
return btif_dm_start_discovery();
}
下面代码直接跳转就可以找到，路径external/bluetooth/bluedroid/btif/src/btif_dm.c
这个代码有点多，不过里面的信息也很多，所以连注释也一起保留的贴出来了，蓝牙的搜索实现并没有像蓝牙打开那样交由vendor厂商实现，在这里已经写出来了，仔细看下那些#if和#else，都是一些查询条件的调置，#if (BLE_INCLUDED == TRUE) 这个应该就google为蓝牙4.0 LE作的准备了，也算是今年google I/O大会上宣布即将支持蓝牙4.0低能耗版一个佐证吧，对于代码里面那些字符串的含义看这里好了external/bluetooth/bluedroid/bta/include/bta_api.h，一个头文件，大部分字符串和结构体的定义都在这了，多少还有些注释。
[cpp] view plaincopy
bt_status_t btif_dm_start_discovery(void)
{
tBTA_DM_INQ inq_params;
tBTA_SERVICE_MASK services = 0;
BTIF_TRACE_EVENT1("%s", __FUNCTION__);
/* TODO: Do we need to handle multiple inquiries at the same time? */
/* Set inquiry params and call API */
#if (BLE_INCLUDED == TRUE)
inq_params.mode = BTA_DM_GENERAL_INQUIRY|BTA_BLE_GENERAL_INQUIRY;
#else
inq_params.mode = BTA_DM_GENERAL_INQUIRY;
#endif
inq_params.ration = BTIF_DM_DEFAULT_INQ_MAX_DURATION;
inq_params.max_resps = BTIF_DM_DEFAULT_INQ_MAX_RESULTS;
inq_params.report_p = TRUE;
inq_params.filter_type = BTA_DM_INQ_CLR;
/* TODO: Filter device by BDA needs to be implemented here */
/* Will be enabled to TRUE once inquiry busy level has been received */
btif_dm_inquiry_in_progress = FALSE;
/* find nearby devices */
BTA_DmSearch(&inq_params, services, bte_search_devices_evt);
return BT_STATUS_SUCCESS;
}
BTA_DmSearch()方法是看起来是要搜索了，不过里面这个家伙bte_search_devices_evt才是真正干活的主力，所以我们先看它，在这个函数里
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static void bte_search_devices_evt(tBTA_DM_SEARCH_EVT event, tBTA_DM_SEARCH *p_data) {
UINT16 param_len = 0;
if (p_data)
param_len += sizeof(tBTA_DM_SEARCH);
/* Allocate buffer to hold the pointers (deep copy). The pointers will point to the end of the tBTA_DM_SEARCH */
switch (event)
{
case BTA_DM_INQ_RES_EVT:
{
if (p_data->inq_res.p_eir)
param_len += HCI_EXT_INQ_RESPONSE_LEN;
}
break;
..............................
}
BTIF_TRACE_DEBUG3("%s event=%s param_len=%d", __FUNCTION__, mp_dm_search_event(event), param_len);
/* if remote name is available in EIR, set teh flag so that stack doesnt trigger RNR */
if (event == BTA_DM_INQ_RES_EVT)
p_data->inq_res.remt_name_not_required = check_eir_remote_name(p_data, NULL, NULL);
btif_transfer_context (btif_dm_search_devices_evt , (UINT16) event, (void *)p_data, param_len,
(param_len > sizeof(tBTA_DM_SEARCH)) ? search_devices_copy_cb : NULL);
}
在上面的这个函数里又有这个bte_search_devices_evt，在它里我们能看一个 HAL_CBACK，这是要往回发消息了，看下这个函数的全貌，说是全貌，不过还是只贴出一个case分支，太长了，大家还是自行还源码吧。到这里已经可以知道扫描到蓝牙设备的mac地址和设备名，那个bdcpy函数就是在解析mac地址，有了这些，蓝牙搜索是到应该在界面展示成果的时候了，开始回调，忘记代码路径了，这个函数都在这个文件里： /external/bluetooth/bluedroid/btif/src/btif_dm.c
[cpp] view plaincopy
static void btif_dm_search_devices_evt (UINT16 event, char *p_param)
tBTA_DM_SEARCH *p_search_data;
BTIF_TRACE_EVENT2("%s event=%s", __FUNCTION__, mp_dm_search_event(event));
switch (event)
{
case BTA_DM_DISC_RES_EVT:
{
p_search_data = (tBTA_DM_SEARCH *)p_param;
/* Remote name update */
if (strlen((const char *) p_search_data->disc_res.bd_name))
{
bt_property_t properties[1];
bt_bdaddr_t bdaddr;
bt_status_t status;
properties[0].type = BT_PROPERTY_BDNAME;
properties[0].val = p_search_data->disc_res.bd_name;
properties[0].len = strlen((char *)p_search_data->disc_res.bd_name);
bdcpy(bdaddr.address, p_search_data->disc_res.bd_addr);
status = btif_storage_set_remote_device_property(&bdaddr, &properties[0]);
ASSERTC(status == BT_STATUS_SUCCESS, "failed to save remote device property", status);
HAL_CBACK(bt_hal_cbacks, remote_device_properties_cb,
status, &bdaddr, 1, properties);
}
/* TODO: Services? */
}
break;
一小段log，下面的文字就在上面的函数里打出来的，即便上面的写的函数没有，肯定也在附近了。
05-30 13:52:14.890 1578 2612 D bt-btif : bte_search_devices_evt event=BTA_DM_INQ_RES_EVT param_len=524
05-30 13:52:14.890 1578 2612 D bt-btif : search_devices_copy_cb: event=BTA_DM_INQ_RES_EVT
05-30 13:52:14.890 1578 2584 I bt-btif : btif_dm_search_devices_evt event=BTA_DM_INQ_RES_EVT
05-30 13:52:14.890 1578 2584 D bt-btif : btif_dm_search_devices_evt() ec:89:f5:ba:fb:03 device_type = 0x1
当然回过头我们还要看下那个BTA_DmSearch()，看它的实现，更应该是起消息发送的作用，代码在/external/bluetooth/bluedroid/bta/dm/bta_dm_api.c，这个函数具体流程并没有看多少，当工具方法看了，有时间看看还是没坏处的。
[cpp] view plaincopy
void BTA_DmSearch(tBTA_DM_INQ *p_dm_inq, tBTA_SERVICE_MASK services, tBTA_DM_SEARCH_CBACK *p_cback)
{ tBTA_DM_API_SEARCH *p_msg;
if ((p_msg = (tBTA_DM_API_SEARCH *) GKI_getbuf(sizeof(tBTA_DM_API_SEARCH))) != NULL)
{
memset(p_msg, 0, sizeof(tBTA_DM_API_SEARCH));
p_msg->hdr.event = BTA_DM_API_SEARCH_EVT;
memcpy(&p_msg->inq_params, p_dm_inq, sizeof(tBTA_DM_INQ));
p_msg->services = services;
p_msg->p_cback = p_cback;
p_msg->rs_res = BTA_DM_RS_NONE;
bta_sys_sendmsg(p_msg);
}
}
看了上面方法后我们 要回去了看看，代码通过JNI下来的，回去也是看JNI的回调方法
[cpp] view plaincopy
method_deviceFoundCallback = env->GetMethodID(jniCallbackClass, "deviceFoundCallback", "([B)V");
deviceFoundCallback方法最后会来java层的/packages/apps/Bluetooth/src/com/android/bluetooth/btservice/RemoteDevices.java
[java] view plaincopy
void deviceFoundCallback(byte[] address) {
// The device properties are already registered - we can send the intent
// now
BluetoothDevice device = getDevice(address);
debugLog("deviceFoundCallback: Remote Address is:" + device);
DeviceProperties deviceProp = getDeviceProperties(device);
if (deviceProp == null) {
errorLog("Device Properties is null for Device:" + device);
return;
}
Intent intent = new Intent(BluetoothDevice.ACTION_FOUND);
intent.putExtra(BluetoothDevice.EXTRA_DEVICE, device);
intent.putExtra(BluetoothDevice.EXTRA_CLASS,
new BluetoothClass(Integer.valueOf(deviceProp.mBluetoothClass)));
intent.putExtra(BluetoothDevice.EXTRA_RSSI, deviceProp.mRssi);
intent.putExtra(BluetoothDevice.EXTRA_NAME, deviceProp.mName);
mAdapterService.sendBroadcast(intent, mAdapterService.BLUETOOTH_PERM);
}
到这里就是给界面发广播，应用层收到广播显示出来，通过这个handle，这个handle可以在BluetoothEventManager.java的构造函数里找到，
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addHandler(BluetoothDevice.ACTION_FOUND, new DeviceFoundHandler());
private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
BluetoothDevice device = intent
.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
Handler handler = mHandlerMap.get(action);
if (handler != null) {
handler.onReceive(context, intent, device);
}
}
};
这里handle对应要看DeviceFoundHandler，也就是下面贴出来的代码，
[java] view plaincopy
private class DeviceFoundHandler implements Handler {
public void onReceive(Context context, Intent intent,
BluetoothDevice device) {
........................
// TODO Pick up UUID. They should be available for 2.1 devices.
// Skip for now, there's a bluez problem and we are not getting uuids even for 2.1.
CachedBluetoothDevice cachedDevice = mDeviceManager.findDevice(device);
if (cachedDevice == null) {
cachedDevice = mDeviceManager.addDevice(mLocalAdapter, mProfileManager, device);
Log.d(TAG, "DeviceFoundHandler created new CachedBluetoothDevice: "
+ cachedDevice);
// callback to UI to create Preference for new device
dispatchDeviceAdded(cachedDevice);
}
......................
}
}
在if语句中dispatchDeviceAdded()向界面分发消息，最后处理消息的地方在这里，已经到settings应用里了
/packages/apps/Settings/src/com/android/settings/bluetooth/DeviceListPreferenceFragment.java
[java] view plaincopy
public void onDeviceAdded(CachedBluetoothDevice cachedDevice) {
if (mDevicePreferenceMap.get(cachedDevice) != null) {
return;
}
// Prevent updates while the list shows one of the state messages
if (mLocalAdapter.getBluetoothState() != BluetoothAdapter.STATE_ON) return;
if (mFilter.matches(cachedDevice.getDevice())) {
createDevicePreference(cachedDevice);
}
}
上面代码中最后一个分支就是界面显示要做的事了，从settings界面开始再到settings界面显示出搜索到蓝牙结束，后面的代码不再写了，本文关心的东东到此结束。
热心网友
时间：2023-10-18 21:12
