蓝牙耳机图标显示过程

来源：互联网发布：数据分析制图软件编辑：程序博客网时间：2024/05/01 22:42

蓝牙耳机图标显示代码路径在：

frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/

在PhoneStatusBarPolicy.java中的函数

private final void updateBluetooth(Intent intent) {

inticonId = R.drawable.stat_sys_data_bluetooth;

String contentDescription = null;

String action = intent.getAction();

if(action.equals(BluetoothAdapter.ACTION_STATE_CHANGED)) {

int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE,BluetoothAdapter.ERROR);

mBluetoothEnabled = state == BluetoothAdapter.STATE_ON;

}else if (action.equals(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED)) {

int state = intent.getIntExtra(BluetoothAdapter.EXTRA_CONNECTION_STATE,

BluetoothAdapter.STATE_DISCONNECTED);

if (state == BluetoothAdapter.STATE_CONNECTED) {

iconId = R.drawable.stat_sys_data_bluetooth_connected;

contentDescription = mContext.getString(R.string.accessibility_bluetooth_connected);

}else {

contentDescription = mContext.getString(

R.string.accessibility_bluetooth_disconnected);

}

}else {

return;

}

mService.setIcon("bluetooth",iconId, 0, contentDescription);

mService.setIconVisibility("bluetooth", mBluetoothEnabled);

}

通过 updateBluetooth这个函数可以看到，蓝牙耳机的图标是根据广播 ACTION_CONNECTION_STATE_CHANGED来判断的。

下面我们来看一看广播ACTION_CONNECTION_STATE_CHANGED是如何发送的，

代码路径在：

packages/apps/Bluetooth/src/com/android/bluetooth/btservice

在AdapterProperties.java中的函数

void sendConnectionStateChange(BluetoothDevicedevice, int profile, int state, int prevState) {

......

synchronized (mObject) {

updateProfileConnectionState(profile,state, prevState);

if (updateCountersAndCheckForConnectionStateChange(state, prevState)) {

setConnectionState(state);

Intent intent = new Intent(BluetoothAdapter.ACTION_CONNECTION_STATE_CHANGED);

intent.putExtra(BluetoothDevice.EXTRA_DEVICE, device);

intent.putExtra(BluetoothAdapter.EXTRA_CONNECTION_STATE,

convertToAdapterState(state));

intent.putExtra(BluetoothAdapter.EXTRA_PREVIOUS_CONNECTION_STATE,

convertToAdapterState(prevState));

......

}

通过函数 sendConnectionStateChange来看广播的发送是由 updateCountersAndCheckForConnectionStateChange()函数的返回值决定的。

private booleanupdateCountersAndCheckForConnectionStateChange(int state, int prevState) {

switch (prevState) {

case BluetoothProfile.STATE_CONNECTING:

mProfilesConnecting--;

break;

case BluetoothProfile.STATE_CONNECTED:

mProfilesConnected--;

break;

case BluetoothProfile.STATE_DISCONNECTING:

mProfilesDisconnecting--;

break;

}

switch (state) {

case BluetoothProfile.STATE_CONNECTING:

mProfilesConnecting++;

return (mProfilesConnected == 0 && mProfilesConnecting == 1);

case BluetoothProfile.STATE_CONNECTED:

mProfilesConnected++;

return (mProfilesConnected == 1);

case BluetoothProfile.STATE_DISCONNECTING:

mProfilesDisconnecting++;

return (mProfilesConnected == 0 && mProfilesDisconnecting == 1);

case BluetoothProfile.STATE_DISCONNECTED:

return (mProfilesConnected == 0 && mProfilesConnecting == 0);

default:

return true;

}

通过updateCountersAndCheckForConnectionStateChange来看，mProfilesConnecting、mProfilesConnected、mProfilesDisconnecting这三个变量满足一定的条件函数返回才为TRUE。而这三个变量会根据连蓝耳机上次状态和当前状态的进行加减。

蓝牙耳机图标显示过程：

蓝牙耳机的连接分为Headset Profile 和A2DP Profile两个Profile，连接的时候只要有一个连接上就会返回TRUE，发送广播，从而显示蓝牙耳机图标，而断开连接的时候只有两个都断开了才会返回TRUE，发送广播，显示蓝牙普通图标。

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