Android P GPS信号模拟

最近有一个需求，需要用GPS的模拟功能，研究了一下源码。

使用流程

1. 在开发者模式中的“选择模拟位置信息应用”选项，选择我们要模拟的app
2. 在我们的app中调用LocationManager.setTestProviderLocation()这个接口

开发者模式源码分析

看了开发者模式的源码，路径在/packages/apps/Settings/src/com/android/settings/development和/frameworks/base/packages/SettingsLib

搜索“选择模拟位置信息应用”，在SettingsLib中strings.xml的找到该声明

进一步搜索关键字“mock_location_app”，发现在MockLocationAppPreferenceController.java中使用了，所以直接看到这个类。发现勾选我们要模拟的app后主要是调用如下代码

    private void writeMockLocation(String mockLocationAppName) {
        removeAllMockLocations();
        // Enable the app op of the new mock location app if such.
        if (!TextUtils.isEmpty(mockLocationAppName)) {
            try {
                final ApplicationInfo ai = mPackageManager.getApplicationInfo(
                        mockLocationAppName, PackageManager.MATCH_DISABLED_COMPONENTS);
                mAppsOpsManager.setMode(AppOpsManager.OP_MOCK_LOCATION, ai.uid,
                        mockLocationAppName, AppOpsManager.MODE_ALLOWED);
            } catch (PackageManager.NameNotFoundException e) {
                /* ignore */
            }
        }
    }

GPS信号模拟源码分析

看到LocationManager.java的setTestProviderLocation方法

首先判断了Location是否是完整的，若不完整，则填充默认值。接着通过ILocationManager.aidl调用到LocationManagerService。

在最后面调用了MockProvider的setLocation方法，看到MockProvider.java

很简单，直接调用了LocationManagerService的reportLocation方法，就这样把GPS信息回调上去了。
后续调用
mLocationHandler.sendMessageAtFrontOfQueue(m);
handleLocationChanged((Location) msg.obj, msg.arg1 == 1)；
handleLocationChangedLocked(myLocation, passive)；
receiver.callLocationChangedLocked(notifyLocation)；
就这样又回到了LocationManager，调用mListener.onLocationChanged(new Location(location))回调到app

APP例子

public class MainActivity extends Activity implements View.OnClickListener {
    private static final String TAG = "GPS_Test";
    private LocationManager locationManager;
    private Button btn_set;
    private AppOpsManager mAppsOpsManager;
    private PackageManagerWrapper mPackageManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btn_set = findViewById(R.id.btn_set);
        btn_set.setOnClickListener(this);

		// 调用以下方法后，就不需要在开发者模式中勾选我们的模拟位置信息的app
        mAppsOpsManager = (AppOpsManager) this.getSystemService(Context.APP_OPS_SERVICE);
        mPackageManager = new PackageManagerWrapper(this.getPackageManager());
        writeMockLocation();
        try {
            Thread.sleep(1000); //延时1秒，确保开发者模式的“选择模拟位置信息应用”选项选择了我们的app
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        locationManager = (LocationManager) this.getSystemService(LOCATION_SERVICE);
        
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            // Android M Permission check
            List<String> permissionLists = new ArrayList<>();
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                permissionLists.add(Manifest.permission.ACCESS_FINE_LOCATION);
            }
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                permissionLists.add(Manifest.permission.ACCESS_COARSE_LOCATION);
            }
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.MANAGE_APP_OPS_MODES) != PackageManager.PERMISSION_GRANTED) {
                permissionLists.add(Manifest.permission.MANAGE_APP_OPS_MODES);
            }
            if (!permissionLists.isEmpty()) {//说明肯定有拒绝的权限
                ActivityCompat.requestPermissions(this, permissionLists.toArray(new String[permissionLists.size()]), 1);
            } else {
                Log.d(TAG, "ALL have permissions");
            }
        }

        // 添加并启动GpsProvider
        locationManager.addTestProvider(LocationManager.GPS_PROVIDER, false, false,
                false, false, true,
                false, false, 0, 5);
        // 开启测试Provider
        locationManager.setTestProviderEnabled(LocationManager.GPS_PROVIDER, true);

        // 设置监听
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
    }

    private void writeMockLocation() {
        try {
            String mockLocationAppName = "android.com.gpstest";
            final ApplicationInfo ai = mPackageManager.getApplicationInfo(
                    mockLocationAppName, PackageManager.MATCH_DISABLED_COMPONENTS);
            mAppsOpsManager.setMode(AppOpsManager.OP_MOCK_LOCATION, ai.uid,
                    mockLocationAppName, AppOpsManager.MODE_ALLOWED);
        } catch (PackageManager.NameNotFoundException e) {
                /* ignore */
        }
    }

    protected final LocationListener locationListener = new LocationListener() {
        @Override
        public void onLocationChanged(Location location) {
            Log.d(TAG, " onLocationChanged " + location.toString());
        }

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {
            Log.d(TAG, "onStatusChanged " + provider);
        }

        @Override
        public void onProviderEnabled(String provider) {
            Log.d(TAG, " onProviderEnabled " + provider);
        }

        @Override
        public void onProviderDisabled(String provider) {
            Log.d(TAG, " onProviderDisabled " + provider);
        }
    };

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btn_set:
                // 创建新的Location对象，并设定必要的属性值
                Location mockLocation = new Location(LocationManager.GPS_PROVIDER);
                mockLocation.setLatitude(39.820036);
                mockLocation.setLongitude(116.813751);
                mockLocation.setAccuracy(501);
                mockLocation.setTime(System.currentTimeMillis());
                mockLocation.setBearing(1.2f);
                mockLocation.setSpeed(10.8f);
                mockLocation.setVerticalAccuracyMeters(1.5f);
                mockLocation.setBearingAccuracyDegrees(3.3f);
                // 这里一定要设置nonasecond单位的值，否则是没法持续收到监听的
                if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN) {
                    mockLocation.setElapsedRealtimeNanos(SystemClock.elapsedRealtimeNanos());
                }

                // 设置最新位置，一定要在requestLocationUpdate完成后进行，才能收到监听
                locationManager.setTestProviderLocation(LocationManager.GPS_PROVIDER, mockLocation);
                break;
        }
    }
}

<!--AndroidManifest.xml-->

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="android.com.gpstest">

    <uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.MANAGE_APP_OPS_MODES" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>