Bugfixes and attempts to use quaternions for the gyroscope.

Fixed support for API18-22 (TIL that one should never write code at 2a.m and make a release).
Added a warning for the user if the magnetic sensor returns weird/wrong values.
Added a way to fill a little bit more the fields of the Sensor class.
Now using the calculations of the gravity sensor to calculate the gyroscope, this allows it to work in any orientation and return the right values.

app/src/main/java/fr/frazew/virtualgyroscope/SensorModel.java

@@ -7,12 +7,16 @@ public class SensorModel {
     public int minDelay;
     public float maxRange;
     public boolean alreadyThere = false;
+    public String stringType;
+    public String permission;
 
-    public SensorModel(int sensorType, String name, int handle, float resolution, int minDelay, float maxRange) {
+    public SensorModel(int sensorType, String name, int handle, float resolution, int minDelay, float maxRange, String stringType, String permission) {
         this.name = name;
         this.handle = (handle == -1 ? sensorType : handle);
         this.resolution = resolution;
         this.minDelay = minDelay;
         this.maxRange = maxRange;
+        this.stringType = stringType;
+        this.permission = permission;
     }
 }

app/src/main/java/fr/frazew/virtualgyroscope/XposedMod.java

@@ -5,15 +5,12 @@
 import android.hardware.Sensor;
 import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
-import android.hardware.SensorManager;
 import android.os.Build;
 import android.util.SparseArray;
 
 import de.robv.android.xposed.XposedBridge;
 
-import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 import de.robv.android.xposed.IXposedHookLoadPackage;
@@ -26,11 +23,11 @@
 public class XposedMod implements IXposedHookLoadPackage {
 
     public static final SparseArray<SensorModel> sensorsToEmulate = new SparseArray<SensorModel>() {{
-        put(Sensor.TYPE_ROTATION_VECTOR, new SensorModel(Sensor.TYPE_ROTATION_VECTOR, "VirtualSensor RotationVector", -1, 0.01F, -1, -1));
-        put(Sensor.TYPE_GYROSCOPE, new SensorModel(Sensor.TYPE_GYROSCOPE, "VirtualSensor Gyroscope", -1, 0.01F, -1, (float)Math.PI));
-        put(Sensor.TYPE_GEOMAGNETIC_ROTATION_VECTOR, new SensorModel(Sensor.TYPE_GEOMAGNETIC_ROTATION_VECTOR, "VirtualSensor GeomagneticRotationVector", -1, 0.01F, -1, -1));
-        put(Sensor.TYPE_GRAVITY, new SensorModel(Sensor.TYPE_GRAVITY, "VirtualSensor Gravity", -1, 0.01F, -1, -1));
-        put(Sensor.TYPE_LINEAR_ACCELERATION, new SensorModel(Sensor.TYPE_LINEAR_ACCELERATION, "VirtualSensor LinearAcceleration", 4242, 0.01F, -1, -1)); // Had to use another handle as it broke the magnetic sensor's readings (?!)
+        put(Sensor.TYPE_ROTATION_VECTOR, new SensorModel(Sensor.TYPE_ROTATION_VECTOR, "VirtualSensor RotationVector", -1, 0.01F, -1, -1, Sensor.STRING_TYPE_ROTATION_VECTOR, "none"));
+        put(Sensor.TYPE_GYROSCOPE, new SensorModel(Sensor.TYPE_GYROSCOPE, "VirtualSensor Gyroscope", -1, 0.01F, -1, (float)Math.PI, Sensor.STRING_TYPE_GYROSCOPE, "android.hardware.sensor.gyroscope"));
+        put(Sensor.TYPE_GEOMAGNETIC_ROTATION_VECTOR, new SensorModel(Sensor.TYPE_GEOMAGNETIC_ROTATION_VECTOR, "VirtualSensor GeomagneticRotationVector", -1, 0.01F, -1, -1, Sensor.STRING_TYPE_GEOMAGNETIC_ROTATION_VECTOR, "none"));
+        put(Sensor.TYPE_GRAVITY, new SensorModel(Sensor.TYPE_GRAVITY, "VirtualSensor Gravity", -1, 0.01F, -1, -1, Sensor.STRING_TYPE_GRAVITY, "none"));
+        put(Sensor.TYPE_LINEAR_ACCELERATION, new SensorModel(Sensor.TYPE_LINEAR_ACCELERATION, "VirtualSensor LinearAcceleration", 4242, 0.01F, -1, -1, Sensor.STRING_TYPE_LINEAR_ACCELERATION, "none")); // Had to use another handle as it broke the magnetic sensor's readings (?!)
     }};
 
     @Override
@@ -101,7 +98,7 @@ protected void beforeHookedMethod(MethodHookParam param) throws Throwable {
             XposedBridge.hookAllMethods(pkgMgrSrv, "hasSystemFeature", new XC_MethodHook() {
                 @Override
                 protected void afterHookedMethod(MethodHookParam param) throws Throwable {
-                    if (!(boolean)param.getResult() && (String)param.args[0] == PackageManager.FEATURE_SENSOR_GYROSCOPE) {
+                    if (!(boolean) param.getResult() && (String) param.args[0] == PackageManager.FEATURE_SENSOR_GYROSCOPE) {
                         Object mPackages = XposedHelpers.getObjectField(param.thisObject, "mPackages");
                         synchronized (mPackages) {
                             Map<String, FeatureInfo> mAvailableFeatures = (Map<String, FeatureInfo>) param.getResult();
@@ -121,7 +118,8 @@ protected void afterHookedMethod(MethodHookParam param) throws Throwable {
 
     private void hookSensorValues(final LoadPackageParam lpparam) {
         if (Build.VERSION.SDK_INT >= 18) {
-            XposedHelpers.findAndHookMethod("android.hardware.SystemSensorManager$SensorEventQueue", lpparam.classLoader, "dispatchSensorEvent", int.class, float[].class, int.class, long.class, new SensorChangeHook.API18Plus(lpparam));
+            if (Build.VERSION.SDK_INT >= 23) XposedHelpers.findAndHookMethod("android.hardware.SystemSensorManager$SensorEventQueue", lpparam.classLoader, "dispatchSensorEvent", int.class, float[].class, int.class, long.class, new SensorChangeHook.API23Plus(lpparam));
+            else XposedHelpers.findAndHookMethod("android.hardware.SystemSensorManager$SensorEventQueue", lpparam.classLoader, "dispatchSensorEvent", int.class, float[].class, int.class, long.class, new SensorChangeHook.API18Plus(lpparam));
         } else {
             XposedHelpers.findAndHookMethod("android.hardware.SystemSensorManager$ListenerDelegate", lpparam.classLoader, "onSensorChangedLocked", Sensor.class, float[].class, long[].class, int.class, new SensorChangeHook.API1617(lpparam));
         }