From aa2228d6c12df10383417e1eb8805cae1ebd584f Mon Sep 17 00:00:00 2001
From: Wetitpig <winsto003@hotmail.com>
Date: Thu, 26 Jan 2017 17:22:25 +0800
Subject: [PATCH] Create AccelerometerAPI.java

My Java scripting is extremely bad. There might be a lot of bugs in this file. Please carefully check it before merging. Thanks.
---
 .../java/com/termux/api/AccelerometerAPI.java | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 app/src/main/java/com/termux/api/AccelerometerAPI.java

diff --git a/app/src/main/java/com/termux/api/AccelerometerAPI.java b/app/src/main/java/com/termux/api/AccelerometerAPI.java
new file mode 100644
index 000000000..ac2bd0e09
--- /dev/null
+++ b/app/src/main/java/com/termux/api/AccelerometerAPI.java
@@ -0,0 +1,87 @@
+package com.termux.api;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
+import android.os.Bundle;
+import android.util.JsonWriter;
+
+import com.termux.api.util.ResultReturner;
+import com.termux.api.util.ResultReturner.ResultJsonWriter;
+import com.termux.api.util.TermuxApiLogger;
+
+public class AccelerometerAPI {
+
+    public static void onReceive(TermuxApiReceiver apiReceiver, final Context context, Intent intent) {
+        ResultReturner.returnData(apiReceiver, intent, new ResultJsonWriter() {
+        private sensorManager SensorManager;
+        double ax,ay,az;   // these are the acceleration in x,y and z axis
+        String accuracy;
+            @Override
+            public void writeJson(JsonWriter out) throws Exception {
+            sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
+            if (sensorManager.getDefaultSensor(Sensor.ACCELEROMETER) != null){
+            public class Accelerometer extends Activity implements SensorEventListener{
+            sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
+            }
+            
+            @Override
+            public void onAccuracyChanged(Sensor arg0, int arg1) {
+            switch (arg1) {
+              case 0:
+                accuracy = "Unreliable";
+                break;
+              case 1:
+                accuracy = "Low";
+                break;
+              case 2:
+                accuracy = "Medium";
+                break;
+              case 3:
+                accuracy = "High";
+                break;
+            }
+            }
+
+            @Override
+            public void onSensorChanged(SensorEvent event) {
+                  // alpha is calculated as t / (t + dT)
+                  // with t, the low-pass filter's time-constant
+                  // and dT, the event delivery rate
+
+                  final float alpha = 0.8;
+                  array gravity;
+                  array linear_acceleration;
+
+                  gravity[0] = alpha * gravity[0] + (1 - alpha) * event.values[0];
+                  gravity[1] = alpha * gravity[1] + (1 - alpha) * event.values[1];
+                  gravity[2] = alpha * gravity[2] + (1 - alpha) * event.values[2];
+
+                  linear_acceleration[0] = event.values[0] - gravity[0];
+                  linear_acceleration[1] = event.values[1] - gravity[1];
+                  linear_acceleration[2] = event.values[2] - gravity[2];
+                  
+                  ax = linear_acceleration[0]
+                  ay = linear_acceleration[1]
+                  az = linear_acceleration[2]
+            }
+            out.beginObject();
+            out.name("accuracy").value(accuracy);
+            out.name("x").value(ax);
+            out.name("y").value(ay);
+            out.name("z").value(az);
+            out.endObject();
+            sensorManager.unregisterListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
+  }
+            else {
+            string error = "No Accelerometer in this device."
+            out.beginObject().name("API_ERROR").value(error).endObject();
+            }
+      }
+      }
+}
+}