The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/*
* Copyright (C) 2007 The Android开源工程
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.apis.graphics;
import android.content.Context;
import android.graphics.*;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
public class SensorTest extends GraphicsActivity {
private final String TAG = "SensorTest";
private SensorManager mSensorManager;
private Sensor mSensor;
private SampleView mView;
private float[] mValues;
private static class RunAve {
private final float[] mWeights;
private final float mWeightScale;
private final float[] mSamples;
private final int mDepth;
private int mCurr;
public RunAve(float[] weights) {
mWeights = weights;
float sum = 0;
for (int i = 0; i < weights.length; i++) {
sum += weights[i];
}
mWeightScale = 1 / sum;
mDepth = weights.length;
mSamples = new float[mDepth];
mCurr = 0;
}
public void addSample(float value) {
mSamples[mCurr] = value;
mCurr = (mCurr + 1) % mDepth;
}
public float computeAve() {
final int depth = mDepth;
int index = mCurr;
float sum = 0;
for (int i = 0; i < depth; i++) {
sum += mWeights[i] * mSamples[index];
index -= 1;
if (index < 0) {
index = depth - 1;
}
}
return sum * mWeightScale;
}
};
private final SensorEventListener mListener = new SensorEventListener() {
private final float[] mScale = new float[] { 2, 2.5f, 0.5f }; // accel
private float[] mPrev = new float[3];
private long mLastGestureTime;
public void onSensorChanged(SensorEvent event) {
boolean show = false;
float[] diff = new float[3];
for (int i = 0; i < 3; i++) {
diff[i] = Math.round(mScale[i] * (event.values[i] - mPrev[i]) * 0.45f);
if (Math.abs(diff[i]) > 0) {
show = true;
}
mPrev[i] = event.values[i];
}
if (show) {
// only shows if we think the delta is big enough, in an attempt
// to detect "serious" moves left/right or up/down
Log.e(TAG, "sensorChanged " + event.sensor.getName() +
" (" + event.values[0] + ", " + event.values[1] + ", " +
event.values[2] + ")" + " diff(" + diff[0] +
" " + diff[1] + " " + diff[2] + ")");
}
long now = android.os.SystemClock.uptimeMillis();
if (now - mLastGestureTime > 1000) {
mLastGestureTime = 0;
float x = diff[0];
float y = diff[1];
boolean gestX = Math.abs(x) > 3;
boolean gestY = Math.abs(y) > 3;
if ((gestX || gestY) && !(gestX && gestY)) {
if (gestX) {
if (x < 0) {
Log.e("test", "<<<<<<<< LEFT <<<<<<<<<<<<");
} else {
Log.e("test", ">>>>>>>>> RITE >>>>>>>>>>>");
}
} else {
if (y < -2) {
Log.e("test", "<<<<<<<< UP <<<<<<<<<<<<");
} else {
Log.e("test", ">>>>>>>>> DOWN >>>>>>>>>>>");
}
}
mLastGestureTime = now;
}
}
}
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
};
@Override
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
mSensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mView = new SampleView(this);
setContentView(mView);
if (false) Log.d(TAG, "create " + mSensorManager);
}
@Override
protected void onResume() {
super.onResume();
mSensorManager.registerListener(mListener, mSensor, SensorManager.SENSOR_DELAY_FASTEST);
if (false) Log.d(TAG, "resume " + mSensorManager);
}
@Override
protected void onStop() {
mSensorManager.unregisterListener(mListener);
super.onStop();
if (false) Log.d(TAG, "stop " + mSensorManager);
}
private class SampleView extends View {
private Paint mPaint = new Paint();
private Path mPath = new Path();
private boolean mAnimate;
public SampleView(Context context) {
super(context);
// Construct a wedge-shaped path
mPath.moveTo(0, -50);
mPath.lineTo(-20, 60);
mPath.lineTo(0, 50);
mPath.lineTo(20, 60);
mPath.close();
}
@Override
protected void onDraw(Canvas canvas) {
Paint paint = mPaint;
canvas.drawColor(Color.WHITE);
paint.setAntiAlias(true);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.FILL);
int w = canvas.getWidth();
int h = canvas.getHeight();
int cx = w / 2;
int cy = h / 2;
canvas.translate(cx, cy);
if (mValues != null) {
canvas.rotate(-mValues[0]);
}
canvas.drawPath(mPath, mPaint);
}
@Override
protected void onAttachedToWindow() {
mAnimate = true;
if (false) Log.d(TAG, "onAttachedToWindow. mAnimate="+mAnimate);
super.onAttachedToWindow();
}
@Override
protected void onDetachedFromWindow() {
mAnimate = false;
if (false) Log.d(TAG, "onAttachedToWindow. mAnimate="+mAnimate);
super.onDetachedFromWindow();
}
}
}