The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/*
* Copyright (C) 2011 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.android.missilelauncher;
import java.nio.ByteBuffer;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.hardware.usb.UsbRequest;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
public class MissileLauncherActivity extends Activity
implements View.OnClickListener, Runnable {
private static final String TAG = "MissileLauncherActivity";
private Button mFire;
private UsbManager mUsbManager;
private UsbDevice mDevice;
private UsbDeviceConnection mConnection;
private UsbEndpoint mEndpointIntr;
private SensorManager mSensorManager;
private Sensor mGravitySensor;
// USB control commands
private static final int COMMAND_UP = 1;
private static final int COMMAND_DOWN = 2;
private static final int COMMAND_RIGHT = 4;
private static final int COMMAND_LEFT = 8;
private static final int COMMAND_FIRE = 16;
private static final int COMMAND_STOP = 32;
private static final int COMMAND_STATUS = 64;
// constants for accelerometer orientation
private static final int TILT_LEFT = 1;
private static final int TILT_RIGHT = 2;
private static final int TILT_UP = 4;
private static final int TILT_DOWN = 8;
private static final double THRESHOLD = 5.0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.launcher);
mFire = (Button)findViewById(R.id.fire);
mFire.setOnClickListener(this);
mUsbManager = (UsbManager)getSystemService(Context.USB_SERVICE);
mSensorManager = (SensorManager)getSystemService(Context.SENSOR_SERVICE);
mGravitySensor = mSensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY);
}
@Override
public void onPause() {
super.onPause();
mSensorManager.unregisterListener(mGravityListener);
}
@Override
public void onResume() {
super.onResume();
mSensorManager.registerListener(mGravityListener, mGravitySensor,
SensorManager.SENSOR_DELAY_NORMAL);
Intent intent = getIntent();
Log.d(TAG, "intent: " + intent);
String action = intent.getAction();
UsbDevice device = (UsbDevice)intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) {
setDevice(device);
} else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) {
if (mDevice != null && mDevice.equals(device)) {
setDevice(null);
}
}
}
@Override
public void onDestroy() {
super.onDestroy();
}
private void setDevice(UsbDevice device) {
Log.d(TAG, "setDevice " + device);
if (device.getInterfaceCount() != 1) {
Log.e(TAG, "could not find interface");
return;
}
UsbInterface intf = device.getInterface(0);
// device should have one endpoint
if (intf.getEndpointCount() != 1) {
Log.e(TAG, "could not find endpoint");
return;
}
// endpoint should be of type interrupt
UsbEndpoint ep = intf.getEndpoint(0);
if (ep.getType() != UsbConstants.USB_ENDPOINT_XFER_INT) {
Log.e(TAG, "endpoint is not interrupt type");
return;
}
mDevice = device;
mEndpointIntr = ep;
if (device != null) {
UsbDeviceConnection connection = mUsbManager.openDevice(device);
if (connection != null && connection.claimInterface(intf, true)) {
Log.d(TAG, "open SUCCESS");
mConnection = connection;
Thread thread = new Thread(this);
thread.start();
} else {
Log.d(TAG, "open FAIL");
mConnection = null;
}
}
}
private void sendCommand(int control) {
synchronized (this) {
if (control != COMMAND_STATUS) {
Log.d(TAG, "sendMove " + control);
}
if (mConnection != null) {
byte[] message = new byte[1];
message[0] = (byte)control;
// Send command via a control request on endpoint zero
mConnection.controlTransfer(0x21, 0x9, 0x200, 0, message, message.length, 0);
}
}
}
public void onClick(View v) {
if (v == mFire) {
sendCommand(COMMAND_FIRE);
}
}
private int mLastValue = 0;
SensorEventListener mGravityListener = new SensorEventListener() {
public void onSensorChanged(SensorEvent event) {
// compute current tilt
int value = 0;
if (event.values[0] < -THRESHOLD) {
value += TILT_LEFT;
} else if (event.values[0] > THRESHOLD) {
value += TILT_RIGHT;
}
if (event.values[1] < -THRESHOLD) {
value += TILT_UP;
} else if (event.values[1] > THRESHOLD) {
value += TILT_DOWN;
}
if (value != mLastValue) {
mLastValue = value;
// send motion command if the tilt changed
switch (value) {
case TILT_LEFT:
sendCommand(COMMAND_LEFT);
break;
case TILT_RIGHT:
sendCommand(COMMAND_RIGHT);
break;
case TILT_UP:
sendCommand(COMMAND_UP);
break;
case TILT_DOWN:
sendCommand(COMMAND_DOWN);
break;
default:
sendCommand(COMMAND_STOP);
break;
}
}
}
public void onAccuracyChanged(Sensor sensor, int accuracy) {
// ignore
}
};
@Override
public void run() {
ByteBuffer buffer = ByteBuffer.allocate(1);
UsbRequest request = new UsbRequest();
request.initialize(mConnection, mEndpointIntr);
byte status = -1;
while (true) {
// queue a request on the interrupt endpoint
request.queue(buffer, 1);
// send poll status command
sendCommand(COMMAND_STATUS);
// wait for status event
if (mConnection.requestWait() == request) {
byte newStatus = buffer.get(0);
if (newStatus != status) {
Log.d(TAG, "got status " + newStatus);
status = newStatus;
if ((status & COMMAND_FIRE) != 0) {
// stop firing
sendCommand(COMMAND_STOP);
}
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
}
} else {
Log.e(TAG, "requestWait failed, exiting");
break;
}
}
}
}