DroidSoundDisplayActivity.java

/**
 * code from the book Arduino + Android Projects for the Evil Genius
 * <br>Copyright 2011 Simon Monk
 *
 * <p>This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation (see COPYING).
 * 
 * <p>This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
 
package org.simonmonk.sounddisplay;

import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;

import android.os.ParcelFileDescriptor;
import android.util.Log;

import com.android.future.usb.UsbAccessory;
import com.android.future.usb.UsbManager;

public class DroidSoundDisplayActivity extends Activity implements Runnable {
	private static final String TAG = "DemoKit";

	private static final String ACTION_USB_PERMISSION = "com.google.android.DemoKit.action.USB_PERMISSION";

	private UsbManager mUsbManager;
	private PendingIntent mPermissionIntent;
	private boolean mPermissionRequestPending;

	UsbAccessory mAccessory;
	ParcelFileDescriptor mFileDescriptor;
	FileInputStream mInputStream;
	FileOutputStream mOutputStream;
	
	int count = 0;

	protected class ValueMsg {
		private char flag;
		private int reading;

		public ValueMsg(char flag, int reading) {
			this.flag = flag;
			this.reading = reading;
		}

		public int getReading() {
			return reading;
		}
		
		public char getFlag() {
			return flag;
		}
	}
	

	private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
			String action = intent.getAction();
			if (ACTION_USB_PERMISSION.equals(action)) {
				synchronized (this) {
					UsbAccessory accessory = UsbManager.getAccessory(intent);
					if (intent.getBooleanExtra(
							UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
						openAccessory(accessory);
					} else {
						Log.d(TAG, "permission denied for accessory "
								+ accessory);
					}
					mPermissionRequestPending = false;
				}
			} else if (UsbManager.ACTION_USB_ACCESSORY_DETACHED.equals(action)) {
				UsbAccessory accessory = UsbManager.getAccessory(intent);
				if (accessory != null && accessory.equals(mAccessory)) {
					closeAccessory();
				}
			}
		}
	};

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		mUsbManager = UsbManager.getInstance(this);
		mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(
				ACTION_USB_PERMISSION), 0);
		IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
		filter.addAction(UsbManager.ACTION_USB_ACCESSORY_DETACHED);
		registerReceiver(mUsbReceiver, filter);

		if (getLastNonConfigurationInstance() != null) {
			mAccessory = (UsbAccessory) getLastNonConfigurationInstance();
			openAccessory(mAccessory);
		}

		setContentView(R.layout.main);

		enableControls(false);
	}

	@Override
	public Object onRetainNonConfigurationInstance() {
		if (mAccessory != null) {
			return mAccessory;
		} else {
			return super.onRetainNonConfigurationInstance();
		}
	}

	@Override
	public void onResume() {
		super.onResume();

		if (mInputStream != null && mOutputStream != null) {
			return;
		}

		UsbAccessory[] accessories = mUsbManager.getAccessoryList();
		UsbAccessory accessory = (accessories == null ? null : accessories[0]);
		if (accessory != null) {
			if (mUsbManager.hasPermission(accessory)) {
				openAccessory(accessory);
			} else {
				synchronized (mUsbReceiver) {
					if (!mPermissionRequestPending) {
						mUsbManager.requestPermission(accessory,
								mPermissionIntent);
						mPermissionRequestPending = true;
					}
				}
			}
		} else {
			Log.d(TAG, "mAccessory is null");
		}
	}

	@Override
	public void onPause() {
		super.onPause();
		closeAccessory();
	}

	@Override
	public void onDestroy() {
		unregisterReceiver(mUsbReceiver);
		super.onDestroy();
	}

	private void openAccessory(UsbAccessory accessory) {
		mFileDescriptor = mUsbManager.openAccessory(accessory);
		if (mFileDescriptor != null) {
			mAccessory = accessory;
			FileDescriptor fd = mFileDescriptor.getFileDescriptor();
			mInputStream = new FileInputStream(fd);
			mOutputStream = new FileOutputStream(fd);
			Thread thread = new Thread(null, this, "DemoKit");
			thread.start();
			Log.d(TAG, "accessory opened");
			enableControls(true);
		} else {
			Log.d(TAG, "accessory open fail");
		}
	}

	private void closeAccessory() {
		enableControls(false);

		try {
			if (mFileDescriptor != null) {
				mFileDescriptor.close();
			}
		} catch (IOException e) {
		} finally {
			mFileDescriptor = null;
			mAccessory = null;
		}
	}

	protected void enableControls(boolean enable) {
	}
	

	public void run() {
		int ret = 0;
		byte[] buffer = new byte[16384];
		int i;

		while (ret >= 0) {
			try {
				ret = mInputStream.read(buffer);
			} catch (IOException e) {
				break;
			}

			i = 0;
			while (i < ret) {
				int len = ret - i;

				switch (buffer[i]) {
				default:
					Log.d(TAG, "unknown msg: " + buffer[i]);
					i = len;
					break;
				}
			}

		}
	}


	
	public void sendCommand(byte command, byte target, int value) {
		byte[] buffer = new byte[3];
		if (value > 255)
			value = 255;

		buffer[0] = command;
		buffer[1] = target;
		buffer[2] = (byte) value;
		if (mOutputStream != null && buffer[1] != -1) {
			try {
				mOutputStream.write(buffer);
			} catch (IOException e) {
				Log.e(TAG, "write failed", e);
			}
		}
	}
}