Android Open Source - accessory-samples Main Usb Activity

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License

The source code is released under:

Copyright (c) 2012 Wireless Designs, LLC Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in ...

Java Source Code

/**
 * MainUsbActivity is a GameActivity that monitors a USB Accessory
 * device and uses the input from that device to control the game.
 *//*from  w  ww.  j av  a2  s.  co m*/

package com.examples.accessory.controller;

import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbAccessory;
import android.hardware.usb.UsbManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.util.Log;

import java.io.FileDescriptor;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class MainUsbActivity extends GameActivity implements Runnable {

  private static final String ACTION_USB_PERMISSION = "com.examples.accessory.controller.action.USB_PERMISSION";

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

  UsbAccessory mAccessory;
  ParcelFileDescriptor mFileDescriptor;
  FileInputStream mInputStream;
  FileOutputStream mOutputStream;

  private static final int MESSAGE_SWITCH = 1;
  private static final int MESSAGE_JOY = 4;
    private static final int MESSAGE_VIBE = 5;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mUsbManager = (UsbManager)getSystemService(Context.USB_SERVICE);
    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);

    setContentView(R.layout.main);

    enableControls(false);
  }

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

    Intent intent = getIntent();
    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();
  }
  
  @Override
  protected boolean isControllerConnected() {
      return (mAccessory != null);
  }

  @Override
  protected void hideControls() {
      setContentView(R.layout.no_device);
      super.hideControls();
  }

    @Override
    protected void sendVibeControl(boolean longDuration) {
        byte[] command = {0x02,
                longDuration ? (byte)0x64 : (byte)0x32,
                0x00};
        Message msg = Message.obtain(null, MESSAGE_VIBE, command);
        mHandler.sendMessage(msg);
    }

    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, "AccessoryController");
      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;
    }
  }

  /*
   * This receiver monitors for the event of a user granting permission to use
   * the attached accessory.  If the user has checked to always allow, this will
   * be generated following attachment without further user interaction.
   */
    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 = (UsbAccessory) intent.getParcelableExtra(UsbManager.EXTRA_ACCESSORY);
                    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 = (UsbAccessory) intent.getParcelableExtra(UsbManager.EXTRA_ACCESSORY);
                if (accessory != null && accessory.equals(mAccessory)) {
                    closeAccessory();
                }
            }
        }
    };

  /*
   * Runnable block that will poll the accessory data stream
   * for regular updates, posting each message it finds to a
   * Handler.  This is run on a spawned background thread.
   */
  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]) {
        case 0x1:
          if (len >= 3) {
            Message m = Message.obtain(mHandler, MESSAGE_SWITCH);
            m.obj = new SwitchMsg(buffer[i + 1], buffer[i + 2]);
            mHandler.sendMessage(m);
          }
          i += 3;
          break;

        case 0x6:
          if (len >= 3) {
            Message m = Message.obtain(mHandler, MESSAGE_JOY);
            m.obj = new JoyMsg(buffer[i + 1], buffer[i + 2]);
            mHandler.sendMessage(m);
          }
          i += 3;
          break;

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

    }
  }

  /*
   * This Handler receives messages from the polling thread and
   * injects them into the GameActivity methods on the main thread.
   */
    Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MESSAGE_SWITCH:
                    SwitchMsg o = (SwitchMsg) msg.obj;
                    handleSwitchMessage(o);
                    break;

                case MESSAGE_JOY:
                    JoyMsg j = (JoyMsg) msg.obj;
                    handleJoyMessage(j);
                    break;

                case MESSAGE_VIBE:
                    try {
                        byte[] v = (byte[]) msg.obj;
                        mOutputStream.write(v);
                        mOutputStream.flush();
                    } catch (IOException e) {
                        Log.w("AccessoryController", "Error writing vibe output");
                    }
                    break;
            }
        }
    };

}

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