/** Called when the activity is resumed from its paused state and immediately after onCreate(). */
  @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");
    }
  }
Exemplo n.º 2
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 private boolean connectDevice() {
   if (mRunning) {
     return true;
   } else {
     UsbAccessory[] accessories = mUsbManager.getAccessoryList();
     UsbAccessory accessory = (accessories == null ? null : accessories[0]);
     Logger.d("onResume accessory:" + accessory);
     if (accessory != null) {
       if (mUsbManager.hasPermission(accessory)) {
         Logger.d("onResume openAccessory START");
         openAccessory(accessory);
       } else {
         Logger.d("permission ERROR?");
         synchronized (mUsbManager) {
           if (!mPermissionRequestPending) {
             mUsbManager.requestPermission(accessory, mPermissionIntent);
             mPermissionRequestPending = true;
           }
         }
       }
       return true;
     } else {
       Logger.d("not attachd USB.");
       return false;
     }
   }
 }
  /**
   * Enables the
   *
   * @param context The context that the USB manager should register to
   * @return RETURN_CODES - the status of the enable request
   */
  public RETURN_CODES enable(Context context, Intent intent) {
    // Grab the packageName to use for an attach Intent
    actionString = context.getPackageName() + ".action.USB_PERMISSION";

    PendingIntent permissionIntent =
        PendingIntent.getBroadcast(context, 0, new Intent(actionString), 0);

    // If the USB manager isn't already enabled
    if (enabled == false) {
      // Create a new filter with the package name (for the accessory
      // attach)

      try {
        Thread.sleep(500);
      } catch (InterruptedException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
      }

      IntentFilter filter = new IntentFilter(actionString);
      // Also add a few other actions to the intent...
      filter.addAction(UsbManager.ACTION_USB_ACCESSORY_ATTACHED);
      filter.addAction(UsbManager.ACTION_USB_ACCESSORY_DETACHED);
      // and register the intent with the specified context
      context.registerReceiver(receiver, filter);

      UsbManager deviceManager = null;
      UsbAccessory[] accessories = null;
      UsbAccessory accessory = null;

      // Get a UsbManager object from the specified intent (only works for
      // v3.1+ devices)
      // deviceManager = (UsbManager) context
      //		.getSystemService(Context.USB_SERVICE);
      deviceManager = UsbManager.getInstance(context);

      // If we were unable to get a UsbManager, return an error
      if (deviceManager == null) {
        return RETURN_CODES.DEVICE_MANAGER_IS_NULL;
      }

      // Get a list of all of the accessories from the UsbManager
      accessories = deviceManager.getAccessoryList();

      // If the list of accessories is empty, then exit
      if (accessories == null) {
        return RETURN_CODES.ACCESSORIES_LIST_IS_EMPTY;
      }

      // Get the first accessory in the list (currently the Android OS
      // only
      // supports one accessory, so this is it)
      accessory = accessories[0];

      // If the accessory isn't null, then let's try to attach to it.
      if (accessory != null) {
        // If we have permission to access the accessory,
        if (deviceManager.hasPermission(accessory)) {
          // Try to open a ParcelFileDescriptor by opening the
          // accessory
          parcelFileDescriptor = deviceManager.openAccessory(accessory);

          if (parcelFileDescriptor != null) {
            // Create a new read thread to handle reading data from
            // the accessory
            readThread = new ReadThread(parcelFileDescriptor);
            readThread.start();

            deviceManager.requestPermission(accessory, permissionIntent);

            if (parcelFileDescriptor == null) {
              Log.d(TAG, "USBAccessoryManager:enable() parcelFileDescriptor == null");
              return RETURN_CODES.FILE_DESCRIPTOR_WOULD_NOT_OPEN;
            }

            // Open the output file stream for writing data out to
            // the accessory
            outputStream = new FileOutputStream(parcelFileDescriptor.getFileDescriptor());

            if (outputStream == null) {
              Log.d(TAG, "USBAccessoryManager:enable() outputStream == null");

              try {
                parcelFileDescriptor.close();
              } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
              }
              return RETURN_CODES.FILE_DESCRIPTOR_WOULD_NOT_OPEN;
            }

            Log.d(TAG, "USBAccessoryManager:enable() outputStream open");

            // If the ParcelFileDescriptor was successfully opened,
            // mark the accessory as enabled and open
            enabled = true;
            open = true;

            handler
                .obtainMessage(
                    what,
                    new USBAccessoryManagerMessage(
                        USBAccessoryManagerMessage.MessageType.READY, accessory))
                .sendToTarget();

            Log.d(TAG, "USBAccessoryManager:enable() device ready");

            return RETURN_CODES.SUCCESS;
          } else {
            /*
             * If we weren't able to open the ParcelFileDescriptor,
             * then we will not be able to talk to the device. Due
             * to a bug in the Android v2.3.4 OS this situation may
             * occur if a user presses the "home" or "back" buttons
             * while an accessory is still attached. In this case
             * the attempt to close the ReadThread will fail if a
             * read() is in progress on the FileInputStream. This
             * results in the ParcelFileDescriptor not being freed
             * up for later access. A future attempt to connect to
             * the accessory (via reopening the app) will end up
             * having the openAccessory() request return null,
             * ending up in this section of code.
             */
            return RETURN_CODES.FILE_DESCRIPTOR_WOULD_NOT_OPEN;
          }
        } else {
          /*
           * If we don't currently have permission to access the
           * accessory, then we need to request it. If we haven't
           * requested it already...
           */
          if (permissionRequested == false) {
            // Then go ahead and request it...
            deviceManager.requestPermission(accessory, permissionIntent);

            permissionRequested = true;
            return RETURN_CODES.PERMISSION_PENDING;
          }
        }
      }

      return RETURN_CODES.ACCESSORIES_LIST_IS_EMPTY;
    }

    return RETURN_CODES.SUCCESS;
  }