/** 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");
}
}
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;
}