/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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.future.usb;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.hardware.usb.IUsbManager;
import android.os.IBinder;
import android.os.ParcelFileDescriptor;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.util.Log;
/**
* This is a wrapper class for the USB Manager to support USB accessories.
*
* <p>You can obtain an instance of this class by calling {@link #getInstance}
*
*/
public class UsbManager {
private static final String TAG = "UsbManager";
/**
* Broadcast Action: A broadcast for USB accessory attached event.
*
* This intent is sent when a USB accessory is attached.
* Call {@link #getAccessory(android.content.Intent)} to retrieve the
* {@link com.google.android.usb.UsbAccessory} for the attached accessory.
*/
public static final String ACTION_USB_ACCESSORY_ATTACHED =
"android.hardware.usb.action.USB_ACCESSORY_ATTACHED";
/**
* Broadcast Action: A broadcast for USB accessory detached event.
*
* This intent is sent when a USB accessory is detached.
* Call {@link #getAccessory(android.content.Intent)} to retrieve the
* {@link com.google.android.usb.UsbAccessory} for the attached accessory that was detached.
*/
public static final String ACTION_USB_ACCESSORY_DETACHED =
"android.hardware.usb.action.USB_ACCESSORY_DETACHED";
/**
* Name of extra added to the {@link android.app.PendingIntent}
* passed into {#requestPermission} or {#requestPermission}
* containing a boolean value indicating whether the user granted permission or not.
*/
public static final String EXTRA_PERMISSION_GRANTED = "permission";
private final Context mContext;
private final IUsbManager mService;
private UsbManager(Context context, IUsbManager service) {
mContext = context;
mService = service;
}
/**
* Returns a new instance of this class.
*
* @param context the caller's {@link android.content.Context}
* @return UsbManager instance.
*/
public static UsbManager getInstance(Context context) {
IBinder b = ServiceManager.getService(Context.USB_SERVICE);
return new UsbManager(context, IUsbManager.Stub.asInterface(b));
}
/**
* Returns the {@link com.google.android.usb.UsbAccessory} for
* a {@link #ACTION_USB_ACCESSORY_ATTACHED} or {@link #ACTION_USB_ACCESSORY_ATTACHED}
* broadcast Intent. This can also be used to retrieve the accessory from the result
* of a call to {#requestPermission}.
*
* @return UsbAccessory for the intent.
*/
public static UsbAccessory getAccessory(Intent intent) {
android.hardware.usb.UsbAccessory accessory =
intent.getParcelableExtra(android.hardware.usb.UsbManager.EXTRA_ACCESSORY);
if (accessory == null) {
return null;
} else {
return new UsbAccessory(accessory);
}
}
/**
* Returns a list of currently attached USB accessories.
* (in the current implementation there can be at most one)
*
* @return list of USB accessories, or null if none are attached.
*/
public UsbAccessory[] getAccessoryList() {
try {
android.hardware.usb.UsbAccessory accessory = mService.getCurrentAccessory();
if (accessory == null) {
return null;
} else {
return new UsbAccessory[] { new UsbAccessory(accessory) };
}
} catch (RemoteException e) {
Log.e(TAG, "RemoteException in getAccessoryList" , e);
return null;
}
}
/**
* Opens a file descriptor for reading and writing data to the USB accessory.
*
* @param accessory the USB accessory to open
* @return file descriptor, or null if the accessor could not be opened.
*/
public ParcelFileDescriptor openAccessory(UsbAccessory accessory) {
try {
return mService.openAccessory(new android.hardware.usb.UsbAccessory(
accessory.getManufacturer(),accessory.getModel(),
accessory.getDescription(), accessory.getVersion(),
accessory.getUri(), accessory.getSerial()));
} catch (RemoteException e) {
Log.e(TAG, "RemoteException in openAccessory" , e);
return null;
}
}
/**
* Returns true if the caller has permission to access the accessory.
* Permission might have been granted temporarily via
* {@link #requestPermission} or
* by the user choosing the caller as the default application for the accessory.
*
* @param accessory to check permissions for
* @return true if caller has permission
*/
public boolean hasPermission(UsbAccessory accessory) {
try {
return mService.hasAccessoryPermission(new android.hardware.usb.UsbAccessory(
accessory.getManufacturer(),accessory.getModel(),
accessory.getDescription(), accessory.getVersion(),
accessory.getUri(), accessory.getSerial()));
} catch (RemoteException e) {
Log.e(TAG, "RemoteException in hasPermission", e);
return false;
}
}
/**
* Requests temporary permission for the given package to access the accessory.
* This may result in a system dialog being displayed to the user
* if permission had not already been granted.
* Success or failure is returned via the {@link android.app.PendingIntent} pi.
* The boolean extra {@link #EXTRA_PERMISSION_GRANTED} will be attached to the
* PendingIntent to indicate success or failure.
* If successful, this grants the caller permission to access the device only
* until the device is disconnected.
*
* @param accessory to request permissions for
* @param pi PendingIntent for returning result
*/
public void requestPermission(UsbAccessory accessory, PendingIntent pi) {
try {
mService.requestAccessoryPermission(new android.hardware.usb.UsbAccessory(
accessory.getManufacturer(),accessory.getModel(),
accessory.getDescription(), accessory.getVersion(),
accessory.getUri(), accessory.getSerial()),
mContext.getPackageName(), pi);
} catch (RemoteException e) {
Log.e(TAG, "RemoteException in requestPermission", e);
}
}
}