Java Code Examples for android.content.pm.PackageManager#FEATURE_USB_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.
 */
@RequiresFeature(PackageManager.FEATURE_USB_ACCESSORY)
public UsbAccessory[] getAccessoryList() {
    if (mService == null) {
        return null;
    }
    try {
        UsbAccessory accessory = mService.getCurrentAccessory();
        if (accessory == null) {
            return null;
        } else {
            return new UsbAccessory[] { accessory };
        }
    } catch (RemoteException e) {
        throw e.rethrowFromSystemServer();
    }
}
 

/**
 * Returns true if the caller has permission to access the accessory.
 * Permission might have been granted temporarily via
 * {@link #requestPermission(UsbAccessory, PendingIntent)} 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
 */
@RequiresFeature(PackageManager.FEATURE_USB_ACCESSORY)
public boolean hasPermission(UsbAccessory accessory) {
    if (mService == null) {
        return false;
    }
    try {
        return mService.hasAccessoryPermission(accessory);
    } catch (RemoteException e) {
        throw e.rethrowFromSystemServer();
    }
}
 

/**
 * Opens a file descriptor for reading and writing data to the USB accessory.
 *
 * <p>If data is read from the {@link java.io.InputStream} created from this file descriptor all
 * data of a USB transfer should be read at once. If only a partial request is read the rest of
 * the transfer is dropped.
 *
 * @param accessory the USB accessory to open
 * @return file descriptor, or null if the accessory could not be opened.
 */
@RequiresFeature(PackageManager.FEATURE_USB_ACCESSORY)
public ParcelFileDescriptor openAccessory(UsbAccessory accessory) {
    try {
        return mService.openAccessory(accessory);
    } catch (RemoteException e) {
        throw e.rethrowFromSystemServer();
    }
}
 

/**
 * 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.
 * If successful, this grants the caller permission to access the accessory only
 * until the device is disconnected.
 *
 * The following extras will be added to pi:
 * <ul>
 * <li> {@link #EXTRA_ACCESSORY} containing the accessory passed into this call
 * <li> {@link #EXTRA_PERMISSION_GRANTED} containing boolean indicating whether
 * permission was granted by the user
 * </ul>
 *
 * @param accessory to request permissions for
 * @param pi PendingIntent for returning result
 */
@RequiresFeature(PackageManager.FEATURE_USB_ACCESSORY)
public void requestPermission(UsbAccessory accessory, PendingIntent pi) {
    try {
        mService.requestAccessoryPermission(accessory, mContext.getPackageName(), pi);
    } catch (RemoteException e) {
        throw e.rethrowFromSystemServer();
    }
}