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Extension for usb4java which implements javax.usb (JSR-80).

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/*
 * Copyright (C) 2011 Klaus Reimer 
 * See LICENSE.md for licensing information.
 */

package org.usb4java.javax;

import javax.usb.UsbHub;
import javax.usb.UsbPort;

/**
 * usb4java implementation of UsbPort.
 *
 * @author Klaus Reimer ([email protected])
 */
final class Port implements UsbPort
{
    /** The USB hub this port belongs to. */
    private final UsbHub hub;

    /** The port number. */
    private final byte portNumber;

    /** The attached device. */
    private AbstractDevice device;

    /**
     * Constructor.
     *
     * @param hub
     *            The USB hub this port belongs to.
     * @param portNumber
     *            The port number.
     */
    Port(final UsbHub hub, final byte portNumber)
    {
        this.hub = hub;
        this.portNumber = portNumber;
    }

    @Override
    public byte getPortNumber()
    {
        return this.portNumber;
    }

    @Override
    public UsbHub getUsbHub()
    {
        return this.hub;
    }

    @Override
    public AbstractDevice getUsbDevice()
    {
        return this.device;
    }

    @Override
    public boolean isUsbDeviceAttached()
    {
        return this.device != null;
    }

    /**
     * Connects the specified device to this port.
     *
     * @param device
     *            The device to connect.
     */
    void connectUsbDevice(final AbstractDevice device)
    {
        if (device == null)
            throw new IllegalArgumentException("device must not be null");
        if (this.device != null)
            throw new IllegalStateException(
                "Port already has a connected device");
        this.device = device;
        device.setParentUsbPort(this);
    }

    /**
     * Disconnects the currently connected device.
     */
    void disconnectUsbDevice()
    {
        if (this.device == null)
            throw new IllegalStateException("Port has no connected device");
        final AbstractDevice device = this.device;
        this.device = null;
        device.setParentUsbPort(null);
    }
}