org.usb4java.HotplugCallback Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of usb4java Show documentation

USB library for Java based on libusb and implementing javax-usb (JSR-80).

The newest version!

/*
 * Copyright 2013 Luca Longinotti 
 * See LICENSE.md for licensing information.
 */

package org.usb4java;

/**
 * Hotplug callback.
 * 
 * When requesting hotplug event notifications, you pass a callback of this
 * type.
 * 
 * @author Luca Longinotti ([email protected])
 */
public interface HotplugCallback
{
    /**
     * Process a hotplug event.
     * 
     * This callback may be called by an internal event thread and as such it 
     * is recommended the callback do minimal processing before returning.
     * 
     * libusb will call this function later, when a matching event had happened
     * on a matching device.
     * 
     * It is safe to call either
     * {@link LibUsb#hotplugRegisterCallback(Context, int, int, int, int, int, 
     * HotplugCallback, Object, HotplugCallbackHandle)} or
     * {@link LibUsb#hotplugDeregisterCallback(Context, HotplugCallbackHandle)}
     * from within a callback.
     * 
     * @param context
     *            Context of this notification.
     * @param device
     *            Device this event occurred on.
     * @param event
     *            Event that occurred.
     * @param userData
     *            user data provided when this callback was registered
     * @return Whether this callback is finished processing events. Returning 1
     *         will cause this callback to be deregistered.
     */
    int processEvent(Context context, Device device, int event, 
        Object userData);
}