/* Device.java{{IS_NOTE	Purpose:			Description:			History:		Mon May 14 19:13:14     2007, Created by tomyeh}}IS_NOTECopyright (C) 2007 Potix Corporation. All Rights Reserved.{{IS_RIGHT	This program is distributed under GPL Version 2.0 in the hope that	it will be useful, but WITHOUT ANY WARRANTY.}}IS_RIGHT*/package org.zkoss.zk.device;import org.zkoss.zk.ui.Desktop;import org.zkoss.zk.ui.sys.ServerPush;/** * Represents a client device. * For example, the HTML browsers with Ajax are called {@link AjaxDevice}, * the XML output called org.zkoss.zml.device.XmlDevice, * and the MIL device called org.zkoss.mil.device.MilDevice. * * <p>Note: the same device is shared by all desktops of the same device * type. * * @author tomyeh * @since 2.4.0 */public interface Device {	/** Returns the device type.	 */	public String getType();	/** Returns whether the output can be cached by the client.	 */	public boolean isCacheable();	/** Returns the unavailable message that is shown to the client	 * if the client doesn't support this device.	 *	 * @return the unavailable message, or null if no such message	 * @since 2.4.0	 */	public String getUnavailableMessage();	/** Sets the unavailable message that is shown to the client	 * if the client doesn't support this device.	 *	 * @param unavailmsg the unavailable message.	 * @return the previous unavailable message, or null if not such message	 * @since 2.4.0	 */	public String setUnavailableMessage(String unavailmsg);	/** Returns the timeout URI for this device.	 * It is used to show the error message if the desktop being requested	 * is not found. It is usually caused by session timeout.	 *	 * <p>Default: null (to shown an error message).	 *	 * @since 3.0.0	 */	public String getTimeoutURI();	/** Sets the timeout URI.	 * It is used to show the error message if the desktop being requested	 * is not found. It is usually caused by session timeout.	 *	 * @param timeoutURI the timeout URI. If empty, it means to reload	 * the same page. If null, an error message is shown instead of	 * redirecting to another page.	 * @return the previous timeout URI, or null if not available.	 * @since 3.0.0	 */	public String setTimeoutURI(String timeoutURI);	/** Returns the class that implements the server-push feature	 * ({@link ServerPush}) for this device, or null if the default is used.	 * @since 3.0.0	 */	public Class getServerPushClass();	/** Sets the class that implements the server-push feature	 * ({@link ServerPush}) for this device, or null to use the default.	 *	 * <p>Default: null.	 *	 * <p>If the professional edition (with zkex.jar) is loaded,	 * the client-polling-based server push (org.zkoss.zkex.ui.impl.PollingServerPush)	 * is the default.	 * If the enterprise edition (with zkmax.jar) is loaded,	 * the COMET-based server push (org.zkoss.zkmax.ui.impl.CometServerPush)	 * is the default.	 * @return the previous class, or null if not available.	 * @since 3.0.0	 */	public Class setServerPushClass(Class cls);	/** Returns the default content type (never null).	 * 	 * @since 3.0.0	 */	public String getContentType();	/** Returns the default doc type, or null if no doc type at all.	 *	 * @since 3.0.0	 */	public String getDocType();	/** Initializes the device.	 * A device is created for each desktop, and this method is called	 * when it is associated to the desktop.	 *	 * @param deviceType the device type (never null)	 * @param config the configuration to initialize the device (never null)	 * @since 3.0.0	 */	public void init(String deviceType, DeviceConfig config);	/** Notification that the desktop, which owns this device,	 * is about to be passivated (aka., serialized) by the Web container.	 * @since 2.4.0	 */	public void sessionWillPassivate(Desktop desktop);	/** Notification that the desktop, which owns this device,	 * has just been activated (aka., deserialized) by the Web container.	 * @since 2.4.0	 */	public void sessionDidActivate(Desktop desktop);}