org.eclipse.osbp.vaadin.addons.suggesttext/src/org/eclipse/osbp/vaadin/addons/suggesttext/client/OQueryDelegate.java

/**
 *                                                                            
 * Copyright (c) 2011, 2016 - Loetz GmbH&Co.KG (69115 Heidelberg, Germany)
 *                                                                            
 * All rights reserved. This program and the accompanying materials           
 * are made available under the terms of the Eclipse Public License v1.0       
 * which accompanies this distribution, and is available at                  
 * http://www.eclipse.org/legal/epl-v10.html                                 
 *                                                                            
 * Contributors:   
 * Florian Pirchner <florian.pirchner@gmail.com> - Initial implementation
 */
package org.eclipse.osbp.vaadin.addons.suggesttext.client;

import java.util.Date;
import java.util.List;

import com.google.gwt.user.client.ui.SuggestOracle.Request;

// TODO: Auto-generated Javadoc
/**
 * This class is responsible to delegate the query for suggestions to the serverside rpc. 
 */
public class OQueryDelegate {

	/** The server rpc. */
	// instance
	private final SuggestTextFieldServerRpc serverRpc;

	/** The current handle. */
	private String currentHandle;
	
	/** The current callback. */
	private FutureCallback currentCallback;

	/**
	 * Instantiates a new o query delegate.
	 *
	 * @param serverRpc the server rpc
	 */
	public OQueryDelegate(SuggestTextFieldServerRpc serverRpc) {
		this.serverRpc = serverRpc;
	}

	/**
	 * Request suggestions.
	 *
	 * @param request the request
	 * @param callback the callback
	 */
	protected void requestSuggestions(Request request, FutureCallback callback) {
		// dismiss older callbacks
		currentHandle = Long.toHexString(new Date().getTime());
		currentCallback = callback;

		serverRpc.requestSuggestions(currentHandle, request.getQuery(), request.getLimit());
	}

	/**
	 * Respond.
	 *
	 * @param handle the handle
	 * @param response the response
	 */
	public void respond(String handle, List<SuggestionResult> response) {
		if (currentHandle.equals(handle)) {
			currentCallback.respondSuggestions(response);
		}
	}
	
	/**
	 * A future to wait for responds from serverside. 
	 */
	public interface FutureCallback {
		
		/**
		 * Respond suggestions.
		 *
		 * @param suggestions the suggestions
		 */
		void respondSuggestions(List<SuggestionResult> suggestions);
	}

	/**
	 * The Class SuggestionResult.
	 */
	public static class SuggestionResult {
		
		/** The uuid. */
		public String uuid;
		
		/** The display text. */
		public String displayText;

		/**
		 * Instantiates a new suggestion result.
		 */
		public SuggestionResult() {

		}

		/**
		 * Instantiates a new suggestion result.
		 *
		 * @param uuid the uuid
		 * @param displayText the display text
		 */
		public SuggestionResult(String uuid, String displayText) {
			super();
			this.uuid = uuid;
			this.displayText = displayText;
		}

	}
}