com.tasktop.c2c.server.common.web.client.navigation.Navigation.java Source code

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Here is the source code for com.tasktop.c2c.server.common.web.client.navigation.Navigation.java

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/*******************************************************************************
 * Copyright (c) 2010, 2012 Tasktop Technologies
 * Copyright (c) 2010, 2011 SpringSource, a division of VMware
 * 
 * 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:
 *     Tasktop Technologies - initial API and implementation
 ******************************************************************************/
package com.tasktop.c2c.server.common.web.client.navigation;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.google.gwt.dom.client.Node;
import com.google.gwt.http.client.URL;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.History;
import com.google.gwt.user.client.Window;

/**
 * utility for working with navigation
 */
public class Navigation {
    /**
     * get request parameters that were passed on the {@link History#getToken() history token}. The history token is
     * used for parameters so that the page doesn't have to reload.
     */
    public static Map<String, List<String>> getNavigationParameterMap() {
        Map<String, List<String>> parameters = new HashMap<String, List<String>>();

        String currentToken = History.getToken();
        if (currentToken != null) {
            int idxOfQueryStringSeparator = currentToken.indexOf('?');
            if (idxOfQueryStringSeparator != -1 && idxOfQueryStringSeparator < (currentToken.length() - 1)) {
                String queryString = currentToken.substring(idxOfQueryStringSeparator + 1);
                String[] parts = queryString.split("&");
                for (String part : parts) {
                    String[] keyValue = part.split("=");
                    if (keyValue.length == 2) {
                        String key = URL.decode(keyValue[0]);
                        String value = URL.decode(keyValue[1]);
                        List<String> values = parameters.get(key);
                        if (values == null) {
                            values = new ArrayList<String>(1);
                            parameters.put(key, values);
                        }
                        values.add(value);
                    }
                }
            }
        }
        return parameters;
    }

    public static String appendQueryParameterToUrl(String url, String paramName, String paramValue) {

        // Make this method null-safe - some calling paths start with a null URL.
        String retUrl = (url == null ? "" : url);

        String encodedValue = URL.encode(paramValue);
        String encodedName = URL.encode(paramName);

        // Check if we already have some parameters in this URL.
        if (retUrl.indexOf('?') > 0) {
            // Already have a parameter, so the next one will be added on with &
            retUrl += "&";
        } else {
            // No parameters yet, so indicate the first one with ?
            retUrl += "?";
        }

        // Attach the rest of our parameter now.
        retUrl += encodedName + "=" + encodedValue;

        return retUrl;
    }

    /**
     * show the element with the given id
     * 
     * @return true if the element was found
     */
    public static boolean showIdElement(Element element, String elementId) {
        Element idElement = findElementById(element, elementId);
        if (idElement != null) {
            Window.scrollTo(idElement.getAbsoluteLeft(), idElement.getAbsoluteTop());
            return true;
        }
        return false;
    }

    /**
     * find an element by its id
     * 
     * @return the element, or null if it could not be found
     */
    public static Element findElementById(Element element, String elementId) {
        String id = element.getAttribute("id");
        if (id != null && elementId.equals(id)) {
            return element;
        }
        for (Node child = element.getFirstChild(); child != null; child = child.getNextSibling()) {
            if (child.getNodeType() == Node.ELEMENT_NODE) {
                Element e = findElementById((Element) child, elementId);
                if (e != null) {
                    return e;
                }
            }
        }
        return null;
    }
}