com.google.gwt.sample.feedreader.client.Configuration.java Source code

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Here is the source code for com.google.gwt.sample.feedreader.client.Configuration.java

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/*
 * Copyright 2007 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.google.gwt.sample.feedreader.client;

import com.google.gwt.core.client.GWT;
import com.google.gwt.jsio.client.JSList;
import com.google.gwt.jsio.client.JSONWrapperException;
import com.google.gwt.jsio.client.JSWrapper;
import com.google.gwt.sample.feedreader.client.resources.Resources;
import com.google.gwt.user.client.Cookies;
import com.google.gwt.user.client.Window;

import java.util.Arrays;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

/**
 * Encapsulates the long-term state of the application.
 */
public class Configuration {
    /**
     * A JSON object that encapsulates the metadata for a feed.
     * 
     * @gwt.beanProperties
     */
    public abstract static class Feed implements JSWrapper {
        public abstract long getLastArticle();

        public abstract String getTitle();

        public abstract String getUrl();

        public abstract void setLastArticle(long time);

        public abstract void setTitle(String title);

        public abstract void setUrl(String url);

        public String toString() {
            return "{" + "\"url\":\"" + getUrl() + "\",\"title\":\"" + getTitle() + "\",\"lastArticle\":"
                    + getLastArticle() + "}";
        }
    }

    /**
     * The top-level JSON object that encapsulates the configuration of the
     * application.
     * 
     * @gwt.beanProperties
     */
    abstract static class Container implements JSWrapper {
        /**
         * @gwt.typeArgs <com.google.gwt.sample.feedreader.client.Configuration.Feed>
         * @return A live List of Feed objects
         */
        public abstract JSList getFeeds();

        public String toString() {
            StringBuffer toReturn = new StringBuffer("{\"feeds\":[");

            Iterator i = getFeeds().iterator();
            if (i.hasNext()) {
                toReturn.append(i.next().toString());
            }
            while (i.hasNext()) {
                toReturn.append(",").append(i.next().toString());
            }

            toReturn.append("]}");
            return toReturn.toString();
        }
    }

    private static final String COOKIE_NAME = "GwtFeedReader";

    /**
     * The one instance of the JSON configuration container.
     */
    private final Container container = (Container) GWT.create(Container.class);

    public Configuration() {
        String cookieData = Cookies.getCookie(COOKIE_NAME);
        if (cookieData != null) {
            try {
                container.setJSONData(cookieData);
            } catch (JSONWrapperException e) {
                // Probably could not parse the json data, revert to builtins
                initialize();
            }
        } else {
            initialize();
        }
    }

    /**
     * Retrieve the metadata associated with a particular feed URL.
     */
    public Feed findFeed(String url) {
        for (Iterator i = getFeeds().iterator(); i.hasNext();) {
            Feed feed = (Feed) i.next();
            if (feed.getUrl().equals(url)) {
                return feed;
            }
        }

        return null;
    }

    /**
     * Returns the live list of Feed metadata objects. Modifications to this
     * object will be reflected throughout the application.
     */
    public List getFeeds() {
        return container.getFeeds();
    }

    /**
     * Add a pipe-delimited set of feed URLs to the configuration.
     * 
     * @return <code>true</code> iff at least one new feed was added.
     */
    public boolean importFeeds(String token) {
        Set toAdd = new HashSet(Arrays.asList(token.split("\\|")));
        List feeds = getFeeds();
        Feed toReturn = null;

        out: for (Iterator i = toAdd.iterator(); i.hasNext();) {
            String url = (String) i.next();
            for (Iterator j = feeds.iterator(); j.hasNext();) {
                Feed feed = (Feed) j.next();
                if (feed.getUrl().equals(url)) {
                    i.remove();
                    if (toReturn == null) {
                        toReturn = feed;
                    }
                    continue out;
                }
            }
        }

        if (toAdd.size() == 0) {
            return false;
        }

        boolean ok = Window.confirm("Do you wish to import " + toAdd.size() + " feeds?");

        if (ok) {
            for (Iterator i = toAdd.iterator(); i.hasNext();) {
                String url = (String) i.next();
                Feed f = (Feed) GWT.create(Feed.class);

                f.setUrl(url);
                f.setTitle(url);
                f.setLastArticle(0);

                if (toReturn == null) {
                    toReturn = f;
                }
                feeds.add(f);
            }
        }

        save();

        return true;
    }

    /**
     * Delete the application's configuration.
     */
    public void reset() {
        Cookies.removeCookie(COOKIE_NAME);
        getFeeds().clear();
        initialize();
    }

    /**
     * Save the configuration into the application's cookie.
     */
    public void save() {
        Cookies.setCookie(COOKIE_NAME, container.toString(),
                new Date(System.currentTimeMillis() + 1000L * 60 * 60 * 24 * 365), null, null, false);

        System.out.println(Cookies.getCookie(COOKIE_NAME));
    }

    /**
     * This method would not be strictly necessary with some server-side support.
     */
    private void initialize() {
        JSList feeds = container.getFeeds();

        String[] defaultFeeds = Resources.INSTANCE.defaultFeeds().getText().split("\n");

        for (int i = 0; i < defaultFeeds.length; i++) {
            String url = defaultFeeds[i];
            if (url.startsWith("#")) {
                continue;
            }

            Feed f = (Feed) GWT.create(Feed.class);

            f.setUrl(url);
            f.setTitle(url);
            f.setLastArticle(0);

            feeds.add(f);
        }

        save();
    }
}