Java tutorial
/* * Copyright 2010 kk-electronic a/s. * * This file is part of KKPortal. * * KKPortal is free software: you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * KKPortal is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with KKPortal. If not, see <http://www.gnu.org/licenses/>. * */ package com.kk_electronic.kkportal.core.activity; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import com.google.gwt.core.client.GWT; import com.google.gwt.event.logical.shared.ValueChangeEvent; import com.google.gwt.event.logical.shared.ValueChangeHandler; import com.google.gwt.event.shared.EventBus; import com.google.gwt.user.client.History; import com.google.gwt.user.client.ui.Anchor; import com.google.gwt.user.client.ui.Hyperlink; import com.google.inject.Inject; import com.google.inject.Singleton; import com.google.inject.name.Named; import com.kk_electronic.kkportal.core.event.LocationChangedEvent; /** * Class responsible for monitoring the History of the browser * and firing event when it happens. * * @author Rasmus Carlsen * @author Jes Andersen * */ @Singleton public class LocationManager implements ValueChangeHandler<String> { private final LocationInfo locationInfo; /** * @return the locationInfo */ public LocationInfo getLocationInfo() { return locationInfo; } private final EventBus eventBus; private final String defaultplace; private static final Map<String, String> tokenMap = new HashMap<String, String>(); private ArrayList<AbstractLink> linkList = new ArrayList<AbstractLink>(); @Inject public LocationManager(@Named("DefaultHistoryToken") String defaultplace, EventBus eventBus, LocationInfo locationInfo) { this.locationInfo = locationInfo; this.eventBus = eventBus; this.defaultplace = defaultplace; History.addValueChangeHandler(this); /* * If we do not have anything in the history stack go to the default * view TODO: Decide if we should redirect like here or just show it */ if ("".equals(History.getToken())) { goHome(); } else { /* * If we have a history token we fire the change event which handles * setup of the activity */ History.fireCurrentHistoryState(); } } public String getToken(String token) { return tokenMap.get(token); } public String addTokens(String partialLink) { tokenMap.entrySet(); return partialLink; } public void refreshLinks() { for (AbstractLink alink : linkList) { alink.updateLink(tokenMap); } } /** * This function is called when ever the history of the browser is changed. * * @see ValueChangeHandler#onValueChange(ValueChangeEvent) */ @Override public void onValueChange(ValueChangeEvent<String> event) { parseToken(event.getValue()); if (!tokenMap.containsKey(null)) { GWT.log("History Token has no location - returning to home page"); goHome(); } else { updateLocationInfo(); } } /** * Decode the map like described in {@link ActivityManager} * * If an invalid rawString is provided it returns to the home activity * * @param rawHistoryString * the anchor part of the current url * @return a map of parameters */ private void parseToken(String rawHistoryString) { tokenMap.clear(); String[] values = rawHistoryString.split(";"); for (String placestring : values) { String[] l = placestring.split("[=]", 2); if (l.length > 1) { assert (!tokenMap.containsKey(l[0])); tokenMap.put(l[0], l[1]); } else { assert (!tokenMap.containsKey(null)); tokenMap.put(null, l[0]); } } } /** * Return the application to the default home activity */ public void goHome() { History.newItem(defaultplace); } /** * Change location to the new place * * @param place * new location to go to */ public void go(String placename) { assert (placename != null && !placename.equals("")); History.newItem(placename); } /** * This one trims the place name a bit before using activitymap to lookup * the name. It is done to provide some nice looking urls. Everything after * $ or / is cut off * * @param tokens * a map if input tokens, where the null key is the main * navigation element * @return the class matching the token set */ private void updateLocationInfo() { assert (tokenMap.containsKey(null)); String location = tokenMap.get(null); String[] matches = location.split("[/$]", 2); // Reset Location Info and start filling in new information locationInfo.setActivity(matches[0]); locationInfo.setSubint(null); locationInfo.setSubpath(null); GWT.log("mainplace: " + matches[0]); if (matches.length > 1) { switch (location.charAt(matches[0].length())) { case '/': locationInfo.setSubpath(matches[1]); break; case '$': locationInfo.setSubint(Integer.valueOf(matches[1])); break; default: GWT.log("LocationManager:Problems with history token" + location); } } else { GWT.log("LocationManager:No Tab selected"); } eventBus.fireEvent(new LocationChangedEvent(locationInfo)); refreshLinks(); } public AbstractLink registerLink(Hyperlink link, String... values) { AbstractLink al = new AbstractHyperLink(link, generateMap(values)); linkList.add(al); return al; } public AbstractLink registerLink(Anchor link, String... values) { AbstractLink al = new AbstractAnchor(link, generateMap(values)); linkList.add(al); al.updateLink(tokenMap); return al; } private Map<String, String> generateMap(String[] values) { assert (values.length % 2 == 0); HashMap<String, String> map = new HashMap<String, String>(); for (int i = 0; i < values.length - 1; i = i + 2) { map.put(values[i], values[i + 1]); } return map; } public static String combineMaps(Map<String, String> baseValues, Map<String, String> tokenMap) { HashMap<String, String> tik = new HashMap<String, String>(); if (tokenMap != null) { tik.putAll(tokenMap); } if (baseValues != null) { tik.putAll(baseValues); } StringBuffer sb = new StringBuffer(); if (tik.containsKey(null)) { sb.append("#"); sb.append(tik.get(null)); } for (Entry<String, String> token : tik.entrySet()) { if (token.getKey() != null) { sb.append(";"); sb.append(token.getKey()); sb.append("="); sb.append(token.getValue()); } } return sb.toString(); } public interface AbstractLink { public void updateLink(Map<String, String> tokenMap); public void changeValues(String... baseValues); } private class AbstractHyperLink implements AbstractLink { private Hyperlink link; private Map<String, String> baseValues; /** * @param link * @param map */ public AbstractHyperLink(Hyperlink link, Map<String, String> map) { this.link = link; this.baseValues = map; } /* (non-Javadoc) * @see com.kk_electronic.kkportal.core.activity.LocationManager.AbstractLink#updateLink(java.util.Map) */ @Override public void updateLink(Map<String, String> tokenMap) { String linkText = LocationManager.combineMaps(tokenMap, baseValues); link.setTargetHistoryToken(linkText); } /* (non-Javadoc) * @see com.kk_electronic.kkportal.core.activity.LocationManager.AbstractLink#changeLink(java.util.Map) */ @Override public void changeValues(String... baseValues) { this.baseValues = generateMap(baseValues); } } private class AbstractAnchor implements AbstractLink { private final Anchor link; private Map<String, String> baseValues; /** * @param link * @param generateMap */ public AbstractAnchor(Anchor link, Map<String, String> generateMap) { this.link = link; this.baseValues = generateMap; } /* (non-Javadoc) * @see com.kk_electronic.kkportal.core.activity.LocationManager.AbstractLink#updateLink(java.util.Map) */ @Override public void updateLink(Map<String, String> tokenMap) { String linkText = LocationManager.combineMaps(tokenMap, baseValues); link.setHref(linkText); } /* (non-Javadoc) * @see com.kk_electronic.kkportal.core.activity.LocationManager.AbstractLink#changeLink(java.util.Map) */ @Override public void changeValues(String... baseValues) { this.baseValues = generateMap(baseValues); this.updateLink(LocationManager.tokenMap); } } }