001/*
002 * ModeShape (http://www.modeshape.org)
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *       http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.modeshape.web.client;
017
018import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
019import com.google.gwt.event.logical.shared.ValueChangeEvent;
020import com.google.gwt.event.logical.shared.ValueChangeHandler;
021import com.google.gwt.event.shared.GwtEvent;
022import com.google.gwt.event.shared.HandlerRegistration;
023import com.google.gwt.event.shared.SimpleEventBus;
024import com.google.gwt.place.shared.PlaceHistoryHandler.Historian;
025import com.google.gwt.user.client.History;
026
027/**
028 *
029 * @author kulikov
030 */
031public class HtmlHistory implements Historian,
032        // allows the use of ValueChangeEvent.fire()
033        HasValueChangeHandlers<String> {
034
035    private final SimpleEventBus handlers = new SimpleEventBus();
036    private String token;
037    
038    public HtmlHistory() {
039        initEvent();
040        this.token = History.getToken();
041    }
042
043    @Override
044    public HandlerRegistration addValueChangeHandler(ValueChangeHandler<String> valueChangeHandler) {
045        return this.handlers.addHandler(ValueChangeEvent.getType(), valueChangeHandler);
046    }
047
048    @Override
049    public String getToken() {
050        return token;
051    }
052
053    @Override
054    public void newItem(String token, boolean issueEvent) {
055        this.token = token;
056        pushState(token);
057    }
058
059    @Override
060    public void fireEvent(GwtEvent<?> event) {
061        this.handlers.fireEvent(event);
062    }
063
064    private native void initEvent() /*-{
065     var that = this;
066     var oldHandler = $wnd.onpopstate;
067     $wnd.onpopstate = $entry(function(e) {
068     var uri = $wnd.location
069     that.@org.modeshape.web.client.HtmlHistory::onPopState(Ljava/lang/String;)(uri);
070     if (oldHandler) {
071     oldHandler();
072     }
073     });
074     }-*/;
075
076    private void onPopState(String url) {
077        StringBuilder b = new StringBuilder();
078        b.append(url);
079        ValueChangeEvent.fire(this, b.toString());
080    }
081
082    private native void pushState(String url) /*-{
083     $wnd.history.pushState(null, $doc.title, url);
084     }-*/;
085}