com.gwtmobile.ui.client.page.BrowserPageHistory.java Source code

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Here is the source code for com.gwtmobile.ui.client.page.BrowserPageHistory.java

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/*
 * Copyright (c) 2011 Zhihua (Dennis) Jiang
 * 
 * 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.
 * 
 * Authors:
 *    Zhihua (Dennis) Jiang
 *    ash
 */

package com.gwtmobile.ui.client.page;

import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.user.client.History;
import com.gwtmobile.ui.client.utils.Utils;

/**
 * This is a web app oriented history navigation model. This navigation model
 * used the browser's forward/back/direct url reference scheme.
 * 
 * If your app needs to run as a web application as well as a native 
 * application then add a reference the following to your GWT module:
 *
 * <pre>
 * &lt;replace-with
 *     class="com.gwtmobile.ui.client.page.BrowserPageHistory"&gt;
 *         &lt;when-type-is
 *         class="com.gwtmobile.ui.client.page.SerialPageHistory" /&gt;
 * &lt;/replace-with&gt;
 * </pre>
 * 
 * @see PageHistory#navigateTo(String, String)
 * @see PageHistory.Mapper
 */
public class BrowserPageHistory extends SerialPageHistory implements ValueChangeHandler<String> {
    private Mapper _mapper;

    public BrowserPageHistory() {
        History.addValueChangeHandler(this);
    }

    @Override
    public void navigate(String token) {
        History.newItem(token, true);
    }

    @Override
    public void navigate(String pageName, String params) {
        String token = pageName + (params == null ? "" : ":" + params);
        navigate(token);
    }

    @Override
    public void goBack(Object returnValue) {
        History.back();
    }

    @Override
    public void setMapper(Mapper mapper) {
        _mapper = mapper;
    }

    @Override
    public void startUp(Page startUpPage) {
        String token = History.getToken();
        loadPage(token);
    }

    @Override
    public void onValueChange(ValueChangeEvent<String> event) {
        String token = event.getValue();
        loadPage(token);
    }

    protected void loadPage(String token) {
        final String[] tokenRef = parseParams(token);
        final Page page = _mapper.getPage(tokenRef[0]);
        if (page == null) // FIXME: Maybe throw an IllegalArgumentException?
            Utils.Console("No page registered for history token:" + token);
        else {
            page._tokenStateInfo = tokenRef[1];
            Page current = current();
            if (current == null) {
                Page.load(page);
                page.initNavigationIfRequired();
            } else
                current.goTo(page);
        }
    }

    private String[] parseParams(String token) {
        String[] ret = { token, null };
        int pos = token.indexOf(':');
        if (pos > -1) {
            ret[0] = token.substring(0, pos);
            ret[1] = token.substring(pos + 1);
        }
        return ret;
    }
}