com.pietschy.gwt.pectin.demo.client.SimpleHistoryTabs.java Source code

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Here is the source code for com.pietschy.gwt.pectin.demo.client.SimpleHistoryTabs.java

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/*
 * Copyright 2009 Andrew Pietsch
 *
 * 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.pietschy.gwt.pectin.demo.client;

import com.google.gwt.event.logical.shared.SelectionEvent;
import com.google.gwt.event.logical.shared.SelectionHandler;
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.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.TabPanel;
import com.google.gwt.user.client.ui.Widget;

import java.util.HashMap;
import java.util.Map;

/**
 * Created by IntelliJ IDEA.
 * User: andrew
 * Date: Oct 28, 2009
 * Time: 12:59:14 PM
 * To change this template use File | Settings | File Templates.
 */
public class SimpleHistoryTabs extends Composite {
    private TabPanel tabs = new TabPanel();
    private Map<Integer, String> historyTokens = new HashMap<Integer, String>();
    private Map<String, Integer> historyLookup = new HashMap<String, Integer>();
    private TabSelectionHandler tabSelectionHandler = new TabSelectionHandler();

    public SimpleHistoryTabs() {
        initWidget(tabs);

        tabs.addSelectionHandler(tabSelectionHandler);

        History.addValueChangeHandler(new ValueChangeHandler<String>() {
            public void onValueChange(ValueChangeEvent<String> event) {
                selectTabFromToken(event.getValue());
            }
        });
    }

    public void add(Widget widget, String tabText, String historyToken) {
        tabs.add(widget, tabText);
        int index = tabs.getWidgetIndex(widget);
        historyLookup.put(historyToken, index);
        historyTokens.put(index, historyToken);
    }

    public void initialiseSelectionFromHistory() {
        selectTabFromToken(History.getToken());
    }

    public void selectTab(int index) {
        tabs.selectTab(index);
    }

    private void selectTabFromToken(String token) {
        try {
            tabSelectionHandler.setIgnoreEvents(true);
            Integer index = historyLookup.get(token);
            selectTab(index != null ? index : 0);
        } finally {
            tabSelectionHandler.setIgnoreEvents(false);
        }
    }

    private class TabSelectionHandler implements SelectionHandler<Integer> {
        private boolean ignoreEvents = false;

        public void onSelection(SelectionEvent<Integer> event) {
            if (!isIgnoreEvents()) {
                Integer index = event.getSelectedItem();
                History.newItem(historyTokens.get(index), false);
            }
        }

        public boolean isIgnoreEvents() {
            return ignoreEvents;
        }

        public void setIgnoreEvents(boolean ignoreEvents) {
            this.ignoreEvents = ignoreEvents;
        }
    }
}