com.seanchenxi.gwt.serenity.client.widget.NavigationBar.java Source code

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Here is the source code for com.seanchenxi.gwt.serenity.client.widget.NavigationBar.java

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/*******************************************************************************
 * Copyright 2012 Xi CHEN
 *
 * 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.seanchenxi.gwt.serenity.client.widget;

import java.util.ArrayList;

import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.HasKeyUpHandlers;
import com.google.gwt.event.dom.client.KeyUpEvent;
import com.google.gwt.event.dom.client.KeyUpHandler;
import com.google.gwt.event.logical.shared.HasSelectionHandlers;
import com.google.gwt.event.logical.shared.SelectionEvent;
import com.google.gwt.event.logical.shared.SelectionHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.CssResource;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;

public class NavigationBar extends Composite
        implements ClickHandler, HasSelectionHandlers<NavigationItem>, HasKeyUpHandlers {

    public interface Resources extends ClientBundle {

        public interface Style extends CssResource {
            final static String DEFAULT_CSS = "com/seanchenxi/gwt/serenity/client/resource/widget/NavigationBar.css";

            String navigationBar();
        }

        @ClientBundle.Source(Style.DEFAULT_CSS)
        Style style();
    }

    private static Resources resources;

    private FlowPanel panel;

    private ArrayList<NavigationItem> items;
    private NavigationItem selectedItem = null;

    public static Resources getResources() {
        if (resources == null) {
            resources = GWT.create(Resources.class);
            resources.style().ensureInjected();
        }
        return resources;
    }

    public NavigationBar() {
        items = new ArrayList<NavigationItem>();
        initWidget(panel = new FlowPanel());
        sinkEvents(Event.KEYEVENTS);
        setStyleName(getResources().style().navigationBar());
    }

    public void addItem(final NavigationItem item) {
        if (item == null) {
            return;
        }

        int oldIndex = panel.getWidgetIndex(item);
        if (oldIndex != -1) {
            panel.remove(oldIndex);
            items.remove(oldIndex);
        } else {
            item.addClickHandler(this);
        }

        int beforeIndex = panel.getWidgetCount();
        item.setNavigationBar(this);
        panel.add(item);
        items.add(beforeIndex, item);
    }

    public NavigationItem findItem(String itemId) {
        if (itemId == null)
            return null;
        for (NavigationItem item : items) {
            if (itemId.equalsIgnoreCase(item.getId())) {
                return item;
            }
        }
        return null;
    }

    public void clearSelection() {
        select(null);
    }

    public boolean select(NavigationItem item) {
        if (item == selectedItem) {
            return false;
        }
        if (item != null && item.getLabelBox() != null && item.getLabelBox().getSelectedLabel() == null) {
            return false;
        }
        if (selectedItem != null) {
            selectedItem.hideLabelBox(true);
            selectedItem.setSelectionStyle(false);
        }
        selectedItem = item;
        if (selectedItem != null) {
            selectedItem.setSelectionStyle(true);
        }
        return true;
    }

    @Override
    public HandlerRegistration addSelectionHandler(SelectionHandler<NavigationItem> handler) {
        return addHandler(handler, SelectionEvent.getType());
    }

    @Override
    public HandlerRegistration addKeyUpHandler(KeyUpHandler handler) {
        return addDomHandler(handler, KeyUpEvent.getType());
    }

    @Override
    public void onClick(ClickEvent event) {
        final Object o = event.getSource();
        Scheduler.get().scheduleDeferred(new ScheduledCommand() {
            @Override
            public void execute() {
                if (o instanceof NavigationItem) {
                    NavigationItem item = (NavigationItem) o;
                    if (item.getLabelBox() == null)
                        fireSelectionEvent(item);
                }
            }
        });
    }

    void fireSelectionEvent(NavigationItem item) {
        if (select(item)) {
            SelectionEvent.fire(NavigationBar.this, selectedItem);
        }
    }

}