org.onebusaway.webapp.gwt.viewkit.TabBarController.java Source code

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Here is the source code for org.onebusaway.webapp.gwt.viewkit.TabBarController.java

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/**
 * Copyright (C) 2011 Brian Ferris <bdferris@onebusaway.org>
 *
 * 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 org.onebusaway.webapp.gwt.viewkit;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.onebusaway.webapp.gwt.common.widgets.SpanWidget;
import org.onebusaway.webapp.gwt.viewkit.events.ViewControllerSelectedEvent;
import org.onebusaway.webapp.gwt.viewkit.events.ViewControllerSelectedHandler;
import org.onebusaway.webapp.gwt.viewkit.resources.ViewKitCssResource;
import org.onebusaway.webapp.gwt.viewkit.resources.ViewKitResources;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.Widget;

public class TabBarController extends ViewController {

    private static final ViewKitCssResource _css = ViewKitResources.INSTANCE.getCSS();

    private List<ViewController> _viewControllers = new ArrayList<ViewController>();

    private Grid _panel = new Grid(2, 1);

    private HorizontalPanel _tabPanel = new HorizontalPanel();

    private int _selectedIndex = -1;

    private Widget _selectedView = null;

    private boolean _visible = false;

    private HandlerManager _handlerManager;

    public void addVieControllerSelectedHandler(ViewControllerSelectedHandler handler) {
        ensureHandlers().addHandler(ViewControllerSelectedEvent.TYPE, handler);
    }

    public void addViewController(ViewController viewController) {

        // Does this really make sense?
        viewController.setNavigationController(getNavigationController());

        _viewControllers.add(viewController);
        addTabForViewController(viewController, _viewControllers.size() - 1);
        if (_selectedIndex == -1)
            setSelectedIndex(_viewControllers.size() - 1);
    }

    public List<ViewController> getViewControllers() {
        return Collections.unmodifiableList(_viewControllers);
    }

    public boolean hasSelectedViewController() {
        return _selectedIndex != -1;
    }

    public ViewController getSelectedViewController() {
        if (!hasSelectedViewController())
            return null;
        return _viewControllers.get(_selectedIndex);
    }

    public void setSelectedViewController(ViewController controller) {
        int index = _viewControllers.indexOf(controller);
        if (index != -1)
            setSelectedIndex(index);
    }

    public void setSelectedIndex(int index) {

        if (index == _selectedIndex)
            return;

        if (_selectedIndex != -1) {
            ViewController vc = _viewControllers.get(_selectedIndex);
            if (_visible)
                vc.viewWillDisappear();
            _panel.setText(0, 0, "");
            _selectedView.removeStyleName(_css.TabBarControllerContent());
            if (_visible)
                vc.viewDidDisappear();
        }

        ViewController viewController = _viewControllers.get(index);
        _selectedIndex = index;
        _selectedView = viewController.getView();

        if (_visible)
            viewController.viewWillAppear();

        _panel.setWidget(0, 0, _selectedView);
        _selectedView.addStyleName(_css.TabBarControllerContent());

        ensureHandlers().fireEvent(new ViewControllerSelectedEvent(viewController, _selectedIndex));

        if (_visible)
            viewController.viewDidAppear();

        fireContextChangedEvent();
    }

    /****
     * {@link ViewController} Methods
     ****/

    @Override
    public void viewWillAppear() {
        super.viewWillAppear();

        if (hasSelectedViewController())
            getSelectedViewController().viewWillAppear();
    }

    @Override
    public void viewDidAppear() {
        super.viewDidAppear();

        _visible = true;

        if (hasSelectedViewController())
            getSelectedViewController().viewDidAppear();
    }

    @Override
    public void viewWillDisappear() {
        super.viewWillDisappear();

        if (hasSelectedViewController())
            getSelectedViewController().viewWillDisappear();
    }

    @Override
    public void viewDidDisappear() {
        super.viewDidDisappear();

        _visible = false;

        if (hasSelectedViewController())
            getSelectedViewController().viewDidDisappear();
    }

    @Override
    protected void loadView() {
        super.loadView();

        _panel.addStyleName(_css.TabBarController());
        _tabPanel.addStyleName(_css.TabBar());

        _panel.setWidget(1, 0, _tabPanel);
        _panel.getCellFormatter().addStyleName(1, 0, _css.TabBarControllerTabBar());

        _view = _panel;
    }

    @Override
    public void setNavigationController(NavigationController controller) {

        super.setNavigationController(controller);

        for (ViewController views : _viewControllers)
            views.setNavigationController(controller);
    }

    @Override
    public void handleContext(List<String> path, Map<String, String> context) {

        if (path.isEmpty())
            return;

        String itemId = path.remove(0);

        for (ViewController viewController : _viewControllers) {
            NavigationItem navItem = viewController.getNavigationItem();
            if (itemId.equals(navItem.getId())) {
                setSelectedViewController(viewController);
                viewController.handleContext(path, context);
                break;
            }
        }
    }

    @Override
    public void retrieveContext(List<String> path, Map<String, String> context) {
        if (_selectedIndex != -1) {
            ViewController vc = _viewControllers.get(_selectedIndex);
            NavigationItem item = vc.getNavigationItem();
            path.add(item.getId());
            vc.retrieveContext(path, context);
        }
    }

    /****
     * Private Methods
     ****/

    private void addTabForViewController(ViewController viewController, final int index) {

        TabBarItem tabBarItem = viewController.getTabBarItem();

        ClickableFlowPanel tab = new ClickableFlowPanel();
        tab.addStyleName(_css.TabBarItem());

        FlowPanel imagePart = new FlowPanel();
        tab.add(imagePart);

        Image image = tabBarItem.getImage();
        if (image != null) {
            imagePart.add(image);
        } else {
            imagePart.addStyleName(_css.TabBarItemNoImage());
        }

        FlowPanel namePart = new FlowPanel();
        tab.add(namePart);

        String name = tabBarItem.getName();
        if (name != null) {
            namePart.add(new SpanWidget(name));
        } else {
            namePart.addStyleName(_css.TabBarItemNoName());
        }

        tab.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent arg0) {
                setSelectedIndex(index);
            }
        });

        _tabPanel.add(tab);
    }

    private HandlerManager ensureHandlers() {
        return _handlerManager == null ? _handlerManager = new HandlerManager(this) : _handlerManager;
    }
}