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

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Here is the source code for org.onebusaway.webapp.gwt.viewkit.NavigationBar.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.List;

import org.onebusaway.webapp.gwt.viewkit.BarButtonItem.EBarButtonSystemItem;
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.resources.client.ImageResource;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.HasHorizontalAlignment;
import com.google.gwt.user.client.ui.HasVerticalAlignment;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.Widget;

public class NavigationBar {

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

    private Grid _panel;

    private List<NavigationItem> _items = new ArrayList<NavigationItem>();

    private NavigationController _controller;

    public NavigationBar(NavigationController controller) {
        _controller = controller;
    }

    public Widget getView() {

        if (_panel == null) {

            _panel = new Grid(1, 3);
            _panel.setCellPadding(0);
            _panel.setCellSpacing(0);

            _panel.addStyleName(_css.NavigationBar());
            _panel.getCellFormatter().addStyleName(0, 0, _css.NavigationBarLeftItem());
            _panel.getCellFormatter().setAlignment(0, 0, HasHorizontalAlignment.ALIGN_LEFT,
                    HasVerticalAlignment.ALIGN_MIDDLE);

            _panel.getCellFormatter().addStyleName(0, 1, _css.NavigationBarCenterItem());
            _panel.getCellFormatter().setAlignment(0, 1, HasHorizontalAlignment.ALIGN_CENTER,
                    HasVerticalAlignment.ALIGN_MIDDLE);

            _panel.getCellFormatter().addStyleName(0, 2, _css.NavigationBarRightItem());
            _panel.getCellFormatter().setAlignment(0, 2, HasHorizontalAlignment.ALIGN_RIGHT,
                    HasVerticalAlignment.ALIGN_MIDDLE);
        }

        return _panel;
    }

    public void pushNavigationItem(NavigationItem item) {
        _items.add(item);
        refresh();
    }

    public void popNavigationItem() {
        if (!_items.isEmpty()) {
            _items.remove(_items.size() - 1);
            refresh();
        }
    }

    public void popToRootNavigationItem() {
        while (_items.size() > 1)
            _items.remove(_items.size() - 1);
        refresh();
    }

    private void refresh() {

        getView();

        _panel.setText(0, 0, "");
        _panel.setText(0, 1, "");
        _panel.setText(0, 2, "");

        if (_items.isEmpty())
            return;

        NavigationItem item = _items.get(_items.size() - 1);

        String title = item.getTitle();
        if (title != null) {
            _panel.setText(0, 1, title);
        }

        if (item.getLeftBarButtonItem() != null) {
            addBarButtonItemToBar(item.getLeftBarButtonItem(), 0);
        } else {
            NavigationItem back = null;
            if (_items.size() > 1)
                back = _items.get(_items.size() - 2);

            if (back != null) {
                String backTitle = "Back";
                if (back.getTitle() != null)
                    backTitle = back.getTitle();

                Grid backButton = createBackButton(backTitle);

                backButton.addClickHandler(new ClickHandler() {
                    @Override
                    public void onClick(ClickEvent arg0) {
                        _controller.popViewController();
                    }
                });
                _panel.setWidget(0, 0, backButton);
            }
        }

        if (item.getRightBarButtonItem() != null)
            addBarButtonItemToBar(item.getRightBarButtonItem(), 2);
    }

    private void addBarButtonItemToBar(BarButtonItem item, int index) {
        Grid button = null;
        if (item.getSystemItem() != null)
            button = createButton(item.getSystemItem());
        else if (item.getTitle() != null)
            button = createButton(item.getTitle());
        if (button != null) {
            _panel.setWidget(0, index, button);
            if (item.getClickHandler() != null)
                button.addClickHandler(item.getClickHandler());
        }
    }

    private Grid createBackButton(String text) {
        Grid backPanel = new Grid(1, 3);
        backPanel.addStyleName(_css.NavigationBarButton());
        backPanel.getCellFormatter().addStyleName(0, 0, _css.NavigationBarButtonLeftArrow());
        backPanel.getCellFormatter().addStyleName(0, 1, _css.NavigationBarButtonCenter());
        backPanel.getCellFormatter().addStyleName(0, 2, _css.NavigationBarButtonRightRounded());
        backPanel.setText(0, 0, "");
        backPanel.setText(0, 1, text);
        backPanel.setText(0, 2, "");
        return backPanel;
    }

    private Grid createButton(String text) {
        Grid button = createButton();
        button.setText(0, 1, text);
        return button;
    }

    private Grid createButton(EBarButtonSystemItem systemItem) {
        ViewKitResources resources = ViewKitResources.INSTANCE;
        ImageResource r = null;
        switch (systemItem) {
        case CROSS_HAIRS:
            r = resources.BarButtonSystemCrossHairsImage();
            break;
        case REFRESH:
        default:
            r = resources.BarButtonSystemRefreshImage();
            break;
        }
        Image image = new Image(r.getURL(), r.getLeft(), r.getTop(), r.getWidth(), r.getHeight());
        Grid button = createButton();
        button.setWidget(0, 1, image);
        return button;
    }

    private Grid createButton() {
        Grid backPanel = new Grid(1, 3);
        backPanel.addStyleName(_css.NavigationBarButton());
        backPanel.getCellFormatter().addStyleName(0, 0, _css.NavigationBarButtonLeftRounded());
        backPanel.getCellFormatter().addStyleName(0, 1, _css.NavigationBarButtonCenter());
        backPanel.getCellFormatter().addStyleName(0, 2, _css.NavigationBarButtonRightRounded());
        backPanel.setText(0, 0, "");
        backPanel.setText(0, 2, "");
        return backPanel;
    }

}