ch.sebastienzurfluh.swissmuseum.parcours.client.view.bookletnavigator.LoadOnDemandPageWidget.java Source code

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Here is the source code for ch.sebastienzurfluh.swissmuseum.parcours.client.view.bookletnavigator.LoadOnDemandPageWidget.java

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/*
 * Copyright 2012-2013 Sebastien Zurfluh
 * 
 * This file is part of "Parcours".
 * 
 * "Parcours" is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * "Parcours" is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with "Parcours".  If not, see <http://www.gnu.org/licenses/>.
 */

package ch.sebastienzurfluh.swissmuseum.parcours.client.view.bookletnavigator;

import java.util.LinkedList;

import ch.sebastienzurfluh.swissmuseum.core.client.control.eventbus.AbstractEvent;
import ch.sebastienzurfluh.swissmuseum.core.client.control.eventbus.AbstractEvent.EventType;
import ch.sebastienzurfluh.swissmuseum.core.client.control.eventbus.EventBus;
import ch.sebastienzurfluh.swissmuseum.core.client.control.eventbus.EventBusListener;
import ch.sebastienzurfluh.swissmuseum.core.client.model.Model;
import ch.sebastienzurfluh.swissmuseum.core.client.model.structure.MenuData;
import ch.sebastienzurfluh.swissmuseum.core.client.patterns.Observable;
import ch.sebastienzurfluh.swissmuseum.core.client.patterns.Observer;
import ch.sebastienzurfluh.swissmuseum.core.client.view.pagewidget.PageToken;
import ch.sebastienzurfluh.swissmuseum.core.client.view.pagewidget.TextParser;

import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.googlecode.mgwt.ui.client.widget.LayoutPanel;
import com.googlecode.mgwt.ui.client.widget.RoundPanel;
import com.googlecode.mgwt.ui.client.widget.ScrollPanel;

public class LoadOnDemandPageWidget extends LayoutPanel implements Observer, EventBusListener {
    private HTML title;
    private Label header;
    private FlowPanel content;
    private RoundPanel mainContainer;
    private ScrollPanel scrollPanel;
    private TextParser parser;
    private Model model;
    private MenuData menuData;
    private EventBus eventBus;

    private static String primaryStyleName = "pageWidget";
    private static String CLIENT_WINDOW_HEIGHT_PX = Window.getClientHeight() + "px";

    public LoadOnDemandPageWidget(MenuData menuData, EventBus pageChangeEventBus, Model model,
            TextParser textParser) {
        this.model = model;
        this.menuData = menuData;
        this.eventBus = pageChangeEventBus;
        this.parser = textParser;

        title = new HTML("");

        header = new Label("");

        content = new FlowPanel();

        mainContainer = new RoundPanel();
        mainContainer.add(title);
        mainContainer.add(header);
        mainContainer.add(content);

        scrollPanel = new ScrollPanel();
        scrollPanel.setScrollingEnabledX(false);
        scrollPanel.setWidget(mainContainer);

        title.setStyleName(primaryStyleName + "-title");
        header.setStyleName(primaryStyleName + "-header");
        content.setStyleName(primaryStyleName + "-content");
        mainContainer.setStyleName(primaryStyleName);

        add(scrollPanel);
        // Needed for the panel to show properly!
        setHeight(CLIENT_WINDOW_HEIGHT_PX);

        if (model.getCurrentPageData().getReference().equals(menuData.getReference()))
            load();
        else
            postponeLoad();
    }

    /** Defer theming until the widget is rendered **/
    @Override
    protected void onLoad() {
        super.onLoad();

    }

    /**
     * Load data from current page in memory (model).
     */
    public void load() {
        this.title.setHTML("<span class='" + primaryStyleName + "-spanTitle'>"
                + model.getCurrentPageData().getPageTitle() + "</span>");
        this.header.setText(" " + model.getCurrentPageData().getPageContentHeader());

        this.content.clear();
        LinkedList<PageToken> tokenisedContent = parser.parse(model.getCurrentPageData().getPageContentBody());
        for (PageToken pageToken : tokenisedContent) {
            if (pageToken.isResource()) {
                this.content.add(pageToken.getResourceWidget());
            } else if (pageToken.isText()) {
                this.content.add(new HTML(pageToken.getText()));
            }
        }

        // Needed for the panel to show properly!
        scrollPanel.refresh();
    }

    /**
     * Postpone the load until the data is available.
     */
    public void postponeLoad() {
        model.currentPageDataObservable.subscribeObserver(this);
    }

    @Override
    public void notifyObserver(Observable source) {
        if (model.getCurrentPageData().getReference().equals(menuData.getReference())) {
            load();

            // this is the main difference with the dynamic PageWidget.
            // the page will only load once.
            model.currentPageDataObservable.unsubscribeObserver(this);
        }
    }

    @Override
    public EventType getEventType() {
        return EventType.PAGE_MODIFIED_EVENT;
    }

    @Override
    public void notify(AbstractEvent e) {
        scrollPanel.refresh();
    }
}