name.martingeisse.admin.navigation.component.NavigationMenuView.java Source code

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Here is the source code for name.martingeisse.admin.navigation.component.NavigationMenuView.java

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/**
 * Copyright (c) 2011 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.admin.navigation.component;

import java.util.List;

import name.martingeisse.admin.navigation.NavigationNode;
import name.martingeisse.admin.navigation.NavigationUtil;

import org.apache.commons.lang3.StringUtils;
import org.apache.wicket.behavior.AttributeAppender;
import org.apache.wicket.markup.html.basic.Label;
import org.apache.wicket.markup.html.link.AbstractLink;
import org.apache.wicket.markup.html.list.ListItem;
import org.apache.wicket.markup.html.list.ListView;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.PropertyModel;

/**
 * This component uses a list model of element type {@link NavigationNode}
 * and shows links for all nodes. It does not have its own markup
 * but is attached to a container element in the markup of outer components.
 * 
 * This component expects two nested component elements inside its markup; the
 * outer one should be a link with the wicket:id="link", and the inner
 * one a span or div with the wicket:id="title". A link and a label are
 * attached to these, respectively, and the markup is repeated for each node.
 * 
 * This class has a maximum nesting depth that determines how many node
 * sub-levels are shown. Each sub-level of each node is recursively handled
 * by an instance of this class. The maximum nesting depth should correspond
 * to the nesting depth of the component tags in the markup. The default
 * value is 0 (only the list from the model is shown, no sub-levels).
 * If the value is greater than 0 then the sub-list-view is attached to a
 * component tag with the wicket:id="children" within the item (but outside
 * the link).
 */
public final class NavigationMenuView extends ListView<NavigationNode> {

    /**
     * the maximumNestingDepth
     */
    private final int maximumNestingDepth;

    /**
     * the currentPagePath
     */
    private transient String currentPagePath;

    /**
     * Constructor.
     * @param id the wicket id
     * @param maximumNestingDepth the maximum nesting depth
     */
    public NavigationMenuView(final String id, final int maximumNestingDepth) {
        super(id);
        this.maximumNestingDepth = maximumNestingDepth;
    }

    /**
     * Constructor.
     * @param id the wicket id
     * @param model the model
     * @param maximumNestingDepth the maximum nesting depth
     */
    public NavigationMenuView(final String id, final IModel<List<NavigationNode>> model,
            final int maximumNestingDepth) {
        super(id, model);
        this.maximumNestingDepth = maximumNestingDepth;
    }

    /* (non-Javadoc)
     * @see org.apache.wicket.markup.repeater.AbstractRepeater#onBeforeRender()
     */
    @Override
    protected void onBeforeRender() {
        currentPagePath = StringUtils.defaultString(NavigationUtil.getNavigationPathForPage(getPage()));
        super.onBeforeRender();
    }

    /* (non-Javadoc)
     * @see org.apache.wicket.markup.html.list.ListView#populateItem(org.apache.wicket.markup.html.list.ListItem)
     */
    @Override
    protected void populateItem(final ListItem<NavigationNode> item) {

        // create the node link
        final NavigationNode node = item.getModelObject();
        final AbstractLink link = node.createLink("link");
        link.add(new Label("title", node.getTitle()));
        item.add(link);

        // mark or disable the link based on the current location
        final String nodePath = node.getPath();
        if (nodePath.equals(currentPagePath)) {
            link.setEnabled(false);
        } else if (node.isEqualOrPlausibleAncestorOf(currentPagePath)) {
            link.add(new AttributeAppender("style", "color: red"));
        }

        // create sub-lists
        if (maximumNestingDepth > 0) {
            final IModel<List<NavigationNode>> childrenModel = new PropertyModel<List<NavigationNode>>(
                    item.getModel(), "children");
            item.add(new NavigationMenuView("children", childrenModel, maximumNestingDepth - 1));
        }

    }

}