# ReportPage.java

    /*******************************************************************************
     * Copyright (c) 2009, 2013 Mountainminds GmbH & Co. KG and Contributors
     * All rights reserved. This program and the accompanying materials
     * are made available under the terms of the Eclipse Public License v1.0
     * which accompanies this distribution, and is available at
     * http://www.eclipse.org/legal/epl-v10.html
     *
     * Contributors:
     *    Marc R. Hoffmann - initial API and implementation
     *
     *******************************************************************************/
    package org.jacoco.report.internal.html.page;

    import java.io.IOException;

    import org.jacoco.core.JaCoCo;
    import org.jacoco.report.internal.ReportOutputFolder;
    import org.jacoco.report.internal.html.HTMLDocument;
    import org.jacoco.report.internal.html.HTMLElement;
    import org.jacoco.report.internal.html.IHTMLReportContext;
    import org.jacoco.report.internal.html.ILinkable;
    import org.jacoco.report.internal.html.resources.Resources;
    import org.jacoco.report.internal.html.resources.Styles;

    /**
     * Base class for HTML page generators. It renders the page skeleton with the
     * breadcrumb, the title and the footer. Every report page is part of a
     * hierarchy and has a parent page (except the root page).
     */
    public abstract class ReportPage implements ILinkable {

    	private final ReportPage parent;

    	/** output folder for this node */
    	protected final ReportOutputFolder folder;

    	/** context for this report */
    	protected final IHTMLReportContext context;

    	/**
    	 * Creates a new report page.
    	 *
    	 * @param parent
    	 *            optional hierarchical parent
    	 * @param folder
    	 *            base folder to create this report in
    	 * @param context
    	 *            settings context
    	 */
    	protected ReportPage(final ReportPage parent,
    			final ReportOutputFolder folder, final IHTMLReportContext context) {
    		this.parent = parent;
    		this.context = context;
    		this.folder = folder;
    	}

    	/**
    	 * Checks whether this is the root page of the report.
    	 *
    	 * @return <code>true</code> if this is the root page
    	 */
    	protected final boolean isRootPage() {
    		return parent == null;
    	}

    	/**
    	 * Renders this page's content and optionally additional pages. This method
    	 * must be called at most once.
    	 *
    	 * @throws IOException
    	 *             if the page can't be written
    	 */
    	public void render() throws IOException {
    		final HTMLDocument doc = new HTMLDocument(
    				folder.createFile(getFileName()), context.getOutputEncoding());
    		doc.attr("lang", context.getLocale().getLanguage());
    		head(doc.head());
    		body(doc.body());
    		doc.close();
    	}

    	/**
    	 * Creates the elements within the head element.
    	 *
    	 * @param head
    	 *            head tag of the page
    	 * @throws IOException
    	 *             in case of IO problems with the report writer
    	 */
    	protected void head(final HTMLElement head) throws IOException {
    		head.meta("Content-Type", "text/html;charset=UTF-8");
    		head.link("stylesheet",
    				context.getResources().getLink(folder, Resources.STYLESHEET),
    				"text/css");
    		head.link("shortcut icon",
    				context.getResources().getLink(folder, "report.gif"),
    				"image/gif");
    		head.title().text(getLinkLabel());
    	}

    	private void body(final HTMLElement body) throws IOException {
    		body.attr("onload", getOnload());
    		final HTMLElement navigation = body.div(Styles.BREADCRUMB);
    		navigation.attr("id", "breadcrumb");
    		infoLinks(navigation.span(Styles.RIGHT));
    		breadcrumb(navigation, folder);
    		body.h1().text(getLinkLabel());
    		content(body);
    		footer(body);
    	}

    	/**
    	 * Returns the onload handler for this page.
    	 *
    	 * @return handler or <code>null</code>
    	 */
    	protected String getOnload() {
    		return null;
    	}

    	private void infoLinks(final HTMLElement span) throws IOException {
    		span.a(context.getSessionsPage(), folder);
    	}

    	private void breadcrumb(final HTMLElement div, final ReportOutputFolder base)
    			throws IOException {
    		breadcrumbParent(parent, div, base);
    		div.span(getLinkStyle()).text(getLinkLabel());
    	}

    	private static void breadcrumbParent(final ReportPage page,
    			final HTMLElement div, final ReportOutputFolder base)
    			throws IOException {
    		if (page != null) {
    			breadcrumbParent(page.parent, div, base);
    			div.a(page, base);
    			div.text(" > ");
    		}
    	}

    	private void footer(final HTMLElement body) throws IOException {
    		final HTMLElement footer = body.div(Styles.FOOTER);
    		final HTMLElement versioninfo = footer.span(Styles.RIGHT);
    		versioninfo.text("Created with ");
    		versioninfo.a(JaCoCo.HOMEURL).text("JaCoCo");
    		versioninfo.text(" ").text(JaCoCo.VERSION);
    		footer.text(context.getFooterText());
    	}

    	/**
    	 * Specifies the local file name of this page.
    	 *
    	 * @return local file name
    	 */
    	protected abstract String getFileName();

    	/**
    	 * Creates the actual content of the page.
    	 *
    	 * @param body
    	 *            body tag of the page
    	 * @throws IOException
    	 *             in case of IO problems with the report writer
    	 */
    	protected abstract void content(final HTMLElement body) throws IOException;

    	// === ILinkable ===

    	public final String getLink(final ReportOutputFolder base) {
    		return folder.getLink(base, getFileName());
    	}

    }