/*
 * $Header: /cvsroot/eclipse-webwiz/com.muimi.webwiz/resource/struts/src/struts/org/apache/struts/taglib/html/ImgTag.java,v 1.1 2004/06/14 02:24:11 muimy Exp $
 * $Revision: 1.1 $
 * $Date: 2004/06/14 02:24:11 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.struts.taglib.html;

import java.util.Iterator;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspException;

import org.apache.struts.Globals;
import org.apache.struts.config.ModuleConfig;
import org.apache.struts.util.MessageResources;
import org.apache.struts.util.RequestUtils;
import org.apache.struts.util.ResponseUtils;

/**
 * Generate an IMG tag to the specified image URI.
 * <p>
 * TODO:
 * <ul>
 *   <li>Make the <strong>alt</strong>, <strong>src</strong>, and
 *       <strong>lowsrc</strong> settable from properties (for i18n)</li>
 * </ul>
 *
 * @author Michael Westbay
 * @author Craig McClanahan
 * @version $Revision: 1.1 $
 */

public class ImgTag extends BaseHandlerTag {

    // ------------------------------------------------------------- Properties

    /**
     * The property to specify where to align the image.
     */
    protected String align = null;

    public String getAlign() {
        return (this.align);
    }

    public void setAlign(String align) {
        this.align = align;
    }

    /**
     * The border size around the image.
     */
    protected String border = null;

    public String getBorder() {
        return (this.border);
    }

    public void setBorder(String border) {
        this.border = border;
    }

    /**
     * The image height.
     */
    protected String height = null;

    public String getHeight() {
        return (this.height);
    }

    public void setHeight(String height) {
        this.height = height;
    }

    /**
     * The horizontal spacing around the image.
     */
    protected String hspace = null;

    public String getHspace() {
        return (this.hspace);
    }

    public void setHspace(String hspace) {
        this.hspace = hspace;
    }

    /**
     * The image name for named images.
     */
    protected String imageName = null;

    public String getImageName() {
        return (this.imageName);
    }

    public void setImageName(String imageName) {
        this.imageName = imageName;
    }

    /**
     * Server-side image map declaration.
     */
    protected String ismap = null;

    public String getIsmap() {
        return (this.ismap);
    }

    public void setIsmap(String ismap) {
        this.ismap = ismap;
    }

    /**
     * The low resolution image source URI.
     * @deprecated This is not defined in the HTML 4.01 spec and will be removed in a
     * future version of Struts.
     */
    protected String lowsrc = null;

    /**
     * @deprecated This is not defined in the HTML 4.01 spec and will be removed in a
     * future version of Struts.
     */
    public String getLowsrc() {
        return (this.lowsrc);
    }

    public void setLowsrc(String lowsrc) {
        this.lowsrc = lowsrc;
    }

    /**
     * The message resources for this package.
     */
    protected static MessageResources messages =
        MessageResources.getMessageResources(Constants.Package + ".LocalStrings");

    /**
     * The JSP bean name for query parameters.
     */
    protected String name = null;

    public String getName() {
        return (this.name);
    }

    public void setName(String name) {
        this.name = name;
    }

    /**
     * The module-relative path, starting with a slash character, of the
     * image to be displayed by this rendered tag.
     */
    protected String page = null;

    public String getPage() {
        return (this.page);
    }

    public void setPage(String page) {
        this.page = page;
    }

    /**
     * The message resources key under which we should look up the
     * <code>page</code> attribute for this generated tag, if any.
     */
    protected String pageKey = null;

    public String getPageKey() {
        return (this.pageKey);
    }

    public void setPageKey(String pageKey) {
        this.pageKey = pageKey;
    }

    /**
     * In situations where an image is dynamically generated (such as to create
     * a chart graph), this specifies the single-parameter request parameter
     * name to generate.
     */
    protected String paramId = null;

    public String getParamId() {
        return (this.paramId);
    }

    public void setParamId(String paramId) {
        this.paramId = paramId;
    }

    /**
     * The single-parameter JSP bean name.
     */
    protected String paramName = null;

    public String getParamName() {
        return (this.paramName);
    }

    public void setParamName(String paramName) {
        this.paramName = paramName;
    }

    /**
     * The single-parameter JSP bean property.
     */
    protected String paramProperty = null;

    public String getParamProperty() {
        return (this.paramProperty);
    }

    public void setParamProperty(String paramProperty) {
        this.paramProperty = paramProperty;
    }

    /**
     * The single-parameter JSP bean scope.
     */
    protected String paramScope = null;

    public String getParamScope() {
        return (this.paramScope);
    }

    public void setParamScope(String paramScope) {
        this.paramScope = paramScope;
    }

    /**
     * The JSP bean property name for query parameters.
     */
    protected String property = null;

    public String getProperty() {
        return (this.property);
    }

    public void setProperty(String property) {
        this.property = property;
    }

    /**
     * The scope of the bean specified by the name property, if any.
     */
    protected String scope = null;

    public String getScope() {
        return (this.scope);
    }

    public void setScope(String scope) {
        this.scope = scope;
    }

    /**
     * The image source URI.
     */
    protected String src = null;

    public String getSrc() {
        return (this.src);
    }

    public void setSrc(String src) {
        this.src = src;
    }

    /**
     * The message resources key under which we should look up the
     * <code>src</code> attribute for this generated tag, if any.
     */
    protected String srcKey = null;

    public String getSrcKey() {
        return (this.srcKey);
    }

    public void setSrcKey(String srcKey) {
        this.srcKey = srcKey;
    }

    /**
     * Client-side image map declaration.
     */
    protected String usemap = null;

    public String getUsemap() {
        return (this.usemap);
    }

    public void setUsemap(String usemap) {
        this.usemap = usemap;
    }

    /**
     * The vertical spacing around the image.
     */
    protected String vspace = null;

    public String getVspace() {
        return (this.vspace);
    }

    public void setVspace(String vspace) {
        this.vspace = vspace;
    }

    /**
     * The image width.
     */
    protected String width = null;

    public String getWidth() {
        return (this.width);
    }

    public void setWidth(String width) {
        this.width = width;
    }

    // --------------------------------------------------------- Public Methods

    /**
     * Render the beginning of the IMG tag.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {

        // Evaluate the body of this tag
        return (EVAL_BODY_TAG);

    }

    /**
     * Render the end of the IMG tag.
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doEndTag() throws JspException {

        // Generate the name definition or image element
        HttpServletResponse response = (HttpServletResponse) pageContext.getResponse();
        StringBuffer results = new StringBuffer("<img");
        String tmp = src();
        String srcurl = url(tmp);
        if (srcurl != null) {
            results.append(" src=\"");
            results.append(response.encodeURL(srcurl));
            results.append("\"");
        }
        String lowsrcurl = url(this.lowsrc);
        if (lowsrcurl != null) {
            results.append(" lowsrc=\"");
            results.append(response.encodeURL(lowsrcurl));
            results.append("\"");
        }
        if (imageName != null) {
            results.append(" name=\"");
            results.append(imageName);
            results.append("\"");
        }
        if (height != null) {
            results.append(" height=\"");
            results.append(height);
            results.append("\"");
        }
        if (width != null) {
            results.append(" width=\"");
            results.append(width);
            results.append("\"");
        }
        if (align != null) {
            results.append(" align=\"");
            results.append(align);
            results.append("\"");
        }
        if (border != null) {
            results.append(" border=\"");
            results.append(border);
            results.append("\"");
        }
        if (hspace != null) {
            results.append(" hspace=\"");
            results.append(hspace);
            results.append("\"");
        }
        if (vspace != null) {
            results.append(" vspace=\"");
            results.append(vspace);
            results.append("\"");
        }
        if (ismap != null) {
            results.append(" ismap=\"");
            results.append(ismap);
            results.append("\"");
        }
        if (usemap != null) {
            results.append(" usemap=\"");
            results.append(usemap);
            results.append("\"");
        }
        results.append(prepareStyles());
        results.append(prepareEventHandlers());
        results.append(getElementClose());

        // Print this element to our output writer
        ResponseUtils.write(pageContext, results.toString());

        // Evaluate the reaminder of this page
        return (EVAL_PAGE);

    }

    /**
     * Release any acquired resources.
     */
    public void release() {

        super.release();

        border = null;
        height = null;
        hspace = null;
        imageName = null;
        ismap = null;
        lowsrc = null;
        name = null;
        page = null;
        pageKey = null;
        paramId = null;
        paramName = null;
        paramProperty = null;
        paramScope = null;
        property = null;
        scope = null;
        src = null;
        srcKey = null;
        usemap = null;
        vspace = null;
        width = null;

    }

    // ------------------------------------------------------ Protected Methods

    /**
     * Return the base source URL that will be rendered in the <code>src</code>
     * property for this generated element, or <code>null</code> if there is
     * no such URL.
     *
     * @exception JspException if an error occurs
     */
    protected String src() throws JspException {

        // Deal with a direct context-relative page that has been specified
        if (this.page != null) {
            if ((this.src != null) || (this.srcKey != null) || (this.pageKey != null)) {
                JspException e = new JspException(messages.getMessage("imgTag.src"));
                RequestUtils.saveException(pageContext, e);
                throw e;
            }
            ModuleConfig config =
                (ModuleConfig) pageContext.getRequest().getAttribute(Globals.MODULE_KEY);
            HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
            if (config == null) {
                return (request.getContextPath() + this.page);
            } else {
                return (request.getContextPath() + config.getPrefix() + this.page);
            }
        }

        // Deal with an indirect context-relative page that has been specified
        if (this.pageKey != null) {
            if ((this.src != null) || (this.srcKey != null)) {
                JspException e = new JspException(messages.getMessage("imgTag.src"));
                RequestUtils.saveException(pageContext, e);
                throw e;
            }
            ModuleConfig config =
                (ModuleConfig) pageContext.getRequest().getAttribute(Globals.MODULE_KEY);
            HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
            if (config == null) {
                return (
                    request.getContextPath()
                        + RequestUtils.message(pageContext, getBundle(), getLocale(), this.pageKey));
            } else {
                return (
                    request.getContextPath()
                        + config.getPrefix()
                        + RequestUtils.message(pageContext, getBundle(), getLocale(), this.pageKey));
            }
        }

        // Deal with an absolute source that has been specified
        if (this.src != null) {
            if (this.srcKey != null) {
                JspException e = new JspException(messages.getMessage("imgTag.src"));
                RequestUtils.saveException(pageContext, e);
                throw e;
            }
            return (this.src);
        }

        // Deal with an indirect source that has been specified
        if (this.srcKey == null) {
            JspException e = new JspException(messages.getMessage("imgTag.src"));
            RequestUtils.saveException(pageContext, e);
            throw e;
        }
        return (RequestUtils.message(pageContext, getBundle(), getLocale(), this.srcKey));

    }

    /**
     * Return the specified src URL, modified as necessary with optional
     * request parameters.
     *
     * @param url The URL to be modified (or null if this url will not be used)
     *
     * @exception JspException if an error occurs preparing the URL
     */
    protected String url(String url) throws JspException {

        if (url == null) {
            return (url);
        }

        // Start with an unadorned URL as specified
        StringBuffer src = new StringBuffer(url);

        // Append a single-parameter name and value, if requested
        if ((paramId != null) && (paramName != null)) {
            if (src.toString().indexOf('?') < 0) {
                src.append('?');
            } else {
                src.append("&amp;");
            }
            src.append(paramId);
            src.append('=');
            Object value = RequestUtils.lookup(pageContext, paramName, paramProperty, paramScope);
            if (value != null)
                src.append(RequestUtils.encodeURL(value.toString()));
        }

        // Just return the URL if there is no bean to look up
        if ((property != null) && (name == null)) {
            JspException e = new JspException(messages.getMessage("getter.name"));
            RequestUtils.saveException(pageContext, e);
            throw e;
        }

        if (name == null) {
            return (src.toString());
        }

        // Look up the map we will be using
        Object mapObject = RequestUtils.lookup(pageContext, name, property, scope);
        Map map = null;
        try {
            map = (Map) mapObject;
        } catch (ClassCastException e) {
            RequestUtils.saveException(pageContext, e);
            throw new JspException(messages.getMessage("imgTag.type"));
        }

        // Append the required query parameters
        boolean question = (src.toString().indexOf("?") >= 0);
        Iterator keys = map.keySet().iterator();
        while (keys.hasNext()) {
            String key = (String) keys.next();
            Object value = map.get(key);
            if (value == null) {
                if (question) {
                    src.append("&amp;");
                } else {
                    src.append('?');
                    question = true;
                }
                src.append(key);
                src.append('=');
                // Interpret null as "no value specified"
            } else if (value instanceof String[]) {
                String values[] = (String[]) value;
                for (int i = 0; i < values.length; i++) {
                    if (question) {
                        src.append("&amp;");
                    } else {
                        src.append('?');
                        question = true;
                    }
                    src.append(key);
                    src.append('=');
                    src.append(RequestUtils.encodeURL(values[i]));
                }
            } else {

                if (question) {
                    src.append("&amp;");
                } else {
                    src.append('?');
                    question = true;
                }
                src.append(key);
                src.append('=');
                src.append(RequestUtils.encodeURL(value.toString()));
            }
        }

        // Return the final result
        return (src.toString());

    }

}
