// ========================================================================// $Id: Element.java,v 1.10 2005/08/13 00:01:23 gregwilkins Exp $// Copyright 1996-2004 Mort Bay Consulting Pty. Ltd.// ------------------------------------------------------------------------// 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.mortbay.html;import java.io.IOException;import java.io.OutputStream;import java.io.OutputStreamWriter;import java.io.StringWriter;import java.io.Writer;import java.util.Enumeration;import java.util.Hashtable;import org.mortbay.log.Log;/* -------------------------------------------------------------------- *//** HTML Element. * <p>This abstract class is the base for all HTML Elements. * The feature of an abstract HTML Element is that it can be added to * HTML Pages, HTML Composites and several other HTML Elements derivations. * Elements may also have attributes set, which are handled by the derived * Element. * @deprecated Unless somebody steps forward to update and maintain this package * @see Page * @see Composite * @version $Id: Element.java,v 1.10 2005/08/13 00:01:23 gregwilkins Exp $ * @author Greg Wilkins*/public abstract class Element{    /* ----------------------------------------------------------------- */    public static final String        noAttributes="",        ALIGN="align",        LEFT="left",        RIGHT="right",        CENTER="center",        VALIGN="valign",        TOP="top",        BOTTOM="bottom",        MIDDLE="middle",        WIDTH="width",        HEIGHT="height",        SIZE="size",        COLOR="color",        BGCOLOR="bgcolor",        STYLE="style",        CLASS="class",        ID="id";                    /* ----------------------------------------------------------------- */    /** Dimensions >=0 if set*/    private int width=-1;    private int height=-1;    private int size=-1;    /* ----------------------------------------------------------------- */    /** The space separated string of HTML element attributes.     */    private String attributes=null;    protected Hashtable attributeMap=null;    /* ----------------------------------------------------------------- */    /** Default constructor.     */    public Element(){}    /* ----------------------------------------------------------------- */    /** Construct with attributes.     * @param attributes The initial attributes of the element     */    public Element(String attributes)    {        attribute(attributes);    }    /* ----------------------------------------------------------------- */    /** Write element to a Writer.     * This abstract method is called by the Page or other containing     * Element to write the HTML for this element. This must be implemented     * by the derived Element classes.     * @param out Writer to write the element to.     */    public abstract void write(Writer out)         throws IOException;    /* ----------------------------------------------------------------- */    /** Write Element to an OutputStream.     * Calls print(Writer) and checks errors     * Elements that override this method should also override     * write(Writer) to avoid infinite recursion.     * @param out OutputStream to write the element to.     */    public void write(OutputStream out)         throws IOException    {        Writer writer = new OutputStreamWriter(out);        write(writer);        writer.flush();    }        /* ----------------------------------------------------------------- */    /** Write Element to an OutputStream.     * Calls print(Writer) and checks errors     * Elements that override this method should also override     * write(Writer) to avoid infinite recursion.     * @param out OutputStream to write the element to.     */    public void write(OutputStream out, String encoding)         throws IOException    {        Writer writer = new OutputStreamWriter(out,encoding);        write(writer);        writer.flush();    }    /* ----------------------------------------------------------------- */    public String attributes()    {        if (attributes==null && attributeMap==null)            return noAttributes;        StringBuffer buf = new StringBuffer(128);        synchronized(buf)        {            if (attributeMap!=null)            {                Enumeration e = attributeMap.keys();                while (e.hasMoreElements())                {                    buf.append(' ');                    String a = (String)e.nextElement();                    buf.append(a);                    buf.append('=');                    buf.append(attributeMap.get(a).toString());                }            }                        if(attributes!=null && attributes.length()>0)            {                if (!attributes.startsWith(" "))                    buf.append(' ');                buf.append(attributes);            }        }        return buf.toString();    }    /* ----------------------------------------------------------------- */    /** Add element Attributes.     * The attributes are added to the Element attributes (separated with     * a space). The attributes are available to the derived class in the     * protected member String <I>attributes</I>     * @deprecated Use attribute(String).     * @param attributes String of HTML attributes to add to the element.     * @return This Element so calls can be chained.     */    public Element attributes(String attributes)    {        if (attributes==null)        {            this.attributes=null;            return this;        }                if (attributes==noAttributes)            return this;                if (this.attributes==null)            this.attributes=attributes;        else            this.attributes += ' '+attributes;        return this;    }    /* ------------------------------------------------------------ */    /** Set attributes from another Element.     * @param e Element     * @return This Element     */    public Element setAttributesFrom(Element e)    {        attributes=e.attributes;        attributeMap=(Hashtable)e.attributeMap.clone();        return this;    }        /* ----------------------------------------------------------------- */    /** Add element Attributes.     * The attributes are added to the Element attributes (separated with     * a space). The attributes are available to the derived class in the     * protected member String <I>attributes</I>     * @param attributes String of HTML attributes to add to the element.     * A null attribute clears the current attributes.     * @return This Element so calls can be chained.     */    public Element attribute(String attributes)    {        if (attributes==null ||            this.attributes==null ||            this.attributes==noAttributes ||            this.attributes.length()==0)            this.attributes=attributes;        else            this.attributes += ' '+attributes;        return this;    }        /* ----------------------------------------------------------------- */    /** Add quoted element Attributes and value.     * @param attribute String of HTML attribute tag     * @param value String value of the attribute to be quoted     * @return This Element so calls can be chained.     */    public Element attribute(String attribute, Object value)    {        if (attributeMap==null)            attributeMap=new Hashtable(10);                if (value!=null)        {            if (value instanceof String && ((String)value).indexOf('"')!=-1)            {                String s=(String)value;                int q=0;                while((q=s.indexOf('"',q))>=0)                {                    s=s.substring(0,q)+"&quot;"+s.substring(++q);                    q+=6;                }                value=s;            }                        attributeMap.put(attribute,"\""+value+'"');        }        return this;    }        /* ----------------------------------------------------------------- */    /** Add quoted element Attributes and value.     * @param attribute String of HTML attribute tag     * @param value String value of the attribute to be quoted     * @return This Element so calls can be chained.     */    public Element attribute(String attribute, long value)    {        if (attributeMap==null)            attributeMap=new Hashtable(10);                attributeMap.put(attribute,Long.toString(value));        return this;    }    /* ----------------------------------------------------------------- */    /** Convert Element to String.     * Uses write() to convert the HTML Element to a string.     * @return String of the HTML element     */    public String toString()    {        try{            StringWriter out = new StringWriter();            write(out);            out.flush();            return out.toString();        }        catch(IOException e){            Log.ignore(e);        }        return null;        }        /* ----------------------------------------------------------------- */    /** left justify.     * Convenience method equivalent to attribute("align","left"). Not     * applicable to all Elements.     */    public Element left()    {        return attribute(ALIGN,LEFT);    }        /* ----------------------------------------------------------------- */    /** right justify.     * Convenience method equivalent to attribute("align","right"). Not     * applicable to all Elements.     */    public Element right()    {        return attribute(ALIGN,RIGHT);    }        /* ----------------------------------------------------------------- */    /** Center.     * Convenience method equivalent to attribute("align","center"). Not     * applicable to all Elements.     */    public Element center()    {        return attribute(ALIGN,CENTER);    }        /* ----------------------------------------------------------------- */    /** Top align.     * Convenience method equivalent to attribute("valign","top"). Not     * applicable to all Elements.     */    public Element top()    {        return attribute(VALIGN,TOP);    }        /* ----------------------------------------------------------------- */    /** Bottom align.     * Convenience method equivalent to attribute("valign","bottom"). Not     * applicable to all Elements.     */    public Element bottom()    {        return attribute(VALIGN,BOTTOM);    }        /* ----------------------------------------------------------------- */    /** Middle align.     * Convenience method equivalent to attribute("valign","middle"). Not     * applicable to all Elements.     */    public Element middle()    {        return attribute(VALIGN,MIDDLE);    }        /* ----------------------------------------------------------------- */    /** set width.     * Convenience method equivalent to attribute("width",w). Not     * applicable to all Elements.     */    public Element width(int w)    {        width=w;        return attribute(WIDTH,w);    }        /* ----------------------------------------------------------------- */    /** set width.     * Convenience method equivalent to attribute("width",w). Not     * applicable to all Elements.     */    public Element width(String w)    {        width=-1;        return attribute(WIDTH,w);    }        /* ----------------------------------------------------------------- */    public int width()    {        return width;    }        /* ----------------------------------------------------------------- */    /** set height.     * Convenience method equivalent to attribute("height",h). Not     * applicable to all Elements.     */    public Element height(int h)    {        height=h;        return attribute(HEIGHT,h);    }        /* ----------------------------------------------------------------- */    /** set height.     * Convenience method equivalent to attribute("height",h). Not     * applicable to all Elements.     */    public Element height(String h)    {        height=-1;        return attribute(HEIGHT,h);    }        /* ----------------------------------------------------------------- */    public int height()    {        return height;    }        /* ----------------------------------------------------------------- */    /** set size.     * Convenience method equivalent to attribute("size",s). Not     * applicable to all Elements.     */    public Element size(int s)    {        size=s;        return attribute(SIZE,s);    }        /* ----------------------------------------------------------------- */    /** set size.     * Convenience method equivalent to attribute("size",s). Not     * applicable to all Elements.     */    public Element size(String s)    {        size=-1;        return attribute(SIZE,s);    }        /* ----------------------------------------------------------------- */    public int size()    {        return size;    }        /* ----------------------------------------------------------------- */    /** set color.     * Convenience method equivalent to attribute("color",color). Not     * applicable to all Elements.     */    public Element color(String color)    {        return attribute(COLOR,color);    }        /* ----------------------------------------------------------------- */    /** set BGCOLOR.     * Convenience method equivalent to attribute("bgcolor",color). Not     * applicable to all Elements.     */    public Element bgColor(String color)    {        return attribute(BGCOLOR,color);    }        /* ----------------------------------------------------------------- */    /** set CSS CLASS.     */    public Element cssClass(String c)    {        return attribute(CLASS,c);    }        /* ----------------------------------------------------------------- */    /** set CSS ID.     * Convenience method equivalent to attribute("id",id).     */    public Element cssID(String id)    {        return attribute(ID,id);    }        /* ----------------------------------------------------------------- */    /** set Style.     * Convenience method equivalent to attribute("style",style).     */    public Element style(String style)    {        return attribute(STYLE,style);    }}