org.openqa.jetty.html.Element Maven / Gradle / Ivy
// ========================================================================
// $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.openqa.jetty.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.apache.commons.logging.Log;
import org.openqa.jetty.log.LogFactory;
import org.openqa.jetty.util.LogSupport;
/* -------------------------------------------------------------------- */
/** HTML Element.
* 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.
* @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
{
private static Log log = LogFactory.getLog(Element.class);
/* ----------------------------------------------------------------- */
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 attributes
* @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 (log.isDebugEnabled() && attributes!=null && attributes.indexOf('=')>=0)
log.debug("Set attribute with old method: "+attributes+
" on " + getClass().getName());
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 attributes
* @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 (log.isDebugEnabled() && attributes!=null && attributes.indexOf('=')>=0)
log.warn("Set attribute with old method: "+attributes+
" on " + getClass().getName());
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)+"""+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){
LogSupport.ignore(log,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);
}
}