package org.richfaces.taglib;
import java.io.Serializable;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.StringTokenizer;
import javax.el.ELContext;
import javax.el.ELException;
import javax.el.ValueExpression;
/**
* @author Kin-man Chung
* @version $Id: IteratedExpression.java,v 1.3 2005/12/08 01:20:43 kchung Exp $
*/
final class IteratedExpression {
private static final long serialVersionUID = 1L;
protected final ValueExpression orig;
protected final String delims;
private Object base;
private int index;
private Iterator iter;
public IteratedExpression(ValueExpression orig, String delims) {
this.orig = orig;
this.delims = delims;
}
/**
* Evaluates the stored ValueExpression and return the indexed item.
*
* @param context
* The ELContext used to evaluate the ValueExpression
* @param i
* The index of the item to be retrieved
*/
public Object getItem(ELContext context, int i) {
if (base == null) {
base = orig.getValue(context);
if (base == null) {
return null;
}
iter = toIterator(base);
index = 0;
}
if (index > i) {
// Restart from index 0
iter = toIterator(base);
index = 0;
}
while (iter.hasNext()) {
Object item = iter.next();
if (index++ == i) {
return item;
}
}
return null;
}
public ValueExpression getValueExpression() {
return orig;
}
private Iterator toIterator(final Object obj) {
Iterator iter;
if (obj instanceof String) {
iter = toIterator(new StringTokenizer((String) obj, delims));
} else if (obj instanceof Iterator) {
iter = (Iterator) obj;
} else if (obj instanceof Collection) {
iter = toIterator(((Collection) obj).iterator());
} else if (obj instanceof Enumeration) {
iter = toIterator((Enumeration) obj);
} else if (obj instanceof Map) {
iter = ((Map) obj).entrySet().iterator();
} else {
throw new ELException("Bad items");
}
return iter;
}
private Iterator toIterator(final Enumeration obj) {
return new Iterator() {
public boolean hasNext() {
return obj.hasMoreElements();
}
public Object next() {
return obj.nextElement();
}
public void remove() {
}
};
}
}
/**
* @author Kin-man Chung
* @version $Id: IteratedValueExpression.java,v 1.2 2005/12/08 01:20:43 kchung
* Exp $
*/
final class IteratedValueExpression extends ValueExpression implements
Serializable {
private static final long serialVersionUID = 1L;
protected final int i;
protected final IteratedExpression iteratedExpression;
public IteratedValueExpression(IteratedExpression iteratedExpr, int i) {
this.i = i;
this.iteratedExpression = iteratedExpr;
}
public Object getValue(ELContext context) {
return iteratedExpression.getItem(context, i);
}
public void setValue(ELContext context, Object value) {
}
public boolean isReadOnly(ELContext context) {
return true;
}
public Class getType(ELContext context) {
return null;
}
public Class getExpectedType() {
return Object.class;
}
public String getExpressionString() {
return iteratedExpression.getValueExpression().getExpressionString();
}
public boolean equals(Object obj) {
return iteratedExpression.getValueExpression().equals(obj);
}
public int hashCode() {
return iteratedExpression.getValueExpression().hashCode();
}
public boolean isLiteralText() {
return false;
}
}
/**
* @author Andrey Markavtsov
* @version $Id: IteratedIndexExpression.java,v 1.2 2007/12/06 01:20:43
*
*/
final class IteratedIndexExpression extends ValueExpression implements
Serializable {
private static final long serialVersionUID = 1L;
protected final Integer i;
public IteratedIndexExpression(int i) {
this.i = i;
}
public Object getValue(ELContext context) {
return i;
}
public void setValue(ELContext context, Object value) {
}
public boolean isReadOnly(ELContext context) {
return true;
}
public Class getType(ELContext context) {
return null;
}
public Class getExpectedType() {
return Object.class;
}
public String getExpressionString() {
return i.toString();
}
public boolean equals(Object obj) {
return i.equals(obj);
}
public int hashCode() {
return i.hashCode();
}
public boolean isLiteralText() {
return false;
}
}