freemarker.core.HexBI Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2013, Heng Yuan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 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.
* Neither the name of the Heng Yuan nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Heng Yuan ''AS IS'' AND ANY
* EXPRESS 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 Heng Yuan 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 USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* 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.
*/
package freemarker.core;
import java.util.List;
import freemarker.template.*;
/**
* This piece of code is from http://osdir.com/ml/web.freemarker.devel/2004-04/msg00010.html
* by Mark van de Veerdonk.
*
* @author Heng Yuan
*/
public class HexBI extends BuiltIn
{
@SuppressWarnings ("unchecked")
public static void init ()
{
BuiltIn.builtins.put ("hex", new HexBI ());
}
@Override
TemplateModel _getAsTemplateModel (Environment env) throws TemplateException
{
TemplateModel model = target.getAsTemplateModel (env);
if (!(model instanceof TemplateNumberModel))
throw invalidTypeException (model, target, env, "number");
TemplateNumberModel nModel = (TemplateNumberModel)model;
return new Hexanizer (nModel.getAsNumber ().intValue ());
}
@SuppressWarnings ("rawtypes")
private class Hexanizer implements TemplateMethodModelEx
{
int value;
Hexanizer (int value)
{
super ();
this.value = value;
}
public TemplateModel exec (List args) throws TemplateModelException
{
if (args.size () != 1)
throw new TemplateModelException ("number?hex(...) requires exactly 1 argument");
Object obj = args.get (0);
if (!(obj instanceof TemplateNumberModel))
throw new TemplateModelException ("Parameter to ?hex(...) must be a number.");
String strValue = Integer.toHexString (value);
int minLength = ((TemplateNumberModel)obj).getAsNumber ().intValue ();
int numLeadingZeros = minLength - strValue.length ();
String prependStr = "";
while (numLeadingZeros > 0)
{
prependStr += "0";
numLeadingZeros--;
}
return new SimpleScalar (prependStr + strValue);
}
}
}