rife2-template-renderers/lib/src/main/java/rife/render/SwapCase.java

78 lines
2.3 KiB
Java

/*
* Copyright 2023 the original author or authors.
*
* 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
*
* https://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 rife.render;
import rife.template.Template;
import rife.template.ValueRenderer;
/**
* <p>Swap case of a template value.</p>
*
* <p>Usage:</p>
*
* <pre>
* &lt;!--v render:rife.render.SwapCase:valueId/--&gt;
* {{v render:rife.render.SwapCase:valueId/}}
* </pre>
*
* @author <a href="https://erik.thauvin.net/">Erik C. Thauvin</a>
* @since 1.0
*/
public class SwapCase implements ValueRenderer {
/**
* Swaps the case of a String.
*
* @param src the String to swap the case of
* @return the modified String or null
*/
public static String swapCase(final String src) {
if (src == null || src.isEmpty()) {
return src;
}
int offset = 0;
var len = src.length();
var buff = new int[len];
for (var i = 0; i < len; ) {
int newCodePoint;
var curCodePoint = src.codePointAt(i);
if (Character.isUpperCase(curCodePoint) || Character.isTitleCase(curCodePoint)) {
newCodePoint = Character.toLowerCase(curCodePoint);
} else if (Character.isLowerCase(curCodePoint)) {
newCodePoint = Character.toUpperCase(curCodePoint);
} else {
newCodePoint = curCodePoint;
}
buff[offset++] = newCodePoint;
i += Character.charCount(newCodePoint);
}
return new String(buff, 0, offset);
}
/**
* {@inheritDoc}
*/
@Override
public String render(Template template, String valueId, String differentiator) {
if (template.hasValueId(differentiator)) {
return swapCase(template.getValue(differentiator));
} else {
return "";
}
}
}