I did this in about 30 mins. I copied part of the reverse lines standard macro. There are two options. One just reverses the selection and the other is a bit better, dealing only with comma delimiters. Maybe you can make it better?


--- BEGIN MACRO ---
reverseCommaList1(textArea) {
JEditBuffer buffer = textArea.getBuffer();
Selection[] selections = textArea.getSelection();

// doesn't work with rectangular selections, check for them up-front
for(int i = 0; i < selections.length; i++) {
if(selections[i] instanceof Selection.Rect) {
Macros.error(view, NotWorkingRectangularSelectionError);
return;
}
}

startLine = selections[0].getStartLine();
startOffset = buffer.getLineStartOffset(startLine);
text = buffer.getLineText(startLine);

sb = new StringBuilder();
for (i = text.length() - 1; i >= 0; i--) {
sb.append(text.charAt(i));
}

reversedStr = sb.toString();

buffer.remove(startOffset, reversedStr.length());
buffer.insert(startOffset, reversedStr);

}

reverseCommaList(textArea) {
JEditBuffer buffer = textArea.getBuffer();
Selection[] selections = textArea.getSelection();

// doesn't work with rectangular selections, check for them up-front
for(int i = 0; i < selections.length; i++) {
if(selections[i] instanceof Selection.Rect) {
Macros.error(view, NotWorkingRectangularSelectionError);
return;
}
}

startLine = selections[0].getStartLine();
startOffset = buffer.getLineStartOffset(startLine);
text = buffer.getLineText(startLine);

tk = new StringTokenizer(text, ",");

words = new String[tk.countTokens()];
lastElement = tk.countTokens() - 1;

while (tk.hasMoreTokens()) {
words[lastElement--] = tk.nextToken().trim();
}

sb = new StringBuffer();
for (int i = 0; i < words.length; i++) {
sb.append(words[i]);
if (i < words.length - 1) {
sb.append(", ");
}
}

reversedStr = sb.toString();

buffer.remove(startOffset, reversedStr.length());
buffer.insert(startOffset, reversedStr);

}

if(buffer.isReadOnly())
Macros.error(view, NotEditableMessage);
else
reverseCommaList(textArea);
--- END MACRO ---