TextSnapshotRange swaps StartOffset/EndOffset?

I'm keeping a list TextSnapshotRange (compilation errors in an DSL), but I want the caret to end up sometimes at the beginning, and sometimes at the end of the range when its selected.

The thing is when I create a new TextSnapshotRange from the TextRange (to keep track of versions) the order of StartOffset/EndOffset are always sorted! (it doesn't keep the original direction of the range).

Let me explain this with an example:

// r1 and r2 are two similar ranges, but in different direction

TextRange r1 = new TextRange(start, end);
TextRange r2 = new TextRange(end, start);

// r1 != r2, but when I convert them to a TextSnapshotRange ...

TextSnapshotRange sr1 = new TextSnapshotRange(Snapshot, r1);
TextSnapshotRange sr2 = new TextSnapshotRange(Snapshot, r2);

// then sr1 == sr2 (it doesn't keep the direction of the selection range)

And I can't find a workaround because all TextSnapshotRange properties are read only, so I can't swap the StartOffset and the EndOffset myself when the direction of the range was backwards.

Thanks.

Please let me know if I didn't explain myself clearly :)

[Modified at 07/22/2009 03:13 PM]