Combine lower and upper case letters in Android AlphabetIndexer

Question

I know that AlphabetIndexer class in Android uses ASCII ordering to order items in the list. It means that if I have items starting for example with lower case "a" it will be ordered after upper case "Z" which seems not so logical. So is there a way to somehow combine lower and upper case letters in such kind of situations?

A good example of success in this is the contacts list of Viber, they don't only managed to put "Y" and "y" in the same section but also show two letters "Yy" in the SectionIndexer. So is it possible to achieve with default AlphabetIndexer? Has anybody some experience with such kind of problem?

Answer 1

It appeared that the solution of this problem is easier but a little bit tricky. It seems that the problem is not in AlphabetIndexer itself, but in the way the elements are ordered in the cursor that it gets. So everything I did to solve this problem is to add a right COLLATE to my SQL query.

So I have added the following as a sort order:

private final String SORT_ORDER = Contacts.DISPLAY_NAME_PRIMARY + " COLLATE LOCALIZED ASC";

Note: Contacts.DISPLAY_NAME_PRIMARY is for API 11+ ... for lower APIs you need Contacts.DISPLAY_NAME .

P.S I think this was the only thing that I did to solve this issue, but I don't remember for sure. If it will not help, please tell me and I will look at my code again.

Answer 2

if you want the ordering to not be case sensitive, you need to create your own extension of AlphabetIndexer and overwrite the Compare function to compare the strings in the same case