android - Getting name and email from contact list is very slow

Question

I'm implementing an AutoCompleteTextView and I need Name and E-Mail of all my contacts. I found this snippet that I'm running asynchronously but it's very slow.

ContentResolver cr = getContentResolver();
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);

if (cur.getCount() > 0) {               
    while (cur.moveToNext()) {                  
        String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));                   
        String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));

        Cursor emailCur = cr.query(ContactsContract.CommonDataKinds.Email.CONTENT_URI, null, ContactsContract.CommonDataKinds.Email.CONTACT_ID + " = ?", new String[]{id}, null); 

            while (emailCur.moveToNext()) { 

                String email = emailCur.getString(emailCur.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA));
                    autoCompleteAdapter.add(name + " - " + email);
            }

            emailCur.close();
        }
    }
}

I'm performing a sort of inner query and I think that's the problem. Is there a way to tune it and make it faster?

Answer 1

private static final String[] PROJECTION = new String[] {
    ContactsContract.CommonDataKinds.Email.CONTACT_ID,
    ContactsContract.Contacts.DISPLAY_NAME,
    ContactsContract.CommonDataKinds.Email.DATA
};

...

ContentResolver cr = getContentResolver();
Cursor cursor = cr.query(ContactsContract.CommonDataKinds.Email.CONTENT_URI, PROJECTION, null, null, null);
if (cursor != null) {
    try {
        final int contactIdIndex = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Email.CONTACT_ID);
        final int displayNameIndex = cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME);
        final int emailIndex = cursor.getColumnIndex(ContactsContract.CommonDataKinds.Email.DATA);
        long contactId;
        String displayName, address;
        while (cursor.moveToNext()) {
            contactId = cursor.getLong(contactIdIndex);
            displayName = cursor.getString(displayNameIndex);
            address = cursor.getString(emailIndex);
            ...
        }
    } finally {
        cursor.close();
    }
}

few notes:

• use just ContactsContract.CommonDataKinds.Email.CONTENT_URI to get information you need, see ContactsContract.CommonDataKinds.Email for information what columns you can query
• use projection to get only those columns you really need, you save some memory and increase query performance
• get column indexes only once, just before the while cycle