Smart searching contacts in android

Question

Following This Retrieving a List of Contacts Tutorial in the android developers site, I managed to implement contacts search functionality. Here is my code so far

private void retrieveContactRecord(String phoneNo) {
        try {
            Log.e("Info", "Input: " + phoneNo);
            Uri uri = Uri.withAppendedPath(ContactsContract.PhoneLookup.CONTENT_FILTER_URI,
                    Uri.encode(phoneNo));
            String[] projection = new String[]{ContactsContract.PhoneLookup._ID, ContactsContract.PhoneLookup.DISPLAY_NAME};


            String sortOrder = ContactsContract.PhoneLookup.DISPLAY_NAME + " COLLATE LOCALIZED ASC";
            ContentResolver cr = getContentResolver();
            if (cr != null) {
                Cursor resultCur = cr.query(uri, projection, null, null, sortOrder);
                if (resultCur != null) {
                    while (resultCur.moveToNext()) {
                        String contactId = resultCur.getString(resultCur.getColumnIndex(ContactsContract.PhoneLookup._ID));
                        String contactName = resultCur.getString(resultCur.getColumnIndexOrThrow(ContactsContract.PhoneLookup.DISPLAY_NAME));
                        Log.e("Info", "Contact Id : " + contactId);
                        Log.e("Info", "Contact Display Name : " + contactName);
                        break;
                    }
                    resultCur.close();
                }
            }
        } catch (Exception sfg) {
            Log.e("Error", "Error in loadContactRecord : " + sfg.toString());
        }
    }

Here is the catch, this code works pretty great, but I need to implement a smart search here. I want 26268 to match Amanu as well as 094 526 2684. I believe it is called T9 dictionary.

I tried looking at other projects for clue, but I couldn't find anything. Any pointers would be appreciated!

score 3 · Answer 1 · answered May 22 '16 at 08:55

3

T9 search can be implemented using trie data structure. You can see an example here - Trie dict. After implementing something similar you will be able to convert your search input into its possible T9 decoded variant and compare if it matches with name.

answered May 22 '16 at 08:55

Yaroslav

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Have you implemented this ? ,I am not able to understand how to use in my project please help – Sagar Sep 12 '17 at 06:54

score 1 · Answer 2 · edited May 23 '17 at 12:24

Dump all contacts to a HashSet

Set<String> contacts = new HashSet<String>();

Then search:

List<List<String>> results = new ArrayList<List<String>>();
// start the search, pass empty stack to represent words found so far
search(input, dictionary, new Stack<String>(), results);

Search method (from @WhiteFang34)

public static void search(String input, Set<String> contacts,
    Stack<String> words, List<List<String>> results) {

    for (int i = 0; i < input.length(); i++) {
        // take the first i characters of the input and see if it is a word
        String substring = input.substring(0, i + 1);

        if (contacts.contains(substring)) {
            // the beginning of the input matches a word, store on stack
            words.push(substring);

            if (i == input.length() - 1) {
                // there's no input left, copy the words stack to results
                results.add(new ArrayList<String>(words));
            } else {
                // there's more input left, search the remaining part
                search(input.substring(i + 1), contacts, words, results);
            }

            // pop the matched word back off so we can move onto the next i
            words.pop();
        }
    }
}

score 0 · Accepted Answer · answered Dec 20 '16 at 12:24

The ContentProvider for contacts doesn't support it. So what I did was to dump all of the contacts in a List then use a RegEx to match for the name.

public static String[] values = new String[]{" 0", "1", "ABC2", "DEF3", "GHI4", "JKL5", "MNO6", "PQRS7", "TUV8", "WXYZ9"};

/**
 * Get the possible pattern
 * You'll get something like ["2ABC","4GHI"] for input "14"
 */
public static List<String> possibleValues(String in) {

    if (in.length() >= 1) {
        List<String> p = possibleValues(in.substring(1));
        String s = "" + in.charAt(0);
        if (s.matches("[0-9]")) {
            int n = Integer.parseInt(s);

            p.add(0, values[n]);
        } else {
            // It is a character, use it as it is
            p.add(s);
        }

        return p;
    }
    return new ArrayList<>();
}

.... Then compile the pattern. I used (?i) to make it case insensitive

List<String> values = Utils.possibleValues(query);
StringBuilder sb = new StringBuilder();
for (String value : values) {
    sb.append("[");
    sb.append(value);
    sb.append("]");
    if (values.get(values.size() - 1) != value) {
    sb.append("\\s*");
    }
}

Log.e("Utils", "Pattern = " + sb.toString());

Pattern queryPattern = Pattern.compile("(?i)(" + sb.toString() + ")");

You'll know what to do after this.

Smart searching contacts in android

3 Answers3