Transformation method that looks for mentions of Twitter-like format in any TextView.

MentionTransformation

/**
 * Created by nikola on 11/28/14.
 */
public class MentionTransformation implements TransformationMethod {
    private int mColor;
    private Pattern MENTIONS_PATTERN = Pattern.compile("\\B@[a-z0-9_-]+");

    private MentionTransformation(int color) {
        mColor = color;
    }

    public static MentionTransformation getInstance(int color) {
        return new MentionTransformation(color);
    }

    @Override
    public CharSequence getTransformation(CharSequence source, View view) {
        return findMentions(source.toString());
    }

    @Override
    public void onFocusChanged(View view, CharSequence sourceText, boolean focused, int direction, Rect previouslyFocusedRect) {

    }

    private SpannableStringBuilder findMentions(String text){
        Matcher matcher = MENTIONS_PATTERN.matcher(text);
        SpannableStringBuilder spanRange = new SpannableStringBuilder(text);
        while(matcher.find()){
           String mention = matcher.group();
           int startMetion = text.indexOf(mention);
           int endMention = startMetion + mention.length();
           spanRange.setSpan(new ForegroundColorSpan(mColor), startMetion, endMention, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
       return spanRange;
    }
}