content: package com.android.launcher3.compat;
  
  import android.content.Context;
  import android.icu.text.AlphabeticIndex;
  import android.os.LocaleList;
  
  import com.android.launcher3.Utilities;
  
  import java.util.Locale;
  
  import androidx.annotation.NonNull;
  
  public class AlphabeticIndexCompat {
  
      private static final String MID_DOT = "\u2219";
      private final String mDefaultMiscLabel;
  
      private final AlphabeticIndex.ImmutableIndex mBaseIndex;
  
      public AlphabeticIndexCompat(Context context) {
          this(context.getResources().getConfiguration().getLocales());
      }
  
      public AlphabeticIndexCompat(LocaleList locales) {
          int localeCount = locales.size();
  
          Locale primaryLocale = localeCount == 0 ? Locale.ENGLISH : locales.get(0);
          AlphabeticIndex indexBuilder = new AlphabeticIndex(primaryLocale);
          for (int i = 1; i < localeCount; i++) {
              indexBuilder.addLabels(locales.get(i));
          }
          indexBuilder.addLabels(Locale.ENGLISH);
          mBaseIndex = indexBuilder.buildImmutableIndex();
  
          if (primaryLocale.getLanguage().equals(Locale.JAPANESE.getLanguage())) {
              // Japanese character 他 ("misc")
              mDefaultMiscLabel = "\u4ed6";
              // TODO(winsonc, omakoto): We need to handle Japanese sections better,
              // especially the kanji
          } else {
              // Dot
              mDefaultMiscLabel = MID_DOT;
          }
      }
  
      /**
       * Computes the section name for an given string {@param s}.
       */
      public String computeSectionName(@NonNull CharSequence cs) {
          String s = Utilities.trim(cs);
          String sectionName = mBaseIndex.getBucket(mBaseIndex.getBucketIndex(s)).getLabel();
          if (Utilities.trim(sectionName).isEmpty() && s.length() > 0) {
              int c = s.codePointAt(0);
              boolean startsWithDigit = Character.isDigit(c);
              if (startsWithDigit) {
                  // Digit section
                  return "#";
              } else {
                  boolean startsWithLetter = Character.isLetter(c);
                  if (startsWithLetter) {
                      return mDefaultMiscLabel;
                  } else {
                      // In languages where these differ, this ensures that we differentiate
                      // between the misc section in the native language and a misc section
                      // for everything else.
                      return MID_DOT;
                  }
              }
          }
          return sectionName;
      }
  }
  