Merge branch 'stripAccents' into 'develop'

Stripaccents

Closes #816

See merge request ultrasonic/ultrasonic!845

ultrasonic/src/main/kotlin/org/moire/ultrasonic/adapters/ArtistRowBinder.kt

@@ -25,6 +25,7 @@ import org.moire.ultrasonic.domain.Identifiable
 import org.moire.ultrasonic.imageloader.ImageLoader
 import org.moire.ultrasonic.util.FileUtil
 import org.moire.ultrasonic.util.Settings
+import org.moire.ultrasonic.util.Util
 
 /**
  * Creates a Row in a RecyclerView which contains the details of an Artist
@@ -106,7 +107,7 @@ class ArtistRowBinder(
         if (name.isEmpty()) return SECTION_KEY_DEFAULT
         val section = name.first().uppercaseChar()
         if (!section.isLetter()) return SECTION_KEY_DEFAULT
-        return section.toString()
+        return Util.stripAccents(section.toString())!!
     }
 
     private fun showArtistPicture(): Boolean {

ultrasonic/src/main/kotlin/org/moire/ultrasonic/util/Util.kt

@@ -46,8 +46,10 @@ import java.io.Closeable
 import java.io.UnsupportedEncodingException
 import java.security.MessageDigest
 import java.text.DecimalFormat
+import java.text.Normalizer
 import java.util.Locale
 import java.util.concurrent.TimeUnit
+import java.util.regex.Pattern
 import kotlin.math.max
 import kotlin.math.min
 import kotlin.math.roundToInt
@@ -670,6 +672,37 @@ object Util {
         )
     }
 
+    /**
+     * Removes diacritics (~= accents) from a string. The case will not be altered.
+     * Note that ligatures will be left as is.
+     *
+     * @param input String to be stripped
+     * @return input text with diacritics removed
+     *
+     */
+    fun stripAccents(input: String): String {
+        val decomposed: java.lang.StringBuilder =
+            java.lang.StringBuilder(Normalizer.normalize(input, Normalizer.Form.NFD))
+        convertRemainingAccentCharacters(decomposed)
+        return STRIP_ACCENTS_PATTERN.matcher(decomposed).replaceAll("")
+    }
+
+    /**
+     * Pattern used in [.stripAccents].
+     */
+    private val STRIP_ACCENTS_PATTERN: Pattern =
+        Pattern.compile("\\p{InCombiningDiacriticalMarks}+") // $NON-NLS-1$
+
+    private fun convertRemainingAccentCharacters(decomposed: java.lang.StringBuilder) {
+        for (i in decomposed.indices) {
+            if (decomposed[i] == '\u0141') {
+                decomposed.setCharAt(i, 'L')
+            } else if (decomposed[i] == '\u0142') {
+                decomposed.setCharAt(i, 'l')
+            }
+        }
+    }
+
     fun getPlayListFromTimeline(
         timeline: Timeline?,
         shuffle: Boolean,