Add Tibetan Extended Wylie combiner

java/src/org/futo/inputmethod/event/combiners/wylie/EwtsConverter.java

@@ -0,0 +1,4 @@
+package org.futo.inputmethod.event.combiners.wylie;
+
+public class EwtsConverter {
+}

java/src/org/futo/inputmethod/event/combiners/wylie/WylieCombiner.kt

@@ -0,0 +1,58 @@
+package org.futo.inputmethod.event.combiners.wylie
+
+import android.text.TextUtils
+import org.futo.inputmethod.event.Combiner
+import org.futo.inputmethod.event.Event
+import org.futo.inputmethod.latin.common.Constants
+import java.util.ArrayList
+
+/**
+ * Combiner that converts Extended Wylie transliteration to Tibetan script
+ * Useful for Tibetan and Dzongkha languages
+ * Uses the ewts-converter library: https://github.com/buda-base/ewts-converter
+ */
+class WylieCombiner: Combiner {
+    private val buffer = StringBuilder() //Holds a single syllable (as divided by "tsheg"s)
+    private val ewtsConverter = EwtsConverter()
+
+    private fun isWylie(char: Char): Boolean {
+        return char.code <= 0x7f &&
+                (char.isLetter() ||
+                        char in listOf('\'', '+', '-', '.', '~', '`', '&', '?') )
+    } //ASCII uppercase and lowercase letters, and a few other characters used in Wylie.
+
+    override fun processEvent(previousEvents: ArrayList<Event>?, event: Event?): Event {
+        if (event == null) return Event.createNotHandledEvent()
+        val keypress = event.mCodePoint.toChar()
+
+        if (!isWylie(keypress)) {
+            if (!TextUtils.isEmpty(buffer)) {
+                if (event.mKeyCode == Constants.CODE_DELETE) {
+                    return if (buffer.length == 1) {
+                        reset()
+                        Event.createHardwareKeypressEvent(0x20, Constants.CODE_SPACE,
+                            event, event.isKeyRepeat)
+                        // for some reason, this is needed, otherwise if there is only one letter
+                        // in the buffer it won't be deleted
+                    }
+                    else {
+                        buffer.setLength(buffer.length - 1)
+                        Event.createConsumedEvent(event)
+                    }
+                }
+            }
+            return event
+        }
+
+        buffer.append(keypress)
+        return Event.createConsumedEvent(event)
+    }
+
+    override fun getCombiningStateFeedback(): CharSequence {
+        return ewtsConverter.toUnicode(buffer.toString())
+    }
+
+    override fun reset() {
+        buffer.setLength(0)
+    }
+}

java/src/org/futo/inputmethod/v2keyboard/CombinerKind.kt

@@ -4,10 +4,12 @@ import org.futo.inputmethod.event.Combiner
 import org.futo.inputmethod.event.DeadKeyCombiner
 import org.futo.inputmethod.event.combiners.DeadKeyPreCombiner
 import org.futo.inputmethod.event.combiners.KoreanCombiner
+import org.futo.inputmethod.event.combiners.WylieCombiner
 
 enum class CombinerKind(val factory: () -> Combiner) {
     DeadKey({ DeadKeyCombiner() }),
     DeadKeyPreCombiner({ DeadKeyPreCombiner() }),
     Korean({ KoreanCombiner() }),
-    KoreanCombineInitials({ KoreanCombiner(combineInitials = true) })
+    KoreanCombineInitials({ KoreanCombiner(combineInitials = true) }),
+    Wylie({ WylieCombiner() })
 }