fix the combiner chain issue

README.md

@@ -13,6 +13,7 @@ Might end up on F-Droid...
 * Load external dictionaries
   * get them [here](https://codeberg.org/Helium314/aosp-dictionaries/src/branch/main/dictionaries), or in the [experimental](https://codeberg.org/Helium314/aosp-dictionaries/src/branch/main/dictionaries_experimental) section (quality may vary)
   * additional dictionaries for emojis or scientific symbols can be used to provide suggestions ("emoji search")
+  * note that for Korean layouts, suggestions only work using [this dictionary](https://github.com/openboard-team/openboard/commit/83fca9533c03b9fecc009fc632577226bbd6301f), the tools in the dictionary repository are not able to create working dictionaries
 * Adjust keyboard themes (style and colors)
   * can follow the system's day/night setting
 * Split keyboard

app/src/main/java/org/dslul/openboard/inputmethod/event/CombinerChain.kt

@@ -2,7 +2,6 @@ package org.dslul.openboard.inputmethod.event
 
 import android.text.SpannableStringBuilder
 import android.text.TextUtils
-import org.dslul.openboard.inputmethod.keyboard.KeyboardSwitcher
 import org.dslul.openboard.inputmethod.latin.common.Constants
 import java.util.*
 
@@ -24,6 +23,19 @@ class CombinerChain(initialText: String) {
     // The feedback on the composing state, as described above
     private val mStateFeedback = SpannableStringBuilder()
     private val mCombiners = ArrayList<Combiner>()
+    // Hangul combiner affects other scripts, e.g. period is seen as port of a word for latin,
+    // so we need to remove the combiner when not writing in hangul script.
+    // Maybe it would be better to always have the Hangul combiner, but make sure it doesn't affect
+    // events for other scripts, but how?
+    var isHangul = false
+        set(value) {
+            if (field == value) return
+            field = value
+            if (!value)
+                mCombiners.removeAll { it is HangulCombiner }
+            else if (mCombiners.none { it is HangulCombiner })
+                mCombiners.add(HangulCombiner())
+        }
 
     /**
      * Create an combiner chain.
@@ -43,15 +55,6 @@ class CombinerChain(initialText: String) {
     fun reset() {
         mCombinedText.setLength(0)
         mStateFeedback.clear()
-        // todo: the first word after language switch is still affected
-        if (KeyboardSwitcher.getInstance().keyboard?.mId?.mSubtype?.locale?.language == "ko") {
-            // if the hangul combiner is added for other keyboards, it leads to weird behavior,
-            // e.g. for latin script, period is seen as part of a word
-            if (mCombiners.none { it is HangulCombiner })
-                mCombiners.add(HangulCombiner())
-        } else {
-            mCombiners.removeAll { it is HangulCombiner }
-        }
         for (c in mCombiners) {
             c.reset()
         }

app/src/main/java/org/dslul/openboard/inputmethod/latin/WordComposer.java

@@ -21,6 +21,8 @@ import androidx.annotation.NonNull;
 import org.dslul.openboard.inputmethod.annotations.UsedForTesting;
 import org.dslul.openboard.inputmethod.event.CombinerChain;
 import org.dslul.openboard.inputmethod.event.Event;
+import org.dslul.openboard.inputmethod.keyboard.Keyboard;
+import org.dslul.openboard.inputmethod.keyboard.KeyboardSwitcher;
 import org.dslul.openboard.inputmethod.latin.SuggestedWords.SuggestedWordInfo;
 import org.dslul.openboard.inputmethod.latin.common.ComposedData;
 import org.dslul.openboard.inputmethod.latin.common.Constants;
@@ -91,6 +93,11 @@ public final class WordComposer {
         mCursorPositionWithinWord = 0;
         mRejectedBatchModeSuggestion = null;
         refreshTypedWordCache();
+        final Keyboard keyboard = KeyboardSwitcher.getInstance().getKeyboard();
+        if (keyboard != null)
+            // initializing with the right state is important for the spell checker,
+            // which creates a new WordComposer when receiving suggestions
+            mCombinerChain.setHangul(keyboard.mId.mSubtype.getLocale().getLanguage().equals("ko"));
     }
 
     public ComposedData getComposedDataSnapshot() {
@@ -109,6 +116,9 @@ public final class WordComposer {
         }
     }
 
+    /** Forwards the state to CombinerChain, which disables or enables the Hangul combiner */
+    public void setHangul(final boolean enabled) { mCombinerChain.setHangul(enabled); }
+
     /**
      * Clear out the keys registered so far.
      */
@@ -274,8 +284,7 @@ public final class WordComposer {
             final int codePoint = Character.codePointAt(word, i);
             // We don't want to override the batch input points that are held in mInputPointers
             // (See {@link #add(int,int,int)}).
-            final Event processedEvent =
+            final Event processedEvent = processEvent(Event.createEventForCodePointFromUnknownSource(codePoint));
-                    processEvent(Event.createEventForCodePointFromUnknownSource(codePoint));
             applyProcessedEvent(processedEvent);
         }
     }
@@ -293,7 +302,8 @@ public final class WordComposer {
             final Event processedEvent =
                     processEvent(Event.createEventForCodePointFromAlreadyTypedText(codePoints[i],
                         CoordinateUtils.xFromArray(coordinates, i),
-                    CoordinateUtils.yFromArray(coordinates, i)));
+                        CoordinateUtils.yFromArray(coordinates, i))
+                    );
             applyProcessedEvent(processedEvent);
         }
         mIsResumed = true;

app/src/main/java/org/dslul/openboard/inputmethod/latin/inputlogic/InputLogic.java

@@ -449,9 +449,11 @@ public final class InputLogic {
         mJustRevertedACommit = false;
         final Event processedEvent;
         if (currentKeyboardScriptId == ScriptUtils.SCRIPT_HANGUL) {
+            mWordComposer.setHangul(true);
             final Event hangulDecodedEvent = HangulEventDecoder.decodeSoftwareKeyEvent(event);
             processedEvent = mWordComposer.processEvent(hangulDecodedEvent);
         } else {
+            mWordComposer.setHangul(false);
             processedEvent = mWordComposer.processEvent(event);
         }
         final InputTransaction inputTransaction = new InputTransaction(settingsValues,