From 1d441a8ca68db2d2444a78a744bd1a20eff3d869 Mon Sep 17 00:00:00 2001
From: Helium314 <helium314@mailbox.org>
Date: Sun, 27 Apr 2025 18:59:29 +0200
Subject: [PATCH] more workarounds for Korean

not just space might delete text, but also other separators
now this problem is avoided in a more generic way
fixes GH-1447
---
 .../keyboard/latin/WordComposer.java          |  5 +++
 .../keyboard/latin/inputlogic/InputLogic.java | 35 ++++++++++++-------
 .../keyboard/latin/InputLogicTest.kt          |  8 +++++
 3 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/app/src/main/java/helium314/keyboard/latin/WordComposer.java b/app/src/main/java/helium314/keyboard/latin/WordComposer.java
index 203eb205c..a5b50f353 100644
--- a/app/src/main/java/helium314/keyboard/latin/WordComposer.java
+++ b/app/src/main/java/helium314/keyboard/latin/WordComposer.java
@@ -218,6 +218,11 @@ public final class WordComposer {
         // TODO: compute where that puts us inside the events
     }
 
+    public void resetInvalidCursorPosition() {
+        if (mCursorPositionWithinWord > mCodePointSize)
+            mCursorPositionWithinWord = 0;
+    }
+
     public boolean isCursorFrontOrMiddleOfComposingWord() {
         if (DebugFlags.DEBUG_ENABLED && mCursorPositionWithinWord > mCodePointSize) {
             throw new RuntimeException("Wrong cursor position : " + mCursorPositionWithinWord
diff --git a/app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java b/app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java
index 79464dee3..4b1bd4df2 100644
--- a/app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java
+++ b/app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java
@@ -440,19 +440,28 @@ public final class InputLogic {
         mWordBeingCorrectedByCursor = null;
         mJustRevertedACommit = false;
         final Event processedEvent;
-        if (currentKeyboardScript.equals(ScriptUtils.SCRIPT_HANGUL)
-                // only use the Hangul chain if codepoint may actually be Hangul
-                // todo: this whole hangul-related logic should probably be somewhere else
-                // need to use hangul combiner for whitespace, because otherwise the current word
-                // seems to get deleted / replaced by space during mConnection.endBatchEdit()
-                // similar for functional keys (codePoint -1)
-                && (event.getMCodePoint() >= 0x1100 || Character.isWhitespace(event.getMCodePoint()) || event.getMCodePoint() == -1)) {
-            mWordComposer.setHangul(true);
-            final Event hangulDecodedEvent = HangulEventDecoder.decodeSoftwareKeyEvent(event);
-            // todo: here hangul combiner does already consume the event, and appends typed codepoint
-            //  to the current word instead of considering the cursor position
-            //  position is actually not visible to the combiner, how to fix?
-            processedEvent = mWordComposer.processEvent(hangulDecodedEvent);
+        if (currentKeyboardScript.equals(ScriptUtils.SCRIPT_HANGUL)) {
+            // only use the Hangul chain if codepoint may actually be Hangul
+            // todo: this whole hangul-related logic should probably be somewhere else
+            // need to use hangul combiner for functional keys (codePoint -1), because otherwise the current word
+            // seems to get deleted / replaced by space during mConnection.endBatchEdit()
+            if (event.getMCodePoint() >= 0x1100 || event.getMCodePoint() == -1) {
+                mWordComposer.setHangul(true);
+                final Event hangulDecodedEvent = HangulEventDecoder.decodeSoftwareKeyEvent(event);
+                // todo: here hangul combiner does already consume the event, and appends typed codepoint
+                //  to the current word instead of considering the cursor position
+                //  position is actually not visible to the combiner, how to fix?
+                processedEvent = mWordComposer.processEvent(hangulDecodedEvent);
+            } else {
+                mWordComposer.setHangul(false);
+                final boolean wasComposingWord = mWordComposer.isComposingWord();
+                processedEvent = mWordComposer.processEvent(event);
+                // workaround for space and some other separators deleting / replacing the word
+                if (wasComposingWord && !mWordComposer.isComposingWord()) {
+                    mWordComposer.resetInvalidCursorPosition();
+                    mConnection.finishComposingText();
+                }
+            }
         } else {
             mWordComposer.setHangul(false);
             processedEvent = mWordComposer.processEvent(event);
diff --git a/app/src/test/java/helium314/keyboard/latin/InputLogicTest.kt b/app/src/test/java/helium314/keyboard/latin/InputLogicTest.kt
index 4f75173e5..1fd8dea0b 100644
--- a/app/src/test/java/helium314/keyboard/latin/InputLogicTest.kt
+++ b/app/src/test/java/helium314/keyboard/latin/InputLogicTest.kt
@@ -152,6 +152,14 @@ class InputLogicTest {
         assertEquals(4, cursor)
     }
 
+    // see issue 1447
+    @Test fun separatorAfterHangul() {
+        reset()
+        currentScript = ScriptUtils.SCRIPT_HANGUL
+        chainInput("ㅛ.")
+        assertEquals("ㅛ.", text)
+    }
+
     @Test fun separatorUnselectsWord() {
         reset()
         setText("hello")