From 6a34f2c832e3b9d7c75dd8887f4f1c5ca0b1cf78 Mon Sep 17 00:00:00 2001
From: Helium314 <helium314@mailbox.org>
Date: Wed, 12 Jun 2024 23:54:23 +0200
Subject: [PATCH] improve emoji detection when deleting still has issues with
 hand + skin tone emojis

---
 .../helium314/keyboard/latin/RichInputConnection.java  | 10 ++++++----
 .../helium314/keyboard/latin/common/StringUtils.kt     |  2 ++
 .../keyboard/latin/inputlogic/InputLogic.java          |  4 ++--
 3 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/app/src/main/java/helium314/keyboard/latin/RichInputConnection.java b/app/src/main/java/helium314/keyboard/latin/RichInputConnection.java
index c1dc91edb..87e699fe6 100644
--- a/app/src/main/java/helium314/keyboard/latin/RichInputConnection.java
+++ b/app/src/main/java/helium314/keyboard/latin/RichInputConnection.java
@@ -1072,10 +1072,12 @@ public final class RichInputConnection implements PrivateCommandPerformer {
 
     public int getCharCountToDeleteBeforeCursor() {
         final int lastCodePoint = getCodePointBeforeCursor();
-        if (!Character.isSupplementaryCodePoint(lastCodePoint)) return 1;
-        if (!StringUtils.mightBeEmoji(lastCodePoint)) return 2;
-        final String text = mCommittedTextBeforeComposingText.toString() + mComposingText;
-        return StringUtilsKt.getFullEmojiAtEnd(text).length();
+        if (StringUtils.mightBeEmoji(lastCodePoint)) {
+            final String text = mCommittedTextBeforeComposingText.toString() + mComposingText;
+            final int emojiLength = StringUtilsKt.getFullEmojiAtEnd(text).length();
+            if (emojiLength > 0) return emojiLength;
+        }
+        return Character.isSupplementaryCodePoint(lastCodePoint) ? 2 : 1;
     }
 
     public boolean hasLetterBeforeLastSpaceBeforeCursor() {
diff --git a/app/src/main/java/helium314/keyboard/latin/common/StringUtils.kt b/app/src/main/java/helium314/keyboard/latin/common/StringUtils.kt
index 3b53668a1..8f3347129 100644
--- a/app/src/main/java/helium314/keyboard/latin/common/StringUtils.kt
+++ b/app/src/main/java/helium314/keyboard/latin/common/StringUtils.kt
@@ -64,6 +64,8 @@ fun getFullEmojiAtEnd(s: CharSequence): String {
         // stop if codepoint can't be emoji
         if (!mightBeEmoji(codepoint)) return ""
         offset -= Character.charCount(codepoint)
+        // todo: if codepoint in 0x1F3FB..0x1F3FF -> combine with other emojis in front, but only if they actually combine
+        //  why isn't this done with zwj like everything else? skin tones can be emojis by themselves...
         if (offset > 0 && text[offset - 1].code == KeyCode.ZWJ) {
             offset -= 1
             continue
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 88f4b9ca1..2c7b2b248 100644
--- a/app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java
+++ b/app/src/main/java/helium314/keyboard/latin/inputlogic/InputLogic.java
@@ -1311,7 +1311,7 @@ public final class InputLogic {
                         // TODO: Add a new StatsUtils method onBackspaceWhenNoText()
                         return;
                     }
-                    final int lengthToDelete = Character.isSupplementaryCodePoint(codePointBeforeCursor)
+                    final int lengthToDelete = codePointBeforeCursor > 0xFE00
                             ? mConnection.getCharCountToDeleteBeforeCursor() : 1;
                     mConnection.deleteTextBeforeCursor(lengthToDelete);
                     int totalDeletedLength = lengthToDelete;
@@ -1324,7 +1324,7 @@ public final class InputLogic {
                         final int codePointBeforeCursorToDeleteAgain =
                                 mConnection.getCodePointBeforeCursor();
                         if (codePointBeforeCursorToDeleteAgain != Constants.NOT_A_CODE) {
-                            final int lengthToDeleteAgain = Character.isSupplementaryCodePoint(codePointBeforeCursorToDeleteAgain)
+                            final int lengthToDeleteAgain = codePointBeforeCursor > 0xFE00
                                     ? mConnection.getCharCountToDeleteBeforeCursor() : 1;
                             mConnection.deleteTextBeforeCursor(lengthToDeleteAgain);
                             totalDeletedLength += lengthToDeleteAgain;