From eec197c32cfc809a82fa88a524fdc317807d8ddc Mon Sep 17 00:00:00 2001
From: Helium314 <helium314@mailbox.org>
Date: Mon, 17 Feb 2025 19:32:02 +0100
Subject: [PATCH] cache subtype display names for improved performance

---
 .../keyboard/keyboard/KeyboardLayoutSet.java     |  2 ++
 .../keyboard/latin/utils/SubtypeLocaleUtils.java | 16 +++++++++++++++-
 .../keyboard/settings/screens/LanguageScreen.kt  |  3 +--
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/helium314/keyboard/keyboard/KeyboardLayoutSet.java b/app/src/main/java/helium314/keyboard/keyboard/KeyboardLayoutSet.java
index 0a834fe76..dc609724a 100644
--- a/app/src/main/java/helium314/keyboard/keyboard/KeyboardLayoutSet.java
+++ b/app/src/main/java/helium314/keyboard/keyboard/KeyboardLayoutSet.java
@@ -26,6 +26,7 @@ import helium314.keyboard.latin.utils.InputTypeUtils;
 import helium314.keyboard.latin.utils.Log;
 import helium314.keyboard.latin.utils.ResourceUtils;
 import helium314.keyboard.latin.utils.ScriptUtils;
+import helium314.keyboard.latin.utils.SubtypeLocaleUtils;
 
 import java.lang.ref.SoftReference;
 import java.util.HashMap;
@@ -95,6 +96,7 @@ public final class KeyboardLayoutSet {
     public static void onSystemLocaleChanged() {
         clearKeyboardCache();
         LocaleKeyboardInfosKt.clearCache();
+        SubtypeLocaleUtils.clearDisplayNameCache();
     }
 
     public static void onKeyboardThemeChanged() {
diff --git a/app/src/main/java/helium314/keyboard/latin/utils/SubtypeLocaleUtils.java b/app/src/main/java/helium314/keyboard/latin/utils/SubtypeLocaleUtils.java
index 65fe4d017..bb99355b6 100644
--- a/app/src/main/java/helium314/keyboard/latin/utils/SubtypeLocaleUtils.java
+++ b/app/src/main/java/helium314/keyboard/latin/utils/SubtypeLocaleUtils.java
@@ -12,6 +12,7 @@ import android.view.inputmethod.InputMethodSubtype;
 
 import helium314.keyboard.compat.ConfigurationCompatKt;
 import helium314.keyboard.latin.R;
+import helium314.keyboard.latin.common.Constants;
 import helium314.keyboard.latin.common.LocaleUtils;
 import helium314.keyboard.latin.common.StringUtils;
 
@@ -56,6 +57,7 @@ public final class SubtypeLocaleUtils {
     private static final HashMap<String, Integer> sExceptionalLocaleToNameIdsMap = new HashMap<>();
     // Exceptional locale to subtype name with layout resource id map.
     private static final HashMap<String, Integer> sExceptionalLocaleToWithLayoutNameIdsMap = new HashMap<>();
+    private static final HashMap<Integer, String> sResourceSubtypeDisplayNames = new HashMap<>();
     private static final String SUBTYPE_NAME_RESOURCE_PREFIX = "string/subtype_";
     private static final String SUBTYPE_NAME_RESOURCE_GENERIC_PREFIX = "string/subtype_generic_";
     private static final String SUBTYPE_NAME_RESOURCE_WITH_LAYOUT_PREFIX = "string/subtype_with_layout_";
@@ -239,8 +241,20 @@ public final class SubtypeLocaleUtils {
 
     @NonNull
     public static String getSubtypeDisplayNameInSystemLocale(@NonNull final InputMethodSubtype subtype) {
+        final String cached = sResourceSubtypeDisplayNames.get(subtype.hashCode());
+        if (cached != null) return cached;
+
         final Locale displayLocale = ConfigurationCompatKt.locale(sResources.getConfiguration());
-        return getSubtypeDisplayNameInternal(subtype, displayLocale);
+        final String displayName = getSubtypeDisplayNameInternal(subtype, displayLocale);
+
+        if (!subtype.containsExtraValueKey(Constants.Subtype.ExtraValue.IS_ADDITIONAL_SUBTYPE)) {
+            sResourceSubtypeDisplayNames.put(subtype.hashCode(), displayName);
+        }
+        return displayName;
+    }
+
+    public static void clearDisplayNameCache() {
+        sResourceSubtypeDisplayNames.clear();
     }
 
     @NonNull
diff --git a/app/src/main/java/helium314/keyboard/settings/screens/LanguageScreen.kt b/app/src/main/java/helium314/keyboard/settings/screens/LanguageScreen.kt
index f19fde7df..16a6630ac 100644
--- a/app/src/main/java/helium314/keyboard/settings/screens/LanguageScreen.kt
+++ b/app/src/main/java/helium314/keyboard/settings/screens/LanguageScreen.kt
@@ -67,7 +67,6 @@ fun LanguageScreen(
             }
         },
         filteredItems = { term ->
-            // todo: maybe better performance with display name cache?
             sortedSubtypes.filter {
                 it.displayName(ctx).replace("(", "")
                     .splitOnWhitespace().any { it.startsWith(term, true) }
@@ -116,7 +115,7 @@ fun LanguageScreen(
     }
 }
 
-// todo: sorting is slow, need to cache displayName (overall or just in getSortedSubtypes), and then it should be fine
+// sorting by display name is still slow, even with the cache... but probably good enough
 private fun getSortedSubtypes(context: Context): List<InputMethodSubtype> {
     val systemLocales = SubtypeSettings.getSystemLocales()
     val enabledSubtypes = SubtypeSettings.getEnabledSubtypes(context.prefs(), true)