stick to language key setting

don't show langauge switch key in comma popups when there is nothing to switch
fixes #897

app/src/main/java/helium314/keyboard/keyboard/internal/keyboard_parser/floris/TextKeyData.kt

@@ -18,6 +18,7 @@ import helium314.keyboard.keyboard.internal.KeyboardParams
 import helium314.keyboard.keyboard.internal.keyboard_parser.floris.KeyCode.checkAndConvertCode
 import helium314.keyboard.keyboard.internal.keyboard_parser.floris.KeyLabel.convertFlorisLabel
 import helium314.keyboard.keyboard.internal.keyboard_parser.floris.KeyLabel.rtlLabel
+import helium314.keyboard.latin.RichInputMethodManager
 import helium314.keyboard.latin.common.Constants
 import helium314.keyboard.latin.common.LocaleUtils.constructLocale
 import helium314.keyboard.latin.common.StringUtils
@@ -121,7 +122,7 @@ sealed interface KeyData : AbstractKeyData {
                 keys.add("!icon/clipboard_normal_key|!code/key_clipboard")
             if (!params.mId.mEmojiKeyEnabled && !params.mId.isNumberLayout)
                 keys.add("!icon/emoji_normal_key|!code/key_emoji")
-            if (!params.mId.mLanguageSwitchKeyEnabled && !params.mId.isNumberLayout)
+            if (!params.mId.mLanguageSwitchKeyEnabled && !params.mId.isNumberLayout && RichInputMethodManager.getInstance().canSwitchLanguage())
                 keys.add("!icon/language_switch_key|!code/key_language_switch")
             if (!params.mId.mOneHandedModeEnabled)
                 keys.add("!icon/start_onehanded_mode_key|!code/key_start_onehanded")

app/src/main/java/helium314/keyboard/latin/LatinIME.java

@@ -1412,8 +1412,9 @@ public class LatinIME extends InputMethodService implements
         if (switchIme && !switchSubtype && switchInputMethod())
             return;
         final boolean hasMoreThanOneSubtype = mRichImm.getMyEnabledInputMethodSubtypeList(false).size() > 1;
-        // switch subtype if wanted and possible
+        // switch subtype if wanted, do nothing if no other subtype is available
-        if (switchSubtype && !switchIme && hasMoreThanOneSubtype) {
+        if (switchSubtype && !switchIme) {
+            if (hasMoreThanOneSubtype)
                 // switch to previous subtype if current one was used, otherwise cycle through list
                 mSubtypeState.switchSubtype(mRichImm);
             return;

app/src/main/java/helium314/keyboard/latin/RichInputMethodManager.java

@@ -360,6 +360,14 @@ public class RichInputMethodManager {
         mCurrentRichInputMethodSubtype = RichInputMethodSubtype.getRichInputMethodSubtype(subtype);
     }
 
+    public boolean canSwitchLanguage() {
+        if (Settings.getInstance().getCurrent().mLanguageSwitchKeyToOtherSubtypes && hasMultipleEnabledSubtypesInThisIme(false))
+            return true;
+        if (Settings.getInstance().getCurrent().mLanguageSwitchKeyToOtherImes && mImm.getEnabledInputMethodList().size() > 1)
+            return true;
+        return false;
+    }
+
     // todo: is shortcutIme only voice input, or can it be something else?
     //  if always voice input, rename it and other things like mHasShortcutKey
     private void updateShortcutIme() {

app/src/main/java/helium314/keyboard/latin/settings/PreferencesSettingsFragment.java

@@ -77,7 +77,8 @@ public final class PreferencesSettingsFragment extends SubScreenFragment {
         if (key == null) return;
         switch (key) {
             case Settings.PREF_POPUP_KEYS_ORDER, Settings.PREF_SHOW_POPUP_HINTS, Settings.PREF_SHOW_NUMBER_ROW,
-                    Settings.PREF_POPUP_KEYS_LABELS_ORDER -> mReloadKeyboard = true;
+                    Settings.PREF_POPUP_KEYS_LABELS_ORDER, Settings.PREF_LANGUAGE_SWITCH_KEY,
+                    Settings.PREF_SHOW_LANGUAGE_SWITCH_KEY -> mReloadKeyboard = true;
             case Settings.PREF_LOCALIZED_NUMBER_ROW -> KeyboardLayoutSet.onSystemLocaleChanged();
             case Settings.PREF_SHOW_HINTS
                     -> findPreference(Settings.PREF_POPUP_KEYS_LABELS_ORDER).setVisible(prefs.getBoolean(Settings.PREF_SHOW_HINTS, false));