improve language swipe cycling

app/src/main/java/helium314/keyboard/keyboard/KeyboardActionListener.java

@@ -97,6 +97,7 @@ public interface KeyboardActionListener {
      */
     boolean onHorizontalSpaceSwipe(int steps);
     boolean onVerticalSpaceSwipe(int steps);
+    void resetSubtypeSwitchCount();
 
     void onMoveDeletePointer(int steps);
     void onUpWithDeletePointerActive();
@@ -142,6 +143,8 @@ public boolean onVerticalSpaceSwipe(int steps) {
             return false;
         }
         @Override
+        public void resetSubtypeSwitchCount() {}
+        @Override
         public void onMoveDeletePointer(int steps) {}
         @Override
         public void onUpWithDeletePointerActive() {}

app/src/main/java/helium314/keyboard/keyboard/KeyboardActionListenerImpl.kt

@@ -14,6 +14,7 @@ class KeyboardActionListenerImpl(private val latinIME: LatinIME, private val inp
 
     private val keyboardSwitcher = KeyboardSwitcher.getInstance()
     private val settings = Settings.getInstance()
+    private var mSubtypeSwitchCount = 0 // for use with onLanguageSlide()
     private var metaState = 0 // is this enough, or are there threading issues with the different PointerTrackers?
 
     // todo: maybe keep meta state presses to KeyboardActionListenerImpl, and avoid calls to press/release key
@@ -96,9 +97,9 @@ class KeyboardActionListenerImpl(private val latinIME: LatinIME, private val inp
     }
 
     private fun onLanguageSlide(steps: Int): Boolean {
-        if (abs(steps) < 4) return false
+        if (abs(steps) < settings.current.mLanguageSwipeDistance) return false
         val subtypes = RichInputMethodManager.getInstance().getMyEnabledInputMethodSubtypeList(false)
-        if (subtypes.size <= 1) { // only allow if we have more than one subtype
+        if (subtypes.size - 1 <= abs(mSubtypeSwitchCount)) { // only allow if we are yet to cycle through all subtypes
             return false
         }
         // decide next or previous dependent on up or down
@@ -108,9 +109,14 @@ class KeyboardActionListenerImpl(private val latinIME: LatinIME, private val inp
         if (wantedIndex < 0)
             wantedIndex += subtypes.size
         KeyboardSwitcher.getInstance().switchToSubtype(subtypes[wantedIndex])
+        if (steps > 0) mSubtypeSwitchCount++ else mSubtypeSwitchCount--
         return true
     }
 
+    override fun resetSubtypeSwitchCount(){
+        mSubtypeSwitchCount = 0
+    }
+
     private fun onMoveCursorVertically(steps: Int): Boolean {
         if (steps == 0) return false
         val code = if (steps < 0) KeyCode.ARROW_UP else KeyCode.ARROW_DOWN

app/src/main/java/helium314/keyboard/keyboard/PointerTracker.java

@@ -1006,6 +1006,7 @@ private void onUpEventInternal(final int x, final int y, final long eventTime) {
         if (mInHorizontalSwipe || mInVerticalSwipe) {
             mInHorizontalSwipe = false;
             mInVerticalSwipe = false;
+            sListener.resetSubtypeSwitchCount();
             return;
         }
 

app/src/main/java/helium314/keyboard/latin/settings/AdvancedSettingsFragment.kt

@@ -20,6 +20,7 @@ import androidx.preference.PreferenceManager
 import kotlinx.serialization.encodeToString
 import kotlinx.serialization.json.Json
 import helium314.keyboard.dictionarypack.DictionaryPackConstants
+import helium314.keyboard.keyboard.KeyboardActionListener
 import helium314.keyboard.latin.utils.ChecksumCalculator
 import helium314.keyboard.keyboard.KeyboardLayoutSet
 import helium314.keyboard.keyboard.KeyboardSwitcher
@@ -126,6 +127,8 @@ class AdvancedSettingsFragment : SubScreenFragment() {
             removePreference("load_gesture_library")
         }
         setupKeyLongpressTimeoutSettings()
+        setupLanguageSwipeDistanceSettings()
+        updateLangSwipeDistanceVisibility(sharedPreferences)
         findPreference<Preference>("load_gesture_library")?.setOnPreferenceClickListener { onClickLoadLibrary() }
         findPreference<Preference>("backup_restore")?.setOnPreferenceClickListener { showBackupRestoreDialog() }
 
@@ -469,10 +472,37 @@ class AdvancedSettingsFragment : SubScreenFragment() {
         })
     }
 
+    private fun setupLanguageSwipeDistanceSettings() {
+        val prefs = sharedPreferences
+        findPreference<SeekBarDialogPreference>(Settings.PREF_LANGUAGE_SWIPE_DISTANCE)?.setInterface(object : ValueProxy {
+            override fun writeValue(value: Int, key: String) = prefs.edit().putInt(key, value).apply()
+
+            override fun writeDefaultValue(key: String) = prefs.edit().remove(key).apply()
+
+            override fun readValue(key: String) = Settings.readLanguageSwipeDistance(prefs, resources)
+
+            override fun readDefaultValue(key: String) = Settings.readDefaultLanguageSwipeDistance(resources)
+
+            override fun getValueText(value: Int) = value.toString()
+
+            override fun feedbackValue(value: Int) {}
+        })
+    }
+
+    private fun updateLangSwipeDistanceVisibility(prefs: SharedPreferences) {
+        val horizontalSpaceSwipe = Settings.readHorizontalSpaceSwipe(prefs)
+        val verticalSpaceSwipe = Settings.readVerticalSpaceSwipe(prefs)
+        val visibility = horizontalSpaceSwipe == KeyboardActionListener.SWIPE_SWITCH_LANGUAGE
+                || verticalSpaceSwipe == KeyboardActionListener.SWIPE_SWITCH_LANGUAGE
+        setPreferenceVisible(Settings.PREF_LANGUAGE_SWIPE_DISTANCE, visibility)
+    }
+
     override fun onSharedPreferenceChanged(prefs: SharedPreferences, key: String?) {
         when (key) {
             Settings.PREF_SHOW_SETUP_WIZARD_ICON -> SystemBroadcastReceiver.toggleAppIcon(requireContext())
             Settings.PREF_MORE_POPUP_KEYS -> KeyboardLayoutSet.onSystemLocaleChanged()
+            Settings.PREF_SPACE_HORIZONTAL_SWIPE -> updateLangSwipeDistanceVisibility(prefs)
+            Settings.PREF_SPACE_VERTICAL_SWIPE -> updateLangSwipeDistanceVisibility(prefs)
         }
     }
 

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

@@ -133,6 +133,7 @@ public final class Settings implements SharedPreferences.OnSharedPreferenceChang
     public static final String PREF_MORE_POPUP_KEYS = "more_popup_keys";
 
     public static final String PREF_SPACE_TO_CHANGE_LANG = "prefs_long_press_keyboard_to_change_lang";
+    public static final String PREF_LANGUAGE_SWIPE_DISTANCE = "language_swipe_distance";
 
     public static final String PREF_ENABLE_CLIPBOARD_HISTORY = "enable_clipboard_history";
     public static final String PREF_CLIPBOARD_HISTORY_RETENTION_TIME = "clipboard_history_retention_time";
@@ -377,6 +378,18 @@ public static int readVerticalSpaceSwipe(final SharedPreferences prefs) {
         };
     }
 
+    public static int readLanguageSwipeDistance(final SharedPreferences prefs,
+                                                   final Resources res) {
+        final int sensitivity = prefs.getInt(
+                PREF_LANGUAGE_SWIPE_DISTANCE, UNDEFINED_PREFERENCE_VALUE_INT);
+        return (sensitivity != UNDEFINED_PREFERENCE_VALUE_INT) ? sensitivity
+                : readDefaultLanguageSwipeDistance(res);
+    }
+
+    public static int readDefaultLanguageSwipeDistance(final Resources res) {
+        return res.getInteger(R.integer.config_default_language_swipe_distance);
+    }
+
     public static boolean readDeleteSwipeEnabled(final SharedPreferences prefs) {
         return prefs.getBoolean(PREF_DELETE_SWIPE, true);
     }

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

@@ -77,6 +77,7 @@ public class SettingsValues {
     public final boolean mBlockPotentiallyOffensive;
     public final int mSpaceSwipeHorizontal;
     public final int mSpaceSwipeVertical;
+    public final int mLanguageSwipeDistance;
     public final boolean mDeleteSwipeEnabled;
     public final boolean mAutospaceAfterPunctuationEnabled;
     public final boolean mClipboardHistoryEnabled;
@@ -204,6 +205,7 @@ public SettingsValues(final Context context, final SharedPreferences prefs, fina
         mDisplayOrientation = res.getConfiguration().orientation;
         mSpaceSwipeHorizontal = Settings.readHorizontalSpaceSwipe(prefs);
         mSpaceSwipeVertical = Settings.readVerticalSpaceSwipe(prefs);
+        mLanguageSwipeDistance = Settings.readLanguageSwipeDistance(prefs, res);
         mDeleteSwipeEnabled = Settings.readDeleteSwipeEnabled(prefs);
         mAutospaceAfterPunctuationEnabled = Settings.readAutospaceAfterPunctuationEnabled(prefs);
         mClipboardHistoryEnabled = Settings.readClipboardHistoryEnabled(prefs);

app/src/main/res/values/config-common.xml

@@ -30,6 +30,11 @@
     <bool name="config_default_vibration_enabled">false</bool>
     <integer name="config_max_vibration_duration">100</integer>
 
+    <integer name="config_default_language_swipe_distance">10</integer>
+    <integer name="config_min_language_swipe_distance">2</integer>
+    <integer name="config_max_language_swipe_distance">18</integer>
+    <integer name="config_language_swipe_distance_step">1</integer>
+
     <integer name="config_default_longpress_key_timeout">300</integer>
     <integer name="config_max_longpress_timeout">700</integer>
     <integer name="config_min_longpress_timeout">100</integer>

app/src/main/res/values/strings.xml

@@ -830,6 +830,8 @@ New dictionary:
     <string name="var_toolbar_direction">Variable toolbar direction</string>
     <!-- Description of the variable toolbar direction setting -->
     <string name="var_toolbar_direction_summary">Reverse direction when a right-to-left keyboard subtype is selected</string>
+    <!-- Title of the settings for adjusting the language swipe gesture distance -->
+    <string name="prefs_language_swipe_distance">Switch language swipe distance</string>
     <!-- Toast message shown when content is copied to the clipboard -->
     <string name="toast_msg_clipboard_copy">Content copied</string>
 </resources>

app/src/main/res/xml/prefs_screen_advanced.xml

@@ -43,6 +43,13 @@
         android:title="@string/show_vertical_space_swipe"
         latin:singleLineTitle="false" />
 
+    <helium314.keyboard.latin.settings.SeekBarDialogPreference
+        android:key="language_swipe_distance"
+        android:title="@string/prefs_language_swipe_distance"
+        latin:minValue="@integer/config_min_language_swipe_distance"
+        latin:maxValue="@integer/config_max_language_swipe_distance"
+        latin:stepValue="@integer/config_language_swipe_distance_step" />
+
     <SwitchPreference
         android:key="delete_swipe"
         android:title="@string/delete_swipe"