Dude gave 2 stars cause of this

Hopefully he gives the app at least 3 stars now

core/base/src/main/res/values/strings.xml

@@ -1368,4 +1368,6 @@ Used in this dialog window. Should be short -->
     <string name="yesterday">Yesterday</string>
     <string name="search_text_field_placeholder">Search…</string>
     <string name="add_time_zone_title">Add time zone</string>
+    <string name="middle_zero_option">Zero in the middle</string>
+    <string name="middle_zero_option_support">Swap zero and decimal buttons</string>
 </resources>

data/userprefs/src/main/java/com/sadellie/unitto/data/userprefs/UserPreferences.kt

@@ -83,6 +83,7 @@ data class UserPreferences(
     val unitConverterFavoritesOnly: Boolean = false,
     val unitConverterFormatTime: Boolean = false,
     val unitConverterSorting: UnitsListSorting = UnitsListSorting.USAGE,
+    val middleZero: Boolean = false,
 )
 
 data class UIPreferences(
@@ -107,6 +108,7 @@ data class MainPreferences(
     val unitConverterFavoritesOnly: Boolean = false,
     val unitConverterFormatTime: Boolean = false,
     val unitConverterSorting: UnitsListSorting = UnitsListSorting.USAGE,
+    val middleZero: Boolean = false,
 )
 
 /**
@@ -135,6 +137,7 @@ class UserPreferencesRepository @Inject constructor(private val dataStore: DataS
         val UNIT_CONVERTER_FAVORITES_ONLY = booleanPreferencesKey("UNIT_CONVERTER_FAVORITES_ONLY_PREF_KEY")
         val UNIT_CONVERTER_FORMAT_TIME = booleanPreferencesKey("UNIT_CONVERTER_FORMAT_TIME_PREF_KEY")
         val UNIT_CONVERTER_SORTING = stringPreferencesKey("UNIT_CONVERTER_SORTING_PREF_KEY")
+        val MIDDLE_ZERO = booleanPreferencesKey("MIDDLE_ZERO_PREF_KEY")
     }
 
     val uiPreferencesFlow: Flow<UIPreferences> = dataStore.data
@@ -199,6 +202,7 @@ class UserPreferencesRepository @Inject constructor(private val dataStore: DataS
             val unitConverterFavoritesOnly: Boolean = preferences[PrefsKeys.UNIT_CONVERTER_FAVORITES_ONLY] ?: false
             val unitConverterFormatTime: Boolean = preferences[PrefsKeys.UNIT_CONVERTER_FORMAT_TIME] ?: false
             val unitConverterSorting: UnitsListSorting = preferences[PrefsKeys.UNIT_CONVERTER_SORTING]?.let { UnitsListSorting.valueOf(it) } ?: UnitsListSorting.USAGE
+            val middleZero: Boolean = preferences[PrefsKeys.MIDDLE_ZERO] ?: false
 
             MainPreferences(
                 digitsPrecision = digitsPrecision,
@@ -212,6 +216,7 @@ class UserPreferencesRepository @Inject constructor(private val dataStore: DataS
                 unitConverterFavoritesOnly = unitConverterFavoritesOnly,
                 unitConverterFormatTime = unitConverterFormatTime,
                 unitConverterSorting = unitConverterSorting,
+                middleZero = middleZero,
             )
         }
 
@@ -237,6 +242,7 @@ class UserPreferencesRepository @Inject constructor(private val dataStore: DataS
             unitConverterFavoritesOnly = main.unitConverterFavoritesOnly,
             unitConverterFormatTime = main.unitConverterFormatTime,
             unitConverterSorting = main.unitConverterSorting,
+            middleZero = main.middleZero,
         )
     }
 
@@ -370,6 +376,17 @@ class UserPreferencesRepository @Inject constructor(private val dataStore: DataS
         }
     }
 
+    /**
+     * Update preference on where zero should be.
+     *
+     * @param enabled True if user wants zero button to be in the middle.
+     */
+    suspend fun updateMiddleZero(enabled: Boolean) {
+        dataStore.edit { preferences ->
+            preferences[PrefsKeys.MIDDLE_ZERO] = enabled
+        }
+    }
+
     /**
      * Update preference on whether or not show tools screen.
      *

feature/calculator/src/main/java/com/sadellie/unitto/feature/calculator/CalculatorScreen.kt

@@ -278,7 +278,8 @@ private fun CalculatorScreen(
                 clearSymbols = clearSymbols,
                 deleteSymbol = deleteSymbol,
                 toggleAngleMode = toggleAngleMode,
-                evaluate = evaluate
+                evaluate = evaluate,
+                middleZero = uiState.middleZero,
             )
         }
     }

feature/calculator/src/main/java/com/sadellie/unitto/feature/calculator/CalculatorUIState.kt

@@ -30,7 +30,8 @@ data class CalculatorUIState(
     val radianMode: Boolean = true,
     val history: List<HistoryItem> = emptyList(),
     val allowVibration: Boolean = false,
-    val formatterSymbols: FormatterSymbols = FormatterSymbols.Spaces
+    val formatterSymbols: FormatterSymbols = FormatterSymbols.Spaces,
+    val middleZero: Boolean = false,
 )
 
 sealed class CalculationResult(@StringRes val label: Int? = null) {

feature/calculator/src/main/java/com/sadellie/unitto/feature/calculator/CalculatorViewModel.kt

@@ -75,7 +75,8 @@ internal class CalculatorViewModel @Inject constructor(
             radianMode = userPrefs.radianMode,
             history = history,
             allowVibration = userPrefs.enableVibrations,
-            formatterSymbols = AllFormatterSymbols.getById(userPrefs.separator)
+            formatterSymbols = AllFormatterSymbols.getById(userPrefs.separator),
+            middleZero = userPrefs.middleZero,
         )
     }.stateIn(
         viewModelScope, SharingStarted.WhileSubscribed(5000L), CalculatorUIState()

feature/calculator/src/main/java/com/sadellie/unitto/feature/calculator/components/CalculatorKeyboard.kt

@@ -104,6 +104,7 @@ internal fun CalculatorKeyboard(
     radianMode: Boolean,
     fractional: String,
     allowVibration: Boolean,
+    middleZero: Boolean,
     addSymbol: (String) -> Unit,
     clearSymbols: () -> Unit,
     deleteSymbol: () -> Unit,
@@ -116,6 +117,7 @@ internal fun CalculatorKeyboard(
             radianMode = radianMode,
             fractional = fractional,
             allowVibration = allowVibration,
+            middleZero = middleZero,
             addSymbol = addSymbol,
             toggleAngleMode = toggleAngleMode,
             deleteSymbol = deleteSymbol,
@@ -128,6 +130,7 @@ internal fun CalculatorKeyboard(
             radianMode = radianMode,
             fractional = fractional,
             allowVibration = allowVibration,
+            middleZero = middleZero,
             addSymbol = addSymbol,
             toggleAngleMode = toggleAngleMode,
             deleteSymbol = deleteSymbol,
@@ -143,6 +146,7 @@ private fun PortraitKeyboard(
     radianMode: Boolean,
     fractional: String,
     allowVibration: Boolean,
+    middleZero: Boolean,
     addSymbol: (String) -> Unit,
     toggleAngleMode: () -> Unit,
     deleteSymbol: () -> Unit,
@@ -257,8 +261,13 @@ private fun PortraitKeyboard(
             KeyboardButtonFilled(mainButtonModifier, UnittoIcons.Plus, allowVibration) { addSymbol(Token.Operator.plus) }
         }
         Row(weightModifier) {
+            if (middleZero) {
+                KeyboardButtonLight(mainButtonModifier, fractionalIcon, allowVibration) { addSymbol(Token.Digit.dot) }
+                KeyboardButtonLight(mainButtonModifier, UnittoIcons.Key0, allowVibration) { addSymbol(Token.Digit._0) }
+            } else {
                 KeyboardButtonLight(mainButtonModifier, UnittoIcons.Key0, allowVibration) { addSymbol(Token.Digit._0) }
                 KeyboardButtonLight(mainButtonModifier, fractionalIcon, allowVibration) { addSymbol(Token.Digit.dot) }
+            }
             KeyboardButtonLight(mainButtonModifier, UnittoIcons.Backspace, allowVibration, clearSymbols) { deleteSymbol() }
             KeyboardButtonFilled(mainButtonModifier, UnittoIcons.Equal, allowVibration) { evaluate() }
         }
@@ -345,6 +354,7 @@ private fun LandscapeKeyboard(
     radianMode: Boolean,
     fractional: String,
     allowVibration: Boolean,
+    middleZero: Boolean,
     addSymbol: (String) -> Unit,
     toggleAngleMode: () -> Unit,
     deleteSymbol: () -> Unit,
@@ -390,14 +400,22 @@ private fun LandscapeKeyboard(
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key7, allowVibration) { addSymbol(Token.Digit._7) }
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key4, allowVibration) { addSymbol(Token.Digit._4) }
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key1, allowVibration) { addSymbol(Token.Digit._1) }
+            if (middleZero) {
+                KeyboardButtonLight(buttonModifier, fractionalIcon, allowVibration) { addSymbol(Token.Digit.dot) }
+            } else {
                 KeyboardButtonLight(buttonModifier, UnittoIcons.Key0, allowVibration) { addSymbol(Token.Digit._0) }
             }
+        }
         Column(Modifier.weight(1f)) {
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key8, allowVibration) { addSymbol(Token.Digit._8) }
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key5, allowVibration) { addSymbol(Token.Digit._5) }
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key2, allowVibration) { addSymbol(Token.Digit._2) }
+            if (middleZero) {
+                KeyboardButtonLight(buttonModifier, UnittoIcons.Key0, allowVibration) { addSymbol(Token.Digit._0) }
+            } else {
                 KeyboardButtonLight(buttonModifier, fractionalIcon, allowVibration) { addSymbol(Token.Digit.dot) }
             }
+        }
         Column(Modifier.weight(1f)) {
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key9, allowVibration) { addSymbol(Token.Digit._9) }
             KeyboardButtonLight(buttonModifier, UnittoIcons.Key6, allowVibration) { addSymbol(Token.Digit._6) }
@@ -496,6 +514,7 @@ private fun PreviewCalculatorKeyboard() {
         deleteSymbol = {},
         toggleAngleMode = {},
         evaluate = {},
-        allowVibration = false
+        allowVibration = false,
+        middleZero = false,
     )
 }

feature/converter/src/main/java/com/sadellie/unitto/feature/converter/ConverterScreen.kt

@@ -121,6 +121,7 @@ private fun ConverterScreen(
                         converterMode = uiState.mode,
                         allowVibration = uiState.allowVibration,
                         fractional = uiState.formatterSymbols.fractional,
+                        middleZero = uiState.middleZero
                     )
                 }
             )

feature/converter/src/main/java/com/sadellie/unitto/feature/converter/ConverterUIState.kt

@@ -47,6 +47,7 @@ data class ConverterUIState(
     val unitTo: AbstractUnit? = null,
     val mode: ConverterMode = ConverterMode.DEFAULT,
     val allowVibration: Boolean = false,
+    val middleZero: Boolean = false,
     val formatterSymbols: FormatterSymbols = FormatterSymbols.Spaces,
 )
 

feature/converter/src/main/java/com/sadellie/unitto/feature/converter/ConverterViewModel.kt

@@ -126,7 +126,8 @@ class ConverterViewModel @Inject constructor(
             unitTo = unitToValue,
             mode = if (_unitFrom.value is NumberBaseUnit) ConverterMode.BASE else ConverterMode.DEFAULT,
             allowVibration = prefs.enableVibrations,
-            formatterSymbols = AllFormatterSymbols.getById(prefs.separator)
+            formatterSymbols = AllFormatterSymbols.getById(prefs.separator),
+            middleZero = prefs.middleZero,
         )
     }.stateIn(
         viewModelScope, SharingStarted.WhileSubscribed(5000), ConverterUIState()

feature/converter/src/main/java/com/sadellie/unitto/feature/converter/components/ConverterKeyboard.kt

@@ -78,10 +78,11 @@ internal fun ConverterKeyboard(
     converterMode: ConverterMode,
     allowVibration: Boolean,
     fractional: String,
+    middleZero: Boolean,
 ) {
     Crossfade(converterMode, modifier = modifier) {
         when (it) {
-            ConverterMode.DEFAULT -> DefaultKeyboard(addDigit, clearInput, deleteDigit, allowVibration, fractional)
+            ConverterMode.DEFAULT -> DefaultKeyboard(addDigit, clearInput, deleteDigit, allowVibration, fractional, middleZero)
             ConverterMode.BASE -> BaseKeyboard(addDigit, clearInput, deleteDigit, allowVibration)
         }
     }
@@ -94,6 +95,7 @@ private fun DefaultKeyboard(
     deleteDigit: () -> Unit,
     allowVibration: Boolean,
     fractional: String,
+    middleZero: Boolean,
 ) {
     val fractionalIcon = remember { if (fractional == Token.Digit.dot) UnittoIcons.Dot else UnittoIcons.Comma }
     ColumnWithConstraints {
@@ -129,8 +131,13 @@ private fun DefaultKeyboard(
             KeyboardButtonFilled(bModifier, UnittoIcons.Minus, allowVibration) { addDigit(Token.Operator.minus) }
         }
         Row(cModifier, horizontalArrangement) {
+            if (middleZero) {
+                KeyboardButtonLight(bModifier, fractionalIcon, allowVibration) { addDigit(Token.Digit.dot) }
+                KeyboardButtonLight(bModifier, UnittoIcons.Key0, allowVibration) { addDigit(Token.Digit._0) }
+            } else {
                 KeyboardButtonLight(bModifier, UnittoIcons.Key0, allowVibration) { addDigit(Token.Digit._0) }
                 KeyboardButtonLight(bModifier, fractionalIcon, allowVibration) { addDigit(Token.Digit.dot) }
+            }
             KeyboardButtonLight(bModifier, UnittoIcons.Backspace, allowVibration, clearInput) { deleteDigit() }
             KeyboardButtonFilled(bModifier, UnittoIcons.Plus, allowVibration) { addDigit(Token.Operator.plus) }
         }

feature/settings/src/main/java/com/sadellie/unitto/feature/settings/SettingsScreen.kt

@@ -21,6 +21,7 @@ package com.sadellie.unitto.feature.settings
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ExposureZero
 import androidx.compose.material.icons.filled.Home
 import androidx.compose.material.icons.filled.Info
 import androidx.compose.material.icons.filled.Palette
@@ -173,6 +174,22 @@ internal fun SettingsScreen(
             // ADDITIONAL GROUP
             item { Header(stringResource(R.string.additional_settings_group)) }
 
+            // MIDDLE ZERO
+            item {
+                UnittoListItem(
+                    label = stringResource(R.string.middle_zero_option),
+                    leadingContent = {
+                        Icon(
+                            Icons.Default.ExposureZero,
+                            stringResource(R.string.middle_zero_option)
+                        )
+                    },
+                    supportContent = stringResource(R.string.middle_zero_option_support),
+                    switchState = userPrefs.value.middleZero,
+                    onSwitchChange = viewModel::updateMiddleZero
+                )
+            }
+
             // VIBRATIONS
             item {
                 UnittoListItem(

feature/settings/src/main/java/com/sadellie/unitto/feature/settings/SettingsViewModel.kt

@@ -49,6 +49,15 @@ class SettingsViewModel @Inject constructor(
         }
     }
 
+    /**
+     * @see UserPreferencesRepository.updateMiddleZero
+     */
+    fun updateMiddleZero(enabled: Boolean) {
+        viewModelScope.launch {
+            userPrefsRepository.updateMiddleZero(enabled)
+        }
+    }
+
     /**
      * @see UserPreferencesRepository.updateStartingScreen
      */