feat: Add feature to change app theme and enable pure black dark theme

Closes: #30

app/src/main/java/org/nsh07/pomodoro/ui/settingsScreen/SettingsScreen.kt

@@ -130,7 +130,7 @@ fun SettingsScreenRoot(
         alarmSound = alarmSound,
         onAlarmEnabledChange = viewModel::saveAlarmEnabled,
         onVibrateEnabledChange = viewModel::saveVibrateEnabled,
-        onBlackThemeChange = {},
+        onBlackThemeChange = viewModel::saveBlackTheme,
         onAlarmSoundChanged = {
             viewModel.saveAlarmSound(it)
             Intent(context, TimerService::class.java).apply {
@@ -138,6 +138,7 @@ fun SettingsScreenRoot(
                 context.startService(this)
             }
         },
+        onThemeChange = viewModel::saveTheme,
         modifier = modifier
     )
 }
@@ -157,6 +158,7 @@ private fun SettingsScreen(
     onVibrateEnabledChange: (Boolean) -> Unit,
     onBlackThemeChange: (Boolean) -> Unit,
     onAlarmSoundChanged: (Uri?) -> Unit,
+    onThemeChange: (String) -> Unit,
     modifier: Modifier = Modifier
 ) {
     val scrollBehavior = TopAppBarDefaults.exitUntilCollapsedScrollBehavior()
@@ -164,6 +166,24 @@ private fun SettingsScreen(
         checkedIconColor = colorScheme.primary,
     )
 
+    val themeMap: Map<String, Pair<Int, String>> = remember {
+        mapOf(
+            "auto" to Pair(
+                R.drawable.brightness_auto,
+                "System default"
+            ),
+            "light" to Pair(R.drawable.light_mode, "Light"),
+            "dark" to Pair(R.drawable.dark_mode, "Dark")
+        )
+    }
+    val reverseThemeMap: Map<String, String> = remember {
+        mapOf(
+            "System default" to "auto",
+            "Light" to "light",
+            "Dark" to "dark"
+        )
+    }
+
     val context = LocalContext.current
 
     val ringtonePickerLauncher = rememberLauncherForActivityResult(
@@ -190,7 +210,7 @@ private fun SettingsScreen(
         putExtra(RingtoneManager.EXTRA_RINGTONE_EXISTING_URI, alarmSound.toUri())
     }
 
-    val switchItems = remember(alarmEnabled, vibrateEnabled) {
+    val switchItems = remember(preferencesState.blackTheme, alarmEnabled, vibrateEnabled) {
         listOf(
             SettingsSwitchItem(
                 checked = preferencesState.blackTheme,
@@ -360,33 +380,13 @@ private fun SettingsScreen(
                 )
             }
             item {
-                ListItem(
+                ThemePickerListItem(
-                    leadingContent = {
+                    theme = preferencesState.theme,
-                        Icon(
+                    themeMap = themeMap,
-                            painter = painterResource(
+                    reverseThemeMap = reverseThemeMap,
-                                when (preferencesState.theme) {
+                    onThemeChange = onThemeChange,
-                                    "dark" -> R.drawable.dark_mode
-                                    "light" -> R.drawable.light_mode
-                                    else -> R.drawable.brightness_auto
-                                }
-                            ),
-                            contentDescription = null
-                        )
-                    },
-                    headlineContent = { Text("Theme") },
-                    supportingContent = {
-                        Text(
-                            when (preferencesState.theme) {
-                                "dark" -> "Dark"
-                                "light" -> "Light"
-                                else -> "System default"
-                            }
-                        )
-                    },
-                    colors = listItemColors,
                     modifier = Modifier
                         .clip(middleListItemShape)
-                        .clickable(onClick = {})
                 )
             }
             item {
@@ -436,7 +436,7 @@ private fun SettingsScreen(
                         Text(
                             remember(alarmSound) {
                                 RingtoneManager.getRingtone(context, alarmSound.toUri())
-                                    .getTitle(context)
+                                    ?.getTitle(context) ?: ""
                             }
                         )
                     },
@@ -530,9 +530,9 @@ fun SettingsScreenPreview() {
     TomatoTheme {
         SettingsScreen(
             preferencesState = PreferencesState(),
-            focusTimeInputFieldState = rememberTextFieldState((25 * 60 * 1000).toString()),
+            focusTimeInputFieldState = rememberTextFieldState((25).toString()),
-            shortBreakTimeInputFieldState = rememberTextFieldState((5 * 60 * 1000).toString()),
+            shortBreakTimeInputFieldState = rememberTextFieldState((5).toString()),
-            longBreakTimeInputFieldState = rememberTextFieldState((15 * 60 * 1000).toString()),
+            longBreakTimeInputFieldState = rememberTextFieldState((15).toString()),
             sessionsSliderState = rememberSliderState(value = 3f, steps = 3, valueRange = 1f..5f),
             alarmEnabled = true,
             vibrateEnabled = true,
@@ -541,6 +541,7 @@ fun SettingsScreenPreview() {
             onVibrateEnabledChange = {},
             onBlackThemeChange = {},
             onAlarmSoundChanged = {},
+            onThemeChange = {},
             modifier = Modifier.fillMaxSize()
         )
     }

app/src/main/java/org/nsh07/pomodoro/ui/settingsScreen/ThemeDialog.kt

@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2025 Nishant Mishra
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.nsh07.pomodoro.ui.settingsScreen
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.wrapContentHeight
+import androidx.compose.foundation.layout.wrapContentWidth
+import androidx.compose.foundation.selection.selectable
+import androidx.compose.foundation.selection.selectableGroup
+import androidx.compose.material3.AlertDialogDefaults
+import androidx.compose.material3.BasicAlertDialog
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
+import androidx.compose.material3.ListItem
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.MaterialTheme.colorScheme
+import androidx.compose.material3.MaterialTheme.shapes
+import androidx.compose.material3.RadioButton
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.semantics.Role
+import androidx.compose.ui.unit.dp
+import org.nsh07.pomodoro.ui.theme.CustomColors.listItemColors
+import org.nsh07.pomodoro.ui.theme.TomatoShapeDefaults.bottomListItemShape
+import org.nsh07.pomodoro.ui.theme.TomatoShapeDefaults.middleListItemShape
+import org.nsh07.pomodoro.ui.theme.TomatoShapeDefaults.topListItemShape
+
+@OptIn(ExperimentalMaterial3Api::class, ExperimentalMaterial3ExpressiveApi::class)
+@Composable
+fun ThemeDialog(
+    themeMap: Map<String, Pair<Int, String>>,
+    reverseThemeMap: Map<String, String>,
+    theme: String,
+    setShowThemeDialog: (Boolean) -> Unit,
+    onThemeChange: (String) -> Unit
+) {
+    val selectedOption =
+        remember { mutableStateOf(themeMap[theme]!!.second) }
+
+    BasicAlertDialog(
+        onDismissRequest = { setShowThemeDialog(false) }
+    ) {
+        Surface(
+            modifier = Modifier
+                .wrapContentWidth()
+                .wrapContentHeight(),
+            shape = shapes.extraLarge,
+            color = colorScheme.surfaceContainer,
+            tonalElevation = AlertDialogDefaults.TonalElevation
+        ) {
+            Column(modifier = Modifier.padding(24.dp)) {
+                Text(
+                    text = "Choose theme",
+                    style = MaterialTheme.typography.headlineSmall
+                )
+                Spacer(modifier = Modifier.height(24.dp))
+                Column(
+                    verticalArrangement = Arrangement.spacedBy(2.dp),
+                    modifier = Modifier.selectableGroup()
+                ) {
+                    themeMap.entries.forEachIndexed { index: Int, pair: Map.Entry<String, Pair<Int, String>> ->
+                        val text = pair.value.second
+                        ListItem(
+                            leadingContent = {
+                                RadioButton(
+                                    selected = (text == selectedOption.value),
+                                    onClick = null // null recommended for accessibility with screenreaders
+                                )
+                            },
+                            headlineContent = {
+                                Text(
+                                    text = text,
+                                    style = MaterialTheme.typography.bodyLarge,
+                                )
+                            },
+                            colors = listItemColors,
+                            modifier = Modifier
+                                .clip(
+                                    when (index) {
+                                        0 -> topListItemShape
+                                        themeMap.size - 1 -> bottomListItemShape
+                                        else -> middleListItemShape
+                                    }
+                                )
+                                .selectable(
+                                    selected = (text == selectedOption.value),
+                                    onClick = {
+                                        selectedOption.value = text
+                                        onThemeChange(reverseThemeMap[selectedOption.value]!!)
+                                    },
+                                    role = Role.RadioButton
+                                )
+                        )
+                    }
+                }
+                Spacer(modifier = Modifier.height(24.dp))
+                TextButton(
+                    shapes = ButtonDefaults.shapes(),
+                    onClick = { setShowThemeDialog(false) },
+                    modifier = Modifier.align(Alignment.End)
+                ) {
+                    Text("Ok")
+                }
+            }
+        }
+    }
+}

app/src/main/java/org/nsh07/pomodoro/ui/settingsScreen/ThemePickerListItem.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2025 Nishant Mishra
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.nsh07.pomodoro.ui.settingsScreen
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ListItem
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.painterResource
+import org.nsh07.pomodoro.ui.theme.CustomColors.listItemColors
+
+@Composable
+fun ThemePickerListItem(
+    theme: String,
+    themeMap: Map<String, Pair<Int, String>>,
+    reverseThemeMap: Map<String, String>,
+    onThemeChange: (String) -> Unit,
+    modifier: Modifier = Modifier
+) {
+    var showDialog by rememberSaveable { mutableStateOf(false) }
+
+    if (showDialog) {
+        ThemeDialog(
+            themeMap = themeMap,
+            reverseThemeMap = reverseThemeMap,
+            theme = theme,
+            setShowThemeDialog = { showDialog = it },
+            onThemeChange = onThemeChange
+        )
+    }
+
+    ListItem(
+        leadingContent = {
+            Icon(
+                painter = painterResource(themeMap[theme]!!.first),
+                contentDescription = null
+            )
+        },
+        headlineContent = { Text("Theme") },
+        supportingContent = {
+            Text(themeMap[theme]!!.second)
+        },
+        colors = listItemColors,
+        modifier = modifier
+            .fillMaxWidth()
+            .clickable { showDialog = true }
+    )
+}

app/src/main/java/org/nsh07/pomodoro/ui/settingsScreen/viewModel/PreferencesState.kt

@@ -12,7 +12,7 @@ import androidx.compose.ui.graphics.Color
 
 @Immutable
 data class PreferencesState(
-    val theme: String = "system",
+    val theme: String = "auto",
     val colorScheme: String = Color.White.toString(),
     val blackTheme: Boolean = false
 )

app/src/main/java/org/nsh07/pomodoro/ui/settingsScreen/viewModel/SettingsViewModel.kt

@@ -65,7 +65,7 @@ class SettingsViewModel(
     init {
         viewModelScope.launch {
             val theme = preferenceRepository.getStringPreference("theme")
-                ?: preferenceRepository.saveStringPreference("theme", "system")
+                ?: preferenceRepository.saveStringPreference("theme", "auto")
             val colorScheme = preferenceRepository.getStringPreference("color_scheme")
                 ?: preferenceRepository.saveStringPreference("color_scheme", Color.White.toString())
             val blackTheme = preferenceRepository.getBooleanPreference("black_theme")
@@ -128,50 +128,50 @@ class SettingsViewModel(
 
     fun saveAlarmEnabled(enabled: Boolean) {
         viewModelScope.launch {
-            preferenceRepository.saveBooleanPreference("alarm_enabled", enabled)
             timerRepository.alarmEnabled = enabled
+            preferenceRepository.saveBooleanPreference("alarm_enabled", enabled)
         }
     }
 
     fun saveVibrateEnabled(enabled: Boolean) {
         viewModelScope.launch {
-            preferenceRepository.saveBooleanPreference("vibrate_enabled", enabled)
             timerRepository.vibrateEnabled = enabled
+            preferenceRepository.saveBooleanPreference("vibrate_enabled", enabled)
         }
     }
 
     fun saveAlarmSound(uri: Uri?) {
         viewModelScope.launch {
+            timerRepository.alarmSoundUri = uri
             preferenceRepository.saveStringPreference("alarm_sound", uri.toString())
         }
-        timerRepository.alarmSoundUri = uri
     }
 
     fun saveColorScheme(colorScheme: Color) {
         viewModelScope.launch {
+            _preferencesState.update { currentState ->
+                currentState.copy(colorScheme = colorScheme.toString())
+            }
             preferenceRepository.saveStringPreference("color_scheme", colorScheme.toString())
         }
-        _preferencesState.update { currentState ->
-            currentState.copy(colorScheme = colorScheme.toString())
-        }
     }
 
     fun saveTheme(theme: String) {
         viewModelScope.launch {
+            _preferencesState.update { currentState ->
+                currentState.copy(theme = theme)
+            }
             preferenceRepository.saveStringPreference("theme", theme)
         }
-        _preferencesState.update { currentState ->
-            currentState.copy(theme = theme)
-        }
     }
 
     fun saveBlackTheme(blackTheme: Boolean) {
         viewModelScope.launch {
+            _preferencesState.update { currentState ->
+                currentState.copy(blackTheme = blackTheme)
+            }
             preferenceRepository.saveBooleanPreference("black_theme", blackTheme)
         }
-        _preferencesState.update { currentState ->
-            currentState.copy(blackTheme = blackTheme)
-        }
     }
 
     companion object {

app/src/main/java/org/nsh07/pomodoro/ui/theme/Color.kt

@@ -18,15 +18,17 @@ val PurpleGrey40 = Color(0xFF625b71)
 val Pink40 = Color(0xFF7D5260)
 
 object CustomColors {
+    var black = false
+
     @OptIn(ExperimentalMaterial3Api::class)
     val topBarColors: TopAppBarColors
-        @Composable get() {
+        @Composable get() =
-            return TopAppBarDefaults.topAppBarColors(
+            TopAppBarDefaults.topAppBarColors(
-                containerColor = colorScheme.surfaceContainer,
+                containerColor = if (!black) colorScheme.surfaceContainer else colorScheme.surface,
-                scrolledContainerColor = colorScheme.surfaceContainer
+                scrolledContainerColor = if (!black) colorScheme.surfaceContainer else colorScheme.surface
             )
-        }
 
     val listItemColors: ListItemColors
-        @Composable get() = ListItemDefaults.colors(containerColor = colorScheme.surfaceBright)
+        @Composable get() =
+            ListItemDefaults.colors(containerColor = if (!black) colorScheme.surfaceBright else colorScheme.surfaceContainer)
 }

app/src/main/java/org/nsh07/pomodoro/ui/theme/Theme.kt

@@ -1,5 +1,6 @@
 package org.nsh07.pomodoro.ui.theme
 
+import android.app.Activity
 import android.os.Build
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
@@ -10,8 +11,11 @@ import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
 import androidx.compose.material3.lightColorScheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalView
+import androidx.core.view.WindowCompat
 import com.materialkolor.dynamiccolor.ColorSpec
 import com.materialkolor.rememberDynamicColorScheme
 
@@ -56,6 +60,15 @@ fun TomatoTheme(
         else -> LightColorScheme
     }
 
+    val view = LocalView.current
+    if (!view.isInEditMode) {
+        SideEffect {
+            val window = (view.context as Activity).window
+            WindowCompat.getInsetsController(window, view).isAppearanceLightStatusBars = !darkTheme
+        }
+    }
+    CustomColors.black = blackTheme && darkTheme
+
     val dynamicColorScheme = rememberDynamicColorScheme(
         seedColor = when (seedColor) {
             Color.White -> colorScheme.primary