Set firstDayOfWeek with Unicode extensions

app/src/main/java/org/tasks/activities/DateAndTimePickerActivity.kt

@@ -66,6 +66,7 @@ class DateAndTimePickerActivity : AppCompatActivity() {
                             )
                         },
                         displayMode = remember { preferences.calendarDisplayMode },
+                        firstDayOfWeek = remember { preferences.firstDayOfWeek },
                         setDisplayMode = {
                             preferences.calendarDisplayMode = it
                         },

app/src/main/java/org/tasks/compose/pickers/CustomRecurrence.kt

@@ -79,6 +79,7 @@ fun CustomRecurrence(
     setMonthSelection: (Int) -> Unit,
     calendarDisplayMode: DisplayMode,
     setDisplayMode: (DisplayMode) -> Unit,
+    firstDayOfWeek: Int,
 ) {
     BackHandler {
         save()
@@ -190,6 +191,7 @@ fun CustomRecurrence(
                         setOccurrences = setOccurrences,
                         calendarDisplayMode = calendarDisplayMode,
                         setDisplayMode = setDisplayMode,
+                        firstDayOfWeek = firstDayOfWeek,
                     )
                 }
             }
@@ -330,6 +332,7 @@ private fun EndsPicker(
     selection: Int,
     endDate: Long,
     endOccurrences: Int,
+    firstDayOfWeek: Int,
     calendarDisplayMode: DisplayMode,
     setDisplayMode: (DisplayMode) -> Unit,
     setOccurrences: (Int) -> Unit,
@@ -361,6 +364,7 @@ private fun EndsPicker(
             DatePickerDialog(
                 initialDate = endDate,
                 displayMode = calendarDisplayMode,
+                firstDayOfWeek = firstDayOfWeek,
                 setDisplayMode = setDisplayMode,
                 selected = {
                     setEndDate(it)
@@ -446,6 +450,7 @@ fun WeeklyPreview() {
             setMonthSelection = {},
             calendarDisplayMode = DisplayMode.Picker,
             setDisplayMode = {},
+            firstDayOfWeek = 0,
         )
     }
 }
@@ -469,6 +474,7 @@ fun MonthlyPreview() {
             setMonthSelection = {},
             calendarDisplayMode = DisplayMode.Picker,
             setDisplayMode = {},
+            firstDayOfWeek = 0,
         )
     }
 }
@@ -492,6 +498,7 @@ fun MinutelyPreview() {
             setMonthSelection = {},
             calendarDisplayMode = DisplayMode.Picker,
             setDisplayMode = {},
+            firstDayOfWeek = 0,
         )
     }
 }
@@ -515,6 +522,7 @@ fun HourlyPreview() {
             setMonthSelection = {},
             calendarDisplayMode = DisplayMode.Picker,
             setDisplayMode = {},
+            firstDayOfWeek = 0,
         )
     }
 }
@@ -538,6 +546,7 @@ fun DailyPreview() {
             setMonthSelection = {},
             calendarDisplayMode = DisplayMode.Picker,
             setDisplayMode = {},
+            firstDayOfWeek = 0,
         )
     }
 }
@@ -561,6 +570,7 @@ fun YearlyPreview() {
             setMonthSelection = {},
             calendarDisplayMode = DisplayMode.Picker,
             setDisplayMode = {},
+            firstDayOfWeek = 0,
         )
     }
 }

app/src/main/java/org/tasks/compose/pickers/DatePickerDialog.kt

@@ -1,6 +1,7 @@
 package org.tasks.compose.pickers
 
 import android.content.res.Configuration
+import android.os.LocaleList
 import androidx.compose.material3.DatePicker
 import androidx.compose.material3.DisplayMode
 import androidx.compose.material3.ExperimentalMaterial3Api
@@ -8,22 +9,26 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.rememberDatePickerState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalConfiguration
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.tooling.preview.Preview
 import org.tasks.R
 import org.tasks.themes.TasksTheme
 import org.tasks.time.DateTime
 import timber.log.Timber
+import java.util.Locale
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun DatePickerDialog(
     initialDate: Long,
     displayMode: DisplayMode,
+    firstDayOfWeek: Int,
     setDisplayMode: (DisplayMode) -> Unit,
     selected: (Long) -> Unit,
     dismiss: () -> Unit,
@@ -48,23 +53,51 @@ fun DatePickerDialog(
     androidx.compose.material3.DatePickerDialog(
         onDismissRequest = { dismiss() },
         dismissButton = {
-                TextButton(onClick = dismiss) {
-                    Text(text = stringResource(id = R.string.cancel))
-                }
+            TextButton(onClick = dismiss) {
+                Text(text = stringResource(id = R.string.cancel))
+            }
         },
         confirmButton = {
-                TextButton(
-                    onClick = {
-                        datePickerState
-                            .selectedDateMillis
-                            ?.let { selected(it - DateTime(it).offset) }
-                    }
-                ) {
-                    Text(text = stringResource(id = R.string.ok))
+            TextButton(
+                onClick = {
+                    datePickerState
+                        .selectedDateMillis
+                        ?.let { selected(it - DateTime(it).offset) }
                 }
+            ) {
+                Text(text = stringResource(id = R.string.ok))
             }
+        }
     ) {
-        DatePicker(state = datePickerState)
+        val currentLocale = LocalConfiguration.current.locales[0]
+        val customLocale = remember(currentLocale) {
+            if (firstDayOfWeek == 0) {
+                currentLocale
+            } else {
+                Locale.Builder()
+                    .setLocale(currentLocale)
+                    .setUnicodeLocaleKeyword(
+                        "fw",
+                        when (firstDayOfWeek) {
+                            2 -> "mon"
+                            3 -> "tue"
+                            4 -> "wed"
+                            5 -> "thu"
+                            6 -> "fri"
+                            7 -> "sat"
+                            else -> "sun"
+                        }
+                    )
+                    .build()
+            }
+        }
+        CompositionLocalProvider(
+            LocalConfiguration provides Configuration(LocalConfiguration.current).apply {
+                setLocales(LocaleList(customLocale))
+            }
+        ) {
+            DatePicker(state = datePickerState)
+        }
     }
 }
 
@@ -77,6 +110,7 @@ fun DatePickerPreview() {
         DatePickerDialog(
             initialDate = DateTime().plusDays(1).millis,
             displayMode = DisplayMode.Picker,
+            firstDayOfWeek = 0,
             setDisplayMode = {},
             selected = {},
             dismiss = {}
@@ -93,6 +127,23 @@ fun DatePickerPreviewInput() {
         DatePickerDialog(
             initialDate = DateTime().plusDays(1).millis,
             displayMode = DisplayMode.Input,
+            firstDayOfWeek = 0,
+            setDisplayMode = {},
+            selected = {},
+            dismiss = {}
+        )
+    }
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Preview(showBackground = true)
+@Composable
+fun DatePickerPreviewOverrideFirstDay() {
+    TasksTheme {
+        DatePickerDialog(
+            initialDate = DateTime().plusDays(1).millis,
+            displayMode = DisplayMode.Picker,
+            firstDayOfWeek = 2,
             setDisplayMode = {},
             selected = {},
             dismiss = {}

app/src/main/java/org/tasks/repeats/CustomRecurrenceActivity.kt

@@ -43,7 +43,8 @@ class CustomRecurrenceActivity : FragmentActivity() {
                     toggleDay = { viewModel.toggleDay(it) },
                     setMonthSelection = { viewModel.setMonthSelection(it) },
                     calendarDisplayMode = remember { preferences.calendarDisplayMode },
-                    setDisplayMode = { preferences.calendarDisplayMode = it }
+                    setDisplayMode = { preferences.calendarDisplayMode = it },
+                    firstDayOfWeek = remember { preferences.firstDayOfWeek },
                 )
             }
         }