feat: clearer shared calendars + move group switch into the menu

Three Android UX fixes reported from on-device testing:

1. A calendar shared with the user now shows read-only affordances: parse the
   server's new read_only flag on events, show a lock icon in the filter sheet,
   and exclude read-only shared calendars from the event editor's calendar
   picker (getWritableCalendars) so saves no longer 403. The calendar's display
   name (owner's name) comes from the server.

2. (server-side) group event name prefix removed — no client change needed.

3. Move the personal/group view switcher out of the crowded top bar into the
   burger MenuSheet as a "group view" section (personal + each group with a
   check mark), mirroring iOS. The GroupSwitcher pill and its top-bar wiring are
   gone; the active-group banner stays.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/src/main/java/com/scarriffle/calendarr/data/CalendarRepository.kt

@@ -270,7 +270,12 @@ class CalendarRepository @Inject constructor(
     /** Resolve all calendars the user can create events in. */
     suspend fun getWritableCalendars(): List<WritableCalendar> = withContext(Dispatchers.IO) {
         val result = mutableListOf<WritableCalendar>()
-        runCatching { api.getLocalCalendars() }.getOrDefault(emptyList()).forEach { cal ->
+        runCatching { api.getLocalCalendars() }.getOrDefault(emptyList())
+            // Exclude read-only shared calendars — offering them in the event
+            // editor only leads to a 403 on save. Own + read_write (incl. group)
+            // calendars stay.
+            .filter { it.owned || it.permission == "read_write" }
+            .forEach { cal ->
                 result += WritableCalendar("local-${cal.id}", cal.name, cal.color, "local", cal.id)
             }
         runCatching { api.getCalDAVAccounts() }.getOrDefault(emptyList())

app/src/main/java/com/scarriffle/calendarr/domain/model/CalEvent.kt

@@ -36,6 +36,8 @@ data class CalEvent(
     val displayTitle: String? = null,
     // Reminder offsets in minutes-before-start (0 = at start). Local events only.
     val reminders: List<Int> = emptyList(),
+    // True for events from a calendar shared with the user read-only.
+    val readOnly: Boolean = false,
 ) {
     /**
      * Group view supplies a server-resolved colour (display_color); otherwise
@@ -126,6 +128,7 @@ data class CalEvent(
                 reminders = json.optJSONArray("reminders")?.let { arr ->
                     (0 until arr.length()).mapNotNull { (arr.opt(it) as? Number)?.toInt() }
                 } ?: emptyList(),
+                readOnly = json.optBoolean("read_only", false),
             )
         }
     }

app/src/main/java/com/scarriffle/calendarr/ui/L10n.kt

@@ -124,6 +124,7 @@ object L10n {
             "filter.button" to "Kalender ein-/ausblenden",
             "filter.sync_error" to "Synchronisierung fehlgeschlagen",
             "filter.banish" to "Dauerhaft ausblenden",
+            "filter.read_only" to "Nur lesen",
             "filter.banished_footer" to "Dauerhaft ausgeblendete Kalender erscheinen unter »Konten & Kalender« und können dort wieder eingeblendet werden.",
             "accounts.banished_header" to "Ausgeblendete Kalender",
             "accounts.banished_unhide" to "Wieder einblenden",
@@ -268,6 +269,7 @@ object L10n {
             "filter.button" to "Show/hide calendars",
             "filter.sync_error" to "Sync failed",
             "filter.banish" to "Hide permanently",
+            "filter.read_only" to "Read-only",
             "filter.banished_footer" to "Permanently hidden calendars appear under “Accounts & Calendars”, where you can show them again.",
             "accounts.banished_header" to "Hidden calendars",
             "accounts.banished_unhide" to "Show again",

app/src/main/java/com/scarriffle/calendarr/ui/calendar/CalendarFilterSheet.kt

@@ -11,6 +11,7 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Archive
+import androidx.compose.material.icons.filled.Lock
 import androidx.compose.material.icons.filled.Notifications
 import androidx.compose.material.icons.filled.NotificationsOff
 import androidx.compose.material.icons.filled.WarningAmber
@@ -33,7 +34,7 @@ import androidx.compose.ui.unit.dp
 import com.scarriffle.calendarr.ui.tr
 import com.scarriffle.calendarr.util.colorFromHex
 
-data class CalendarFilterEntry(val key: String, val name: String, val color: String, val source: String = "")
+data class CalendarFilterEntry(val key: String, val name: String, val color: String, val source: String = "", val readOnly: Boolean = false)
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -109,6 +110,14 @@ fun CalendarFilterSheet(
                         modifier = Modifier.weight(1f).padding(start = 12.dp),
                         style = MaterialTheme.typography.bodyLarge,
                     )
+                    if (entry.readOnly) {
+                        Icon(
+                            Icons.Filled.Lock,
+                            contentDescription = tr("filter.read_only"),
+                            tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                            modifier = Modifier.padding(end = 4.dp).size(15.dp),
+                        )
+                    }
                     if (!groupMode) {
                         val remDisabled = entry.key in state.reminderDisabledKeys
                         IconButton(onClick = { vm.setCalendarRemindersDisabled(entry.key, disabled = !remDisabled) }) {

app/src/main/java/com/scarriffle/calendarr/ui/calendar/CalendarScreen.kt

@@ -18,12 +18,10 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Add
-import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.ChevronLeft
 import androidx.compose.material.icons.filled.ChevronRight
 import androidx.compose.material.icons.filled.FilterList
 import androidx.compose.material.icons.filled.Menu
-import androidx.compose.material.icons.filled.People
 import androidx.compose.material.icons.filled.Today
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.DropdownMenu
@@ -156,9 +154,6 @@ fun CalendarScreen(
                 viewType = state.viewType,
                 loading = state.isLoading || state.isBackgroundCaching,
                 viewMenuOpen = viewMenuOpen,
-                groups = state.groups,
-                activeGroup = state.activeGroup,
-                onSwitchGroup = { vm.switchGroup(it) },
                 onMenu = { showMenu = true },
                 onPrev = { goPrev() },
                 onToday = { goToday() },
@@ -213,6 +208,9 @@ fun CalendarScreen(
     if (showMenu) {
         MenuSheet(
             isAdmin = false,
+            groups = state.groups,
+            activeGroup = state.activeGroup,
+            onSwitchGroup = { showMenu = false; vm.switchGroup(it) },
             onDismiss = { showMenu = false },
             onProfile = { showMenu = false; overlay = Overlay.PROFILE },
             onAppearance = { showMenu = false; overlay = Overlay.SETTINGS },
@@ -398,9 +396,6 @@ private fun CompactTopBar(
     viewType: CalViewType,
     loading: Boolean,
     viewMenuOpen: Boolean,
-    groups: List<Group>,
-    activeGroup: Group?,
-    onSwitchGroup: (Group?) -> Unit,
     onMenu: () -> Unit,
     onPrev: () -> Unit,
     onToday: () -> Unit,
@@ -437,9 +432,6 @@ private fun CompactTopBar(
                     strokeWidth = 2.dp,
                 )
             }
-            if (groups.isNotEmpty()) {
-                GroupSwitcher(groups = groups, activeGroup = activeGroup, onSwitchGroup = onSwitchGroup)
-            }
             CompactIcon(Icons.Filled.FilterList, onFilter, tr("filter.button"))
             Box {
                 CompactIcon(viewType.icon, { onViewMenuToggle(true) }, tr("view.change"))
@@ -474,50 +466,6 @@ private fun CompactIcon(
     }
 }
 
-/**
- * Top-bar switcher: "My calendar" + each group; flips the calendar into the
- * group overlay. Rendered as a tonal pill so it stands out from the flat icons
- * (filled in the accent colour while a group overlay is active).
- */
-@Composable
-private fun GroupSwitcher(groups: List<Group>, activeGroup: Group?, onSwitchGroup: (Group?) -> Unit) {
-    var open by remember { mutableStateOf(false) }
-    val active = activeGroup != null
-    Box {
-        Box(
-            Modifier
-                .padding(horizontal = 2.dp)
-                .size(38.dp)
-                .clip(CircleShape)
-                .background(if (active) MaterialTheme.colorScheme.primary else MaterialTheme.colorScheme.surfaceVariant)
-                .clickable { open = true },
-            contentAlignment = Alignment.Center,
-        ) {
-            Icon(
-                Icons.Filled.People,
-                contentDescription = tr("groups.title"),
-                modifier = Modifier.size(21.dp),
-                tint = if (active) MaterialTheme.colorScheme.onPrimary else MaterialTheme.colorScheme.onSurfaceVariant,
-            )
-        }
-        DropdownMenu(expanded = open, onDismissRequest = { open = false }) {
-            DropdownMenuItem(
-                text = { Text(tr("group.switch.personal")) },
-                trailingIcon = { if (!active) Icon(Icons.Filled.Check, contentDescription = null) },
-                onClick = { open = false; onSwitchGroup(null) },
-            )
-            groups.forEach { g ->
-                DropdownMenuItem(
-                    text = { Text(g.name) },
-                    leadingIcon = { GroupIcon(g.icon) },
-                    trailingIcon = { if (activeGroup?.id == g.id) Icon(Icons.Filled.Check, contentDescription = null) },
-                    onClick = { open = false; onSwitchGroup(g) },
-                )
-            }
-        }
-    }
-}
-
 @Composable
 private fun GroupBanner(group: Group, onExit: () -> Unit) {
     Surface(color = MaterialTheme.colorScheme.primary.copy(alpha = 0.15f), modifier = Modifier.fillMaxWidth()) {
@@ -543,7 +491,7 @@ private fun GroupBanner(group: Group, onExit: () -> Unit) {
  *  can be toggled back on. */
 private fun allKnownCalendars(vm: CalendarViewModel): List<CalendarFilterEntry> {
     return vm.knownCalendars()
-        .map { CalendarFilterEntry(calendarKey(it.source, it.calendarId), it.calendarName.ifBlank { it.source }, it.effectiveColor, it.source) }
+        .map { CalendarFilterEntry(calendarKey(it.source, it.calendarId), it.calendarName.ifBlank { it.source }, it.effectiveColor, it.source, it.readOnly) }
         .distinctBy { it.key }
         .sortedBy { it.name.lowercase() }
 }

app/src/main/java/com/scarriffle/calendarr/ui/menu/MenuSheet.kt

@@ -13,12 +13,14 @@ import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.AccountCircle
+import androidx.compose.material.icons.filled.CalendarMonth
+import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Dns
 import androidx.compose.material.icons.filled.Logout
 import androidx.compose.material.icons.filled.Palette
 import androidx.compose.material.icons.filled.People
+import androidx.compose.material.icons.filled.Person
 import androidx.compose.material.icons.filled.Sync
-import androidx.compose.material.icons.filled.CalendarMonth
 import androidx.compose.material3.Divider
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.Icon
@@ -31,12 +33,17 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
+import com.scarriffle.calendarr.domain.model.Group
+import com.scarriffle.calendarr.ui.groups.GroupIcon
 import com.scarriffle.calendarr.ui.tr
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun MenuSheet(
     isAdmin: Boolean,
+    groups: List<Group>,
+    activeGroup: Group?,
+    onSwitchGroup: (Group?) -> Unit,
     onDismiss: () -> Unit,
     onProfile: () -> Unit,
     onAppearance: () -> Unit,
@@ -64,6 +71,27 @@ fun MenuSheet(
             MenuRow(Icons.Filled.AccountCircle, tr("menu.profile"), onProfile)
             MenuRow(Icons.Filled.Palette, tr("menu.appearance"), onAppearance)
             MenuRow(Icons.Filled.CalendarMonth, tr("menu.accounts"), onAccounts)
+            // Group view switch (personal + each group) — moved here from the
+            // top bar to free up space. Group *management* stays below.
+            if (groups.isNotEmpty()) {
+                Divider(Modifier.padding(vertical = 4.dp))
+                MenuSectionLabel(tr("groups.view"))
+                GroupSwitchRow(
+                    label = tr("group.switch.personal"),
+                    checked = activeGroup == null,
+                    leading = { Icon(Icons.Filled.Person, contentDescription = null, tint = MaterialTheme.colorScheme.onSurfaceVariant) },
+                    onClick = { onSwitchGroup(null) },
+                )
+                groups.forEach { g ->
+                    GroupSwitchRow(
+                        label = g.name,
+                        checked = activeGroup?.id == g.id,
+                        leading = { GroupIcon(g.icon) },
+                        onClick = { onSwitchGroup(g) },
+                    )
+                }
+            }
+            Divider(Modifier.padding(vertical = 4.dp))
             MenuRow(Icons.Filled.People, tr("menu.groups"), onGroups)
             Divider(Modifier.padding(vertical = 4.dp))
             MenuRow(Icons.Filled.Sync, tr("menu.sync"), onSync)
@@ -85,3 +113,34 @@ private fun MenuRow(icon: ImageVector, label: String, onClick: () -> Unit) {
         Text(label, style = MaterialTheme.typography.bodyLarge)
     }
 }
+
+@Composable
+private fun MenuSectionLabel(text: String) {
+    Text(
+        text,
+        style = MaterialTheme.typography.labelMedium,
+        color = MaterialTheme.colorScheme.onSurfaceVariant,
+        modifier = Modifier.padding(horizontal = 20.dp, vertical = 4.dp),
+    )
+}
+
+/** A group-view choice (personal or a specific group) with a trailing check. */
+@Composable
+private fun GroupSwitchRow(
+    label: String,
+    checked: Boolean,
+    leading: @Composable () -> Unit,
+    onClick: () -> Unit,
+) {
+    Row(
+        Modifier.fillMaxWidth().clickable(onClick = onClick).padding(horizontal = 20.dp, vertical = 12.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        leading()
+        Spacer(Modifier.width(18.dp))
+        Text(label, style = MaterialTheme.typography.bodyLarge, modifier = Modifier.weight(1f))
+        if (checked) {
+            Icon(Icons.Filled.Check, contentDescription = null, tint = MaterialTheme.colorScheme.primary)
+        }
+    }
+}