fix(month): dim the overflow dots of a completed day too (#79)

"Dim completed events" faded a day's bars and pills but never the dots standing
for the events that didn't fit it, so a past day with four or more events kept
its "+N" and its dots at full strength.

Both dot renderers only ever received colours and a count, which is not enough
to ask whether an event has ended. They now take the events themselves:
overflowEvents() is the documented complement of laneEvents(), so the split
grid's "+N" knows what it stands for, and the paged grid passes its hidden
events instead of their colours. A dot covers every hidden event sharing its
colour, so it dims once all of them are over; the "+N" dims once the whole
overflow is.

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthScreen.kt

@@ -137,6 +137,7 @@ import kotlinx.datetime.toJavaLocalDate
 import kotlinx.datetime.toLocalDateTime
 import kotlin.math.abs
 import kotlin.time.Clock
+import kotlin.time.Instant
 import java.time.format.TextStyle as JavaTextStyle
 import java.util.Locale
 
@@ -1277,7 +1278,7 @@ internal fun SplitMonthGrid(
                     SplitDayCell(
                         date = day,
                         events = seated,
-                        hidden = (week.countByDay[day] ?: 0) - seated.size,
+                        hidden = week.overflowEvents(col, day, MAX_EVENT_ROWS),
                         isToday = day == state.today,
                         // A page marks only the days its own month owns. Paging
                         // moves the selection before this month's replacement
@@ -1318,7 +1319,7 @@ private fun SplitDayCell(
     date: LocalDate,
     events: List<EventInstance>,
     /** Events on this day that didn't fit a lane, shown as a "+N" beside the dots. */
-    hidden: Int,
+    hidden: List<EventInstance>,
     isToday: Boolean,
     isSelected: Boolean,
     inMonth: Boolean,
@@ -1436,9 +1437,15 @@ private fun SplitDayCell(
  * bar with no dot to grow out of.
  */
 @Composable
-private fun SplitDots(date: LocalDate, events: List<EventInstance>, hidden: Int, dark: Boolean) {
+private fun SplitDots(
+    date: LocalDate,
+    events: List<EventInstance>,
+    hidden: List<EventInstance>,
+    dark: Boolean,
+) {
     if (events.isEmpty()) return
     val soften = LocalSoftenColors.current
+    val dimCutoff = LocalDimCutoff.current
     Row(
         horizontalArrangement = Arrangement.spacedBy(2.dp),
         verticalAlignment = Alignment.CenterVertically,
@@ -1461,18 +1468,21 @@ private fun SplitDots(date: LocalDate, events: List<EventInstance>, hidden: Int,
                 modifier = Modifier
                     .morphBounds(MonthMorphKey.Event(date, event.instanceId))
                     .size(SPLIT_DOT_SIZE)
+                    .alpha(if (dimCutoff != null && event.hasEnded(dimCutoff)) EventDimAlpha else 1f)
                     .background(eventFill(event.color, dark, soften), CircleShape),
             )
         }
-        if (hidden > 0) {
+        if (hidden.isNotEmpty()) {
             // Tagged, not lifted: this count and the expanded grid's dot row are
             // the same marker on the same day, so it travels with its cell like
             // everything else rather than riding above the grid on its own layer.
             Text(
-                text = "+$hidden",
+                text = "+${hidden.size}",
                 style = MaterialTheme.typography.labelSmall,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
-                modifier = Modifier.morphBounds(MonthMorphKey.Overflow(date)),
+                modifier = Modifier
+                    .morphBounds(MonthMorphKey.Overflow(date))
+                    .alpha(if (allEnded(hidden, dimCutoff)) EventDimAlpha else 1f),
             )
         }
     }
@@ -1870,15 +1880,15 @@ private fun MonthWeekRow(
                         }
                         val hidden = (week.countByDay[d] ?: 0) - occupied.size - pillsShown.size
                         if (hidden > 0) {
-                            val hiddenColors = buildList {
+                            val hiddenEvents = buildList {
                                 week.spans
                                     .filter { it.lane >= shownLanes && col in it.startCol..it.endCol }
-                                    .forEach { add(it.event.color) }
-                                timed.drop(pillsShown.size).forEach { add(it.color) }
-                            }.distinct().take(3)
+                                    .forEach { add(it.event) }
+                                addAll(timed.drop(pillsShown.size))
+                            }
                             OverflowDots(
-                                colors = hiddenColors,
-                                extra = hidden - hiddenColors.size,
+                                events = hiddenEvents,
+                                total = hidden,
                                 dark = dark,
                                 modifier = Modifier
                                     .offset(x = colW * col, y = EVENT_ROW_HEIGHT * MAX_EVENT_ROWS)
@@ -2058,37 +2068,52 @@ private fun MonthBar(
     }
 }
 
-/** Overflow row: a dot per hidden event (up to three) plus "+N" for the rest. */
+/**
+ * Overflow row: a dot per hidden colour (up to three) plus "+N" for the rest.
+ *
+ * A dot stands for every hidden event sharing its colour, so it dims only once
+ * all of them have ended; the "+N" dims once the whole overflow has (#79).
+ */
 @Composable
 private fun OverflowDots(
-    colors: List<Int>,
-    extra: Int,
+    events: List<EventInstance>,
+    total: Int,
     dark: Boolean,
     modifier: Modifier = Modifier,
 ) {
     val soften = LocalSoftenColors.current
+    val dimCutoff = LocalDimCutoff.current
+    val byColor = events.groupBy { it.color }
+    val dots = byColor.keys.take(3)
     Row(
         modifier = modifier.height(EVENT_ROW_HEIGHT),
         horizontalArrangement = Arrangement.spacedBy(2.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
-        colors.forEach { argb ->
+        dots.forEach { argb ->
             Box(
                 modifier = Modifier
                     .size(6.dp)
+                    .alpha(if (allEnded(byColor.getValue(argb), dimCutoff)) EventDimAlpha else 1f)
                     .background(eventFill(argb, dark, soften), CircleShape),
             )
         }
+        val extra = total - dots.size
         if (extra > 0) {
             Text(
                 text = "+$extra",
                 style = MaterialTheme.typography.labelSmall,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
+                modifier = Modifier.alpha(if (allEnded(events, dimCutoff)) EventDimAlpha else 1f),
             )
         }
     }
 }
 
+/** True when dimming is on and every one of [events] is already over. */
+private fun allEnded(events: List<EventInstance>, dimCutoff: Instant?): Boolean =
+    dimCutoff != null && events.isNotEmpty() && events.all { it.hasEnded(dimCutoff) }
+
 @Composable
 private fun MonthGridLoading() {
     val shape = MaterialTheme.shapes.medium

app/src/main/java/de/jeanlucmakiola/calendula/ui/month/MonthUiState.kt

@@ -67,6 +67,24 @@ fun MonthWeek.laneEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInst
     return byLane.filterNotNull()
 }
 
+/**
+ * The events on [day] that [laneEvents] had no lane left for — the exact
+ * complement of what it seats, in the same bars-then-pills order. Together the
+ * two partition the day, so their sizes add up to [countByDay].
+ *
+ * The "+N" marker needs the events themselves, not just how many there are:
+ * dimming a completed event is a per-event question (#79).
+ */
+fun MonthWeek.overflowEvents(col: Int, day: LocalDate, laneCap: Int): List<EventInstance> {
+    val seatedLanes = spans.count { it.lane < laneCap && col in it.startCol..it.endCol }
+    return buildList {
+        spans.forEach { span ->
+            if (span.lane >= laneCap && col in span.startCol..span.endCol) add(span.event)
+        }
+        addAll(timedByDay[day].orEmpty().drop(laneCap - seatedLanes))
+    }
+}
+
 /**
  * State for the continuous style (#38): a vertical stream of *self-contained*
  * months rather than one undifferentiated run of weeks. Each month is keyed by

app/src/test/java/de/jeanlucmakiola/calendula/ui/month/LaneEventsTest.kt

@@ -122,6 +122,42 @@ class LaneEventsTest {
             .containsNoneIn(seated)
     }
 
+    @Test
+    fun `overflow is exactly what seating left behind`() {
+        val events = (0 until 5).map { timed(LocalDate(2026, 7, 6), hour = 8 + it, id = it + 1L) }
+        val week = rowOfJuly6(events)
+        val day = LocalDate(2026, 7, 6)
+
+        val seated = week.laneEvents(col = 0, day = day, laneCap = 3)
+        val overflow = week.overflowEvents(col = 0, day = day, laneCap = 3)
+
+        assertThat(overflow).containsExactlyElementsIn(events.drop(3)).inOrder()
+        assertThat(seated + overflow).containsExactlyElementsIn(events)
+        assertThat(seated.size + overflow.size).isEqualTo(week.countByDay[day])
+    }
+
+    @Test
+    fun `a bar beyond the cap overflows on every day it covers`() {
+        val bars = (0 until 4).map {
+            allDay(LocalDate(2026, 7, 6), LocalDate(2026, 7, 8), id = it + 1L)
+        }
+        val week = rowOfJuly6(bars)
+        val parked = week.spans.filter { it.lane >= 3 }.map { it.event }
+
+        (0..2).forEach { col ->
+            val day = LocalDate(2026, 7, 6 + col)
+            assertThat(week.overflowEvents(col, day, laneCap = 3))
+                .containsExactlyElementsIn(parked)
+        }
+    }
+
+    @Test
+    fun `a day that fits has no overflow`() {
+        val week = rowOfJuly6(listOf(timed(LocalDate(2026, 7, 6), hour = 9, id = 1L)))
+
+        assertThat(week.overflowEvents(col = 0, day = LocalDate(2026, 7, 6), laneCap = 3)).isEmpty()
+    }
+
     private companion object {
         const val BLUE = 0xFF3366CC.toInt()
         const val RED = 0xFFCC3333.toInt()