Revert the chip's FAB colours, quicken it, and end the settle flicker (#68)

The chip goes back to the neutral fill and its motion is cut to a receipt's
length — the default visibility spring overshot and read as sluggish.

The landed copy is now handed back when the grid actually draws the drop,
not on a timer: releasing early put the source ghost back at full opacity in
its old slot for the rest of the re-read, which is the flicker.

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/EventMoveHost.kt

@@ -6,8 +6,6 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.navigationBarsPadding
 import androidx.compose.foundation.layout.padding
-import androidx.compose.material3.FloatingActionButtonDefaults
-import androidx.compose.material3.contentColorFor
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
@@ -108,10 +106,6 @@ fun EventMoveHost(viewModel: RescheduleViewModel, modifier: Modifier = Modifier)
                 actionLabel = stringResource(R.string.event_move_undo)
                     .takeIf { shownUndo != null },
                 onAction = shownUndo?.let { undo -> { viewModel.undo(undo) } },
-                // The FAB's own colours: the chip shares its band, so sharing its
-                // fill reads as one bottom layer rather than two competing ones.
-                color = FloatingActionButtonDefaults.containerColor,
-                contentColor = contentColorFor(FloatingActionButtonDefaults.containerColor),
             )
         }
     }

app/src/main/java/de/jeanlucmakiola/calendula/ui/common/TimelineDrag.kt

@@ -144,6 +144,15 @@ class TimelineDragController {
     var isDragging: Boolean by mutableStateOf(false)
         private set
 
+    /**
+     * Whether the grid itself now draws the settled drop at its landing slot.
+     * The copy may only be handed back once this is true: releasing on a timer
+     * puts the source ghost back at full opacity in its *old* slot for whatever
+     * is left of the re-read — a flicker of the event where it no longer is.
+     */
+    var settledOnGrid: Boolean by mutableStateOf(false)
+        private set
+
     private var source: TimedBlock? = null
     private var grab = Offset.Zero
     private var pointer = Offset.Zero
@@ -180,6 +189,25 @@ class TimelineDragController {
         originSlot = null
         drag = null
         settling = null
+        settledOnGrid = false
+    }
+
+    /**
+     * What a day column now holds, so a settled drop can tell when the grid has
+     * caught up with it. Matched on the landing slot plus either the event row
+     * or its title: a single-occurrence move writes an exception row with a new
+     * `eventId`, which nothing else about the drop can predict.
+     */
+    fun noteGrid(date: LocalDate, blocks: List<TimedBlock>) {
+        val landed = settling ?: return
+        if (settledOnGrid || landed.date != date) return
+        settledOnGrid = blocks.any { block ->
+            block.startMin == landed.startMin &&
+                (
+                    block.event.eventId == landed.event.eventId ||
+                        block.event.title == landed.event.title
+                    )
+        }
     }
 
     /**
@@ -201,6 +229,7 @@ class TimelineDragController {
     fun release() {
         settling = null
         liftedInstanceId = null
+        settledOnGrid = false
     }
 
     /**
@@ -301,11 +330,17 @@ fun TimelineDrop.startInstant(zone: TimeZone): Instant =
     LocalDateTime(date, LocalTime(startMin / 60, startMin % 60)).toInstant(zone)
 
 /**
- * How long a landed block keeps its position after the write reports back — the
+ * A beat after the grid draws the drop, so its own block is under way before the
- * provider's change notification and the re-query land a beat later, and
+ * copy starts dissolving.
- * releasing on the write alone would still flash the old slot.
  */
-const val SETTLE_GRACE_MILLIS: Long = 200L
+const val SETTLE_GRACE_MILLIS: Long = 60L
+
+/**
+ * How long to wait for a grid that never confirms the drop — the event landed on
+ * a day this timeline doesn't show, or the write failed and nothing changed. The
+ * copy has to go either way.
+ */
+private const val SETTLE_TIMEOUT_MILLIS = 900L
 
 /**
  * The hand-over: the copy dissolves over this while the grid's own block slides
@@ -337,12 +372,12 @@ fun TimelineDragOverlay(controller: TimelineDragController, modifier: Modifier =
         if (controller.isDragging) controller.autoScroll()
     }
     // Hold the landed copy until the write is done — including the whole time a
-    // recurring drop's scope dialog is up — then a grace for the re-read, then
+    // recurring drop's scope dialog is up — and then until the grid draws the
-    // fade it into the grid's own block, which has slid in underneath by now.
+    // drop itself, so the copy dissolves onto a block that is already there.
     var handingOver by remember(controller.settling) { mutableStateOf(false) }
-    LaunchedEffect(controller.settling, moveInFlight) {
+    LaunchedEffect(controller.settling, moveInFlight, controller.settledOnGrid) {
         if (controller.settling == null || moveInFlight) return@LaunchedEffect
-        delay(SETTLE_GRACE_MILLIS)
+        delay(if (controller.settledOnGrid) SETTLE_GRACE_MILLIS else SETTLE_TIMEOUT_MILLIS)
         handingOver = true
         delay(SETTLE_FADE_MILLIS.toLong())
         controller.release()

app/src/main/java/de/jeanlucmakiola/calendula/ui/day/DayScreen.kt

@@ -615,6 +615,10 @@ private fun DayColumnCard(
     val hourPx = with(LocalDensity.current) { hourHeight.toPx() }
     val showHourLines = LocalShowHourLines.current
     val hourLineColor = MaterialTheme.colorScheme.outlineVariant
+    // Tells a settled drop when this column has caught up with it.
+    LaunchedEffect(blocks, dragController.settling) {
+        dragController.noteGrid(date, blocks)
+    }
     Card(
         // Plain rectangular column — the soft corners come from the outer
         // rounded scroll viewport, so inner rounding would look odd at the edges.

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

@@ -92,7 +92,6 @@ import de.jeanlucmakiola.calendula.ui.common.LocalEventMove
 import de.jeanlucmakiola.calendula.ui.common.moveInFlight
 import de.jeanlucmakiola.calendula.ui.common.ghostAlpha
 import de.jeanlucmakiola.calendula.ui.common.DragSnapHaptics
-import de.jeanlucmakiola.calendula.ui.common.SETTLE_GRACE_MILLIS
 import de.jeanlucmakiola.calendula.ui.common.EventMoveScope
 import de.jeanlucmakiola.calendula.domain.spanFirstDay
 import androidx.compose.ui.unit.IntSize
@@ -466,6 +465,9 @@ fun MonthScreen(
     }
 }
 
+/** How long a landed chip holds its day while the write and re-read land. */
+private const val MONTH_SETTLE_HOLD_MILLIS = 450L
+
 /** The chip in flight, drawn over the grid and following the finger. */
 @Composable
 private fun MonthDragOverlay(controller: MonthDragController) {
@@ -478,10 +480,12 @@ private fun MonthDragOverlay(controller: MonthDragController) {
     // every frame, and this composable is the one that is meant to.
     DragSnapHaptics(controller.drag?.targetDate)
     // Hold the landed chip until the write is done — including the whole time a
-    // recurring drop's scope dialog is up — then a grace for the re-read.
+    // recurring drop's scope dialog is up — then a grace for the re-read. A flat
+    // wait, unlike the timeline's: the grid re-lays a whole month of rows, so
+    // there is no single column to watch for the chip arriving.
     LaunchedEffect(controller.settling, moveInFlight) {
         if (controller.settling == null || moveInFlight) return@LaunchedEffect
-        delay(SETTLE_GRACE_MILLIS)
+        delay(MONTH_SETTLE_HOLD_MILLIS)
         controller.release()
     }
     Box(

app/src/main/java/de/jeanlucmakiola/calendula/ui/week/WeekScreen.kt

@@ -764,6 +764,10 @@ private fun DayColumnCard(
     val hourPx = with(LocalDensity.current) { hourHeight.toPx() }
     val showHourLines = LocalShowHourLines.current
     val hourLineColor = MaterialTheme.colorScheme.outlineVariant
+    // Tells a settled drop when this column has caught up with it.
+    LaunchedEffect(blocks, dragController.settling) {
+        dragController.noteGrid(date, blocks)
+    }
     Card(
         // Plain rectangular columns — the soft corners come from the outer
         // rounded scroll viewport, so inner rounding would look odd at the edges.