Trim the chip line box and give the rows back the space (#190)

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

@@ -0,0 +1,41 @@
+package de.jeanlucmakiola.calendula.ui.common
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.rememberTextMeasurer
+import androidx.compose.ui.text.style.LineHeightStyle
+import androidx.compose.ui.unit.Dp
+
+/**
+ * The calendar surfaces' line-height treatment. Material wraps an 11sp glyph in
+ * a 16sp line box — room a label wants when it stands on its own, and close to
+ * a fifth of an event row when it doesn't. The outer edges only, so a wrapped
+ * title keeps its interior line spacing (#190).
+ *
+ * Trimmed rather than set to a smaller line height: the font picker can load a
+ * serif, a monospace or a file of the user's own, and a line height under a
+ * face's own ascent and descent overlaps its lines. There is nothing to trim
+ * below that, so this is safe whatever font is chosen.
+ */
+private val TrimmedLines = LineHeightStyle(
+    alignment = LineHeightStyle.Alignment.Center,
+    trim = LineHeightStyle.Trim.Both,
+)
+
+/** Ascenders and descenders both, so a line is measured at its full extent. */
+private const val LINE_SAMPLE = "Ag"
+
+/** [this] with Material's outer leading trimmed — see [TrimmedLines]. */
+fun TextStyle.trimmedLines(): TextStyle = copy(lineHeightStyle = TrimmedLines)
+
+/** What one trimmed line of [style] actually draws in. */
+@Composable
+fun rememberTrimmedLineHeight(style: TextStyle): Dp {
+    val measurer = rememberTextMeasurer()
+    val density = LocalDensity.current
+    return remember(style, density, measurer) {
+        with(density) { measurer.measure(LINE_SAMPLE, style.trimmedLines()).size.height.toDp() }
+    }
+}

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

@@ -115,6 +115,7 @@ import de.jeanlucmakiola.calendula.ui.common.rememberCalendarPageSwipe
 import de.jeanlucmakiola.floret.identity.rememberReduceMotion
 import de.jeanlucmakiola.calendula.ui.common.next
 import de.jeanlucmakiola.calendula.ui.common.EventChipShape
+import de.jeanlucmakiola.calendula.ui.common.trimmedLines
 import de.jeanlucmakiola.calendula.ui.common.rememberCalendarSlideSpec
 import de.jeanlucmakiola.floret.locale.currentLocale
 import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
@@ -140,7 +141,8 @@ import kotlin.time.Clock
 import java.util.Locale
 import kotlin.math.roundToInt
 
-private val ALL_DAY_ROW_HEIGHT = 24.dp
+/** One lane of the all-day strip, sized to a trimmed bar line (#190). */
+private val ALL_DAY_ROW_HEIGHT = 20.dp
 private val ALL_DAY_VERTICAL_PADDING = 6.dp
 
 /** Total all-day strip height for the day (0 when there are no all-day events). */
@@ -529,7 +531,7 @@ private fun AllDayBar(
         val titleOverflow = eventTitleOverflow()
         Text(
             text = title,
-            style = MaterialTheme.typography.labelSmall,
+            style = MaterialTheme.typography.labelSmall.trimmedLines(),
             maxLines = 1,
             overflow = titleOverflow.overflow,
             softWrap = titleOverflow.softWrap,

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

@@ -153,6 +153,7 @@ import de.jeanlucmakiola.calendula.ui.common.LocalUse24HourFormat
 import de.jeanlucmakiola.calendula.ui.common.inlineTimeLabel
 import de.jeanlucmakiola.calendula.ui.common.eventAccent
 import de.jeanlucmakiola.calendula.ui.common.EventChipShape
+import de.jeanlucmakiola.calendula.ui.common.trimmedLines
 import de.jeanlucmakiola.calendula.ui.common.monthBarShape
 import de.jeanlucmakiola.calendula.ui.common.rememberCurrentMinute
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
@@ -760,7 +761,12 @@ internal fun WeekdayHeader(weekStart: DayOfWeek, showWeekNumbers: Boolean) {
     }
 }
 
-private val EVENT_ROW_HEIGHT = 20.dp
+/**
+ * One lane of a day cell. Sized to a trimmed chip line rather than to Material's
+ * line box, so the three lanes a cell can draw cost it nine dp less and a
+ * six-row month keeps its third chip instead of demoting it to a dot (#190).
+ */
+private val EVENT_ROW_HEIGHT = 17.dp
 private val DAY_NUMBER_HEIGHT = 22.dp
 /** Width of the optional left calendar-week gutter (#25); narrow, since it only
  *  seats a one- or two-digit week number in a full-height tonal pill. */
@@ -2544,7 +2550,7 @@ private fun MonthBar(
         val titleOverflow = eventTitleOverflow()
         Text(
             text = label,
-            style = MaterialTheme.typography.labelSmall,
+            style = MaterialTheme.typography.labelSmall.trimmedLines(),
             maxLines = 1,
             overflow = titleOverflow.overflow,
             softWrap = titleOverflow.softWrap,

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

@@ -118,6 +118,7 @@ import de.jeanlucmakiola.calendula.ui.common.rememberTimelineDragController
 import de.jeanlucmakiola.calendula.ui.common.startInstant
 import de.jeanlucmakiola.calendula.ui.common.LocalDimCutoff
 import de.jeanlucmakiola.calendula.ui.common.EventChipShape
+import de.jeanlucmakiola.calendula.ui.common.trimmedLines
 import de.jeanlucmakiola.calendula.ui.common.NowLine
 import de.jeanlucmakiola.calendula.ui.common.rememberCurrentMinute
 import de.jeanlucmakiola.calendula.ui.common.ViewSwitcherPill
@@ -155,7 +156,8 @@ import kotlin.time.Clock
 import java.time.format.TextStyle as JavaTextStyle
 import java.util.Locale
 
-private val ALL_DAY_ROW_HEIGHT = 24.dp
+/** One lane of the all-day strip, sized to a trimmed bar line (#190). */
+private val ALL_DAY_ROW_HEIGHT = 20.dp
 private val ALL_DAY_VERTICAL_PADDING = 6.dp
 /** Gap between day columns; part of the column pitch a drag maps positions through. */
 private val COLUMN_GAP = 2.dp
@@ -664,7 +666,7 @@ private fun AllDayBar(
         val titleOverflow = eventTitleOverflow()
         Text(
             text = title,
-            style = MaterialTheme.typography.labelSmall,
+            style = MaterialTheme.typography.labelSmall.trimmedLines(),
             maxLines = 1,
             overflow = titleOverflow.overflow,
             softWrap = titleOverflow.softWrap,