Flex chips

core/ui/src/main/java/com/sadellie/unitto/core/ui/common/Chip.kt

@@ -18,7 +18,8 @@
 
 package com.sadellie.unitto.core.ui.common
 
-import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.animateColor
+import androidx.compose.animation.core.updateTransition
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
 import androidx.compose.foundation.clickable
@@ -26,7 +27,6 @@ import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Check
 import androidx.compose.material.icons.filled.Settings
 import androidx.compose.material3.AssistChipDefaults
 import androidx.compose.material3.FilterChipDefaults
@@ -40,6 +40,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.tooling.preview.Preview
@@ -48,41 +49,37 @@ import androidx.compose.ui.unit.dp
 @Composable
 fun FilterChip(
     modifier: Modifier = Modifier,
-    selected: Boolean,
+    isSelected: Boolean,
     onClick: () -> Unit,
     label: String,
-    imageVector: ImageVector,
-    contentDescription: String,
 ) {
+    val transition = updateTransition(targetState = isSelected, label = "Selected transition")
+    val backgroundColor = transition.animateColor(label = "Background color") {
+        if (it) MaterialTheme.colorScheme.primaryContainer else MaterialTheme.colorScheme.surface
+    }
+    val borderColor = transition.animateColor(label = "Border color") {
+        if (it) Color.Transparent else MaterialTheme.colorScheme.outline
+    }
+
     Row(
         modifier = modifier
-            .background(
-                color = if (selected) MaterialTheme.colorScheme.primaryContainer else MaterialTheme.colorScheme.surface,
-                shape = FilterChipDefaults.shape
-            )
+            .padding(vertical = 8.dp)
+            .clip(FilterChipDefaults.shape)
+            .clickable { onClick() }
+            .background(backgroundColor.value)
             .border(
                 width = 1.dp,
-                color = if (selected) Color.Transparent else MaterialTheme.colorScheme.outline,
+                color = borderColor.value,
                 shape = FilterChipDefaults.shape
             )
             .height(FilterChipDefaults.Height)
-            .clickable { onClick() }
-            .padding(start = 8.dp, end = 16.dp),
+            .padding(horizontal = 16.dp),
         verticalAlignment = Alignment.CenterVertically
     ) {
-        AnimatedVisibility(visible = selected) {
-            Icon(
-                modifier = Modifier.height(FilterChipDefaults.IconSize),
-                imageVector = imageVector,
-                contentDescription = contentDescription,
-                tint = MaterialTheme.colorScheme.onPrimaryContainer
-            )
-        }
         Text(
-            modifier = Modifier.padding(start = 8.dp),
             text = label,
             style = MaterialTheme.typography.labelLarge,
-            color = if (selected) MaterialTheme.colorScheme.onPrimaryContainer else MaterialTheme.colorScheme.onSurfaceVariant
+            color = if (isSelected) MaterialTheme.colorScheme.onPrimaryContainer else MaterialTheme.colorScheme.onSurfaceVariant
         )
     }
 }
@@ -96,17 +93,16 @@ fun AssistChip(
 ) {
     Row(
         modifier = modifier
-            .background(
-                color = MaterialTheme.colorScheme.surface,
-                shape = AssistChipDefaults.shape
-            )
+            .padding(vertical = 8.dp)
+            .clip(FilterChipDefaults.shape)
+            .clickable { onClick() }
+            .background(MaterialTheme.colorScheme.surface)
             .border(
                 width = 1.dp,
                 color = MaterialTheme.colorScheme.outline,
                 shape = AssistChipDefaults.shape
             )
             .height(32.dp)
-            .clickable { onClick() }
             .padding(horizontal = 8.dp),
         verticalAlignment = Alignment.CenterVertically
     ) {
@@ -135,10 +131,8 @@ fun PreviewFilterChip() {
     var isSelected by remember { mutableStateOf(true) }
 
     FilterChip(
-        selected = isSelected,
+        isSelected = isSelected,
         onClick = { isSelected = !isSelected },
         label = "Label",
-        imageVector = Icons.Default.Check,
-        contentDescription = ""
     )
 }

feature/converter/src/main/java/com/sadellie/unitto/feature/converter/LeftSideScreen.kt

@@ -20,6 +20,7 @@ package com.sadellie.unitto.feature.converter
 
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material3.MaterialTheme
@@ -32,6 +33,7 @@ import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.input.TextFieldValue
 import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.sadellie.unitto.core.base.R
 import com.sadellie.unitto.core.ui.common.EmptyScreen
@@ -114,10 +116,12 @@ private fun LeftSideScreen(
                 )
 
                 ChipsRow(
+                    modifier = Modifier
+                        .padding(start = 8.dp, end = 8.dp, bottom = 4.dp)
+                        .fillMaxWidth(),
                     chosenUnitGroup = uiState.unitGroup,
                     items = uiState.shownUnitGroups,
                     selectAction = updateUnitGroup,
-                    lazyListState = chipsRowLazyListState,
                     navigateToSettingsAction = navigateToUnitGroups
                 )
             }
@@ -161,7 +165,7 @@ private fun LeftSideScreenPreview() {
             units = units,
             query = TextFieldValue("test"),
             favorites = false,
-            shownUnitGroups = listOf(UnitGroup.LENGTH, UnitGroup.TEMPERATURE, UnitGroup.CURRENCY),
+            shownUnitGroups = UnitGroup.entries,
             unitGroup = units.keys.toList().first(),
             sorting = UnitsListSorting.USAGE,
         ),

feature/converter/src/main/java/com/sadellie/unitto/feature/converter/components/ChipsRow.kt

@@ -18,23 +18,30 @@
 
 package com.sadellie.unitto.feature.converter.components
 
-import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.animation.expandVertically
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.shrinkVertically
+import androidx.compose.animation.togetherWith
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.lazy.LazyListState
-import androidx.compose.foundation.lazy.LazyRow
-import androidx.compose.foundation.lazy.items
-import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Check
+import androidx.compose.material.icons.filled.ExpandLess
+import androidx.compose.material.icons.filled.ExpandMore
 import androidx.compose.material.icons.filled.Settings
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout.Placeable
+import androidx.compose.ui.layout.SubcomposeLayout
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
@@ -50,51 +57,156 @@ import com.sadellie.unitto.data.model.UnitGroup
  * @param chosenUnitGroup Currently selected [UnitGroup]
  * @param selectAction Action to perform when a chip is clicked
  * @param navigateToSettingsAction Action to perform when clicking settings chip at the end
- * @param lazyListState Used for animated scroll when entering unit selection screen
  */
 @Composable
 internal fun ChipsRow(
-    items: List<UnitGroup> = UnitGroup.entries,
+    modifier: Modifier,
+    items: List<UnitGroup>,
     chosenUnitGroup: UnitGroup?,
     selectAction: (UnitGroup?) -> Unit,
     navigateToSettingsAction: () -> Unit,
-    lazyListState: LazyListState
 ) {
-    LazyRow(
-        modifier = Modifier
-            .padding(bottom = 4.dp)
-            .fillMaxWidth(),
-        state = lazyListState,
-        contentPadding = PaddingValues(8.dp),
-        horizontalArrangement = Arrangement.spacedBy(8.dp)
-    ) {
-        items(items, key = { it.name }) { item ->
-            val selected: Boolean = item == chosenUnitGroup
-            FilterChip(
-                selected = selected,
-                onClick = { selectAction(if (selected) null else item) },
-                label = stringResource(item.res),
-                imageVector = Icons.Default.Check,
-                contentDescription = stringResource(R.string.checked_filter_description)
-            )
+    var expanded by remember { mutableStateOf(false) }
+    val chipModifier = Modifier.padding(horizontal = 4.dp)
+
+    AnimatedContent(
+        targetState = expanded,
+        transitionSpec = {
+            expandVertically(expandFrom = Alignment.Top) { it } + fadeIn() togetherWith
+                    shrinkVertically(shrinkTowards = Alignment.Top) { it } + fadeOut()
+        }
+    ) { isExpanded ->
+        FlexRow(
+            modifier = modifier,
+            maxRows = if (isExpanded) Int.MAX_VALUE else 2,
+            mainContent = {
+                items.forEach { item ->
+                    val selected: Boolean = item == chosenUnitGroup
+                    FilterChip(
+                        modifier = chipModifier,
+                        isSelected = selected,
+                        onClick = { 
+                            selectAction(if (selected) null else item)
+                            expanded = false 
+                        },
+                        label = stringResource(item.res),
+                    )
+                }
+
+                AssistChip(
+                    modifier = chipModifier,
+                    onClick = navigateToSettingsAction,
+                    imageVector = Icons.Default.Settings,
+                    contentDescription = stringResource(R.string.open_settings_label)
+                )
+
+                if (expanded) {
+                    AssistChip(
+                        modifier = chipModifier,
+                        onClick = { expanded = false },
+                        imageVector = Icons.Default.ExpandLess,
+                        contentDescription = "" // TODO
+                    )
+                }
+            },
+            expandContent = {
+                AssistChip(
+                    modifier = chipModifier,
+                    onClick = { expanded = true },
+                    imageVector = Icons.Default.ExpandMore,
+                    contentDescription = "" // TODO
+                )
+            },
+        )
+    }
+}
+
+/**
+ * Foldable row that places a specified element if overflown.
+ *
+ * @param modifier [Modifier] to be applied to this layout.
+ * @param maxRows Max amount of rows including with [expandContent].
+ * @param mainContent Main content (list of items) that will be folded.
+ * @param expandContent Item that will be placed at the end if given [maxRows] wasn't high enough to
+ * place all [mainContent] items.
+ */
+@Composable
+private fun FlexRow(
+    modifier: Modifier = Modifier,
+    maxRows: Int = Int.MAX_VALUE,
+    mainContent: @Composable () -> Unit,
+    expandContent: @Composable () -> Unit,
+) {
+    SubcomposeLayout(
+        modifier = modifier
+    ) { constraints ->
+        val localConstraints = constraints.copy(minWidth = 0, minHeight = 0)
+        val layoutWidth = localConstraints.maxWidth
+
+        val mainMeasurables = subcompose(FlexRowSlots.Main, mainContent)
+        val expandMeasurables = subcompose(
+            slotId = FlexRowSlots.Expand,
+            content = { expandContent() }
+        ).map {
+            it.measure(localConstraints)
+        }
+        val expandContentWidth = expandMeasurables.sumOf { it.measuredWidth }
+
+        val placeables = mutableListOf<MutableList<Placeable>>(mutableListOf())
+
+        var widthLeft = layoutWidth
+        var index = 0
+        for (measurable in mainMeasurables) {
+            val mainPlaceable = measurable.measure(localConstraints)
+
+            val lastAvailableRow = placeables.size >= maxRows
+            val notLastItem = index < mainMeasurables.lastIndex
+
+			// count expandContent width only for last row and not last main placeable
+            val measuredWidth = if (lastAvailableRow and notLastItem) {
+                mainPlaceable.measuredWidth + expandContentWidth
+            } else {
+                mainPlaceable.measuredWidth
+            }
+
+            // need new row
+            if (widthLeft <= measuredWidth) {
+                // Can't add more rows, add expandContent
+                if (lastAvailableRow) {
+                    expandMeasurables.forEach {
+                        placeables.last().add(it)
+                    }
+                    break
+                }
+
+                placeables.add(mutableListOf())
+                widthLeft = layoutWidth
+            }
+            placeables.last().add(mainPlaceable)
+            index++
+            widthLeft -= mainPlaceable.measuredWidth
         }
 
-        /**
-         * Usually this chip is placed at the start, but since we scroll to currently selected
-         * chip, user may never find it. There is higher chance that user will notice this chip when
-         * scrolling right (to the last one).
-         */
-        item("settings") {
-            AssistChip(
-                onClick = navigateToSettingsAction,
-                imageVector = Icons.Default.Settings,
-                contentDescription = stringResource(R.string.open_settings_label)
-            )
+        val flattenPlaceables = placeables.flatten()
+        val layoutHeight = placeables.size * (flattenPlaceables.maxByOrNull { it.height }?.height ?: 0)
+
+        layout(layoutWidth, layoutHeight) {
+            var yPos = 0
+            placeables.forEach { row ->
+                var xPos = 0
+                row.forEach { placeable ->
+                    placeable.place(x = xPos, y = yPos)
+                    xPos += placeable.width
+                }
+                yPos += row.maxByOrNull { it.height }?.height ?: 0
+            }
         }
     }
 }
 
-@Preview
+private enum class FlexRowSlots { Main, Expand }
+
+@Preview(device = "spec:width=380dp,height=850.9dp,dpi=440")
 @Composable
 fun PreviewUnittoChips() {
     var selected by remember { mutableStateOf<UnitGroup?>(UnitGroup.LENGTH) }
@@ -103,11 +215,25 @@ fun PreviewUnittoChips() {
         selected = unitGroup
     }
 
-    ChipsRow(
-        items = UnitGroup.entries,
-        chosenUnitGroup = selected,
-        selectAction = { selectAction(it) },
-        navigateToSettingsAction = {},
-        lazyListState = rememberLazyListState()
-    )
+    Column {
+        ChipsRow(
+            modifier = Modifier
+                .background(MaterialTheme.colorScheme.background)
+                .fillMaxWidth(),
+            items = UnitGroup.entries.take(7),
+            chosenUnitGroup = selected,
+            selectAction = { selectAction(it) },
+            navigateToSettingsAction = {},
+        )
+
+        ChipsRow(
+            modifier = Modifier
+                .background(MaterialTheme.colorScheme.background)
+                .fillMaxWidth(),
+            items = UnitGroup.entries.take(10),
+            chosenUnitGroup = selected,
+            selectAction = { selectAction(it) },
+            navigateToSettingsAction = {},
+        )
+    }
 }