Snippet for animated sorted list with add/remove buttons.

Author: jakeroseman

compose/snippets/src/main/java/com/example/compose/snippets/lists/AnimatedOrderedList.kt

@@ -0,0 +1,154 @@
+package com.example.compose.snippets.lists
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.Button
+import androidx.compose.material3.ListItem
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SegmentedButton
+import androidx.compose.material3.SegmentedButtonDefaults
+import androidx.compose.material3.SingleChoiceSegmentedButtonRow
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+
+// [START android_compose_layouts_list_listanimateditems]
+@Composable
+fun ListAnimatedItems(
+    items: List<String>,
+    modifier: Modifier = Modifier
+) {
+    LazyColumn {
+        items(items, key = { it }) {
+            ListItem(
+                headlineContent = { Text(it) },
+                modifier = Modifier
+                    .animateItem()
+                    .fillParentMaxWidth()
+                    .padding(horizontal = 8.dp, vertical = 0.dp),
+            )
+        }
+    }
+}
+// [END android_compose_layouts_list_listanimateditems]
+
+// [START android_compose_layouts_list_listanimateditemsexample]
+@Composable
+private fun ListAnimatedItemsExample(data: List<String>) {
+    Scaffold { paddingValues ->
+        Column(
+            modifier = Modifier
+                .padding(paddingValues)
+                .fillMaxSize()
+        ) {
+            val displayedItems = remember { mutableStateOf(data) }
+
+            // Buttons that change the value of displayedItems.
+            AddRemoveButtons(data, displayedItems)
+            OrderButtons(data, displayedItems)
+
+            // List that displays the values of displayedItems.
+            ListAnimatedItems(displayedItems.value)
+        }
+    }
+}
+// [END android_compose_layouts_list_listanimateditemsexample]
+
+// [START android_compose_layouts_list_addremovebuttons]
+@Composable
+private fun AddRemoveButtons(
+    data: List<String>,
+    displayedItems: MutableState<List<String>>
+) {
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalArrangement = Arrangement.Center
+    ) {
+        Button(
+            enabled = displayedItems.value.size < data.size,
+            onClick = {
+                // Avoid duplicate items
+                val remainingItems = data.filter { it !in displayedItems.value }
+                if (remainingItems.isNotEmpty()) displayedItems.value += remainingItems.first()
+            },
+        ) {
+            Text("Add Item")
+        }
+        Spacer(modifier = Modifier.padding(25.dp))
+        Button(
+            enabled = displayedItems.value.isNotEmpty(),
+            onClick = {
+                displayedItems.value =
+                    displayedItems.value.toMutableList().dropLast(1).toList()
+            },
+        ) {
+            Text("Delete Item")
+        }
+    }
+}
+// [END android_compose_layouts_list_addremovebuttons]
+
+// [START android_compose_layouts_list_orderbuttons]
+@Composable
+private fun OrderButtons(
+    data: List<String>,
+    displayedItems: MutableState<List<String>>
+) {
+    val sortAlpha = Comparator { str: String, str2: String -> str.compareTo(str2) }
+    val sortLength = Comparator { str1: String, str2: String -> str1.length - str2.length }
+
+    Row(
+        modifier = Modifier.fillMaxWidth(),
+        horizontalArrangement = Arrangement.Center
+    ) {
+        var selectedIndex by remember { mutableIntStateOf(0) }
+        val options = listOf("Reset", "Alphabetical", "Length")
+
+        SingleChoiceSegmentedButtonRow {
+            options.forEachIndexed { index, label ->
+                SegmentedButton(
+                    shape = SegmentedButtonDefaults.itemShape(
+                        index = index,
+                        count = options.size
+                    ),
+                    onClick = {
+                        selectedIndex = index
+                        when (options[selectedIndex]) {
+                            "Reset" -> displayedItems.value = data
+                            "Alphabetical" -> displayedItems.value =
+                                displayedItems.value.sortedWith(sortAlpha)
+                            "Length" -> displayedItems.value =
+                                displayedItems.value.sortedWith(sortLength)
+                        }
+                    },
+                    selected = index == selectedIndex
+                ) {
+                    Text(label)
+                }
+            }
+        }
+    }
+}
+// [END android_compose_layouts_list_orderbuttons]
+
+@Preview
+@Composable
+fun ListAnimatingItemsExamplePreview(){
+    val list = listOf("One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten")
+    ListAnimatedItemsExample(list)
+}