Add Swipe to reveal examples (#412)

* Add Swipe to reveal examples

* Apply Spotless

* Adding swipe to dismiss examples to the top compose examples.

* Tidy up merge conflict errors

---------

Co-authored-by: jakeroseman <[email protected]>

compose/snippets/src/main/java/com/example/compose/snippets/SnippetsActivity.kt

@@ -49,6 +49,7 @@ import com.example.compose.snippets.components.ScaffoldExample
 import com.example.compose.snippets.components.SearchBarExamples
 import com.example.compose.snippets.components.SegmentedButtonExamples
 import com.example.compose.snippets.components.SliderExamples
+import com.example.compose.snippets.components.SwipeToDismissBoxExamples
 import com.example.compose.snippets.components.SwitchExamples
 import com.example.compose.snippets.components.TimePickerExamples
 import com.example.compose.snippets.components.TooltipExamples
@@ -122,6 +123,7 @@ class SnippetsActivity : ComponentActivity() {
                                     TopComponentsDestination.TooltipExamples -> TooltipExamples()
                                     TopComponentsDestination.NavigationDrawerExamples -> NavigationDrawerExamples()
                                     TopComponentsDestination.SegmentedButtonExamples -> SegmentedButtonExamples()
+                                    TopComponentsDestination.SwipeToDismissBoxExamples -> SwipeToDismissBoxExamples()
                                     TopComponentsDestination.SearchBarExamples -> SearchBarExamples()
                                 }
                             }

compose/snippets/src/main/java/com/example/compose/snippets/components/SwipeToDismissBox.kt

@@ -0,0 +1,339 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.compose.snippets.components
+
+import androidx.compose.animation.animateColorAsState
+import androidx.compose.foundation.background
+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.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.CheckBox
+import androidx.compose.material.icons.filled.CheckBoxOutlineBlank
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ListItem
+import androidx.compose.material3.OutlinedCard
+import androidx.compose.material3.SwipeToDismissBox
+import androidx.compose.material3.SwipeToDismissBoxValue
+import androidx.compose.material3.Text
+import androidx.compose.material3.rememberSwipeToDismissBoxState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateListOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.RectangleShape
+import androidx.compose.ui.graphics.lerp
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+
+@Preview
+@Composable
+fun SwipeToDismissBoxExamples() {
+    Column(
+        modifier = Modifier
+            .padding(16.dp)
+            .fillMaxSize(),
+        verticalArrangement = Arrangement.spacedBy(24.dp),
+        horizontalAlignment = Alignment.CenterHorizontally,
+    ) {
+        Text("Swipe to dismiss with change of background", fontWeight = FontWeight.Bold)
+        SwipeItemExample()
+        Text("Swipe to dismiss with a cross-fade animation", fontWeight = FontWeight.Bold)
+        SwipeCardItemExample()
+    }
+}
+
+// [START android_compose_components_todoitem]
+data class TodoItem(
+    var isItemDone: Boolean,
+    var itemDescription: String
+)
+// [END android_compose_components_todoitem]
+
+// [START android_compose_components_swipeitem]
+@Composable
+fun SwipeItem(
+    value: TodoItem,
+    startToEndAction: (TodoItem) -> Unit,
+    endToStartAction: (TodoItem) -> Unit,
+    modifier: Modifier = Modifier,
+    content: @Composable (TodoItem) -> Unit
+) {
+    val swipeToDismissBoxState = rememberSwipeToDismissBoxState(
+        confirmValueChange = {
+            when (it) {
+                SwipeToDismissBoxValue.StartToEnd -> {
+                    startToEndAction(value)
+                    // Do not dismiss this item.
+                    false
+                }
+                SwipeToDismissBoxValue.EndToStart -> {
+                    endToStartAction(value)
+                    true
+                }
+                SwipeToDismissBoxValue.Settled -> {
+                    false
+                }
+            }
+        }
+    )
+
+    SwipeToDismissBox(
+        state = swipeToDismissBoxState,
+        modifier = modifier
+            .fillMaxSize(),
+        backgroundContent = {
+            Row(
+                modifier = Modifier
+                    .background(
+                        when (swipeToDismissBoxState.dismissDirection) {
+                            SwipeToDismissBoxValue.StartToEnd -> {
+                                Color.Blue
+                            }
+                            SwipeToDismissBoxValue.EndToStart -> {
+                                Color.Red
+                            }
+                            SwipeToDismissBoxValue.Settled -> {
+                                Color.LightGray
+                            }
+                        }
+                    )
+                    .fillMaxSize(),
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.SpaceBetween
+            ) {
+                when (swipeToDismissBoxState.dismissDirection) {
+                    SwipeToDismissBoxValue.StartToEnd -> {
+                        if (value.isItemDone) {
+                            Icon(
+                                imageVector = Icons.Default.CheckBox,
+                                contentDescription = "Item done",
+                                tint = Color.White,
+                                modifier = Modifier
+                                    .padding(12.dp)
+                            )
+                        } else {
+                            Icon(
+                                imageVector = Icons.Default.CheckBoxOutlineBlank,
+                                contentDescription = "Item not done",
+                                tint = Color.White,
+                                modifier = Modifier
+                                    .padding(12.dp)
+                            )
+                        }
+                    }
+
+                    SwipeToDismissBoxValue.EndToStart -> {
+                        Spacer(modifier = Modifier)
+                        Icon(
+                            imageVector = Icons.Default.Delete,
+                            contentDescription = "Remove item",
+                            tint = Color.White,
+                            modifier = Modifier
+                                .padding(12.dp)
+                        )
+                    }
+
+                    SwipeToDismissBoxValue.Settled -> {}
+                }
+            }
+        }
+    ) {
+        content(value)
+    }
+}
+// [END android_compose_components_swipeitem]
+
+@Preview(showBackground = true)
+// [START android_compose_components_swipeitemexample]
+@Composable
+private fun SwipeItemExample() {
+    val todoItems = remember {
+        mutableStateListOf(
+            TodoItem(isItemDone = false, itemDescription = "Pay bills"),
+            TodoItem(isItemDone = false, itemDescription = "Buy groceries"),
+            TodoItem(isItemDone = false, itemDescription = "Go to gym"),
+            TodoItem(isItemDone = false, itemDescription = "Get dinner")
+        )
+    }
+
+    LazyColumn {
+        items(
+            items = todoItems,
+            key = { it.itemDescription }
+        ) { todoItem ->
+            SwipeItem(
+                value = todoItem,
+                startToEndAction = {
+                    todoItem.isItemDone = !todoItem.isItemDone
+                },
+                endToStartAction = {
+                    todoItems -= todoItem
+                }
+            ) {
+                ListItem(
+                    headlineContent = { Text(text = todoItem.itemDescription) },
+                    supportingContent = { Text(text = "swipe me to update or remove.") }
+                )
+            }
+        }
+    }
+}
+// [END android_compose_components_swipeitemexample]
+
+// [START android_compose_components_swipecarditem]
+@Composable
+fun SwipeCardItem(
+    value: TodoItem,
+    startToEndAction: (TodoItem) -> Unit,
+    endToStartAction: (TodoItem) -> Unit,
+    modifier: Modifier = Modifier,
+    content: @Composable (TodoItem) -> Unit
+) {
+    val swipeToDismissState = rememberSwipeToDismissBoxState(
+        positionalThreshold = { totalDistance -> totalDistance * 0.25f },
+        confirmValueChange = {
+            when (it) {
+                SwipeToDismissBoxValue.StartToEnd -> {
+                    startToEndAction(value)
+                    // Do not dismiss this item.
+                    false
+                }
+                SwipeToDismissBoxValue.EndToStart -> {
+                    endToStartAction(value)
+                    true
+                }
+                SwipeToDismissBoxValue.Settled -> {
+                    false
+                }
+            }
+        }
+    )
+
+    SwipeToDismissBox(
+        modifier = Modifier,
+        state = swipeToDismissState,
+        backgroundContent = {
+            // Cross-fade the background color as the drag gesture progresses.
+            val color by animateColorAsState(
+                when (swipeToDismissState.targetValue) {
+                    SwipeToDismissBoxValue.Settled -> Color.LightGray
+                    SwipeToDismissBoxValue.StartToEnd ->
+                        lerp(Color.LightGray, Color.Blue, swipeToDismissState.progress)
+
+                    SwipeToDismissBoxValue.EndToStart ->
+                        lerp(Color.LightGray, Color.Red, swipeToDismissState.progress)
+                },
+                label = "swipeable card item background color"
+            )
+            Row(
+                modifier = Modifier
+                    .background(color)
+                    .fillMaxSize(),
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.SpaceBetween
+            ) {
+                when (swipeToDismissState.dismissDirection) {
+                    SwipeToDismissBoxValue.StartToEnd -> {
+                        if (value.isItemDone) {
+                            Icon(
+                                imageVector = Icons.Default.CheckBox,
+                                contentDescription = "Item done",
+                                tint = Color.White,
+                                modifier = Modifier
+                                    .padding(12.dp)
+                            )
+                        } else {
+                            Icon(
+                                imageVector = Icons.Default.CheckBoxOutlineBlank,
+                                contentDescription = "Item not done",
+                                tint = Color.White,
+                                modifier = Modifier
+                                    .padding(12.dp)
+                            )
+                        }
+                    }
+
+                    SwipeToDismissBoxValue.EndToStart -> {
+                        Spacer(modifier = Modifier)
+                        Icon(
+                            imageVector = Icons.Default.Delete,
+                            contentDescription = "Remove item",
+                            tint = Color.White,
+                            modifier = Modifier
+                                .padding(12.dp)
+                        )
+                    }
+
+                    SwipeToDismissBoxValue.Settled -> {}
+                }
+            }
+        }
+    ) {
+        content(value)
+    }
+}
+// [END android_compose_components_swipecarditem]
+
+// [START android_compose_components_swipecarditemexample]
+@Preview
+@Composable
+private fun SwipeCardItemExample() {
+    val todoItems = remember {
+        mutableStateListOf(
+            TodoItem(isItemDone = false, itemDescription = "Pay bills"),
+            TodoItem(isItemDone = false, itemDescription = "Buy groceries"),
+            TodoItem(isItemDone = false, itemDescription = "Go to gym"),
+            TodoItem(isItemDone = false, itemDescription = "Get dinner")
+        )
+    }
+
+    LazyColumn {
+        items(
+            items = todoItems,
+            key = { it.itemDescription }
+        ) { todoItem ->
+            SwipeCardItem(
+                value = todoItem,
+                startToEndAction = {
+                    todoItem.isItemDone = !todoItem.isItemDone
+                },
+                endToStartAction = {
+                    todoItems -= todoItem
+                }
+            ) {
+                OutlinedCard(shape = RectangleShape) {
+                    ListItem(
+                        headlineContent = { Text(todoItem.itemDescription) },
+                        supportingContent = { Text("swipe me to update or remove.") }
+                    )
+                }
+            }
+        }
+    }
+}
+// [END android_compose_components_swipecarditemexample]

compose/snippets/src/main/java/com/example/compose/snippets/navigation/Destination.kt

@@ -50,5 +50,6 @@ enum class TopComponentsDestination(val route: String, val title: String) {
     TooltipExamples("tooltipExamples", "Tooltips"),
     NavigationDrawerExamples("navigationDrawerExamples", "Navigation drawer"),
     SegmentedButtonExamples("segmentedButtonExamples", "Segmented button"),
+    SwipeToDismissBoxExamples("swipeToDismissBoxExamples", "Swipe to dismiss box examples"),
     SearchBarExamples("searchBarExamples", "Search bar")
 }