| /* |
| * Copyright 2021 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 |
| * |
| * http://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 androidx.compose.animation.demos |
| |
| import androidx.compose.animation.core.animateOffsetAsState |
| import androidx.compose.foundation.background |
| import androidx.compose.foundation.gestures.detectDragGestures |
| import androidx.compose.foundation.layout.Box |
| import androidx.compose.foundation.layout.fillMaxSize |
| import androidx.compose.foundation.layout.offset |
| import androidx.compose.foundation.layout.size |
| import androidx.compose.foundation.shape.CircleShape |
| import androidx.compose.material.Text |
| import androidx.compose.runtime.Composable |
| import androidx.compose.runtime.State |
| 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.geometry.Offset |
| import androidx.compose.ui.graphics.Color |
| import androidx.compose.ui.input.pointer.consumeAllChanges |
| import androidx.compose.ui.input.pointer.pointerInput |
| import androidx.compose.ui.unit.dp |
| import androidx.compose.ui.unit.round |
| |
| @Composable |
| fun SpringChainDemo() { |
| var leader by remember { mutableStateOf(Offset(200f, 200f)) } |
| Box( |
| Modifier.fillMaxSize().pointerInput(Unit) { |
| detectDragGestures { change, dragAmount -> |
| change.consumeAllChanges() |
| leader += dragAmount |
| } |
| } |
| ) { |
| Text( |
| modifier = Modifier.align(Alignment.Center), |
| text = "Since we are here, why not drag me around?" |
| ) |
| val size = pastelAwakening.size |
| val followers = remember { Array<State<Offset>>(size) { mutableStateOf(Offset.Zero) } } |
| for (i in 0 until size) { |
| // Each follower on the spring chain uses the previous follower's position as target |
| followers[i] = animateOffsetAsState(if (i == 0) leader else followers[i - 1].value) |
| } |
| |
| // Followers stacked in reverse orders |
| for (i in followers.size - 1 downTo 0) { |
| Box( |
| Modifier |
| .offset { followers[i].value.round() } |
| .size(80.dp) |
| .background(pastelAwakening[i], CircleShape) |
| ) |
| } |
| // Leader |
| Box( |
| Modifier.offset { leader.round() }.size(80.dp) |
| .background(Color(0xFFfffbd0), CircleShape) |
| ) |
| } |
| } |
| |
| private val pastelAwakening = listOf( |
| Color(0xffdfdeff), |
| Color(0xffffe0f5), |
| Color(0xffffefd8), |
| Color(0xffe6ffd0), |
| Color(0xffd9f6ff) |
| ) |