| /* |
| * Copyright 2019 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 android.os.Handler |
| import android.os.Looper |
| import androidx.compose.animation.core.FloatPropKey |
| import androidx.compose.animation.core.TransitionState |
| import androidx.compose.animation.core.spring |
| import androidx.compose.animation.core.transitionDefinition |
| import androidx.compose.animation.core.tween |
| import androidx.compose.Composable |
| import androidx.compose.getValue |
| import androidx.compose.mutableStateOf |
| import androidx.compose.setValue |
| import androidx.compose.animation.ColorPropKey |
| import androidx.compose.animation.transition |
| import androidx.ui.core.Modifier |
| import androidx.compose.foundation.Box |
| import androidx.compose.foundation.Canvas |
| import androidx.compose.foundation.background |
| import androidx.ui.geometry.Offset |
| import androidx.ui.geometry.Size |
| import androidx.ui.graphics.Color |
| import androidx.compose.foundation.layout.fillMaxSize |
| |
| @Composable |
| fun StateAnimationWithInterruptionsDemo() { |
| Box(Modifier.fillMaxSize()) { |
| ColorRect() |
| } |
| } |
| |
| private val background = ColorPropKey() |
| private val y = FloatPropKey() |
| |
| private enum class OverlayState { |
| Open, |
| Closed |
| } |
| |
| private val definition = transitionDefinition { |
| state(OverlayState.Open) { |
| this[background] = Color(red = 128, green = 128, blue = 128, alpha = 255) |
| this[y] = 1f // percentage |
| } |
| state(OverlayState.Closed) { |
| this[background] = Color(red = 188, green = 222, blue = 145, alpha = 255) |
| this[y] = 0f // percentage |
| } |
| // Apply this transition to all state changes (i.e. Open -> Closed and Closed -> Open) |
| transition { |
| background using tween( |
| durationMillis = 800 |
| ) |
| y using spring( |
| // Extremely low stiffness |
| stiffness = 40f |
| ) |
| } |
| } |
| |
| private val handler = Handler(Looper.getMainLooper()) |
| |
| @Composable |
| private fun ColorRect() { |
| var toState by mutableStateOf(OverlayState.Closed) |
| handler.postDelayed(object : Runnable { |
| override fun run() { |
| if ((0..1).random() == 0) { |
| toState = OverlayState.Open |
| } else { |
| toState = OverlayState.Closed |
| } |
| } |
| }, (200..800).random().toLong()) |
| val state = transition(definition = definition, toState = toState) |
| ColorRectState(state = state) |
| } |
| |
| @Composable |
| private fun ColorRectState(state: TransitionState) { |
| val color = state[background] |
| val scaleY = state[y] |
| Canvas(Modifier.fillMaxSize().background(color = color)) { |
| drawRect( |
| Color(alpha = 255, red = 255, green = 255, blue = 255), |
| topLeft = Offset(100f, 0f), |
| size = Size(size.width - 200f, scaleY * size.height) |
| ) |
| } |
| } |