| /* |
| * 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.samples |
| |
| import androidx.compose.animation.core.transitionDefinition |
| import androidx.annotation.Sampled |
| import androidx.compose.Composable |
| import androidx.compose.animation.ColorPropKey |
| import androidx.compose.animation.DpPropKey |
| import androidx.compose.animation.transition |
| import androidx.ui.core.Modifier |
| import androidx.compose.foundation.Box |
| import androidx.compose.foundation.background |
| import androidx.compose.ui.graphics.Color |
| import androidx.compose.foundation.layout.preferredSize |
| import androidx.ui.unit.dp |
| |
| private enum class State { |
| First, |
| Second |
| } |
| |
| @Sampled |
| fun TransitionSample() { |
| val colorKey = ColorPropKey() |
| val widthKey = DpPropKey() |
| val heightKey = DpPropKey() |
| |
| val definition = transitionDefinition { |
| state(State.First) { |
| this[colorKey] = Color.Red |
| this[widthKey] = 200.dp |
| this[heightKey] = 400.dp |
| } |
| state(State.Second) { |
| this[colorKey] = Color.Green |
| this[widthKey] = 300.dp |
| this[heightKey] = 300.dp |
| } |
| } |
| |
| @Composable |
| fun TransitionBasedColoredRect() { |
| // This puts the transition in State.First. Any subsequent state change will trigger a |
| // transition animation, as defined in the transition definition. |
| val state = transition(definition = definition, toState = State.First) |
| Box( |
| Modifier |
| .preferredSize(state[widthKey], state[heightKey]) |
| .background(color = state[colorKey]) |
| ) |
| } |
| |
| @Composable |
| fun ColorRectWithInitState() { |
| // This starts the transition going from State.First to State.Second when this composable |
| // gets composed for the first time. |
| val state = transition( |
| definition = definition, initState = State.First, toState = State.Second) |
| Box( |
| Modifier |
| .preferredSize(state[widthKey], state[heightKey]) |
| .background(state[colorKey]) |
| ) |
| } |
| } |