| /* |
| * Copyright 2020 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 |
| |
| import androidx.compose.animation.core.AnimationClockObservable |
| import androidx.compose.animation.core.TransitionDefinition |
| import androidx.compose.animation.core.TransitionState |
| import androidx.compose.Composable |
| import androidx.compose.getValue |
| import androidx.compose.setValue |
| import androidx.ui.core.AnimationClockAmbient |
| |
| /** |
| * [Transition] composable creates a state-based transition using the animation configuration |
| * defined in [TransitionDefinition]. This can be especially useful when animating multiple |
| * values from a predefined set of values to another. For animating a single value, consider using |
| * [animatedValue], [animatedFloat], [animatedColor] or the more light-weight [animate] APIs. |
| * |
| * [Transition] starts a new animation or changes the on-going animation when the [toState] |
| * parameter is changed to a different value. It dutifully ensures that the animation will head |
| * towards new [toState] regardless of what state (or in-between state) it’s currently in: If the |
| * transition is not currently animating, having a new [toState] value will start a new animation, |
| * otherwise the in-flight animation will correct course and animate towards the new [toState] |
| * based on the interruption handling logic. |
| * |
| * [Transition] takes a transition definition, a target state and child composables. |
| * These child composables will be receiving a [TransitionState] object as an argument, which |
| * captures all the current values of the animation. Child composables should read the animation |
| * values from the [TransitionState] object, and apply the value wherever necessary. |
| * |
| * @sample androidx.compose.animation.samples.TransitionSample |
| * |
| * @param definition Transition definition that defines states and transitions |
| * @param toState New state to transition to |
| * @param clock Optional animation clock that pulses animations when time changes. By default, |
| * the system uses a choreographer based clock read from the [AnimationClockAmbient]. |
| * A custom implementation of the [AnimationClockObservable] (such as a |
| * [androidx.compose.animation.core.ManualAnimationClock]) can be supplied here if there’s a need to |
| * manually control the clock (for example in tests). |
| * @param initState Optional initial state for the transition. When undefined, the initial state |
| * will be set to the first [toState] seen in the transition. |
| * @param onStateChangeFinished An optional listener to get notified when state change animation |
| * has completed |
| * @param children The children composables that will be animated |
| * |
| * @see [TransitionDefinition] |
| */ |
| @Deprecated("Transition has been renamed to transition, which returns a TransitionState instead " + |
| "of passing it to children", |
| replaceWith = ReplaceWith( |
| "transition(definition, toState, clock, initState, null, onStateChangeFinished)", |
| "androidx.compose.animation.transition")) |
| @Composable |
| fun <T> Transition( |
| definition: TransitionDefinition<T>, |
| toState: T, |
| clock: AnimationClockObservable = AnimationClockAmbient.current, |
| initState: T = toState, |
| onStateChangeFinished: ((T) -> Unit)? = null, |
| children: @Composable (state: TransitionState) -> Unit |
| ) { |
| val state = transition(definition, toState, clock, initState, null, onStateChangeFinished) |
| children(state) |
| } |