1 /*
2  * Copyright 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package androidx.core.animation;
18 
19 import androidx.annotation.FloatRange;
20 
21 /**
22  * An interpolator defines the rate of change of an animation. This allows animations
23  * to have non-linear motion, such as acceleration and deceleration.
24  */
25 public interface Interpolator {
26 
27     /**
28      * Maps a value representing the elapsed fraction of an animation to a value that represents
29      * the interpolated fraction. This interpolated value is then multiplied by the change in
30      * value of an animation to derive the animated value at the current elapsed animation time.
31      *
32      * @param input A value between 0 and 1.0 indicating our current point
33      *        in the animation where 0 represents the start and 1.0 represents
34      *        the end
35      * @return The interpolation value. This value can be more than 1.0 for
36      *         interpolators which overshoot their targets, or less than 0 for
37      *         interpolators that undershoot their targets.
38      */
getInterpolation(@loatRangefrom = 0, to = 1) float input)39     float getInterpolation(@FloatRange(from = 0, to = 1) float input);
40 }
41