1/*
2 * Copyright (C) 2010 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
17package android.animation;
18
19/**
20 * A time interpolator defines the rate of change of an animation. This allows animations
21 * to have non-linear motion, such as acceleration and deceleration.
22 */
23public interface TimeInterpolator {
24
25    /**
26     * Maps a value representing the elapsed fraction of an animation to a value that represents
27     * the interpolated fraction. This interpolated value is then multiplied by the change in
28     * value of an animation to derive the animated value at the current elapsed animation time.
29     *
30     * @param input A value between 0 and 1.0 indicating our current point
31     *        in the animation where 0 represents the start and 1.0 represents
32     *        the end
33     * @return The interpolation value. This value can be more than 1.0 for
34     *         interpolators which overshoot their targets, or less than 0 for
35     *         interpolators that undershoot their targets.
36     */
37    float getInterpolation(float input);
38}
39