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 17 package 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 */ 23 public 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 */ getInterpolation(float input)37 float getInterpolation(float input); 38 } 39