1 /* 2 * Copyright (C) 2017 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 com.android.launcher3.anim; 18 19 import android.graphics.Path; 20 import android.view.animation.AccelerateDecelerateInterpolator; 21 import android.view.animation.AccelerateInterpolator; 22 import android.view.animation.DecelerateInterpolator; 23 import android.view.animation.Interpolator; 24 import android.view.animation.LinearInterpolator; 25 import android.view.animation.OvershootInterpolator; 26 import android.view.animation.PathInterpolator; 27 28 import com.android.launcher3.Utilities; 29 30 /** 31 * Common interpolators used in Launcher 32 */ 33 public class Interpolators { 34 35 public static final Interpolator LINEAR = new LinearInterpolator(); 36 37 public static final Interpolator ACCEL = new AccelerateInterpolator(); 38 public static final Interpolator ACCEL_0_5 = new AccelerateInterpolator(0.5f); 39 public static final Interpolator ACCEL_0_75 = new AccelerateInterpolator(0.75f); 40 public static final Interpolator ACCEL_1_5 = new AccelerateInterpolator(1.5f); 41 public static final Interpolator ACCEL_2 = new AccelerateInterpolator(2); 42 43 public static final Interpolator DEACCEL = new DecelerateInterpolator(); 44 public static final Interpolator DEACCEL_1_5 = new DecelerateInterpolator(1.5f); 45 public static final Interpolator DEACCEL_1_7 = new DecelerateInterpolator(1.7f); 46 public static final Interpolator DEACCEL_2 = new DecelerateInterpolator(2); 47 public static final Interpolator DEACCEL_2_5 = new DecelerateInterpolator(2.5f); 48 public static final Interpolator DEACCEL_3 = new DecelerateInterpolator(3f); 49 50 public static final Interpolator ACCEL_DEACCEL = new AccelerateDecelerateInterpolator(); 51 52 public static final Interpolator FAST_OUT_SLOW_IN = new PathInterpolator(0.4f, 0f, 0.2f, 1f); 53 54 public static final Interpolator AGGRESSIVE_EASE = new PathInterpolator(0.2f, 0f, 0f, 1f); 55 public static final Interpolator AGGRESSIVE_EASE_IN_OUT = new PathInterpolator(0.6f,0, 0.4f, 1); 56 57 public static final Interpolator DECELERATED_EASE = new PathInterpolator(0, 0, .2f, 1f); 58 public static final Interpolator ACCELERATED_EASE = new PathInterpolator(0.4f, 0, 1f, 1f); 59 60 public static final Interpolator EXAGGERATED_EASE; 61 62 public static final Interpolator INSTANT = t -> 1; 63 /** 64 * All values of t map to 0 until t == 1. This is primarily useful for setting view visibility, 65 * which should only happen at the very end of the animation (when it's already hidden). 66 */ 67 public static final Interpolator FINAL_FRAME = t -> t < 1 ? 0 : 1; 68 69 static { 70 Path exaggeratedEase = new Path(); 71 exaggeratedEase.moveTo(0, 0); 72 exaggeratedEase.cubicTo(0.05f, 0f, 0.133333f, 0.08f, 0.166666f, 0.4f); 73 exaggeratedEase.cubicTo(0.225f, 0.94f, 0.5f, 1f, 1f, 1f); 74 EXAGGERATED_EASE = new PathInterpolator(exaggeratedEase); 75 } 76 77 public static final Interpolator OVERSHOOT_1_2 = new OvershootInterpolator(1.2f); 78 public static final Interpolator OVERSHOOT_1_7 = new OvershootInterpolator(1.7f); 79 80 public static final Interpolator TOUCH_RESPONSE_INTERPOLATOR = 81 new PathInterpolator(0.3f, 0f, 0.1f, 1f); 82 public static final Interpolator TOUCH_RESPONSE_INTERPOLATOR_ACCEL_DEACCEL = 83 v -> ACCEL_DEACCEL.getInterpolation(TOUCH_RESPONSE_INTERPOLATOR.getInterpolation(v)); 84 85 86 /** 87 * Inversion of ZOOM_OUT, compounded with an ease-out. 88 */ 89 public static final Interpolator ZOOM_IN = new Interpolator() { 90 @Override 91 public float getInterpolation(float v) { 92 return DEACCEL_3.getInterpolation(1 - ZOOM_OUT.getInterpolation(1 - v)); 93 } 94 }; 95 96 public static final Interpolator ZOOM_OUT = new Interpolator() { 97 98 private static final float FOCAL_LENGTH = 0.35f; 99 100 @Override 101 public float getInterpolation(float v) { 102 return zInterpolate(v); 103 } 104 105 /** 106 * This interpolator emulates the rate at which the perceived scale of an object changes 107 * as its distance from a camera increases. When this interpolator is applied to a scale 108 * animation on a view, it evokes the sense that the object is shrinking due to moving away 109 * from the camera. 110 */ 111 private float zInterpolate(float input) { 112 return (1.0f - FOCAL_LENGTH / (FOCAL_LENGTH + input)) / 113 (1.0f - FOCAL_LENGTH / (FOCAL_LENGTH + 1.0f)); 114 } 115 }; 116 117 public static final Interpolator SCROLL = new Interpolator() { 118 @Override 119 public float getInterpolation(float t) { 120 t -= 1.0f; 121 return t*t*t*t*t + 1; 122 } 123 }; 124 125 public static final Interpolator SCROLL_CUBIC = new Interpolator() { 126 @Override 127 public float getInterpolation(float t) { 128 t -= 1.0f; 129 return t*t*t + 1; 130 } 131 }; 132 133 private static final float FAST_FLING_PX_MS = 10; 134 scrollInterpolatorForVelocity(float velocity)135 public static Interpolator scrollInterpolatorForVelocity(float velocity) { 136 return Math.abs(velocity) > FAST_FLING_PX_MS ? SCROLL : SCROLL_CUBIC; 137 } 138 139 /** 140 * Create an OvershootInterpolator with tension directly related to the velocity (in px/ms). 141 * @param velocity The start velocity of the animation we want to overshoot. 142 */ overshootInterpolatorForVelocity(float velocity)143 public static Interpolator overshootInterpolatorForVelocity(float velocity) { 144 return new OvershootInterpolator(Math.min(Math.abs(velocity), 3f)); 145 } 146 147 /** 148 * Runs the given interpolator such that the entire progress is set between the given bounds. 149 * That is, we set the interpolation to 0 until lowerBound and reach 1 by upperBound. 150 */ clampToProgress(Interpolator interpolator, float lowerBound, float upperBound)151 public static Interpolator clampToProgress(Interpolator interpolator, float lowerBound, 152 float upperBound) { 153 if (upperBound < lowerBound) { 154 throw new IllegalArgumentException( 155 String.format("upperBound (%f) must be greater than lowerBound (%f)", 156 upperBound, lowerBound)); 157 } 158 return t -> { 159 if (t == lowerBound && t == upperBound) { 160 return t == 0f ? 0 : 1; 161 } 162 if (t < lowerBound) { 163 return 0; 164 } 165 if (t > upperBound) { 166 return 1; 167 } 168 return interpolator.getInterpolation((t - lowerBound) / (upperBound - lowerBound)); 169 }; 170 } 171 172 /** 173 * Runs the given interpolator such that the interpolated value is mapped to the given range. 174 * This is useful, for example, if we only use this interpolator for part of the animation, 175 * such as to take over a user-controlled animation when they let go. 176 */ 177 public static Interpolator mapToProgress(Interpolator interpolator, float lowerBound, 178 float upperBound) { 179 return t -> Utilities.mapRange(interpolator.getInterpolation(t), lowerBound, upperBound); 180 } 181 } 182