1 /* 2 * Copyright (C) 2023 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.app.animation; 18 19 import android.graphics.Path; 20 21 import androidx.core.animation.AccelerateDecelerateInterpolator; 22 import androidx.core.animation.AccelerateInterpolator; 23 import androidx.core.animation.BounceInterpolator; 24 import androidx.core.animation.DecelerateInterpolator; 25 import androidx.core.animation.Interpolator; 26 import androidx.core.animation.LinearInterpolator; 27 import androidx.core.animation.OvershootInterpolator; 28 import androidx.core.animation.PathInterpolator; 29 30 /** 31 * Utility class to receive interpolators from. (androidx compatible version) 32 * 33 * This is the androidx compatible version of {@link Interpolators}. Make sure that changes made to 34 * this class are also reflected in {@link Interpolators}. 35 * 36 * Using the androidx versions of {@link androidx.core.animation.ValueAnimator} or 37 * {@link androidx.core.animation.ObjectAnimator} improves animation testability. This file provides 38 * the androidx compatible versions of the interpolators defined in {@link Interpolators}. 39 * AnimatorTestRule can be used in Tests to manipulate the animation under test (e.g. artificially 40 * advancing the time). 41 */ 42 public class InterpolatorsAndroidX { 43 44 /* 45 * ============================================================================================ 46 * Emphasized interpolators. 47 * ============================================================================================ 48 */ 49 50 /** 51 * The default emphasized interpolator. Used for hero / emphasized movement of content. 52 */ 53 public static final Interpolator EMPHASIZED = createEmphasizedInterpolator(); 54 55 /** 56 * The accelerated emphasized interpolator. Used for hero / emphasized movement of content that 57 * is disappearing e.g. when moving off screen. 58 */ 59 public static final Interpolator EMPHASIZED_ACCELERATE = new PathInterpolator( 60 0.3f, 0f, 0.8f, 0.15f); 61 62 /** 63 * The decelerating emphasized interpolator. Used for hero / emphasized movement of content that 64 * is appearing e.g. when coming from off screen 65 */ 66 public static final Interpolator EMPHASIZED_DECELERATE = new PathInterpolator( 67 0.05f, 0.7f, 0.1f, 1f); 68 69 public static final Interpolator EXAGGERATED_EASE; 70 static { 71 Path exaggeratedEase = new Path(); 72 exaggeratedEase.moveTo(0, 0); 73 exaggeratedEase.cubicTo(0.05f, 0f, 0.133333f, 0.08f, 0.166666f, 0.4f); 74 exaggeratedEase.cubicTo(0.225f, 0.94f, 0.5f, 1f, 1f, 1f); 75 EXAGGERATED_EASE = new PathInterpolator(exaggeratedEase); 76 } 77 78 public static final Interpolator INSTANT = t -> 1; 79 /** 80 * All values of t map to 0 until t == 1. This is primarily useful for setting view visibility, 81 * which should only happen at the very end of the animation (when it's already hidden). 82 */ 83 public static final Interpolator FINAL_FRAME = t -> t < 1 ? 0 : 1; 84 85 public static final Interpolator OVERSHOOT_0_75 = new OvershootInterpolator(0.75f); 86 public static final Interpolator OVERSHOOT_1_2 = new OvershootInterpolator(1.2f); 87 public static final Interpolator OVERSHOOT_1_7 = new OvershootInterpolator(1.7f); 88 89 /* 90 * ============================================================================================ 91 * Standard interpolators. 92 * ============================================================================================ 93 */ 94 95 /** 96 * The standard interpolator that should be used on every normal animation 97 */ 98 public static final Interpolator STANDARD = new PathInterpolator( 99 0.2f, 0f, 0f, 1f); 100 101 /** 102 * The standard accelerating interpolator that should be used on every regular movement of 103 * content that is disappearing e.g. when moving off screen. 104 */ 105 public static final Interpolator STANDARD_ACCELERATE = new PathInterpolator( 106 0.3f, 0f, 1f, 1f); 107 108 /** 109 * The standard decelerating interpolator that should be used on every regular movement of 110 * content that is appearing e.g. when coming from off screen. 111 */ 112 public static final Interpolator STANDARD_DECELERATE = new PathInterpolator( 113 0f, 0f, 0f, 1f); 114 115 /* 116 * ============================================================================================ 117 * Legacy 118 * ============================================================================================ 119 */ 120 121 /** 122 * The default legacy interpolator as defined in Material 1. Also known as FAST_OUT_SLOW_IN. 123 */ 124 public static final Interpolator LEGACY = new PathInterpolator(0.4f, 0f, 0.2f, 1f); 125 126 /** 127 * The default legacy accelerating interpolator as defined in Material 1. 128 * Also known as FAST_OUT_LINEAR_IN. 129 */ 130 public static final Interpolator LEGACY_ACCELERATE = new PathInterpolator(0.4f, 0f, 1f, 1f); 131 132 /** 133 * The default legacy decelerating interpolator as defined in Material 1. 134 * Also known as LINEAR_OUT_SLOW_IN. 135 */ 136 public static final Interpolator LEGACY_DECELERATE = new PathInterpolator(0f, 0f, 0.2f, 1f); 137 138 /** 139 * Linear interpolator. Often used if the interpolator is for different properties who need 140 * different interpolations. 141 */ 142 public static final Interpolator LINEAR = new LinearInterpolator(); 143 144 /* 145 * ============================================================================================ 146 * Custom interpolators 147 * ============================================================================================ 148 */ 149 150 public static final Interpolator FAST_OUT_SLOW_IN = LEGACY; 151 public static final Interpolator FAST_OUT_LINEAR_IN = LEGACY_ACCELERATE; 152 public static final Interpolator LINEAR_OUT_SLOW_IN = LEGACY_DECELERATE; 153 154 /** 155 * Like {@link #FAST_OUT_SLOW_IN}, but used in case the animation is played in reverse (i.e. t 156 * goes from 1 to 0 instead of 0 to 1). 157 */ 158 public static final Interpolator FAST_OUT_SLOW_IN_REVERSE = 159 new PathInterpolator(0.8f, 0f, 0.6f, 1f); 160 public static final Interpolator SLOW_OUT_LINEAR_IN = new PathInterpolator(0.8f, 0f, 1f, 1f); 161 public static final Interpolator AGGRESSIVE_EASE = new PathInterpolator(0.2f, 0f, 0f, 1f); 162 public static final Interpolator AGGRESSIVE_EASE_IN_OUT = new PathInterpolator(0.6f,0, 0.4f, 1); 163 164 public static final Interpolator DECELERATED_EASE = new PathInterpolator(0, 0, .2f, 1f); 165 public static final Interpolator ACCELERATED_EASE = new PathInterpolator(0.4f, 0, 1f, 1f); 166 public static final Interpolator PREDICTIVE_BACK_DECELERATED_EASE = 167 new PathInterpolator(0, 0, 0, 1f); 168 public static final Interpolator ALPHA_IN = new PathInterpolator(0.4f, 0f, 1f, 1f); 169 public static final Interpolator ALPHA_OUT = new PathInterpolator(0f, 0f, 0.8f, 1f); 170 public static final Interpolator ACCELERATE = new AccelerateInterpolator(); 171 public static final Interpolator ACCELERATE_0_5 = new AccelerateInterpolator(0.5f); 172 public static final Interpolator ACCELERATE_0_75 = new AccelerateInterpolator(0.75f); 173 public static final Interpolator ACCELERATE_1_5 = new AccelerateInterpolator(1.5f); 174 public static final Interpolator ACCELERATE_2 = new AccelerateInterpolator(2); 175 public static final Interpolator ACCELERATE_DECELERATE = new AccelerateDecelerateInterpolator(); 176 public static final Interpolator DECELERATE = new DecelerateInterpolator(); 177 public static final Interpolator DECELERATE_1_5 = new DecelerateInterpolator(1.5f); 178 public static final Interpolator DECELERATE_1_7 = new DecelerateInterpolator(1.7f); 179 public static final Interpolator DECELERATE_2 = new DecelerateInterpolator(2); 180 public static final Interpolator DECELERATE_QUINT = new DecelerateInterpolator(2.5f); 181 public static final Interpolator DECELERATE_3 = new DecelerateInterpolator(3f); 182 public static final Interpolator CUSTOM_40_40 = new PathInterpolator(0.4f, 0f, 0.6f, 1f); 183 public static final Interpolator ICON_OVERSHOT = new PathInterpolator(0.4f, 0f, 0.2f, 1.4f); 184 public static final Interpolator ICON_OVERSHOT_LESS = new PathInterpolator(0.4f, 0f, 0.2f, 185 1.1f); 186 public static final Interpolator PANEL_CLOSE_ACCELERATED = new PathInterpolator(0.3f, 0, 0.5f, 187 1); 188 public static final Interpolator BOUNCE = new BounceInterpolator(); 189 /** 190 * For state transitions on the control panel that lives in GlobalActions. 191 */ 192 public static final Interpolator CONTROL_STATE = new PathInterpolator(0.4f, 0f, 0.2f, 193 1.0f); 194 195 /** 196 * Interpolator to be used when animating a move based on a click. Pair with enough duration. 197 */ 198 public static final Interpolator TOUCH_RESPONSE = 199 new PathInterpolator(0.3f, 0f, 0.1f, 1f); 200 201 /** 202 * Like {@link #TOUCH_RESPONSE}, but used in case the animation is played in reverse (i.e. t 203 * goes from 1 to 0 instead of 0 to 1). 204 */ 205 public static final Interpolator TOUCH_RESPONSE_REVERSE = 206 new PathInterpolator(0.9f, 0f, 0.7f, 1f); 207 208 public static final Interpolator TOUCH_RESPONSE_ACCEL_DEACCEL = 209 v -> ACCELERATE_DECELERATE.getInterpolation(TOUCH_RESPONSE.getInterpolation(v)); 210 211 212 /** 213 * Inversion of ZOOM_OUT, compounded with an ease-out. 214 */ 215 public static final Interpolator ZOOM_IN = new Interpolator() { 216 @Override 217 public float getInterpolation(float v) { 218 return DECELERATE_3.getInterpolation(1 - ZOOM_OUT.getInterpolation(1 - v)); 219 } 220 }; 221 222 public static final Interpolator ZOOM_OUT = new Interpolator() { 223 224 private static final float FOCAL_LENGTH = 0.35f; 225 226 @Override 227 public float getInterpolation(float v) { 228 return zInterpolate(v); 229 } 230 231 /** 232 * This interpolator emulates the rate at which the perceived scale of an object changes 233 * as its distance from a camera increases. When this interpolator is applied to a scale 234 * animation on a view, it evokes the sense that the object is shrinking due to moving away 235 * from the camera. 236 */ 237 private float zInterpolate(float input) { 238 return (1.0f - FOCAL_LENGTH / (FOCAL_LENGTH + input)) / 239 (1.0f - FOCAL_LENGTH / (FOCAL_LENGTH + 1.0f)); 240 } 241 }; 242 243 public static final Interpolator SCROLL = new Interpolator() { 244 @Override 245 public float getInterpolation(float t) { 246 t -= 1.0f; 247 return t*t*t*t*t + 1; 248 } 249 }; 250 251 public static final Interpolator SCROLL_CUBIC = new Interpolator() { 252 @Override 253 public float getInterpolation(float t) { 254 t -= 1.0f; 255 return t*t*t + 1; 256 } 257 }; 258 259 private static final float FAST_FLING_PX_MS = 10; 260 261 /* 262 * ============================================================================================ 263 * Functions / Utilities 264 * ============================================================================================ 265 */ 266 scrollInterpolatorForVelocity(float velocity)267 public static Interpolator scrollInterpolatorForVelocity(float velocity) { 268 return Math.abs(velocity) > FAST_FLING_PX_MS ? SCROLL : SCROLL_CUBIC; 269 } 270 271 /** 272 * Create an OvershootInterpolator with tension directly related to the velocity (in px/ms). 273 * @param velocity The start velocity of the animation we want to overshoot. 274 */ overshootInterpolatorForVelocity(float velocity)275 public static Interpolator overshootInterpolatorForVelocity(float velocity) { 276 return new OvershootInterpolator(Math.min(Math.abs(velocity), 3f)); 277 } 278 279 /** 280 * Calculate the amount of overshoot using an exponential falloff function with desired 281 * properties, where the overshoot smoothly transitions at the 1.0f boundary into the 282 * overshoot, retaining its acceleration. 283 * 284 * @param progress a progress value going from 0 to 1 285 * @param overshootAmount the amount > 0 of overshoot desired. A value of 0.1 means the max 286 * value of the overall progress will be at 1.1. 287 * @param overshootStart the point in (0,1] where the result should reach 1 288 * @return the interpolated overshoot 289 */ getOvershootInterpolation(float progress, float overshootAmount, float overshootStart)290 public static float getOvershootInterpolation(float progress, float overshootAmount, 291 float overshootStart) { 292 if (overshootAmount == 0.0f || overshootStart == 0.0f) { 293 throw new IllegalArgumentException("Invalid values for overshoot"); 294 } 295 float b = MathUtils.log((overshootAmount + 1) / (overshootAmount)) / overshootStart; 296 return MathUtils.max(0.0f, 297 (float) (1.0f - Math.exp(-b * progress)) * (overshootAmount + 1.0f)); 298 } 299 300 /** 301 * Similar to {@link #getOvershootInterpolation(float, float, float)} but the overshoot 302 * starts immediately here, instead of first having a section of non-overshooting 303 * 304 * @param progress a progress value going from 0 to 1 305 */ getOvershootInterpolation(float progress)306 public static float getOvershootInterpolation(float progress) { 307 return MathUtils.max(0.0f, (float) (1.0f - Math.exp(-4 * progress))); 308 } 309 310 // Create the default emphasized interpolator createEmphasizedInterpolator()311 private static PathInterpolator createEmphasizedInterpolator() { 312 Path path = new Path(); 313 // Doing the same as fast_out_extra_slow_in 314 path.moveTo(0f, 0f); 315 path.cubicTo(0.05f, 0f, 0.133333f, 0.06f, 0.166666f, 0.4f); 316 path.cubicTo(0.208333f, 0.82f, 0.25f, 1f, 1f, 1f); 317 return new PathInterpolator(path); 318 } 319 320 /** 321 * Returns a function that runs the given interpolator such that the entire progress is set 322 * between the given bounds. That is, we set the interpolation to 0 until lowerBound and reach 323 * 1 by upperBound. 324 */ clampToProgress(Interpolator interpolator, float lowerBound, float upperBound)325 public static Interpolator clampToProgress(Interpolator interpolator, float lowerBound, 326 float upperBound) { 327 if (upperBound < lowerBound) { 328 throw new IllegalArgumentException( 329 String.format("upperBound (%f) must be greater than lowerBound (%f)", 330 upperBound, lowerBound)); 331 } 332 return t -> clampToProgress(interpolator, t, lowerBound, upperBound); 333 } 334 335 /** 336 * Returns the progress value's progress between the lower and upper bounds. That is, the 337 * progress will be 0f from 0f to lowerBound, and reach 1f by upperBound. 338 * 339 * Between lowerBound and upperBound, the progress value will be interpolated using the provided 340 * interpolator. 341 */ clampToProgress( Interpolator interpolator, float progress, float lowerBound, float upperBound)342 public static float clampToProgress( 343 Interpolator interpolator, float progress, float lowerBound, float upperBound) { 344 if (upperBound < lowerBound) { 345 throw new IllegalArgumentException( 346 String.format("upperBound (%f) must be greater than lowerBound (%f)", 347 upperBound, lowerBound)); 348 } 349 350 if (progress == lowerBound && progress == upperBound) { 351 return progress == 0f ? 0 : 1; 352 } 353 if (progress < lowerBound) { 354 return 0; 355 } 356 if (progress > upperBound) { 357 return 1; 358 } 359 return interpolator.getInterpolation((progress - lowerBound) / (upperBound - lowerBound)); 360 } 361 362 /** 363 * Returns the progress value's progress between the lower and upper bounds. That is, the 364 * progress will be 0f from 0f to lowerBound, and reach 1f by upperBound. 365 */ clampToProgress(float progress, float lowerBound, float upperBound)366 public static float clampToProgress(float progress, float lowerBound, float upperBound) { 367 return clampToProgress(LINEAR, progress, lowerBound, upperBound); 368 } 369 mapRange(float value, float min, float max)370 private static float mapRange(float value, float min, float max) { 371 return min + (value * (max - min)); 372 } 373 374 /** 375 * Runs the given interpolator such that the interpolated value is mapped to the given range. 376 * This is useful, for example, if we only use this interpolator for part of the animation, 377 * such as to take over a user-controlled animation when they let go. 378 */ mapToProgress(Interpolator interpolator, float lowerBound, float upperBound)379 public static Interpolator mapToProgress(Interpolator interpolator, float lowerBound, 380 float upperBound) { 381 return t -> mapRange(interpolator.getInterpolation(t), lowerBound, upperBound); 382 } 383 384 /** 385 * Returns the reverse of the provided interpolator, following the formula: g(x) = 1 - f(1 - x). 386 * In practice, this means that if f is an interpolator used to model a value animating between 387 * m and n, g is the interpolator to use to obtain the specular behavior when animating from n 388 * to m. 389 */ reverse(Interpolator interpolator)390 public static Interpolator reverse(Interpolator interpolator) { 391 return t -> 1 - interpolator.getInterpolation(1 - t); 392 } 393 }