ValueAnimator.java revision 49a513b571bcb8e5da94bd50ae465cbaafa44734
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 19import android.annotation.CallSuper; 20import android.annotation.IntDef; 21import android.annotation.TestApi; 22import android.os.Looper; 23import android.os.Trace; 24import android.util.AndroidRuntimeException; 25import android.util.Log; 26import android.view.animation.AccelerateDecelerateInterpolator; 27import android.view.animation.AnimationUtils; 28import android.view.animation.LinearInterpolator; 29 30import java.lang.annotation.Retention; 31import java.lang.annotation.RetentionPolicy; 32import java.util.ArrayList; 33import java.util.HashMap; 34 35/** 36 * This class provides a simple timing engine for running animations 37 * which calculate animated values and set them on target objects. 38 * 39 * <p>There is a single timing pulse that all animations use. It runs in a 40 * custom handler to ensure that property changes happen on the UI thread.</p> 41 * 42 * <p>By default, ValueAnimator uses non-linear time interpolation, via the 43 * {@link AccelerateDecelerateInterpolator} class, which accelerates into and decelerates 44 * out of an animation. This behavior can be changed by calling 45 * {@link ValueAnimator#setInterpolator(TimeInterpolator)}.</p> 46 * 47 * <p>Animators can be created from either code or resource files. Here is an example 48 * of a ValueAnimator resource file:</p> 49 * 50 * {@sample development/samples/ApiDemos/res/anim/animator.xml ValueAnimatorResources} 51 * 52 * <p>It is also possible to use a combination of {@link PropertyValuesHolder} and 53 * {@link Keyframe} resource tags to create a multi-step animation. 54 * Note that you can specify explicit fractional values (from 0 to 1) for 55 * each keyframe to determine when, in the overall duration, the animation should arrive at that 56 * value. Alternatively, you can leave the fractions off and the keyframes will be equally 57 * distributed within the total duration:</p> 58 * 59 * {@sample development/samples/ApiDemos/res/anim/value_animator_pvh_kf.xml 60 * ValueAnimatorKeyframeResources} 61 * 62 * <div class="special reference"> 63 * <h3>Developer Guides</h3> 64 * <p>For more information about animating with {@code ValueAnimator}, read the 65 * <a href="{@docRoot}guide/topics/graphics/prop-animation.html#value-animator">Property 66 * Animation</a> developer guide.</p> 67 * </div> 68 */ 69@SuppressWarnings("unchecked") 70public class ValueAnimator extends Animator implements AnimationHandler.AnimationFrameCallback { 71 private static final String TAG = "ValueAnimator"; 72 private static final boolean DEBUG = false; 73 74 /** 75 * Internal constants 76 */ 77 private static float sDurationScale = 1.0f; 78 79 /** 80 * Internal variables 81 * NOTE: This object implements the clone() method, making a deep copy of any referenced 82 * objects. As other non-trivial fields are added to this class, make sure to add logic 83 * to clone() to make deep copies of them. 84 */ 85 86 /** 87 * The first time that the animation's animateFrame() method is called. This time is used to 88 * determine elapsed time (and therefore the elapsed fraction) in subsequent calls 89 * to animateFrame(). 90 * 91 * Whenever mStartTime is set, you must also update mStartTimeCommitted. 92 */ 93 long mStartTime; 94 95 /** 96 * When true, the start time has been firmly committed as a chosen reference point in 97 * time by which the progress of the animation will be evaluated. When false, the 98 * start time may be updated when the first animation frame is committed so as 99 * to compensate for jank that may have occurred between when the start time was 100 * initialized and when the frame was actually drawn. 101 * 102 * This flag is generally set to false during the first frame of the animation 103 * when the animation playing state transitions from STOPPED to RUNNING or 104 * resumes after having been paused. This flag is set to true when the start time 105 * is firmly committed and should not be further compensated for jank. 106 */ 107 boolean mStartTimeCommitted; 108 109 /** 110 * Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked 111 * to a value. 112 */ 113 float mSeekFraction = -1; 114 115 /** 116 * Set on the next frame after pause() is called, used to calculate a new startTime 117 * or delayStartTime which allows the animator to continue from the point at which 118 * it was paused. If negative, has not yet been set. 119 */ 120 private long mPauseTime; 121 122 /** 123 * Set when an animator is resumed. This triggers logic in the next frame which 124 * actually resumes the animator. 125 */ 126 private boolean mResumed = false; 127 128 // The time interpolator to be used if none is set on the animation 129 private static final TimeInterpolator sDefaultInterpolator = 130 new AccelerateDecelerateInterpolator(); 131 132 /** 133 * Flag to indicate whether this animator is playing in reverse mode, specifically 134 * by being started or interrupted by a call to reverse(). This flag is different than 135 * mPlayingBackwards, which indicates merely whether the current iteration of the 136 * animator is playing in reverse. It is used in corner cases to determine proper end 137 * behavior. 138 */ 139 private boolean mReversing; 140 141 /** 142 * Tracks the overall fraction of the animation, ranging from 0 to mRepeatCount + 1 143 */ 144 private float mOverallFraction = 0f; 145 146 /** 147 * Tracks current elapsed/eased fraction, for querying in getAnimatedFraction(). 148 * This is calculated by interpolating the fraction (range: [0, 1]) in the current iteration. 149 */ 150 private float mCurrentFraction = 0f; 151 152 /** 153 * Tracks the time (in milliseconds) when the last frame arrived. 154 */ 155 private long mLastFrameTime = 0; 156 157 /** 158 * Additional playing state to indicate whether an animator has been start()'d. There is 159 * some lag between a call to start() and the first animation frame. We should still note 160 * that the animation has been started, even if it's first animation frame has not yet 161 * happened, and reflect that state in isRunning(). 162 * Note that delayed animations are different: they are not started until their first 163 * animation frame, which occurs after their delay elapses. 164 */ 165 private boolean mRunning = false; 166 167 /** 168 * Additional playing state to indicate whether an animator has been start()'d, whether or 169 * not there is a nonzero startDelay. 170 */ 171 private boolean mStarted = false; 172 173 /** 174 * Tracks whether we've notified listeners of the onAnimationStart() event. This can be 175 * complex to keep track of since we notify listeners at different times depending on 176 * startDelay and whether start() was called before end(). 177 */ 178 private boolean mStartListenersCalled = false; 179 180 /** 181 * Flag that denotes whether the animation is set up and ready to go. Used to 182 * set up animation that has not yet been started. 183 */ 184 boolean mInitialized = false; 185 186 /** 187 * Flag that tracks whether animation has been requested to end. 188 */ 189 private boolean mAnimationEndRequested = false; 190 191 // 192 // Backing variables 193 // 194 195 // How long the animation should last in ms 196 private long mDuration = 300; 197 198 // The amount of time in ms to delay starting the animation after start() is called. Note 199 // that this start delay is unscaled. When there is a duration scale set on the animator, the 200 // scaling factor will be applied to this delay. 201 private long mStartDelay = 0; 202 203 // The number of times the animation will repeat. The default is 0, which means the animation 204 // will play only once 205 private int mRepeatCount = 0; 206 207 /** 208 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 209 * animation will start from the beginning on every new cycle. REVERSE means the animation 210 * will reverse directions on each iteration. 211 */ 212 private int mRepeatMode = RESTART; 213 214 /** 215 * The time interpolator to be used. The elapsed fraction of the animation will be passed 216 * through this interpolator to calculate the interpolated fraction, which is then used to 217 * calculate the animated values. 218 */ 219 private TimeInterpolator mInterpolator = sDefaultInterpolator; 220 221 /** 222 * The set of listeners to be sent events through the life of an animation. 223 */ 224 ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 225 226 /** 227 * The property/value sets being animated. 228 */ 229 PropertyValuesHolder[] mValues; 230 231 /** 232 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 233 * by property name during calls to getAnimatedValue(String). 234 */ 235 HashMap<String, PropertyValuesHolder> mValuesMap; 236 237 /** 238 * Public constants 239 */ 240 241 /** @hide */ 242 @IntDef({RESTART, REVERSE}) 243 @Retention(RetentionPolicy.SOURCE) 244 public @interface RepeatMode {} 245 246 /** 247 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 248 * or a positive value, the animation restarts from the beginning. 249 */ 250 public static final int RESTART = 1; 251 /** 252 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 253 * or a positive value, the animation reverses direction on every iteration. 254 */ 255 public static final int REVERSE = 2; 256 /** 257 * This value used used with the {@link #setRepeatCount(int)} property to repeat 258 * the animation indefinitely. 259 */ 260 public static final int INFINITE = -1; 261 262 /** 263 * @hide 264 */ 265 @TestApi 266 public static void setDurationScale(float durationScale) { 267 sDurationScale = durationScale; 268 } 269 270 /** 271 * @hide 272 */ 273 @TestApi 274 public static float getDurationScale() { 275 return sDurationScale; 276 } 277 278 /** 279 * Returns whether animators are currently enabled, system-wide. By default, all 280 * animators are enabled. This can change if either the user sets a Developer Option 281 * to set the animator duration scale to 0 or by Battery Savery mode being enabled 282 * (which disables all animations). 283 * 284 * <p>Developers should not typically need to call this method, but should an app wish 285 * to show a different experience when animators are disabled, this return value 286 * can be used as a decider of which experience to offer. 287 * 288 * @return boolean Whether animators are currently enabled. The default value is 289 * <code>true</code>. 290 */ 291 public static boolean areAnimatorsEnabled() { 292 return !(sDurationScale == 0); 293 } 294 295 /** 296 * Creates a new ValueAnimator object. This default constructor is primarily for 297 * use internally; the factory methods which take parameters are more generally 298 * useful. 299 */ 300 public ValueAnimator() { 301 } 302 303 /** 304 * Constructs and returns a ValueAnimator that animates between int values. A single 305 * value implies that that value is the one being animated to. However, this is not typically 306 * useful in a ValueAnimator object because there is no way for the object to determine the 307 * starting value for the animation (unlike ObjectAnimator, which can derive that value 308 * from the target object and property being animated). Therefore, there should typically 309 * be two or more values. 310 * 311 * @param values A set of values that the animation will animate between over time. 312 * @return A ValueAnimator object that is set up to animate between the given values. 313 */ 314 public static ValueAnimator ofInt(int... values) { 315 ValueAnimator anim = new ValueAnimator(); 316 anim.setIntValues(values); 317 return anim; 318 } 319 320 /** 321 * Constructs and returns a ValueAnimator that animates between color values. A single 322 * value implies that that value is the one being animated to. However, this is not typically 323 * useful in a ValueAnimator object because there is no way for the object to determine the 324 * starting value for the animation (unlike ObjectAnimator, which can derive that value 325 * from the target object and property being animated). Therefore, there should typically 326 * be two or more values. 327 * 328 * @param values A set of values that the animation will animate between over time. 329 * @return A ValueAnimator object that is set up to animate between the given values. 330 */ 331 public static ValueAnimator ofArgb(int... values) { 332 ValueAnimator anim = new ValueAnimator(); 333 anim.setIntValues(values); 334 anim.setEvaluator(ArgbEvaluator.getInstance()); 335 return anim; 336 } 337 338 /** 339 * Constructs and returns a ValueAnimator that animates between float values. A single 340 * value implies that that value is the one being animated to. However, this is not typically 341 * useful in a ValueAnimator object because there is no way for the object to determine the 342 * starting value for the animation (unlike ObjectAnimator, which can derive that value 343 * from the target object and property being animated). Therefore, there should typically 344 * be two or more values. 345 * 346 * @param values A set of values that the animation will animate between over time. 347 * @return A ValueAnimator object that is set up to animate between the given values. 348 */ 349 public static ValueAnimator ofFloat(float... values) { 350 ValueAnimator anim = new ValueAnimator(); 351 anim.setFloatValues(values); 352 return anim; 353 } 354 355 /** 356 * Constructs and returns a ValueAnimator that animates between the values 357 * specified in the PropertyValuesHolder objects. 358 * 359 * @param values A set of PropertyValuesHolder objects whose values will be animated 360 * between over time. 361 * @return A ValueAnimator object that is set up to animate between the given values. 362 */ 363 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 364 ValueAnimator anim = new ValueAnimator(); 365 anim.setValues(values); 366 return anim; 367 } 368 /** 369 * Constructs and returns a ValueAnimator that animates between Object values. A single 370 * value implies that that value is the one being animated to. However, this is not typically 371 * useful in a ValueAnimator object because there is no way for the object to determine the 372 * starting value for the animation (unlike ObjectAnimator, which can derive that value 373 * from the target object and property being animated). Therefore, there should typically 374 * be two or more values. 375 * 376 * <p><strong>Note:</strong> The Object values are stored as references to the original 377 * objects, which means that changes to those objects after this method is called will 378 * affect the values on the animator. If the objects will be mutated externally after 379 * this method is called, callers should pass a copy of those objects instead. 380 * 381 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 382 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 383 * to perform that interpolation. 384 * 385 * @param evaluator A TypeEvaluator that will be called on each animation frame to 386 * provide the ncessry interpolation between the Object values to derive the animated 387 * value. 388 * @param values A set of values that the animation will animate between over time. 389 * @return A ValueAnimator object that is set up to animate between the given values. 390 */ 391 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 392 ValueAnimator anim = new ValueAnimator(); 393 anim.setObjectValues(values); 394 anim.setEvaluator(evaluator); 395 return anim; 396 } 397 398 /** 399 * Sets int values that will be animated between. A single 400 * value implies that that value is the one being animated to. However, this is not typically 401 * useful in a ValueAnimator object because there is no way for the object to determine the 402 * starting value for the animation (unlike ObjectAnimator, which can derive that value 403 * from the target object and property being animated). Therefore, there should typically 404 * be two or more values. 405 * 406 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 407 * than one PropertyValuesHolder object, this method will set the values for the first 408 * of those objects.</p> 409 * 410 * @param values A set of values that the animation will animate between over time. 411 */ 412 public void setIntValues(int... values) { 413 if (values == null || values.length == 0) { 414 return; 415 } 416 if (mValues == null || mValues.length == 0) { 417 setValues(PropertyValuesHolder.ofInt("", values)); 418 } else { 419 PropertyValuesHolder valuesHolder = mValues[0]; 420 valuesHolder.setIntValues(values); 421 } 422 // New property/values/target should cause re-initialization prior to starting 423 mInitialized = false; 424 } 425 426 /** 427 * Sets float values that will be animated between. A single 428 * value implies that that value is the one being animated to. However, this is not typically 429 * useful in a ValueAnimator object because there is no way for the object to determine the 430 * starting value for the animation (unlike ObjectAnimator, which can derive that value 431 * from the target object and property being animated). Therefore, there should typically 432 * be two or more values. 433 * 434 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 435 * than one PropertyValuesHolder object, this method will set the values for the first 436 * of those objects.</p> 437 * 438 * @param values A set of values that the animation will animate between over time. 439 */ 440 public void setFloatValues(float... values) { 441 if (values == null || values.length == 0) { 442 return; 443 } 444 if (mValues == null || mValues.length == 0) { 445 setValues(PropertyValuesHolder.ofFloat("", values)); 446 } else { 447 PropertyValuesHolder valuesHolder = mValues[0]; 448 valuesHolder.setFloatValues(values); 449 } 450 // New property/values/target should cause re-initialization prior to starting 451 mInitialized = false; 452 } 453 454 /** 455 * Sets the values to animate between for this animation. A single 456 * value implies that that value is the one being animated to. However, this is not typically 457 * useful in a ValueAnimator object because there is no way for the object to determine the 458 * starting value for the animation (unlike ObjectAnimator, which can derive that value 459 * from the target object and property being animated). Therefore, there should typically 460 * be two or more values. 461 * 462 * <p><strong>Note:</strong> The Object values are stored as references to the original 463 * objects, which means that changes to those objects after this method is called will 464 * affect the values on the animator. If the objects will be mutated externally after 465 * this method is called, callers should pass a copy of those objects instead. 466 * 467 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 468 * than one PropertyValuesHolder object, this method will set the values for the first 469 * of those objects.</p> 470 * 471 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 472 * between these value objects. ValueAnimator only knows how to interpolate between the 473 * primitive types specified in the other setValues() methods.</p> 474 * 475 * @param values The set of values to animate between. 476 */ 477 public void setObjectValues(Object... values) { 478 if (values == null || values.length == 0) { 479 return; 480 } 481 if (mValues == null || mValues.length == 0) { 482 setValues(PropertyValuesHolder.ofObject("", null, values)); 483 } else { 484 PropertyValuesHolder valuesHolder = mValues[0]; 485 valuesHolder.setObjectValues(values); 486 } 487 // New property/values/target should cause re-initialization prior to starting 488 mInitialized = false; 489 } 490 491 /** 492 * Sets the values, per property, being animated between. This function is called internally 493 * by the constructors of ValueAnimator that take a list of values. But a ValueAnimator can 494 * be constructed without values and this method can be called to set the values manually 495 * instead. 496 * 497 * @param values The set of values, per property, being animated between. 498 */ 499 public void setValues(PropertyValuesHolder... values) { 500 int numValues = values.length; 501 mValues = values; 502 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 503 for (int i = 0; i < numValues; ++i) { 504 PropertyValuesHolder valuesHolder = values[i]; 505 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 506 } 507 // New property/values/target should cause re-initialization prior to starting 508 mInitialized = false; 509 } 510 511 /** 512 * Returns the values that this ValueAnimator animates between. These values are stored in 513 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 514 * of value objects instead. 515 * 516 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 517 * values, per property, that define the animation. 518 */ 519 public PropertyValuesHolder[] getValues() { 520 return mValues; 521 } 522 523 /** 524 * This function is called immediately before processing the first animation 525 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 526 * function is called after that delay ends. 527 * It takes care of the final initialization steps for the 528 * animation. 529 * 530 * <p>Overrides of this method should call the superclass method to ensure 531 * that internal mechanisms for the animation are set up correctly.</p> 532 */ 533 @CallSuper 534 void initAnimation() { 535 if (!mInitialized) { 536 int numValues = mValues.length; 537 for (int i = 0; i < numValues; ++i) { 538 mValues[i].init(); 539 } 540 mInitialized = true; 541 } 542 } 543 544 /** 545 * Sets the length of the animation. The default duration is 300 milliseconds. 546 * 547 * @param duration The length of the animation, in milliseconds. This value cannot 548 * be negative. 549 * @return ValueAnimator The object called with setDuration(). This return 550 * value makes it easier to compose statements together that construct and then set the 551 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 552 */ 553 @Override 554 public ValueAnimator setDuration(long duration) { 555 if (duration < 0) { 556 throw new IllegalArgumentException("Animators cannot have negative duration: " + 557 duration); 558 } 559 mDuration = duration; 560 return this; 561 } 562 563 private long getScaledDuration() { 564 return (long)(mDuration * sDurationScale); 565 } 566 567 /** 568 * Gets the length of the animation. The default duration is 300 milliseconds. 569 * 570 * @return The length of the animation, in milliseconds. 571 */ 572 @Override 573 public long getDuration() { 574 return mDuration; 575 } 576 577 @Override 578 public long getTotalDuration() { 579 if (mRepeatCount == INFINITE) { 580 return DURATION_INFINITE; 581 } else { 582 return mStartDelay + (mDuration * (mRepeatCount + 1)); 583 } 584 } 585 586 /** 587 * Sets the position of the animation to the specified point in time. This time should 588 * be between 0 and the total duration of the animation, including any repetition. If 589 * the animation has not yet been started, then it will not advance forward after it is 590 * set to this time; it will simply set the time to this value and perform any appropriate 591 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 592 * will set the current playing time to this value and continue playing from that point. 593 * 594 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 595 */ 596 public void setCurrentPlayTime(long playTime) { 597 float fraction = mDuration > 0 ? (float) playTime / mDuration : 1; 598 setCurrentFraction(fraction); 599 } 600 601 /** 602 * Sets the position of the animation to the specified fraction. This fraction should 603 * be between 0 and the total fraction of the animation, including any repetition. That is, 604 * a fraction of 0 will position the animation at the beginning, a value of 1 at the end, 605 * and a value of 2 at the end of a reversing animator that repeats once. If 606 * the animation has not yet been started, then it will not advance forward after it is 607 * set to this fraction; it will simply set the fraction to this value and perform any 608 * appropriate actions based on that fraction. If the animation is already running, then 609 * setCurrentFraction() will set the current fraction to this value and continue 610 * playing from that point. {@link Animator.AnimatorListener} events are not called 611 * due to changing the fraction; those events are only processed while the animation 612 * is running. 613 * 614 * @param fraction The fraction to which the animation is advanced or rewound. Values 615 * outside the range of 0 to the maximum fraction for the animator will be clamped to 616 * the correct range. 617 */ 618 public void setCurrentFraction(float fraction) { 619 initAnimation(); 620 fraction = clampFraction(fraction); 621 long seekTime = (long) (getScaledDuration() * fraction); 622 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 623 mStartTime = currentTime - seekTime; 624 mStartTimeCommitted = true; // do not allow start time to be compensated for jank 625 if (!isPulsingInternal()) { 626 // If the animation loop hasn't started, the startTime will be adjusted in the first 627 // frame based on seek fraction. 628 mSeekFraction = fraction; 629 } 630 mOverallFraction = fraction; 631 final float currentIterationFraction = getCurrentIterationFraction(fraction); 632 animateValue(currentIterationFraction); 633 } 634 635 /** 636 * Calculates current iteration based on the overall fraction. The overall fraction will be 637 * in the range of [0, mRepeatCount + 1]. Both current iteration and fraction in the current 638 * iteration can be derived from it. 639 */ 640 private int getCurrentIteration(float fraction) { 641 fraction = clampFraction(fraction); 642 // If the overall fraction is a positive integer, we consider the current iteration to be 643 // complete. In other words, the fraction for the current iteration would be 1, and the 644 // current iteration would be overall fraction - 1. 645 double iteration = Math.floor(fraction); 646 if (fraction == iteration && fraction > 0) { 647 iteration--; 648 } 649 return (int) iteration; 650 } 651 652 /** 653 * Calculates the fraction of the current iteration, taking into account whether the animation 654 * should be played backwards. E.g. When the animation is played backwards in an iteration, 655 * the fraction for that iteration will go from 1f to 0f. 656 */ 657 private float getCurrentIterationFraction(float fraction) { 658 fraction = clampFraction(fraction); 659 int iteration = getCurrentIteration(fraction); 660 float currentFraction = fraction - iteration; 661 return shouldPlayBackward(iteration) ? 1f - currentFraction : currentFraction; 662 } 663 664 /** 665 * Clamps fraction into the correct range: [0, mRepeatCount + 1]. If repeat count is infinite, 666 * no upper bound will be set for the fraction. 667 * 668 * @param fraction fraction to be clamped 669 * @return fraction clamped into the range of [0, mRepeatCount + 1] 670 */ 671 private float clampFraction(float fraction) { 672 if (fraction < 0) { 673 fraction = 0; 674 } else if (mRepeatCount != INFINITE) { 675 fraction = Math.min(fraction, mRepeatCount + 1); 676 } 677 return fraction; 678 } 679 680 /** 681 * Calculates the direction of animation playing (i.e. forward or backward), based on 1) 682 * whether the entire animation is being reversed, 2) repeat mode applied to the current 683 * iteration. 684 */ 685 private boolean shouldPlayBackward(int iteration) { 686 if (iteration > 0 && mRepeatMode == REVERSE && 687 (iteration < (mRepeatCount + 1) || mRepeatCount == INFINITE)) { 688 // if we were seeked to some other iteration in a reversing animator, 689 // figure out the correct direction to start playing based on the iteration 690 if (mReversing) { 691 return (iteration % 2) == 0; 692 } else { 693 return (iteration % 2) != 0; 694 } 695 } else { 696 return mReversing; 697 } 698 } 699 700 /** 701 * Gets the current position of the animation in time, which is equal to the current 702 * time minus the time that the animation started. An animation that is not yet started will 703 * return a value of zero, unless the animation has has its play time set via 704 * {@link #setCurrentPlayTime(long)} or {@link #setCurrentFraction(float)}, in which case 705 * it will return the time that was set. 706 * 707 * @return The current position in time of the animation. 708 */ 709 public long getCurrentPlayTime() { 710 if (!mInitialized || (!mStarted && mSeekFraction < 0)) { 711 return 0; 712 } 713 if (mSeekFraction >= 0) { 714 return (long) (mDuration * mSeekFraction); 715 } 716 float durationScale = sDurationScale == 0 ? 1 : sDurationScale; 717 return (long) ((AnimationUtils.currentAnimationTimeMillis() - mStartTime) / durationScale); 718 } 719 720 /** 721 * The amount of time, in milliseconds, to delay starting the animation after 722 * {@link #start()} is called. 723 * 724 * @return the number of milliseconds to delay running the animation 725 */ 726 @Override 727 public long getStartDelay() { 728 return mStartDelay; 729 } 730 731 /** 732 * The amount of time, in milliseconds, to delay starting the animation after 733 * {@link #start()} is called. Note that the start delay should always be non-negative. Any 734 * negative start delay will be clamped to 0 on N and above. 735 * 736 * @param startDelay The amount of the delay, in milliseconds 737 */ 738 @Override 739 public void setStartDelay(long startDelay) { 740 // Clamp start delay to non-negative range. 741 if (startDelay < 0) { 742 Log.w(TAG, "Start delay should always be non-negative"); 743 startDelay = 0; 744 } 745 mStartDelay = startDelay; 746 } 747 748 /** 749 * The amount of time, in milliseconds, between each frame of the animation. This is a 750 * requested time that the animation will attempt to honor, but the actual delay between 751 * frames may be different, depending on system load and capabilities. This is a static 752 * function because the same delay will be applied to all animations, since they are all 753 * run off of a single timing loop. 754 * 755 * The frame delay may be ignored when the animation system uses an external timing 756 * source, such as the display refresh rate (vsync), to govern animations. 757 * 758 * Note that this method should be called from the same thread that {@link #start()} is 759 * called in order to check the frame delay for that animation. A runtime exception will be 760 * thrown if the calling thread does not have a Looper. 761 * 762 * @return the requested time between frames, in milliseconds 763 */ 764 public static long getFrameDelay() { 765 return AnimationHandler.getInstance().getFrameDelay(); 766 } 767 768 /** 769 * The amount of time, in milliseconds, between each frame of the animation. This is a 770 * requested time that the animation will attempt to honor, but the actual delay between 771 * frames may be different, depending on system load and capabilities. This is a static 772 * function because the same delay will be applied to all animations, since they are all 773 * run off of a single timing loop. 774 * 775 * The frame delay may be ignored when the animation system uses an external timing 776 * source, such as the display refresh rate (vsync), to govern animations. 777 * 778 * Note that this method should be called from the same thread that {@link #start()} is 779 * called in order to have the new frame delay take effect on that animation. A runtime 780 * exception will be thrown if the calling thread does not have a Looper. 781 * 782 * @param frameDelay the requested time between frames, in milliseconds 783 */ 784 public static void setFrameDelay(long frameDelay) { 785 AnimationHandler.getInstance().setFrameDelay(frameDelay); 786 } 787 788 /** 789 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 790 * property being animated. This value is only sensible while the animation is running. The main 791 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 792 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 793 * is called during each animation frame, immediately after the value is calculated. 794 * 795 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 796 * the single property being animated. If there are several properties being animated 797 * (specified by several PropertyValuesHolder objects in the constructor), this function 798 * returns the animated value for the first of those objects. 799 */ 800 public Object getAnimatedValue() { 801 if (mValues != null && mValues.length > 0) { 802 return mValues[0].getAnimatedValue(); 803 } 804 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 805 return null; 806 } 807 808 /** 809 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 810 * The main purpose for this read-only property is to retrieve the value from the 811 * <code>ValueAnimator</code> during a call to 812 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 813 * is called during each animation frame, immediately after the value is calculated. 814 * 815 * @return animatedValue The value most recently calculated for the named property 816 * by this <code>ValueAnimator</code>. 817 */ 818 public Object getAnimatedValue(String propertyName) { 819 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 820 if (valuesHolder != null) { 821 return valuesHolder.getAnimatedValue(); 822 } else { 823 // At least avoid crashing if called with bogus propertyName 824 return null; 825 } 826 } 827 828 /** 829 * Sets how many times the animation should be repeated. If the repeat 830 * count is 0, the animation is never repeated. If the repeat count is 831 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 832 * into account. The repeat count is 0 by default. 833 * 834 * @param value the number of times the animation should be repeated 835 */ 836 public void setRepeatCount(int value) { 837 mRepeatCount = value; 838 } 839 /** 840 * Defines how many times the animation should repeat. The default value 841 * is 0. 842 * 843 * @return the number of times the animation should repeat, or {@link #INFINITE} 844 */ 845 public int getRepeatCount() { 846 return mRepeatCount; 847 } 848 849 /** 850 * Defines what this animation should do when it reaches the end. This 851 * setting is applied only when the repeat count is either greater than 852 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 853 * 854 * @param value {@link #RESTART} or {@link #REVERSE} 855 */ 856 public void setRepeatMode(@RepeatMode int value) { 857 mRepeatMode = value; 858 } 859 860 /** 861 * Defines what this animation should do when it reaches the end. 862 * 863 * @return either one of {@link #REVERSE} or {@link #RESTART} 864 */ 865 @RepeatMode 866 public int getRepeatMode() { 867 return mRepeatMode; 868 } 869 870 /** 871 * Adds a listener to the set of listeners that are sent update events through the life of 872 * an animation. This method is called on all listeners for every frame of the animation, 873 * after the values for the animation have been calculated. 874 * 875 * @param listener the listener to be added to the current set of listeners for this animation. 876 */ 877 public void addUpdateListener(AnimatorUpdateListener listener) { 878 if (mUpdateListeners == null) { 879 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 880 } 881 mUpdateListeners.add(listener); 882 } 883 884 /** 885 * Removes all listeners from the set listening to frame updates for this animation. 886 */ 887 public void removeAllUpdateListeners() { 888 if (mUpdateListeners == null) { 889 return; 890 } 891 mUpdateListeners.clear(); 892 mUpdateListeners = null; 893 } 894 895 /** 896 * Removes a listener from the set listening to frame updates for this animation. 897 * 898 * @param listener the listener to be removed from the current set of update listeners 899 * for this animation. 900 */ 901 public void removeUpdateListener(AnimatorUpdateListener listener) { 902 if (mUpdateListeners == null) { 903 return; 904 } 905 mUpdateListeners.remove(listener); 906 if (mUpdateListeners.size() == 0) { 907 mUpdateListeners = null; 908 } 909 } 910 911 912 /** 913 * The time interpolator used in calculating the elapsed fraction of this animation. The 914 * interpolator determines whether the animation runs with linear or non-linear motion, 915 * such as acceleration and deceleration. The default value is 916 * {@link android.view.animation.AccelerateDecelerateInterpolator} 917 * 918 * @param value the interpolator to be used by this animation. A value of <code>null</code> 919 * will result in linear interpolation. 920 */ 921 @Override 922 public void setInterpolator(TimeInterpolator value) { 923 if (value != null) { 924 mInterpolator = value; 925 } else { 926 mInterpolator = new LinearInterpolator(); 927 } 928 } 929 930 /** 931 * Returns the timing interpolator that this ValueAnimator uses. 932 * 933 * @return The timing interpolator for this ValueAnimator. 934 */ 935 @Override 936 public TimeInterpolator getInterpolator() { 937 return mInterpolator; 938 } 939 940 /** 941 * The type evaluator to be used when calculating the animated values of this animation. 942 * The system will automatically assign a float or int evaluator based on the type 943 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 944 * are not one of these primitive types, or if different evaluation is desired (such as is 945 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 946 * For example, when running an animation on color values, the {@link ArgbEvaluator} 947 * should be used to get correct RGB color interpolation. 948 * 949 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 950 * will be used for that set. If there are several sets of values being animated, which is 951 * the case if PropertyValuesHolder objects were set on the ValueAnimator, then the evaluator 952 * is assigned just to the first PropertyValuesHolder object.</p> 953 * 954 * @param value the evaluator to be used this animation 955 */ 956 public void setEvaluator(TypeEvaluator value) { 957 if (value != null && mValues != null && mValues.length > 0) { 958 mValues[0].setEvaluator(value); 959 } 960 } 961 962 private void notifyStartListeners() { 963 if (mListeners != null && !mStartListenersCalled) { 964 ArrayList<AnimatorListener> tmpListeners = 965 (ArrayList<AnimatorListener>) mListeners.clone(); 966 int numListeners = tmpListeners.size(); 967 for (int i = 0; i < numListeners; ++i) { 968 tmpListeners.get(i).onAnimationStart(this); 969 } 970 } 971 mStartListenersCalled = true; 972 } 973 974 /** 975 * Start the animation playing. This version of start() takes a boolean flag that indicates 976 * whether the animation should play in reverse. The flag is usually false, but may be set 977 * to true if called from the reverse() method. 978 * 979 * <p>The animation started by calling this method will be run on the thread that called 980 * this method. This thread should have a Looper on it (a runtime exception will be thrown if 981 * this is not the case). Also, if the animation will animate 982 * properties of objects in the view hierarchy, then the calling thread should be the UI 983 * thread for that view hierarchy.</p> 984 * 985 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 986 */ 987 private void start(boolean playBackwards) { 988 if (Looper.myLooper() == null) { 989 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 990 } 991 mReversing = playBackwards; 992 // Special case: reversing from seek-to-0 should act as if not seeked at all. 993 if (playBackwards && mSeekFraction != -1 && mSeekFraction != 0) { 994 if (mRepeatCount == INFINITE) { 995 // Calculate the fraction of the current iteration. 996 float fraction = (float) (mSeekFraction - Math.floor(mSeekFraction)); 997 mSeekFraction = 1 - fraction; 998 } else { 999 mSeekFraction = 1 + mRepeatCount - mSeekFraction; 1000 } 1001 } 1002 mStarted = true; 1003 mPaused = false; 1004 mRunning = false; 1005 mAnimationEndRequested = false; 1006 // Resets mLastFrameTime when start() is called, so that if the animation was running, 1007 // calling start() would put the animation in the 1008 // started-but-not-yet-reached-the-first-frame phase. 1009 mLastFrameTime = 0; 1010 AnimationHandler animationHandler = AnimationHandler.getInstance(); 1011 animationHandler.addAnimationFrameCallback(this, (long) (mStartDelay * sDurationScale)); 1012 1013 if (mStartDelay == 0 || mSeekFraction >= 0) { 1014 // If there's no start delay, init the animation and notify start listeners right away 1015 // to be consistent with the previous behavior. Otherwise, postpone this until the first 1016 // frame after the start delay. 1017 startAnimation(); 1018 if (mSeekFraction == -1) { 1019 // No seek, start at play time 0. Note that the reason we are not using fraction 0 1020 // is because for animations with 0 duration, we want to be consistent with pre-N 1021 // behavior: skip to the final value immediately. 1022 setCurrentPlayTime(0); 1023 } else { 1024 setCurrentFraction(mSeekFraction); 1025 } 1026 } 1027 } 1028 1029 @Override 1030 public void start() { 1031 start(false); 1032 } 1033 1034 @Override 1035 public void cancel() { 1036 if (Looper.myLooper() == null) { 1037 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 1038 } 1039 1040 // If end has already been requested, through a previous end() or cancel() call, no-op 1041 // until animation starts again. 1042 if (mAnimationEndRequested) { 1043 return; 1044 } 1045 1046 // Only cancel if the animation is actually running or has been started and is about 1047 // to run 1048 // Only notify listeners if the animator has actually started 1049 if ((mStarted || mRunning) && mListeners != null) { 1050 if (!mRunning) { 1051 // If it's not yet running, then start listeners weren't called. Call them now. 1052 notifyStartListeners(); 1053 } 1054 ArrayList<AnimatorListener> tmpListeners = 1055 (ArrayList<AnimatorListener>) mListeners.clone(); 1056 for (AnimatorListener listener : tmpListeners) { 1057 listener.onAnimationCancel(this); 1058 } 1059 } 1060 endAnimation(); 1061 1062 } 1063 1064 @Override 1065 public void end() { 1066 if (Looper.myLooper() == null) { 1067 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 1068 } 1069 if (!mRunning) { 1070 // Special case if the animation has not yet started; get it ready for ending 1071 startAnimation(); 1072 mStarted = true; 1073 } else if (!mInitialized) { 1074 initAnimation(); 1075 } 1076 animateValue(shouldPlayBackward(mRepeatCount) ? 0f : 1f); 1077 endAnimation(); 1078 } 1079 1080 @Override 1081 public void resume() { 1082 if (Looper.myLooper() == null) { 1083 throw new AndroidRuntimeException("Animators may only be resumed from the same " + 1084 "thread that the animator was started on"); 1085 } 1086 if (mPaused && !mResumed) { 1087 mResumed = true; 1088 if (mPauseTime > 0) { 1089 AnimationHandler handler = AnimationHandler.getInstance(); 1090 handler.addAnimationFrameCallback(this, 0); 1091 } 1092 } 1093 super.resume(); 1094 } 1095 1096 @Override 1097 public void pause() { 1098 boolean previouslyPaused = mPaused; 1099 super.pause(); 1100 if (!previouslyPaused && mPaused) { 1101 mPauseTime = -1; 1102 mResumed = false; 1103 } 1104 } 1105 1106 @Override 1107 public boolean isRunning() { 1108 return mRunning; 1109 } 1110 1111 @Override 1112 public boolean isStarted() { 1113 return mStarted; 1114 } 1115 1116 /** 1117 * Plays the ValueAnimator in reverse. If the animation is already running, 1118 * it will stop itself and play backwards from the point reached when reverse was called. 1119 * If the animation is not currently running, then it will start from the end and 1120 * play backwards. This behavior is only set for the current animation; future playing 1121 * of the animation will use the default behavior of playing forward. 1122 */ 1123 @Override 1124 public void reverse() { 1125 if (isPulsingInternal()) { 1126 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 1127 long currentPlayTime = currentTime - mStartTime; 1128 long timeLeft = getScaledDuration() - currentPlayTime; 1129 mStartTime = currentTime - timeLeft; 1130 mStartTimeCommitted = true; // do not allow start time to be compensated for jank 1131 mReversing = !mReversing; 1132 } else if (mStarted) { 1133 mReversing = !mReversing; 1134 end(); 1135 } else { 1136 start(true); 1137 } 1138 } 1139 1140 /** 1141 * @hide 1142 */ 1143 @Override 1144 public boolean canReverse() { 1145 return true; 1146 } 1147 1148 /** 1149 * Called internally to end an animation by removing it from the animations list. Must be 1150 * called on the UI thread. 1151 */ 1152 private void endAnimation() { 1153 if (mAnimationEndRequested) { 1154 return; 1155 } 1156 AnimationHandler handler = AnimationHandler.getInstance(); 1157 handler.removeCallback(this); 1158 1159 mAnimationEndRequested = true; 1160 mPaused = false; 1161 boolean notify = (mStarted || mRunning) && mListeners != null; 1162 if (notify && !mRunning) { 1163 // If it's not yet running, then start listeners weren't called. Call them now. 1164 notifyStartListeners(); 1165 } 1166 mRunning = false; 1167 mStarted = false; 1168 mStartListenersCalled = false; 1169 mReversing = false; 1170 mLastFrameTime = 0; 1171 if (notify && mListeners != null) { 1172 ArrayList<AnimatorListener> tmpListeners = 1173 (ArrayList<AnimatorListener>) mListeners.clone(); 1174 int numListeners = tmpListeners.size(); 1175 for (int i = 0; i < numListeners; ++i) { 1176 tmpListeners.get(i).onAnimationEnd(this); 1177 } 1178 } 1179 if (Trace.isTagEnabled(Trace.TRACE_TAG_VIEW)) { 1180 Trace.asyncTraceEnd(Trace.TRACE_TAG_VIEW, getNameForTrace(), 1181 System.identityHashCode(this)); 1182 } 1183 } 1184 1185 /** 1186 * Called internally to start an animation by adding it to the active animations list. Must be 1187 * called on the UI thread. 1188 */ 1189 private void startAnimation() { 1190 if (Trace.isTagEnabled(Trace.TRACE_TAG_VIEW)) { 1191 Trace.asyncTraceBegin(Trace.TRACE_TAG_VIEW, getNameForTrace(), 1192 System.identityHashCode(this)); 1193 } 1194 1195 mAnimationEndRequested = false; 1196 initAnimation(); 1197 mRunning = true; 1198 if (mSeekFraction >= 0) { 1199 mOverallFraction = mSeekFraction; 1200 } else { 1201 mOverallFraction = 0f; 1202 } 1203 if (mListeners != null) { 1204 notifyStartListeners(); 1205 } 1206 } 1207 1208 /** 1209 * Internal only: This tracks whether the animation has gotten on the animation loop. Note 1210 * this is different than {@link #isRunning()} in that the latter tracks the time after start() 1211 * is called (or after start delay if any), which may be before the animation loop starts. 1212 */ 1213 private boolean isPulsingInternal() { 1214 return mLastFrameTime > 0; 1215 } 1216 1217 /** 1218 * Returns the name of this animator for debugging purposes. 1219 */ 1220 String getNameForTrace() { 1221 return "animator"; 1222 } 1223 1224 /** 1225 * Applies an adjustment to the animation to compensate for jank between when 1226 * the animation first ran and when the frame was drawn. 1227 * @hide 1228 */ 1229 public void commitAnimationFrame(long frameTime) { 1230 if (!mStartTimeCommitted) { 1231 mStartTimeCommitted = true; 1232 long adjustment = frameTime - mLastFrameTime; 1233 if (adjustment > 0) { 1234 mStartTime += adjustment; 1235 if (DEBUG) { 1236 Log.d(TAG, "Adjusted start time by " + adjustment + " ms: " + toString()); 1237 } 1238 } 1239 } 1240 } 1241 1242 /** 1243 * This internal function processes a single animation frame for a given animation. The 1244 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1245 * elapsed duration, and therefore 1246 * the elapsed fraction, of the animation. The return value indicates whether the animation 1247 * should be ended (which happens when the elapsed time of the animation exceeds the 1248 * animation's duration, including the repeatCount). 1249 * 1250 * @param currentTime The current time, as tracked by the static timing handler 1251 * @return true if the animation's duration, including any repetitions due to 1252 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1253 */ 1254 boolean animateBasedOnTime(long currentTime) { 1255 boolean done = false; 1256 if (mRunning) { 1257 final long scaledDuration = getScaledDuration(); 1258 final float fraction = scaledDuration > 0 ? 1259 (float)(currentTime - mStartTime) / scaledDuration : 1f; 1260 final float lastFraction = mOverallFraction; 1261 final boolean newIteration = (int) fraction > (int) lastFraction; 1262 final boolean lastIterationFinished = (fraction >= mRepeatCount + 1) && 1263 (mRepeatCount != INFINITE); 1264 if (scaledDuration == 0) { 1265 // 0 duration animator, ignore the repeat count and skip to the end 1266 done = true; 1267 } else if (newIteration && !lastIterationFinished) { 1268 // Time to repeat 1269 if (mListeners != null) { 1270 int numListeners = mListeners.size(); 1271 for (int i = 0; i < numListeners; ++i) { 1272 mListeners.get(i).onAnimationRepeat(this); 1273 } 1274 } 1275 } else if (lastIterationFinished) { 1276 done = true; 1277 } 1278 mOverallFraction = clampFraction(fraction); 1279 float currentIterationFraction = getCurrentIterationFraction(mOverallFraction); 1280 animateValue(currentIterationFraction); 1281 } 1282 return done; 1283 } 1284 1285 /** 1286 * Processes a frame of the animation, adjusting the start time if needed. 1287 * 1288 * @param frameTime The frame time. 1289 * @return true if the animation has ended. 1290 * @hide 1291 */ 1292 public final void doAnimationFrame(long frameTime) { 1293 AnimationHandler handler = AnimationHandler.getInstance(); 1294 if (mLastFrameTime == 0) { 1295 // First frame 1296 handler.addOneShotCommitCallback(this); 1297 if (mStartDelay > 0) { 1298 startAnimation(); 1299 } 1300 if (mSeekFraction < 0) { 1301 mStartTime = frameTime; 1302 } else { 1303 long seekTime = (long) (getScaledDuration() * mSeekFraction); 1304 mStartTime = frameTime - seekTime; 1305 mSeekFraction = -1; 1306 } 1307 mStartTimeCommitted = false; // allow start time to be compensated for jank 1308 } 1309 mLastFrameTime = frameTime; 1310 if (mPaused) { 1311 mPauseTime = frameTime; 1312 handler.removeCallback(this); 1313 return; 1314 } else if (mResumed) { 1315 mResumed = false; 1316 if (mPauseTime > 0) { 1317 // Offset by the duration that the animation was paused 1318 mStartTime += (frameTime - mPauseTime); 1319 mStartTimeCommitted = false; // allow start time to be compensated for jank 1320 } 1321 handler.addOneShotCommitCallback(this); 1322 } 1323 // The frame time might be before the start time during the first frame of 1324 // an animation. The "current time" must always be on or after the start 1325 // time to avoid animating frames at negative time intervals. In practice, this 1326 // is very rare and only happens when seeking backwards. 1327 final long currentTime = Math.max(frameTime, mStartTime); 1328 boolean finished = animateBasedOnTime(currentTime); 1329 1330 if (finished) { 1331 endAnimation(); 1332 } 1333 } 1334 1335 /** 1336 * Returns the current animation fraction, which is the elapsed/interpolated fraction used in 1337 * the most recent frame update on the animation. 1338 * 1339 * @return Elapsed/interpolated fraction of the animation. 1340 */ 1341 public float getAnimatedFraction() { 1342 return mCurrentFraction; 1343 } 1344 1345 /** 1346 * This method is called with the elapsed fraction of the animation during every 1347 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1348 * and then into an animated value (from the evaluator. The function is called mostly during 1349 * animation updates, but it is also called when the <code>end()</code> 1350 * function is called, to set the final value on the property. 1351 * 1352 * <p>Overrides of this method must call the superclass to perform the calculation 1353 * of the animated value.</p> 1354 * 1355 * @param fraction The elapsed fraction of the animation. 1356 */ 1357 @CallSuper 1358 void animateValue(float fraction) { 1359 fraction = mInterpolator.getInterpolation(fraction); 1360 mCurrentFraction = fraction; 1361 int numValues = mValues.length; 1362 for (int i = 0; i < numValues; ++i) { 1363 mValues[i].calculateValue(fraction); 1364 } 1365 if (mUpdateListeners != null) { 1366 int numListeners = mUpdateListeners.size(); 1367 for (int i = 0; i < numListeners; ++i) { 1368 mUpdateListeners.get(i).onAnimationUpdate(this); 1369 } 1370 } 1371 } 1372 1373 @Override 1374 public ValueAnimator clone() { 1375 final ValueAnimator anim = (ValueAnimator) super.clone(); 1376 if (mUpdateListeners != null) { 1377 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(mUpdateListeners); 1378 } 1379 anim.mSeekFraction = -1; 1380 anim.mReversing = false; 1381 anim.mInitialized = false; 1382 anim.mStarted = false; 1383 anim.mRunning = false; 1384 anim.mPaused = false; 1385 anim.mResumed = false; 1386 anim.mStartListenersCalled = false; 1387 anim.mStartTime = 0; 1388 anim.mStartTimeCommitted = false; 1389 anim.mAnimationEndRequested = false; 1390 anim.mPauseTime = 0; 1391 anim.mLastFrameTime = 0; 1392 anim.mOverallFraction = 0; 1393 anim.mCurrentFraction = 0; 1394 1395 PropertyValuesHolder[] oldValues = mValues; 1396 if (oldValues != null) { 1397 int numValues = oldValues.length; 1398 anim.mValues = new PropertyValuesHolder[numValues]; 1399 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1400 for (int i = 0; i < numValues; ++i) { 1401 PropertyValuesHolder newValuesHolder = oldValues[i].clone(); 1402 anim.mValues[i] = newValuesHolder; 1403 anim.mValuesMap.put(newValuesHolder.getPropertyName(), newValuesHolder); 1404 } 1405 } 1406 return anim; 1407 } 1408 1409 /** 1410 * Implementors of this interface can add themselves as update listeners 1411 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1412 * frame, after the current frame's values have been calculated for that 1413 * <code>ValueAnimator</code>. 1414 */ 1415 public static interface AnimatorUpdateListener { 1416 /** 1417 * <p>Notifies the occurrence of another frame of the animation.</p> 1418 * 1419 * @param animation The animation which was repeated. 1420 */ 1421 void onAnimationUpdate(ValueAnimator animation); 1422 1423 } 1424 1425 /** 1426 * Return the number of animations currently running. 1427 * 1428 * Used by StrictMode internally to annotate violations. 1429 * May be called on arbitrary threads! 1430 * 1431 * @hide 1432 */ 1433 public static int getCurrentAnimationsCount() { 1434 return AnimationHandler.getAnimationCount(); 1435 } 1436 1437 @Override 1438 public String toString() { 1439 String returnVal = "ValueAnimator@" + Integer.toHexString(hashCode()); 1440 if (mValues != null) { 1441 for (int i = 0; i < mValues.length; ++i) { 1442 returnVal += "\n " + mValues[i].toString(); 1443 } 1444 } 1445 return returnVal; 1446 } 1447 1448 /** 1449 * <p>Whether or not the ValueAnimator is allowed to run asynchronously off of 1450 * the UI thread. This is a hint that informs the ValueAnimator that it is 1451 * OK to run the animation off-thread, however ValueAnimator may decide 1452 * that it must run the animation on the UI thread anyway. For example if there 1453 * is an {@link AnimatorUpdateListener} the animation will run on the UI thread, 1454 * regardless of the value of this hint.</p> 1455 * 1456 * <p>Regardless of whether or not the animation runs asynchronously, all 1457 * listener callbacks will be called on the UI thread.</p> 1458 * 1459 * <p>To be able to use this hint the following must be true:</p> 1460 * <ol> 1461 * <li>{@link #getAnimatedFraction()} is not needed (it will return undefined values).</li> 1462 * <li>The animator is immutable while {@link #isStarted()} is true. Requests 1463 * to change values, duration, delay, etc... may be ignored.</li> 1464 * <li>Lifecycle callback events may be asynchronous. Events such as 1465 * {@link Animator.AnimatorListener#onAnimationEnd(Animator)} or 1466 * {@link Animator.AnimatorListener#onAnimationRepeat(Animator)} may end up delayed 1467 * as they must be posted back to the UI thread, and any actions performed 1468 * by those callbacks (such as starting new animations) will not happen 1469 * in the same frame.</li> 1470 * <li>State change requests ({@link #cancel()}, {@link #end()}, {@link #reverse()}, etc...) 1471 * may be asynchronous. It is guaranteed that all state changes that are 1472 * performed on the UI thread in the same frame will be applied as a single 1473 * atomic update, however that frame may be the current frame, 1474 * the next frame, or some future frame. This will also impact the observed 1475 * state of the Animator. For example, {@link #isStarted()} may still return true 1476 * after a call to {@link #end()}. Using the lifecycle callbacks is preferred over 1477 * queries to {@link #isStarted()}, {@link #isRunning()}, and {@link #isPaused()} 1478 * for this reason.</li> 1479 * </ol> 1480 * @hide 1481 */ 1482 @Override 1483 public void setAllowRunningAsynchronously(boolean mayRunAsync) { 1484 // It is up to subclasses to support this, if they can. 1485 } 1486} 1487