ValueAnimator.java revision 907c177b04d07d5d84005ac92df9bde6af7c394d
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.os.Looper; 22import android.os.Trace; 23import android.util.AndroidRuntimeException; 24import android.util.Log; 25import android.view.animation.AccelerateDecelerateInterpolator; 26import android.view.animation.AnimationUtils; 27import android.view.animation.LinearInterpolator; 28 29import java.lang.annotation.Retention; 30import java.lang.annotation.RetentionPolicy; 31import java.util.ArrayList; 32import java.util.HashMap; 33 34/** 35 * This class provides a simple timing engine for running animations 36 * which calculate animated values and set them on target objects. 37 * 38 * <p>There is a single timing pulse that all animations use. It runs in a 39 * custom handler to ensure that property changes happen on the UI thread.</p> 40 * 41 * <p>By default, ValueAnimator uses non-linear time interpolation, via the 42 * {@link AccelerateDecelerateInterpolator} class, which accelerates into and decelerates 43 * out of an animation. This behavior can be changed by calling 44 * {@link ValueAnimator#setInterpolator(TimeInterpolator)}.</p> 45 * 46 * <p>Animators can be created from either code or resource files. Here is an example 47 * of a ValueAnimator resource file:</p> 48 * 49 * {@sample development/samples/ApiDemos/res/anim/animator.xml ValueAnimatorResources} 50 * 51 * <p>It is also possible to use a combination of {@link PropertyValuesHolder} and 52 * {@link Keyframe} resource tags to create a multi-step animation. 53 * Note that you can specify explicit fractional values (from 0 to 1) for 54 * each keyframe to determine when, in the overall duration, the animation should arrive at that 55 * value. Alternatively, you can leave the fractions off and the keyframes will be equally 56 * distributed within the total duration:</p> 57 * 58 * {@sample development/samples/ApiDemos/res/anim/value_animator_pvh_kf.xml 59 * ValueAnimatorKeyframeResources} 60 * 61 * <div class="special reference"> 62 * <h3>Developer Guides</h3> 63 * <p>For more information about animating with {@code ValueAnimator}, read the 64 * <a href="{@docRoot}guide/topics/graphics/prop-animation.html#value-animator">Property 65 * Animation</a> developer guide.</p> 66 * </div> 67 */ 68@SuppressWarnings("unchecked") 69public class ValueAnimator extends Animator implements AnimationHandler.AnimationFrameCallback { 70 private static final String TAG = "ValueAnimator"; 71 private static final boolean DEBUG = false; 72 73 /** 74 * Internal constants 75 */ 76 private static float sDurationScale = 1.0f; 77 78 /** 79 * Internal variables 80 * NOTE: This object implements the clone() method, making a deep copy of any referenced 81 * objects. As other non-trivial fields are added to this class, make sure to add logic 82 * to clone() to make deep copies of them. 83 */ 84 85 /** 86 * The first time that the animation's animateFrame() method is called. This time is used to 87 * determine elapsed time (and therefore the elapsed fraction) in subsequent calls 88 * to animateFrame(). 89 * 90 * Whenever mStartTime is set, you must also update mStartTimeCommitted. 91 */ 92 long mStartTime; 93 94 /** 95 * When true, the start time has been firmly committed as a chosen reference point in 96 * time by which the progress of the animation will be evaluated. When false, the 97 * start time may be updated when the first animation frame is committed so as 98 * to compensate for jank that may have occurred between when the start time was 99 * initialized and when the frame was actually drawn. 100 * 101 * This flag is generally set to false during the first frame of the animation 102 * when the animation playing state transitions from STOPPED to RUNNING or 103 * resumes after having been paused. This flag is set to true when the start time 104 * is firmly committed and should not be further compensated for jank. 105 */ 106 boolean mStartTimeCommitted; 107 108 /** 109 * Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked 110 * to a value. 111 */ 112 float mSeekFraction = -1; 113 114 /** 115 * Set on the next frame after pause() is called, used to calculate a new startTime 116 * or delayStartTime which allows the animator to continue from the point at which 117 * it was paused. If negative, has not yet been set. 118 */ 119 private long mPauseTime; 120 121 /** 122 * Set when an animator is resumed. This triggers logic in the next frame which 123 * actually resumes the animator. 124 */ 125 private boolean mResumed = false; 126 127 // The time interpolator to be used if none is set on the animation 128 private static final TimeInterpolator sDefaultInterpolator = 129 new AccelerateDecelerateInterpolator(); 130 131 /** 132 * Flag to indicate whether this animator is playing in reverse mode, specifically 133 * by being started or interrupted by a call to reverse(). This flag is different than 134 * mPlayingBackwards, which indicates merely whether the current iteration of the 135 * animator is playing in reverse. It is used in corner cases to determine proper end 136 * behavior. 137 */ 138 private boolean mReversing; 139 140 /** 141 * Tracks the overall fraction of the animation, ranging from 0 to mRepeatCount + 1 142 */ 143 private float mOverallFraction = 0f; 144 145 /** 146 * Tracks current elapsed/eased fraction, for querying in getAnimatedFraction(). 147 * This is calculated by interpolating the fraction (range: [0, 1]) in the current iteration. 148 */ 149 private float mCurrentFraction = 0f; 150 151 /** 152 * Tracks the time (in milliseconds) when the last frame arrived. 153 */ 154 private long mLastFrameTime = 0; 155 156 /** 157 * Additional playing state to indicate whether an animator has been start()'d. There is 158 * some lag between a call to start() and the first animation frame. We should still note 159 * that the animation has been started, even if it's first animation frame has not yet 160 * happened, and reflect that state in isRunning(). 161 * Note that delayed animations are different: they are not started until their first 162 * animation frame, which occurs after their delay elapses. 163 */ 164 private boolean mRunning = false; 165 166 /** 167 * Additional playing state to indicate whether an animator has been start()'d, whether or 168 * not there is a nonzero startDelay. 169 */ 170 private boolean mStarted = false; 171 172 /** 173 * Tracks whether we've notified listeners of the onAnimationStart() event. This can be 174 * complex to keep track of since we notify listeners at different times depending on 175 * startDelay and whether start() was called before end(). 176 */ 177 private boolean mStartListenersCalled = false; 178 179 /** 180 * Flag that denotes whether the animation is set up and ready to go. Used to 181 * set up animation that has not yet been started. 182 */ 183 boolean mInitialized = false; 184 185 /** 186 * Flag that tracks whether animation has been requested to end. 187 */ 188 private boolean mAnimationEndRequested = false; 189 190 // 191 // Backing variables 192 // 193 194 // How long the animation should last in ms 195 private long mDuration = 300; 196 197 // The amount of time in ms to delay starting the animation after start() is called. Note 198 // that this start delay is unscaled. When there is a duration scale set on the animator, the 199 // scaling factor will be applied to this delay. 200 private long mStartDelay = 0; 201 202 // The number of times the animation will repeat. The default is 0, which means the animation 203 // will play only once 204 private int mRepeatCount = 0; 205 206 /** 207 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 208 * animation will start from the beginning on every new cycle. REVERSE means the animation 209 * will reverse directions on each iteration. 210 */ 211 private int mRepeatMode = RESTART; 212 213 /** 214 * The time interpolator to be used. The elapsed fraction of the animation will be passed 215 * through this interpolator to calculate the interpolated fraction, which is then used to 216 * calculate the animated values. 217 */ 218 private TimeInterpolator mInterpolator = sDefaultInterpolator; 219 220 /** 221 * The set of listeners to be sent events through the life of an animation. 222 */ 223 ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 224 225 /** 226 * The property/value sets being animated. 227 */ 228 PropertyValuesHolder[] mValues; 229 230 /** 231 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 232 * by property name during calls to getAnimatedValue(String). 233 */ 234 HashMap<String, PropertyValuesHolder> mValuesMap; 235 236 /** 237 * Public constants 238 */ 239 240 /** @hide */ 241 @IntDef({RESTART, REVERSE}) 242 @Retention(RetentionPolicy.SOURCE) 243 public @interface RepeatMode {} 244 245 /** 246 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 247 * or a positive value, the animation restarts from the beginning. 248 */ 249 public static final int RESTART = 1; 250 /** 251 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 252 * or a positive value, the animation reverses direction on every iteration. 253 */ 254 public static final int REVERSE = 2; 255 /** 256 * This value used used with the {@link #setRepeatCount(int)} property to repeat 257 * the animation indefinitely. 258 */ 259 public static final int INFINITE = -1; 260 261 /** 262 * @hide 263 */ 264 public static void setDurationScale(float durationScale) { 265 sDurationScale = durationScale; 266 } 267 268 /** 269 * @hide 270 */ 271 public static float getDurationScale() { 272 return sDurationScale; 273 } 274 275 /** 276 * Creates a new ValueAnimator object. This default constructor is primarily for 277 * use internally; the factory methods which take parameters are more generally 278 * useful. 279 */ 280 public ValueAnimator() { 281 } 282 283 /** 284 * Constructs and returns a ValueAnimator that animates between int values. A single 285 * value implies that that value is the one being animated to. However, this is not typically 286 * useful in a ValueAnimator object because there is no way for the object to determine the 287 * starting value for the animation (unlike ObjectAnimator, which can derive that value 288 * from the target object and property being animated). Therefore, there should typically 289 * be two or more values. 290 * 291 * @param values A set of values that the animation will animate between over time. 292 * @return A ValueAnimator object that is set up to animate between the given values. 293 */ 294 public static ValueAnimator ofInt(int... values) { 295 ValueAnimator anim = new ValueAnimator(); 296 anim.setIntValues(values); 297 return anim; 298 } 299 300 /** 301 * Constructs and returns a ValueAnimator that animates between color values. A single 302 * value implies that that value is the one being animated to. However, this is not typically 303 * useful in a ValueAnimator object because there is no way for the object to determine the 304 * starting value for the animation (unlike ObjectAnimator, which can derive that value 305 * from the target object and property being animated). Therefore, there should typically 306 * be two or more values. 307 * 308 * @param values A set of values that the animation will animate between over time. 309 * @return A ValueAnimator object that is set up to animate between the given values. 310 */ 311 public static ValueAnimator ofArgb(int... values) { 312 ValueAnimator anim = new ValueAnimator(); 313 anim.setIntValues(values); 314 anim.setEvaluator(ArgbEvaluator.getInstance()); 315 return anim; 316 } 317 318 /** 319 * Constructs and returns a ValueAnimator that animates between float values. A single 320 * value implies that that value is the one being animated to. However, this is not typically 321 * useful in a ValueAnimator object because there is no way for the object to determine the 322 * starting value for the animation (unlike ObjectAnimator, which can derive that value 323 * from the target object and property being animated). Therefore, there should typically 324 * be two or more values. 325 * 326 * @param values A set of values that the animation will animate between over time. 327 * @return A ValueAnimator object that is set up to animate between the given values. 328 */ 329 public static ValueAnimator ofFloat(float... values) { 330 ValueAnimator anim = new ValueAnimator(); 331 anim.setFloatValues(values); 332 return anim; 333 } 334 335 /** 336 * Constructs and returns a ValueAnimator that animates between the values 337 * specified in the PropertyValuesHolder objects. 338 * 339 * @param values A set of PropertyValuesHolder objects whose values will be animated 340 * between over time. 341 * @return A ValueAnimator object that is set up to animate between the given values. 342 */ 343 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 344 ValueAnimator anim = new ValueAnimator(); 345 anim.setValues(values); 346 return anim; 347 } 348 /** 349 * Constructs and returns a ValueAnimator that animates between Object values. A single 350 * value implies that that value is the one being animated to. However, this is not typically 351 * useful in a ValueAnimator object because there is no way for the object to determine the 352 * starting value for the animation (unlike ObjectAnimator, which can derive that value 353 * from the target object and property being animated). Therefore, there should typically 354 * be two or more values. 355 * 356 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 357 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 358 * to perform that interpolation. 359 * 360 * @param evaluator A TypeEvaluator that will be called on each animation frame to 361 * provide the ncessry interpolation between the Object values to derive the animated 362 * value. 363 * @param values A set of values that the animation will animate between over time. 364 * @return A ValueAnimator object that is set up to animate between the given values. 365 */ 366 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 367 ValueAnimator anim = new ValueAnimator(); 368 anim.setObjectValues(values); 369 anim.setEvaluator(evaluator); 370 return anim; 371 } 372 373 /** 374 * Sets int values that will be animated between. A single 375 * value implies that that value is the one being animated to. However, this is not typically 376 * useful in a ValueAnimator object because there is no way for the object to determine the 377 * starting value for the animation (unlike ObjectAnimator, which can derive that value 378 * from the target object and property being animated). Therefore, there should typically 379 * be two or more values. 380 * 381 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 382 * than one PropertyValuesHolder object, this method will set the values for the first 383 * of those objects.</p> 384 * 385 * @param values A set of values that the animation will animate between over time. 386 */ 387 public void setIntValues(int... values) { 388 if (values == null || values.length == 0) { 389 return; 390 } 391 if (mValues == null || mValues.length == 0) { 392 setValues(PropertyValuesHolder.ofInt("", values)); 393 } else { 394 PropertyValuesHolder valuesHolder = mValues[0]; 395 valuesHolder.setIntValues(values); 396 } 397 // New property/values/target should cause re-initialization prior to starting 398 mInitialized = false; 399 } 400 401 /** 402 * Sets float values that will be animated between. A single 403 * value implies that that value is the one being animated to. However, this is not typically 404 * useful in a ValueAnimator object because there is no way for the object to determine the 405 * starting value for the animation (unlike ObjectAnimator, which can derive that value 406 * from the target object and property being animated). Therefore, there should typically 407 * be two or more values. 408 * 409 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 410 * than one PropertyValuesHolder object, this method will set the values for the first 411 * of those objects.</p> 412 * 413 * @param values A set of values that the animation will animate between over time. 414 */ 415 public void setFloatValues(float... values) { 416 if (values == null || values.length == 0) { 417 return; 418 } 419 if (mValues == null || mValues.length == 0) { 420 setValues(PropertyValuesHolder.ofFloat("", values)); 421 } else { 422 PropertyValuesHolder valuesHolder = mValues[0]; 423 valuesHolder.setFloatValues(values); 424 } 425 // New property/values/target should cause re-initialization prior to starting 426 mInitialized = false; 427 } 428 429 /** 430 * Sets the values to animate between for this animation. A single 431 * value implies that that value is the one being animated to. However, this is not typically 432 * useful in a ValueAnimator object because there is no way for the object to determine the 433 * starting value for the animation (unlike ObjectAnimator, which can derive that value 434 * from the target object and property being animated). Therefore, there should typically 435 * be two or more values. 436 * 437 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 438 * than one PropertyValuesHolder object, this method will set the values for the first 439 * of those objects.</p> 440 * 441 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 442 * between these value objects. ValueAnimator only knows how to interpolate between the 443 * primitive types specified in the other setValues() methods.</p> 444 * 445 * @param values The set of values to animate between. 446 */ 447 public void setObjectValues(Object... values) { 448 if (values == null || values.length == 0) { 449 return; 450 } 451 if (mValues == null || mValues.length == 0) { 452 setValues(PropertyValuesHolder.ofObject("", null, values)); 453 } else { 454 PropertyValuesHolder valuesHolder = mValues[0]; 455 valuesHolder.setObjectValues(values); 456 } 457 // New property/values/target should cause re-initialization prior to starting 458 mInitialized = false; 459 } 460 461 /** 462 * Sets the values, per property, being animated between. This function is called internally 463 * by the constructors of ValueAnimator that take a list of values. But a ValueAnimator can 464 * be constructed without values and this method can be called to set the values manually 465 * instead. 466 * 467 * @param values The set of values, per property, being animated between. 468 */ 469 public void setValues(PropertyValuesHolder... values) { 470 int numValues = values.length; 471 mValues = values; 472 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 473 for (int i = 0; i < numValues; ++i) { 474 PropertyValuesHolder valuesHolder = values[i]; 475 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 476 } 477 // New property/values/target should cause re-initialization prior to starting 478 mInitialized = false; 479 } 480 481 /** 482 * Returns the values that this ValueAnimator animates between. These values are stored in 483 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 484 * of value objects instead. 485 * 486 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 487 * values, per property, that define the animation. 488 */ 489 public PropertyValuesHolder[] getValues() { 490 return mValues; 491 } 492 493 /** 494 * This function is called immediately before processing the first animation 495 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 496 * function is called after that delay ends. 497 * It takes care of the final initialization steps for the 498 * animation. 499 * 500 * <p>Overrides of this method should call the superclass method to ensure 501 * that internal mechanisms for the animation are set up correctly.</p> 502 */ 503 @CallSuper 504 void initAnimation() { 505 if (!mInitialized) { 506 int numValues = mValues.length; 507 for (int i = 0; i < numValues; ++i) { 508 mValues[i].init(); 509 } 510 mInitialized = true; 511 } 512 } 513 514 /** 515 * Sets the length of the animation. The default duration is 300 milliseconds. 516 * 517 * @param duration The length of the animation, in milliseconds. This value cannot 518 * be negative. 519 * @return ValueAnimator The object called with setDuration(). This return 520 * value makes it easier to compose statements together that construct and then set the 521 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 522 */ 523 @Override 524 public ValueAnimator setDuration(long duration) { 525 if (duration < 0) { 526 throw new IllegalArgumentException("Animators cannot have negative duration: " + 527 duration); 528 } 529 mDuration = duration; 530 return this; 531 } 532 533 private long getScaledDuration() { 534 return (long)(mDuration * sDurationScale); 535 } 536 537 /** 538 * Gets the length of the animation. The default duration is 300 milliseconds. 539 * 540 * @return The length of the animation, in milliseconds. 541 */ 542 @Override 543 public long getDuration() { 544 return mDuration; 545 } 546 547 @Override 548 public long getTotalDuration() { 549 if (mRepeatCount == INFINITE) { 550 return DURATION_INFINITE; 551 } else { 552 return mStartDelay + (mDuration * (mRepeatCount + 1)); 553 } 554 } 555 556 /** 557 * Sets the position of the animation to the specified point in time. This time should 558 * be between 0 and the total duration of the animation, including any repetition. If 559 * the animation has not yet been started, then it will not advance forward after it is 560 * set to this time; it will simply set the time to this value and perform any appropriate 561 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 562 * will set the current playing time to this value and continue playing from that point. 563 * 564 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 565 */ 566 public void setCurrentPlayTime(long playTime) { 567 float fraction = mDuration > 0 ? (float) playTime / mDuration : 1; 568 setCurrentFraction(fraction); 569 } 570 571 /** 572 * Sets the position of the animation to the specified fraction. This fraction should 573 * be between 0 and the total fraction of the animation, including any repetition. That is, 574 * a fraction of 0 will position the animation at the beginning, a value of 1 at the end, 575 * and a value of 2 at the end of a reversing animator that repeats once. If 576 * the animation has not yet been started, then it will not advance forward after it is 577 * set to this fraction; it will simply set the fraction to this value and perform any 578 * appropriate actions based on that fraction. If the animation is already running, then 579 * setCurrentFraction() will set the current fraction to this value and continue 580 * playing from that point. {@link Animator.AnimatorListener} events are not called 581 * due to changing the fraction; those events are only processed while the animation 582 * is running. 583 * 584 * @param fraction The fraction to which the animation is advanced or rewound. Values 585 * outside the range of 0 to the maximum fraction for the animator will be clamped to 586 * the correct range. 587 */ 588 public void setCurrentFraction(float fraction) { 589 initAnimation(); 590 fraction = clampFraction(fraction); 591 long seekTime = (long) (getScaledDuration() * fraction); 592 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 593 mStartTime = currentTime - seekTime; 594 mStartTimeCommitted = true; // do not allow start time to be compensated for jank 595 if (!mRunning) { 596 mSeekFraction = fraction; 597 } 598 mOverallFraction = fraction; 599 final float currentIterationFraction = getCurrentIterationFraction(fraction); 600 animateValue(currentIterationFraction); 601 } 602 603 /** 604 * Calculates current iteration based on the overall fraction. The overall fraction will be 605 * in the range of [0, mRepeatCount + 1]. Both current iteration and fraction in the current 606 * iteration can be derived from it. 607 */ 608 private int getCurrentIteration(float fraction) { 609 fraction = clampFraction(fraction); 610 // If the overall fraction is a positive integer, we consider the current iteration to be 611 // complete. In other words, the fraction for the current iteration would be 1, and the 612 // current iteration would be overall fraction - 1. 613 double iteration = Math.floor(fraction); 614 if (fraction == iteration && fraction > 0) { 615 iteration--; 616 } 617 return (int) iteration; 618 } 619 620 /** 621 * Calculates the fraction of the current iteration, taking into account whether the animation 622 * should be played backwards. E.g. When the animation is played backwards in an iteration, 623 * the fraction for that iteration will go from 1f to 0f. 624 */ 625 private float getCurrentIterationFraction(float fraction) { 626 fraction = clampFraction(fraction); 627 int iteration = getCurrentIteration(fraction); 628 float currentFraction = fraction - iteration; 629 return shouldPlayBackward(iteration) ? 1f - currentFraction : currentFraction; 630 } 631 632 /** 633 * Clamps fraction into the correct range: [0, mRepeatCount + 1]. If repeat count is infinite, 634 * no upper bound will be set for the fraction. 635 * 636 * @param fraction fraction to be clamped 637 * @return fraction clamped into the range of [0, mRepeatCount + 1] 638 */ 639 private float clampFraction(float fraction) { 640 if (fraction < 0) { 641 fraction = 0; 642 } else if (mRepeatCount != INFINITE) { 643 fraction = Math.min(fraction, mRepeatCount + 1); 644 } 645 return fraction; 646 } 647 648 /** 649 * Calculates the direction of animation playing (i.e. forward or backward), based on 1) 650 * whether the entire animation is being reversed, 2) repeat mode applied to the current 651 * iteration. 652 */ 653 private boolean shouldPlayBackward(int iteration) { 654 if (iteration > 0 && mRepeatMode == REVERSE && 655 (iteration < (mRepeatCount + 1) || mRepeatCount == INFINITE)) { 656 // if we were seeked to some other iteration in a reversing animator, 657 // figure out the correct direction to start playing based on the iteration 658 if (mReversing) { 659 return (iteration % 2) == 0; 660 } else { 661 return (iteration % 2) != 0; 662 } 663 } else { 664 return mReversing; 665 } 666 } 667 668 /** 669 * Gets the current position of the animation in time, which is equal to the current 670 * time minus the time that the animation started. An animation that is not yet started will 671 * return a value of zero, unless the animation has has its play time set via 672 * {@link #setCurrentPlayTime(long)} or {@link #setCurrentFraction(float)}, in which case 673 * it will return the time that was set. 674 * 675 * @return The current position in time of the animation. 676 */ 677 public long getCurrentPlayTime() { 678 if (!mInitialized || (!mStarted && mSeekFraction < 0)) { 679 return 0; 680 } 681 if (mSeekFraction >= 0) { 682 return (long) (mDuration * mSeekFraction); 683 } 684 float durationScale = sDurationScale == 0 ? 1 : sDurationScale; 685 return (long) ((AnimationUtils.currentAnimationTimeMillis() - mStartTime) / durationScale); 686 } 687 688 /** 689 * The amount of time, in milliseconds, to delay starting the animation after 690 * {@link #start()} is called. 691 * 692 * @return the number of milliseconds to delay running the animation 693 */ 694 @Override 695 public long getStartDelay() { 696 return mStartDelay; 697 } 698 699 /** 700 * The amount of time, in milliseconds, to delay starting the animation after 701 * {@link #start()} is called. 702 703 * @param startDelay The amount of the delay, in milliseconds 704 */ 705 @Override 706 public void setStartDelay(long startDelay) { 707 mStartDelay = startDelay; 708 } 709 710 /** 711 * The amount of time, in milliseconds, between each frame of the animation. This is a 712 * requested time that the animation will attempt to honor, but the actual delay between 713 * frames may be different, depending on system load and capabilities. This is a static 714 * function because the same delay will be applied to all animations, since they are all 715 * run off of a single timing loop. 716 * 717 * The frame delay may be ignored when the animation system uses an external timing 718 * source, such as the display refresh rate (vsync), to govern animations. 719 * 720 * Note that this method should be called from the same thread that {@link #start()} is 721 * called in order to check the frame delay for that animation. A runtime exception will be 722 * thrown if the calling thread does not have a Looper. 723 * 724 * @return the requested time between frames, in milliseconds 725 */ 726 public static long getFrameDelay() { 727 return AnimationHandler.getInstance().getFrameDelay(); 728 } 729 730 /** 731 * The amount of time, in milliseconds, between each frame of the animation. This is a 732 * requested time that the animation will attempt to honor, but the actual delay between 733 * frames may be different, depending on system load and capabilities. This is a static 734 * function because the same delay will be applied to all animations, since they are all 735 * run off of a single timing loop. 736 * 737 * The frame delay may be ignored when the animation system uses an external timing 738 * source, such as the display refresh rate (vsync), to govern animations. 739 * 740 * Note that this method should be called from the same thread that {@link #start()} is 741 * called in order to have the new frame delay take effect on that animation. A runtime 742 * exception will be thrown if the calling thread does not have a Looper. 743 * 744 * @param frameDelay the requested time between frames, in milliseconds 745 */ 746 public static void setFrameDelay(long frameDelay) { 747 AnimationHandler.getInstance().setFrameDelay(frameDelay); 748 } 749 750 /** 751 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 752 * property being animated. This value is only sensible while the animation is running. The main 753 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 754 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 755 * is called during each animation frame, immediately after the value is calculated. 756 * 757 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 758 * the single property being animated. If there are several properties being animated 759 * (specified by several PropertyValuesHolder objects in the constructor), this function 760 * returns the animated value for the first of those objects. 761 */ 762 public Object getAnimatedValue() { 763 if (mValues != null && mValues.length > 0) { 764 return mValues[0].getAnimatedValue(); 765 } 766 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 767 return null; 768 } 769 770 /** 771 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 772 * The main purpose for this read-only property is to retrieve the value from the 773 * <code>ValueAnimator</code> during a call to 774 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 775 * is called during each animation frame, immediately after the value is calculated. 776 * 777 * @return animatedValue The value most recently calculated for the named property 778 * by this <code>ValueAnimator</code>. 779 */ 780 public Object getAnimatedValue(String propertyName) { 781 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 782 if (valuesHolder != null) { 783 return valuesHolder.getAnimatedValue(); 784 } else { 785 // At least avoid crashing if called with bogus propertyName 786 return null; 787 } 788 } 789 790 /** 791 * Sets how many times the animation should be repeated. If the repeat 792 * count is 0, the animation is never repeated. If the repeat count is 793 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 794 * into account. The repeat count is 0 by default. 795 * 796 * @param value the number of times the animation should be repeated 797 */ 798 public void setRepeatCount(int value) { 799 mRepeatCount = value; 800 } 801 /** 802 * Defines how many times the animation should repeat. The default value 803 * is 0. 804 * 805 * @return the number of times the animation should repeat, or {@link #INFINITE} 806 */ 807 public int getRepeatCount() { 808 return mRepeatCount; 809 } 810 811 /** 812 * Defines what this animation should do when it reaches the end. This 813 * setting is applied only when the repeat count is either greater than 814 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 815 * 816 * @param value {@link #RESTART} or {@link #REVERSE} 817 */ 818 public void setRepeatMode(@RepeatMode int value) { 819 mRepeatMode = value; 820 } 821 822 /** 823 * Defines what this animation should do when it reaches the end. 824 * 825 * @return either one of {@link #REVERSE} or {@link #RESTART} 826 */ 827 @RepeatMode 828 public int getRepeatMode() { 829 return mRepeatMode; 830 } 831 832 /** 833 * Adds a listener to the set of listeners that are sent update events through the life of 834 * an animation. This method is called on all listeners for every frame of the animation, 835 * after the values for the animation have been calculated. 836 * 837 * @param listener the listener to be added to the current set of listeners for this animation. 838 */ 839 public void addUpdateListener(AnimatorUpdateListener listener) { 840 if (mUpdateListeners == null) { 841 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 842 } 843 mUpdateListeners.add(listener); 844 } 845 846 /** 847 * Removes all listeners from the set listening to frame updates for this animation. 848 */ 849 public void removeAllUpdateListeners() { 850 if (mUpdateListeners == null) { 851 return; 852 } 853 mUpdateListeners.clear(); 854 mUpdateListeners = null; 855 } 856 857 /** 858 * Removes a listener from the set listening to frame updates for this animation. 859 * 860 * @param listener the listener to be removed from the current set of update listeners 861 * for this animation. 862 */ 863 public void removeUpdateListener(AnimatorUpdateListener listener) { 864 if (mUpdateListeners == null) { 865 return; 866 } 867 mUpdateListeners.remove(listener); 868 if (mUpdateListeners.size() == 0) { 869 mUpdateListeners = null; 870 } 871 } 872 873 874 /** 875 * The time interpolator used in calculating the elapsed fraction of this animation. The 876 * interpolator determines whether the animation runs with linear or non-linear motion, 877 * such as acceleration and deceleration. The default value is 878 * {@link android.view.animation.AccelerateDecelerateInterpolator} 879 * 880 * @param value the interpolator to be used by this animation. A value of <code>null</code> 881 * will result in linear interpolation. 882 */ 883 @Override 884 public void setInterpolator(TimeInterpolator value) { 885 if (value != null) { 886 mInterpolator = value; 887 } else { 888 mInterpolator = new LinearInterpolator(); 889 } 890 } 891 892 /** 893 * Returns the timing interpolator that this ValueAnimator uses. 894 * 895 * @return The timing interpolator for this ValueAnimator. 896 */ 897 @Override 898 public TimeInterpolator getInterpolator() { 899 return mInterpolator; 900 } 901 902 /** 903 * The type evaluator to be used when calculating the animated values of this animation. 904 * The system will automatically assign a float or int evaluator based on the type 905 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 906 * are not one of these primitive types, or if different evaluation is desired (such as is 907 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 908 * For example, when running an animation on color values, the {@link ArgbEvaluator} 909 * should be used to get correct RGB color interpolation. 910 * 911 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 912 * will be used for that set. If there are several sets of values being animated, which is 913 * the case if PropertyValuesHolder objects were set on the ValueAnimator, then the evaluator 914 * is assigned just to the first PropertyValuesHolder object.</p> 915 * 916 * @param value the evaluator to be used this animation 917 */ 918 public void setEvaluator(TypeEvaluator value) { 919 if (value != null && mValues != null && mValues.length > 0) { 920 mValues[0].setEvaluator(value); 921 } 922 } 923 924 private void notifyStartListeners() { 925 if (mListeners != null && !mStartListenersCalled) { 926 ArrayList<AnimatorListener> tmpListeners = 927 (ArrayList<AnimatorListener>) mListeners.clone(); 928 int numListeners = tmpListeners.size(); 929 for (int i = 0; i < numListeners; ++i) { 930 tmpListeners.get(i).onAnimationStart(this); 931 } 932 } 933 mStartListenersCalled = true; 934 } 935 936 /** 937 * Start the animation playing. This version of start() takes a boolean flag that indicates 938 * whether the animation should play in reverse. The flag is usually false, but may be set 939 * to true if called from the reverse() method. 940 * 941 * <p>The animation started by calling this method will be run on the thread that called 942 * this method. This thread should have a Looper on it (a runtime exception will be thrown if 943 * this is not the case). Also, if the animation will animate 944 * properties of objects in the view hierarchy, then the calling thread should be the UI 945 * thread for that view hierarchy.</p> 946 * 947 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 948 */ 949 private void start(boolean playBackwards) { 950 if (Looper.myLooper() == null) { 951 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 952 } 953 mReversing = playBackwards; 954 // Special case: reversing from seek-to-0 should act as if not seeked at all. 955 if (playBackwards && mSeekFraction != -1 && mSeekFraction != 0) { 956 if (mRepeatCount == INFINITE) { 957 // Calculate the fraction of the current iteration. 958 float fraction = (float) (mSeekFraction - Math.floor(mSeekFraction)); 959 mSeekFraction = 1 - fraction; 960 } else { 961 mSeekFraction = 1 + mRepeatCount - mSeekFraction; 962 } 963 } 964 mStarted = true; 965 mPaused = false; 966 mRunning = false; 967 AnimationHandler animationHandler = AnimationHandler.getInstance(); 968 animationHandler.addAnimationFrameCallback(this, (long) (mStartDelay * sDurationScale)); 969 970 if (mStartDelay == 0 || mSeekFraction >= 0) { 971 // If there's no start delay, init the animation and notify start listeners right away 972 // to be consistent with the previous behavior. Otherwise, postpone this until the first 973 // frame after the start delay. 974 startAnimation(); 975 if (mSeekFraction == -1) { 976 // No seek, start at play time 0. Note that the reason we are not using fraction 0 977 // is because for animations with 0 duration, we want to be consistent with pre-N 978 // behavior: skip to the final value immediately. 979 setCurrentPlayTime(0); 980 } else { 981 setCurrentFraction(mSeekFraction); 982 } 983 } 984 } 985 986 @Override 987 public void start() { 988 start(false); 989 } 990 991 @Override 992 public void cancel() { 993 if (Looper.myLooper() == null) { 994 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 995 } 996 997 // If end has already been requested, through a previous end() or cancel() call, no-op 998 // until animation starts again. 999 if (mAnimationEndRequested) { 1000 return; 1001 } 1002 1003 // Only cancel if the animation is actually running or has been started and is about 1004 // to run 1005 // Only notify listeners if the animator has actually started 1006 if ((mStarted || mRunning) && mListeners != null) { 1007 if (!mRunning) { 1008 // If it's not yet running, then start listeners weren't called. Call them now. 1009 notifyStartListeners(); 1010 } 1011 ArrayList<AnimatorListener> tmpListeners = 1012 (ArrayList<AnimatorListener>) mListeners.clone(); 1013 for (AnimatorListener listener : tmpListeners) { 1014 listener.onAnimationCancel(this); 1015 } 1016 } 1017 endAnimation(); 1018 1019 } 1020 1021 @Override 1022 public void end() { 1023 if (Looper.myLooper() == null) { 1024 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 1025 } 1026 if (!mRunning) { 1027 // Special case if the animation has not yet started; get it ready for ending 1028 startAnimation(); 1029 mStarted = true; 1030 } else if (!mInitialized) { 1031 initAnimation(); 1032 } 1033 animateValue(shouldPlayBackward(mRepeatCount) ? 0f : 1f); 1034 endAnimation(); 1035 } 1036 1037 @Override 1038 public void resume() { 1039 if (Looper.myLooper() == null) { 1040 throw new AndroidRuntimeException("Animators may only be resumed from the same " + 1041 "thread that the animator was started on"); 1042 } 1043 if (mPaused && !mResumed) { 1044 mResumed = true; 1045 if (mPauseTime > 0) { 1046 AnimationHandler handler = AnimationHandler.getInstance(); 1047 handler.addAnimationFrameCallback(this, 0); 1048 } 1049 } 1050 super.resume(); 1051 } 1052 1053 @Override 1054 public void pause() { 1055 boolean previouslyPaused = mPaused; 1056 super.pause(); 1057 if (!previouslyPaused && mPaused) { 1058 mPauseTime = -1; 1059 mResumed = false; 1060 } 1061 } 1062 1063 @Override 1064 public boolean isRunning() { 1065 return mRunning; 1066 } 1067 1068 @Override 1069 public boolean isStarted() { 1070 return mStarted; 1071 } 1072 1073 /** 1074 * Plays the ValueAnimator in reverse. If the animation is already running, 1075 * it will stop itself and play backwards from the point reached when reverse was called. 1076 * If the animation is not currently running, then it will start from the end and 1077 * play backwards. This behavior is only set for the current animation; future playing 1078 * of the animation will use the default behavior of playing forward. 1079 */ 1080 @Override 1081 public void reverse() { 1082 if (mRunning) { 1083 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 1084 long currentPlayTime = currentTime - mStartTime; 1085 long timeLeft = getScaledDuration() - currentPlayTime; 1086 mStartTime = currentTime - timeLeft; 1087 mStartTimeCommitted = true; // do not allow start time to be compensated for jank 1088 mReversing = !mReversing; 1089 } else if (mStarted) { 1090 end(); 1091 } else { 1092 start(true); 1093 } 1094 } 1095 1096 /** 1097 * @hide 1098 */ 1099 @Override 1100 public boolean canReverse() { 1101 return true; 1102 } 1103 1104 /** 1105 * Called internally to end an animation by removing it from the animations list. Must be 1106 * called on the UI thread. 1107 */ 1108 private void endAnimation() { 1109 if (mAnimationEndRequested) { 1110 return; 1111 } 1112 AnimationHandler handler = AnimationHandler.getInstance(); 1113 handler.removeCallback(this); 1114 1115 mAnimationEndRequested = true; 1116 mPaused = false; 1117 if ((mStarted || mRunning) && mListeners != null) { 1118 if (!mRunning) { 1119 // If it's not yet running, then start listeners weren't called. Call them now. 1120 notifyStartListeners(); 1121 } 1122 ArrayList<AnimatorListener> tmpListeners = 1123 (ArrayList<AnimatorListener>) mListeners.clone(); 1124 int numListeners = tmpListeners.size(); 1125 for (int i = 0; i < numListeners; ++i) { 1126 tmpListeners.get(i).onAnimationEnd(this); 1127 } 1128 } 1129 mRunning = false; 1130 mStarted = false; 1131 mStartListenersCalled = false; 1132 mReversing = false; 1133 mLastFrameTime = 0; 1134 if (Trace.isTagEnabled(Trace.TRACE_TAG_VIEW)) { 1135 Trace.asyncTraceEnd(Trace.TRACE_TAG_VIEW, getNameForTrace(), 1136 System.identityHashCode(this)); 1137 } 1138 } 1139 1140 /** 1141 * Called internally to start an animation by adding it to the active animations list. Must be 1142 * called on the UI thread. 1143 */ 1144 private void startAnimation() { 1145 if (Trace.isTagEnabled(Trace.TRACE_TAG_VIEW)) { 1146 Trace.asyncTraceBegin(Trace.TRACE_TAG_VIEW, getNameForTrace(), 1147 System.identityHashCode(this)); 1148 } 1149 1150 mAnimationEndRequested = false; 1151 initAnimation(); 1152 mRunning = true; 1153 if (mSeekFraction >= 0) { 1154 mOverallFraction = mSeekFraction; 1155 } else { 1156 mOverallFraction = 0f; 1157 } 1158 if (mListeners != null) { 1159 notifyStartListeners(); 1160 } 1161 } 1162 1163 /** 1164 * Returns the name of this animator for debugging purposes. 1165 */ 1166 String getNameForTrace() { 1167 return "animator"; 1168 } 1169 1170 /** 1171 * Applies an adjustment to the animation to compensate for jank between when 1172 * the animation first ran and when the frame was drawn. 1173 * @hide 1174 */ 1175 public void commitAnimationFrame(long frameTime) { 1176 if (!mStartTimeCommitted) { 1177 mStartTimeCommitted = true; 1178 long adjustment = frameTime - mLastFrameTime; 1179 if (adjustment > 0) { 1180 mStartTime += adjustment; 1181 if (DEBUG) { 1182 Log.d(TAG, "Adjusted start time by " + adjustment + " ms: " + toString()); 1183 } 1184 } 1185 } 1186 } 1187 1188 /** 1189 * This internal function processes a single animation frame for a given animation. The 1190 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1191 * elapsed duration, and therefore 1192 * the elapsed fraction, of the animation. The return value indicates whether the animation 1193 * should be ended (which happens when the elapsed time of the animation exceeds the 1194 * animation's duration, including the repeatCount). 1195 * 1196 * @param currentTime The current time, as tracked by the static timing handler 1197 * @return true if the animation's duration, including any repetitions due to 1198 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1199 */ 1200 boolean animateBasedOnTime(long currentTime) { 1201 boolean done = false; 1202 if (mRunning) { 1203 final float fraction = getScaledDuration() > 0 ? 1204 (float)(currentTime - mStartTime) / getScaledDuration() : 1f; 1205 final float lastFraction = mOverallFraction; 1206 final boolean newIteration = (int) fraction > (int) lastFraction; 1207 final boolean lastIterationFinished = (fraction >= mRepeatCount + 1) && 1208 (mRepeatCount != INFINITE); 1209 if (newIteration && !lastIterationFinished) { 1210 // Time to repeat 1211 if (mListeners != null) { 1212 int numListeners = mListeners.size(); 1213 for (int i = 0; i < numListeners; ++i) { 1214 mListeners.get(i).onAnimationRepeat(this); 1215 } 1216 } 1217 } else if (lastIterationFinished) { 1218 done = true; 1219 } 1220 mOverallFraction = clampFraction(fraction); 1221 float currentIterationFraction = getCurrentIterationFraction(mOverallFraction); 1222 animateValue(currentIterationFraction); 1223 } 1224 return done; 1225 } 1226 1227 /** 1228 * Processes a frame of the animation, adjusting the start time if needed. 1229 * 1230 * @param frameTime The frame time. 1231 * @return true if the animation has ended. 1232 * @hide 1233 */ 1234 public final void doAnimationFrame(long frameTime) { 1235 AnimationHandler handler = AnimationHandler.getInstance(); 1236 if (mLastFrameTime == 0) { 1237 // First frame 1238 handler.addOneShotCommitCallback(this); 1239 if (mStartDelay > 0) { 1240 startAnimation(); 1241 } 1242 if (mSeekFraction < 0) { 1243 mStartTime = frameTime; 1244 } else { 1245 long seekTime = (long) (getScaledDuration() * mSeekFraction); 1246 mStartTime = frameTime - seekTime; 1247 mSeekFraction = -1; 1248 } 1249 mStartTimeCommitted = false; // allow start time to be compensated for jank 1250 } 1251 mLastFrameTime = frameTime; 1252 if (mPaused) { 1253 mPauseTime = frameTime; 1254 handler.removeCallback(this); 1255 return; 1256 } else if (mResumed) { 1257 mResumed = false; 1258 if (mPauseTime > 0) { 1259 // Offset by the duration that the animation was paused 1260 mStartTime += (frameTime - mPauseTime); 1261 mStartTimeCommitted = false; // allow start time to be compensated for jank 1262 } 1263 handler.addOneShotCommitCallback(this); 1264 } 1265 // The frame time might be before the start time during the first frame of 1266 // an animation. The "current time" must always be on or after the start 1267 // time to avoid animating frames at negative time intervals. In practice, this 1268 // is very rare and only happens when seeking backwards. 1269 final long currentTime = Math.max(frameTime, mStartTime); 1270 boolean finished = animateBasedOnTime(currentTime); 1271 1272 if (finished) { 1273 endAnimation(); 1274 } 1275 } 1276 1277 /** 1278 * Returns the current animation fraction, which is the elapsed/interpolated fraction used in 1279 * the most recent frame update on the animation. 1280 * 1281 * @return Elapsed/interpolated fraction of the animation. 1282 */ 1283 public float getAnimatedFraction() { 1284 return mCurrentFraction; 1285 } 1286 1287 /** 1288 * This method is called with the elapsed fraction of the animation during every 1289 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1290 * and then into an animated value (from the evaluator. The function is called mostly during 1291 * animation updates, but it is also called when the <code>end()</code> 1292 * function is called, to set the final value on the property. 1293 * 1294 * <p>Overrides of this method must call the superclass to perform the calculation 1295 * of the animated value.</p> 1296 * 1297 * @param fraction The elapsed fraction of the animation. 1298 */ 1299 @CallSuper 1300 void animateValue(float fraction) { 1301 fraction = mInterpolator.getInterpolation(fraction); 1302 mCurrentFraction = fraction; 1303 int numValues = mValues.length; 1304 for (int i = 0; i < numValues; ++i) { 1305 mValues[i].calculateValue(fraction); 1306 } 1307 if (mUpdateListeners != null) { 1308 int numListeners = mUpdateListeners.size(); 1309 for (int i = 0; i < numListeners; ++i) { 1310 mUpdateListeners.get(i).onAnimationUpdate(this); 1311 } 1312 } 1313 } 1314 1315 @Override 1316 public ValueAnimator clone() { 1317 final ValueAnimator anim = (ValueAnimator) super.clone(); 1318 if (mUpdateListeners != null) { 1319 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(mUpdateListeners); 1320 } 1321 anim.mSeekFraction = -1; 1322 anim.mReversing = false; 1323 anim.mInitialized = false; 1324 anim.mStarted = false; 1325 anim.mRunning = false; 1326 anim.mPaused = false; 1327 anim.mResumed = false; 1328 anim.mStartListenersCalled = false; 1329 anim.mStartTime = 0; 1330 anim.mStartTimeCommitted = false; 1331 anim.mAnimationEndRequested = false; 1332 anim.mPauseTime = 0; 1333 anim.mLastFrameTime = 0; 1334 anim.mOverallFraction = 0; 1335 anim.mCurrentFraction = 0; 1336 1337 PropertyValuesHolder[] oldValues = mValues; 1338 if (oldValues != null) { 1339 int numValues = oldValues.length; 1340 anim.mValues = new PropertyValuesHolder[numValues]; 1341 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1342 for (int i = 0; i < numValues; ++i) { 1343 PropertyValuesHolder newValuesHolder = oldValues[i].clone(); 1344 anim.mValues[i] = newValuesHolder; 1345 anim.mValuesMap.put(newValuesHolder.getPropertyName(), newValuesHolder); 1346 } 1347 } 1348 return anim; 1349 } 1350 1351 /** 1352 * Implementors of this interface can add themselves as update listeners 1353 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1354 * frame, after the current frame's values have been calculated for that 1355 * <code>ValueAnimator</code>. 1356 */ 1357 public static interface AnimatorUpdateListener { 1358 /** 1359 * <p>Notifies the occurrence of another frame of the animation.</p> 1360 * 1361 * @param animation The animation which was repeated. 1362 */ 1363 void onAnimationUpdate(ValueAnimator animation); 1364 1365 } 1366 1367 /** 1368 * Return the number of animations currently running. 1369 * 1370 * Used by StrictMode internally to annotate violations. 1371 * May be called on arbitrary threads! 1372 * 1373 * @hide 1374 */ 1375 public static int getCurrentAnimationsCount() { 1376 return AnimationHandler.getAnimationCount(); 1377 } 1378 1379 @Override 1380 public String toString() { 1381 String returnVal = "ValueAnimator@" + Integer.toHexString(hashCode()); 1382 if (mValues != null) { 1383 for (int i = 0; i < mValues.length; ++i) { 1384 returnVal += "\n " + mValues[i].toString(); 1385 } 1386 } 1387 return returnVal; 1388 } 1389 1390 /** 1391 * <p>Whether or not the ValueAnimator is allowed to run asynchronously off of 1392 * the UI thread. This is a hint that informs the ValueAnimator that it is 1393 * OK to run the animation off-thread, however ValueAnimator may decide 1394 * that it must run the animation on the UI thread anyway. For example if there 1395 * is an {@link AnimatorUpdateListener} the animation will run on the UI thread, 1396 * regardless of the value of this hint.</p> 1397 * 1398 * <p>Regardless of whether or not the animation runs asynchronously, all 1399 * listener callbacks will be called on the UI thread.</p> 1400 * 1401 * <p>To be able to use this hint the following must be true:</p> 1402 * <ol> 1403 * <li>{@link #getAnimatedFraction()} is not needed (it will return undefined values).</li> 1404 * <li>The animator is immutable while {@link #isStarted()} is true. Requests 1405 * to change values, duration, delay, etc... may be ignored.</li> 1406 * <li>Lifecycle callback events may be asynchronous. Events such as 1407 * {@link Animator.AnimatorListener#onAnimationEnd(Animator)} or 1408 * {@link Animator.AnimatorListener#onAnimationRepeat(Animator)} may end up delayed 1409 * as they must be posted back to the UI thread, and any actions performed 1410 * by those callbacks (such as starting new animations) will not happen 1411 * in the same frame.</li> 1412 * <li>State change requests ({@link #cancel()}, {@link #end()}, {@link #reverse()}, etc...) 1413 * may be asynchronous. It is guaranteed that all state changes that are 1414 * performed on the UI thread in the same frame will be applied as a single 1415 * atomic update, however that frame may be the current frame, 1416 * the next frame, or some future frame. This will also impact the observed 1417 * state of the Animator. For example, {@link #isStarted()} may still return true 1418 * after a call to {@link #end()}. Using the lifecycle callbacks is preferred over 1419 * queries to {@link #isStarted()}, {@link #isRunning()}, and {@link #isPaused()} 1420 * for this reason.</li> 1421 * </ol> 1422 * @hide 1423 */ 1424 @Override 1425 public void setAllowRunningAsynchronously(boolean mayRunAsync) { 1426 // It is up to subclasses to support this, if they can. 1427 } 1428} 1429