ValueAnimator.java revision b8f574a165bf6ec5b316734b367ac274ded4809b
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.os.Handler; 20import android.os.Looper; 21import android.os.Message; 22import android.util.AndroidRuntimeException; 23import android.view.animation.AccelerateDecelerateInterpolator; 24import android.view.animation.AnimationUtils; 25import android.view.animation.LinearInterpolator; 26 27import java.util.ArrayList; 28import java.util.HashMap; 29 30/** 31 * This class provides a simple timing engine for running animations 32 * which calculate animated values and set them on target objects. 33 * 34 * <p>There is a single timing pulse that all animations use. It runs in a 35 * custom handler to ensure that property changes happen on the UI thread.</p> 36 * 37 * <p>By default, ValueAnimator uses non-linear time interpolation, via the 38 * {@link AccelerateDecelerateInterpolator} class, which accelerates into and decelerates 39 * out of an animation. This behavior can be changed by calling 40 * {@link ValueAnimator#setInterpolator(TimeInterpolator)}.</p> 41 */ 42public class ValueAnimator extends Animator { 43 44 /** 45 * Internal constants 46 */ 47 48 /* 49 * The default amount of time in ms between animation frames 50 */ 51 private static final long DEFAULT_FRAME_DELAY = 10; 52 53 /** 54 * Messages sent to timing handler: START is sent when an animation first begins, FRAME is sent 55 * by the handler to itself to process the next animation frame 56 */ 57 private static final int ANIMATION_START = 0; 58 private static final int ANIMATION_FRAME = 1; 59 60 /** 61 * Values used with internal variable mPlayingState to indicate the current state of an 62 * animation. 63 */ 64 static final int STOPPED = 0; // Not yet playing 65 static final int RUNNING = 1; // Playing normally 66 static final int SEEKED = 2; // Seeked to some time value 67 68 /** 69 * Internal variables 70 * NOTE: This object implements the clone() method, making a deep copy of any referenced 71 * objects. As other non-trivial fields are added to this class, make sure to add logic 72 * to clone() to make deep copies of them. 73 */ 74 75 // The first time that the animation's animateFrame() method is called. This time is used to 76 // determine elapsed time (and therefore the elapsed fraction) in subsequent calls 77 // to animateFrame() 78 long mStartTime; 79 80 /** 81 * Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked 82 * to a value. 83 */ 84 long mSeekTime = -1; 85 86 // TODO: We access the following ThreadLocal variables often, some of them on every update. 87 // If ThreadLocal access is significantly expensive, we may want to put all of these 88 // fields into a structure sot hat we just access ThreadLocal once to get the reference 89 // to that structure, then access the structure directly for each field. 90 91 // The static sAnimationHandler processes the internal timing loop on which all animations 92 // are based 93 private static ThreadLocal<AnimationHandler> sAnimationHandler = 94 new ThreadLocal<AnimationHandler>(); 95 96 // The per-thread list of all active animations 97 private static final ThreadLocal<ArrayList<ValueAnimator>> sAnimations = 98 new ThreadLocal<ArrayList<ValueAnimator>>() { 99 @Override 100 protected ArrayList<ValueAnimator> initialValue() { 101 return new ArrayList<ValueAnimator>(); 102 } 103 }; 104 105 // The per-thread set of animations to be started on the next animation frame 106 private static final ThreadLocal<ArrayList<ValueAnimator>> sPendingAnimations = 107 new ThreadLocal<ArrayList<ValueAnimator>>() { 108 @Override 109 protected ArrayList<ValueAnimator> initialValue() { 110 return new ArrayList<ValueAnimator>(); 111 } 112 }; 113 114 /** 115 * Internal per-thread collections used to avoid set collisions as animations start and end 116 * while being processed. 117 */ 118 private static final ThreadLocal<ArrayList<ValueAnimator>> sDelayedAnims = 119 new ThreadLocal<ArrayList<ValueAnimator>>() { 120 @Override 121 protected ArrayList<ValueAnimator> initialValue() { 122 return new ArrayList<ValueAnimator>(); 123 } 124 }; 125 126 private static final ThreadLocal<ArrayList<ValueAnimator>> sEndingAnims = 127 new ThreadLocal<ArrayList<ValueAnimator>>() { 128 @Override 129 protected ArrayList<ValueAnimator> initialValue() { 130 return new ArrayList<ValueAnimator>(); 131 } 132 }; 133 134 private static final ThreadLocal<ArrayList<ValueAnimator>> sReadyAnims = 135 new ThreadLocal<ArrayList<ValueAnimator>>() { 136 @Override 137 protected ArrayList<ValueAnimator> initialValue() { 138 return new ArrayList<ValueAnimator>(); 139 } 140 }; 141 142 // The time interpolator to be used if none is set on the animation 143 private static final TimeInterpolator sDefaultInterpolator = 144 new AccelerateDecelerateInterpolator(); 145 146 // type evaluators for the primitive types handled by this implementation 147 private static final TypeEvaluator sIntEvaluator = new IntEvaluator(); 148 private static final TypeEvaluator sFloatEvaluator = new FloatEvaluator(); 149 150 /** 151 * Used to indicate whether the animation is currently playing in reverse. This causes the 152 * elapsed fraction to be inverted to calculate the appropriate values. 153 */ 154 private boolean mPlayingBackwards = false; 155 156 /** 157 * This variable tracks the current iteration that is playing. When mCurrentIteration exceeds the 158 * repeatCount (if repeatCount!=INFINITE), the animation ends 159 */ 160 private int mCurrentIteration = 0; 161 162 /** 163 * Tracks current elapsed/eased fraction, for querying in getAnimatedFraction(). 164 */ 165 private float mCurrentFraction = 0f; 166 167 /** 168 * Tracks whether a startDelay'd animation has begun playing through the startDelay. 169 */ 170 private boolean mStartedDelay = false; 171 172 /** 173 * Tracks the time at which the animation began playing through its startDelay. This is 174 * different from the mStartTime variable, which is used to track when the animation became 175 * active (which is when the startDelay expired and the animation was added to the active 176 * animations list). 177 */ 178 private long mDelayStartTime; 179 180 /** 181 * Flag that represents the current state of the animation. Used to figure out when to start 182 * an animation (if state == STOPPED). Also used to end an animation that 183 * has been cancel()'d or end()'d since the last animation frame. Possible values are 184 * STOPPED, RUNNING, SEEKED. 185 */ 186 int mPlayingState = STOPPED; 187 188 /** 189 * Additional playing state to indicate whether an animator has been start()'d. There is 190 * some lag between a call to start() and the first animation frame. We should still note 191 * that the animation has been started, even if it's first animation frame has not yet 192 * happened, and reflect that state in isRunning(). 193 * Note that delayed animations are different: they are not started until their first 194 * animation frame, which occurs after their delay elapses. 195 */ 196 private boolean mStarted = false; 197 198 /** 199 * Flag that denotes whether the animation is set up and ready to go. Used to 200 * set up animation that has not yet been started. 201 */ 202 boolean mInitialized = false; 203 204 // 205 // Backing variables 206 // 207 208 // How long the animation should last in ms 209 private long mDuration = 300; 210 211 // The amount of time in ms to delay starting the animation after start() is called 212 private long mStartDelay = 0; 213 214 // The number of milliseconds between animation frames 215 private static long sFrameDelay = DEFAULT_FRAME_DELAY; 216 217 // The number of times the animation will repeat. The default is 0, which means the animation 218 // will play only once 219 private int mRepeatCount = 0; 220 221 /** 222 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 223 * animation will start from the beginning on every new cycle. REVERSE means the animation 224 * will reverse directions on each iteration. 225 */ 226 private int mRepeatMode = RESTART; 227 228 /** 229 * The time interpolator to be used. The elapsed fraction of the animation will be passed 230 * through this interpolator to calculate the interpolated fraction, which is then used to 231 * calculate the animated values. 232 */ 233 private TimeInterpolator mInterpolator = sDefaultInterpolator; 234 235 /** 236 * The set of listeners to be sent events through the life of an animation. 237 */ 238 private ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 239 240 /** 241 * The property/value sets being animated. 242 */ 243 PropertyValuesHolder[] mValues; 244 245 /** 246 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 247 * by property name during calls to getAnimatedValue(String). 248 */ 249 HashMap<String, PropertyValuesHolder> mValuesMap; 250 251 /** 252 * Public constants 253 */ 254 255 /** 256 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 257 * or a positive value, the animation restarts from the beginning. 258 */ 259 public static final int RESTART = 1; 260 /** 261 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 262 * or a positive value, the animation reverses direction on every iteration. 263 */ 264 public static final int REVERSE = 2; 265 /** 266 * This value used used with the {@link #setRepeatCount(int)} property to repeat 267 * the animation indefinitely. 268 */ 269 public static final int INFINITE = -1; 270 271 /** 272 * Creates a new ValueAnimator object. This default constructor is primarily for 273 * use internally; the factory methods which take parameters are more generally 274 * useful. 275 */ 276 public ValueAnimator() { 277 } 278 279 /** 280 * Constructs and returns a ValueAnimator that animates between int values. A single 281 * value implies that that value is the one being animated to. However, this is not typically 282 * useful in a ValueAnimator object because there is no way for the object to determine the 283 * starting value for the animation (unlike ObjectAnimator, which can derive that value 284 * from the target object and property being animated). Therefore, there should typically 285 * be two or more values. 286 * 287 * @param values A set of values that the animation will animate between over time. 288 * @return A ValueAnimator object that is set up to animate between the given values. 289 */ 290 public static ValueAnimator ofInt(int... values) { 291 ValueAnimator anim = new ValueAnimator(); 292 anim.setIntValues(values); 293 return anim; 294 } 295 296 /** 297 * Constructs and returns a ValueAnimator that animates between float values. A single 298 * value implies that that value is the one being animated to. However, this is not typically 299 * useful in a ValueAnimator object because there is no way for the object to determine the 300 * starting value for the animation (unlike ObjectAnimator, which can derive that value 301 * from the target object and property being animated). Therefore, there should typically 302 * be two or more values. 303 * 304 * @param values A set of values that the animation will animate between over time. 305 * @return A ValueAnimator object that is set up to animate between the given values. 306 */ 307 public static ValueAnimator ofFloat(float... values) { 308 ValueAnimator anim = new ValueAnimator(); 309 anim.setFloatValues(values); 310 return anim; 311 } 312 313 /** 314 * Constructs and returns a ValueAnimator that animates between the values 315 * specified in the PropertyValuesHolder objects. 316 * 317 * @param values A set of PropertyValuesHolder objects whose values will be animated 318 * between over time. 319 * @return A ValueAnimator object that is set up to animate between the given values. 320 */ 321 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 322 ValueAnimator anim = new ValueAnimator(); 323 anim.setValues(values); 324 return anim; 325 } 326 /** 327 * Constructs and returns a ValueAnimator that animates between Object values. A single 328 * value implies that that value is the one being animated to. However, this is not typically 329 * useful in a ValueAnimator object because there is no way for the object to determine the 330 * starting value for the animation (unlike ObjectAnimator, which can derive that value 331 * from the target object and property being animated). Therefore, there should typically 332 * be two or more values. 333 * 334 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 335 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 336 * to perform that interpolation. 337 * 338 * @param evaluator A TypeEvaluator that will be called on each animation frame to 339 * provide the ncessry interpolation between the Object values to derive the animated 340 * value. 341 * @param values A set of values that the animation will animate between over time. 342 * @return A ValueAnimator object that is set up to animate between the given values. 343 */ 344 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 345 ValueAnimator anim = new ValueAnimator(); 346 anim.setObjectValues(values); 347 anim.setEvaluator(evaluator); 348 return anim; 349 } 350 351 /** 352 * Sets int values that will be animated between. A single 353 * value implies that that value is the one being animated to. However, this is not typically 354 * useful in a ValueAnimator object because there is no way for the object to determine the 355 * starting value for the animation (unlike ObjectAnimator, which can derive that value 356 * from the target object and property being animated). Therefore, there should typically 357 * be two or more values. 358 * 359 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 360 * than one PropertyValuesHolder object, this method will set the values for the first 361 * of those objects.</p> 362 * 363 * @param values A set of values that the animation will animate between over time. 364 */ 365 public void setIntValues(int... values) { 366 if (values == null || values.length == 0) { 367 return; 368 } 369 if (mValues == null || mValues.length == 0) { 370 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofInt("", values)}); 371 } else { 372 PropertyValuesHolder valuesHolder = mValues[0]; 373 valuesHolder.setIntValues(values); 374 } 375 // New property/values/target should cause re-initialization prior to starting 376 mInitialized = false; 377 } 378 379 /** 380 * Sets float values that will be animated between. A single 381 * value implies that that value is the one being animated to. However, this is not typically 382 * useful in a ValueAnimator object because there is no way for the object to determine the 383 * starting value for the animation (unlike ObjectAnimator, which can derive that value 384 * from the target object and property being animated). Therefore, there should typically 385 * be two or more values. 386 * 387 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 388 * than one PropertyValuesHolder object, this method will set the values for the first 389 * of those objects.</p> 390 * 391 * @param values A set of values that the animation will animate between over time. 392 */ 393 public void setFloatValues(float... values) { 394 if (values == null || values.length == 0) { 395 return; 396 } 397 if (mValues == null || mValues.length == 0) { 398 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofFloat("", values)}); 399 } else { 400 PropertyValuesHolder valuesHolder = mValues[0]; 401 valuesHolder.setFloatValues(values); 402 } 403 // New property/values/target should cause re-initialization prior to starting 404 mInitialized = false; 405 } 406 407 /** 408 * Sets the values to animate between for this animation. A single 409 * value implies that that value is the one being animated to. However, this is not typically 410 * useful in a ValueAnimator object because there is no way for the object to determine the 411 * starting value for the animation (unlike ObjectAnimator, which can derive that value 412 * from the target object and property being animated). Therefore, there should typically 413 * be two or more values. 414 * 415 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 416 * than one PropertyValuesHolder object, this method will set the values for the first 417 * of those objects.</p> 418 * 419 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 420 * between these value objects. ValueAnimator only knows how to interpolate between the 421 * primitive types specified in the other setValues() methods.</p> 422 * 423 * @param values The set of values to animate between. 424 */ 425 public void setObjectValues(Object... values) { 426 if (values == null || values.length == 0) { 427 return; 428 } 429 if (mValues == null || mValues.length == 0) { 430 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofObject("", 431 (TypeEvaluator)null, values)}); 432 } else { 433 PropertyValuesHolder valuesHolder = mValues[0]; 434 valuesHolder.setObjectValues(values); 435 } 436 // New property/values/target should cause re-initialization prior to starting 437 mInitialized = false; 438 } 439 440 /** 441 * Sets the values, per property, being animated between. This function is called internally 442 * by the constructors of ValueAnimator that take a list of values. But an ValueAnimator can 443 * be constructed without values and this method can be called to set the values manually 444 * instead. 445 * 446 * @param values The set of values, per property, being animated between. 447 */ 448 public void setValues(PropertyValuesHolder... values) { 449 int numValues = values.length; 450 mValues = values; 451 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 452 for (int i = 0; i < numValues; ++i) { 453 PropertyValuesHolder valuesHolder = (PropertyValuesHolder) values[i]; 454 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 455 } 456 // New property/values/target should cause re-initialization prior to starting 457 mInitialized = false; 458 } 459 460 /** 461 * Returns the values that this ValueAnimator animates between. These values are stored in 462 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 463 * of value objects instead. 464 * 465 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 466 * values, per property, that define the animation. 467 */ 468 public PropertyValuesHolder[] getValues() { 469 return mValues; 470 } 471 472 /** 473 * This function is called immediately before processing the first animation 474 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 475 * function is called after that delay ends. 476 * It takes care of the final initialization steps for the 477 * animation. 478 * 479 * <p>Overrides of this method should call the superclass method to ensure 480 * that internal mechanisms for the animation are set up correctly.</p> 481 */ 482 void initAnimation() { 483 if (!mInitialized) { 484 int numValues = mValues.length; 485 for (int i = 0; i < numValues; ++i) { 486 mValues[i].init(); 487 } 488 mInitialized = true; 489 } 490 } 491 492 493 /** 494 * Sets the length of the animation. The default duration is 300 milliseconds. 495 * 496 * @param duration The length of the animation, in milliseconds. This value cannot 497 * be negative. 498 * @return ValueAnimator The object called with setDuration(). This return 499 * value makes it easier to compose statements together that construct and then set the 500 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 501 */ 502 public ValueAnimator setDuration(long duration) { 503 if (duration < 0) { 504 throw new IllegalArgumentException("Animators cannot have negative duration: " + 505 duration); 506 } 507 mDuration = duration; 508 return this; 509 } 510 511 /** 512 * Gets the length of the animation. The default duration is 300 milliseconds. 513 * 514 * @return The length of the animation, in milliseconds. 515 */ 516 public long getDuration() { 517 return mDuration; 518 } 519 520 /** 521 * Sets the position of the animation to the specified point in time. This time should 522 * be between 0 and the total duration of the animation, including any repetition. If 523 * the animation has not yet been started, then it will not advance forward after it is 524 * set to this time; it will simply set the time to this value and perform any appropriate 525 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 526 * will set the current playing time to this value and continue playing from that point. 527 * 528 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 529 */ 530 public void setCurrentPlayTime(long playTime) { 531 initAnimation(); 532 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 533 if (mPlayingState != RUNNING) { 534 mSeekTime = playTime; 535 mPlayingState = SEEKED; 536 } 537 mStartTime = currentTime - playTime; 538 animationFrame(currentTime); 539 } 540 541 /** 542 * Gets the current position of the animation in time, which is equal to the current 543 * time minus the time that the animation started. An animation that is not yet started will 544 * return a value of zero. 545 * 546 * @return The current position in time of the animation. 547 */ 548 public long getCurrentPlayTime() { 549 if (!mInitialized || mPlayingState == STOPPED) { 550 return 0; 551 } 552 return AnimationUtils.currentAnimationTimeMillis() - mStartTime; 553 } 554 555 /** 556 * This custom, static handler handles the timing pulse that is shared by 557 * all active animations. This approach ensures that the setting of animation 558 * values will happen on the UI thread and that all animations will share 559 * the same times for calculating their values, which makes synchronizing 560 * animations possible. 561 * 562 */ 563 private static class AnimationHandler extends Handler { 564 /** 565 * There are only two messages that we care about: ANIMATION_START and 566 * ANIMATION_FRAME. The START message is sent when an animation's start() 567 * method is called. It cannot start synchronously when start() is called 568 * because the call may be on the wrong thread, and it would also not be 569 * synchronized with other animations because it would not start on a common 570 * timing pulse. So each animation sends a START message to the handler, which 571 * causes the handler to place the animation on the active animations queue and 572 * start processing frames for that animation. 573 * The FRAME message is the one that is sent over and over while there are any 574 * active animations to process. 575 */ 576 @Override 577 public void handleMessage(Message msg) { 578 boolean callAgain = true; 579 ArrayList<ValueAnimator> animations = sAnimations.get(); 580 ArrayList<ValueAnimator> delayedAnims = sDelayedAnims.get(); 581 switch (msg.what) { 582 // TODO: should we avoid sending frame message when starting if we 583 // were already running? 584 case ANIMATION_START: 585 ArrayList<ValueAnimator> pendingAnimations = sPendingAnimations.get(); 586 if (animations.size() > 0 || delayedAnims.size() > 0) { 587 callAgain = false; 588 } 589 // pendingAnims holds any animations that have requested to be started 590 // We're going to clear sPendingAnimations, but starting animation may 591 // cause more to be added to the pending list (for example, if one animation 592 // starting triggers another starting). So we loop until sPendingAnimations 593 // is empty. 594 while (pendingAnimations.size() > 0) { 595 ArrayList<ValueAnimator> pendingCopy = 596 (ArrayList<ValueAnimator>) pendingAnimations.clone(); 597 pendingAnimations.clear(); 598 int count = pendingCopy.size(); 599 for (int i = 0; i < count; ++i) { 600 ValueAnimator anim = pendingCopy.get(i); 601 // If the animation has a startDelay, place it on the delayed list 602 if (anim.mStartDelay == 0) { 603 anim.startAnimation(); 604 } else { 605 delayedAnims.add(anim); 606 } 607 } 608 } 609 // fall through to process first frame of new animations 610 case ANIMATION_FRAME: 611 // currentTime holds the common time for all animations processed 612 // during this frame 613 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 614 ArrayList<ValueAnimator> readyAnims = sReadyAnims.get(); 615 ArrayList<ValueAnimator> endingAnims = sEndingAnims.get(); 616 617 // First, process animations currently sitting on the delayed queue, adding 618 // them to the active animations if they are ready 619 int numDelayedAnims = delayedAnims.size(); 620 for (int i = 0; i < numDelayedAnims; ++i) { 621 ValueAnimator anim = delayedAnims.get(i); 622 if (anim.delayedAnimationFrame(currentTime)) { 623 readyAnims.add(anim); 624 } 625 } 626 int numReadyAnims = readyAnims.size(); 627 if (numReadyAnims > 0) { 628 for (int i = 0; i < numReadyAnims; ++i) { 629 ValueAnimator anim = readyAnims.get(i); 630 anim.startAnimation(); 631 anim.mStarted = true; 632 delayedAnims.remove(anim); 633 } 634 readyAnims.clear(); 635 } 636 637 // Now process all active animations. The return value from animationFrame() 638 // tells the handler whether it should now be ended 639 int numAnims = animations.size(); 640 int i = 0; 641 while (i < numAnims) { 642 ValueAnimator anim = animations.get(i); 643 if (anim.animationFrame(currentTime)) { 644 endingAnims.add(anim); 645 } 646 if (animations.size() == numAnims) { 647 ++i; 648 } else { 649 // An animation might be canceled or ended by client code 650 // during the animation frame. Check to see if this happened by 651 // seeing whether the current index is the same as it was before 652 // calling animationFrame(). Another approach would be to copy 653 // animations to a temporary list and process that list instead, 654 // but that entails garbage and processing overhead that would 655 // be nice to avoid. 656 --numAnims; 657 endingAnims.remove(anim); 658 } 659 } 660 if (endingAnims.size() > 0) { 661 for (i = 0; i < endingAnims.size(); ++i) { 662 endingAnims.get(i).endAnimation(); 663 } 664 endingAnims.clear(); 665 } 666 667 // If there are still active or delayed animations, call the handler again 668 // after the frameDelay 669 if (callAgain && (!animations.isEmpty() || !delayedAnims.isEmpty())) { 670 sendEmptyMessageDelayed(ANIMATION_FRAME, Math.max(0, sFrameDelay - 671 (AnimationUtils.currentAnimationTimeMillis() - currentTime))); 672 } 673 break; 674 } 675 } 676 } 677 678 /** 679 * The amount of time, in milliseconds, to delay starting the animation after 680 * {@link #start()} is called. 681 * 682 * @return the number of milliseconds to delay running the animation 683 */ 684 public long getStartDelay() { 685 return mStartDelay; 686 } 687 688 /** 689 * The amount of time, in milliseconds, to delay starting the animation after 690 * {@link #start()} is called. 691 692 * @param startDelay The amount of the delay, in milliseconds 693 */ 694 public void setStartDelay(long startDelay) { 695 this.mStartDelay = startDelay; 696 } 697 698 /** 699 * The amount of time, in milliseconds, between each frame of the animation. This is a 700 * requested time that the animation will attempt to honor, but the actual delay between 701 * frames may be different, depending on system load and capabilities. This is a static 702 * function because the same delay will be applied to all animations, since they are all 703 * run off of a single timing loop. 704 * 705 * @return the requested time between frames, in milliseconds 706 */ 707 public static long getFrameDelay() { 708 return sFrameDelay; 709 } 710 711 /** 712 * The amount of time, in milliseconds, between each frame of the animation. This is a 713 * requested time that the animation will attempt to honor, but the actual delay between 714 * frames may be different, depending on system load and capabilities. This is a static 715 * function because the same delay will be applied to all animations, since they are all 716 * run off of a single timing loop. 717 * 718 * @param frameDelay the requested time between frames, in milliseconds 719 */ 720 public static void setFrameDelay(long frameDelay) { 721 sFrameDelay = frameDelay; 722 } 723 724 /** 725 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 726 * property being animated. This value is only sensible while the animation is running. The main 727 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 728 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 729 * is called during each animation frame, immediately after the value is calculated. 730 * 731 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 732 * the single property being animated. If there are several properties being animated 733 * (specified by several PropertyValuesHolder objects in the constructor), this function 734 * returns the animated value for the first of those objects. 735 */ 736 public Object getAnimatedValue() { 737 if (mValues != null && mValues.length > 0) { 738 return mValues[0].getAnimatedValue(); 739 } 740 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 741 return null; 742 } 743 744 /** 745 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 746 * The main purpose for this read-only property is to retrieve the value from the 747 * <code>ValueAnimator</code> during a call to 748 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 749 * is called during each animation frame, immediately after the value is calculated. 750 * 751 * @return animatedValue The value most recently calculated for the named property 752 * by this <code>ValueAnimator</code>. 753 */ 754 public Object getAnimatedValue(String propertyName) { 755 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 756 if (valuesHolder != null) { 757 return valuesHolder.getAnimatedValue(); 758 } else { 759 // At least avoid crashing if called with bogus propertyName 760 return null; 761 } 762 } 763 764 /** 765 * Sets how many times the animation should be repeated. If the repeat 766 * count is 0, the animation is never repeated. If the repeat count is 767 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 768 * into account. The repeat count is 0 by default. 769 * 770 * @param value the number of times the animation should be repeated 771 */ 772 public void setRepeatCount(int value) { 773 mRepeatCount = value; 774 } 775 /** 776 * Defines how many times the animation should repeat. The default value 777 * is 0. 778 * 779 * @return the number of times the animation should repeat, or {@link #INFINITE} 780 */ 781 public int getRepeatCount() { 782 return mRepeatCount; 783 } 784 785 /** 786 * Defines what this animation should do when it reaches the end. This 787 * setting is applied only when the repeat count is either greater than 788 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 789 * 790 * @param value {@link #RESTART} or {@link #REVERSE} 791 */ 792 public void setRepeatMode(int value) { 793 mRepeatMode = value; 794 } 795 796 /** 797 * Defines what this animation should do when it reaches the end. 798 * 799 * @return either one of {@link #REVERSE} or {@link #RESTART} 800 */ 801 public int getRepeatMode() { 802 return mRepeatMode; 803 } 804 805 /** 806 * Adds a listener to the set of listeners that are sent update events through the life of 807 * an animation. This method is called on all listeners for every frame of the animation, 808 * after the values for the animation have been calculated. 809 * 810 * @param listener the listener to be added to the current set of listeners for this animation. 811 */ 812 public void addUpdateListener(AnimatorUpdateListener listener) { 813 if (mUpdateListeners == null) { 814 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 815 } 816 mUpdateListeners.add(listener); 817 } 818 819 /** 820 * Removes all listeners from the set listening to frame updates for this animation. 821 */ 822 public void removeAllUpdateListeners() { 823 if (mUpdateListeners == null) { 824 return; 825 } 826 mUpdateListeners.clear(); 827 mUpdateListeners = null; 828 } 829 830 /** 831 * Removes a listener from the set listening to frame updates for this animation. 832 * 833 * @param listener the listener to be removed from the current set of update listeners 834 * for this animation. 835 */ 836 public void removeUpdateListener(AnimatorUpdateListener listener) { 837 if (mUpdateListeners == null) { 838 return; 839 } 840 mUpdateListeners.remove(listener); 841 if (mUpdateListeners.size() == 0) { 842 mUpdateListeners = null; 843 } 844 } 845 846 847 /** 848 * The time interpolator used in calculating the elapsed fraction of this animation. The 849 * interpolator determines whether the animation runs with linear or non-linear motion, 850 * such as acceleration and deceleration. The default value is 851 * {@link android.view.animation.AccelerateDecelerateInterpolator} 852 * 853 * @param value the interpolator to be used by this animation. A value of <code>null</code> 854 * will result in linear interpolation. 855 */ 856 @Override 857 public void setInterpolator(TimeInterpolator value) { 858 if (value != null) { 859 mInterpolator = value; 860 } else { 861 mInterpolator = new LinearInterpolator(); 862 } 863 } 864 865 /** 866 * Returns the timing interpolator that this ValueAnimator uses. 867 * 868 * @return The timing interpolator for this ValueAnimator. 869 */ 870 public TimeInterpolator getInterpolator() { 871 return mInterpolator; 872 } 873 874 /** 875 * The type evaluator to be used when calculating the animated values of this animation. 876 * The system will automatically assign a float or int evaluator based on the type 877 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 878 * are not one of these primitive types, or if different evaluation is desired (such as is 879 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 880 * For example, when running an animation on color values, the {@link ArgbEvaluator} 881 * should be used to get correct RGB color interpolation. 882 * 883 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 884 * will be used for that set. If there are several sets of values being animated, which is 885 * the case if PropertyValuesHOlder objects were set on the ValueAnimator, then the evaluator 886 * is assigned just to the first PropertyValuesHolder object.</p> 887 * 888 * @param value the evaluator to be used this animation 889 */ 890 public void setEvaluator(TypeEvaluator value) { 891 if (value != null && mValues != null && mValues.length > 0) { 892 mValues[0].setEvaluator(value); 893 } 894 } 895 896 /** 897 * Start the animation playing. This version of start() takes a boolean flag that indicates 898 * whether the animation should play in reverse. The flag is usually false, but may be set 899 * to true if called from the reverse() method. 900 * 901 * <p>The animation started by calling this method will be run on the thread that called 902 * this method. This thread should have a Looper on it (a runtime exception will be thrown if 903 * this is not the case). Also, if the animation will animate 904 * properties of objects in the view hierarchy, then the calling thread should be the UI 905 * thread for that view hierarchy.</p> 906 * 907 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 908 */ 909 private void start(boolean playBackwards) { 910 if (Looper.myLooper() == null) { 911 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 912 } 913 mPlayingBackwards = playBackwards; 914 mCurrentIteration = 0; 915 mPlayingState = STOPPED; 916 mStartedDelay = false; 917 sPendingAnimations.get().add(this); 918 if (mStartDelay == 0) { 919 // This sets the initial value of the animation, prior to actually starting it running 920 setCurrentPlayTime(getCurrentPlayTime()); 921 mPlayingState = STOPPED; 922 mStarted = true; 923 924 if (mListeners != null) { 925 ArrayList<AnimatorListener> tmpListeners = 926 (ArrayList<AnimatorListener>) mListeners.clone(); 927 int numListeners = tmpListeners.size(); 928 for (int i = 0; i < numListeners; ++i) { 929 tmpListeners.get(i).onAnimationStart(this); 930 } 931 } 932 } 933 AnimationHandler animationHandler = sAnimationHandler.get(); 934 if (animationHandler == null) { 935 animationHandler = new AnimationHandler(); 936 sAnimationHandler.set(animationHandler); 937 } 938 animationHandler.sendEmptyMessage(ANIMATION_START); 939 } 940 941 @Override 942 public void start() { 943 start(false); 944 } 945 946 @Override 947 public void cancel() { 948 // Only cancel if the animation is actually running or has been started and is about 949 // to run 950 if (mPlayingState != STOPPED || sPendingAnimations.get().contains(this) || 951 sDelayedAnims.get().contains(this)) { 952 // Only notify listeners if the animator has actually started 953 if (mStarted && mListeners != null) { 954 ArrayList<AnimatorListener> tmpListeners = 955 (ArrayList<AnimatorListener>) mListeners.clone(); 956 for (AnimatorListener listener : tmpListeners) { 957 listener.onAnimationCancel(this); 958 } 959 } 960 endAnimation(); 961 } 962 } 963 964 @Override 965 public void end() { 966 if (!sAnimations.get().contains(this) && !sPendingAnimations.get().contains(this)) { 967 // Special case if the animation has not yet started; get it ready for ending 968 mStartedDelay = false; 969 startAnimation(); 970 } else if (!mInitialized) { 971 initAnimation(); 972 } 973 // The final value set on the target varies, depending on whether the animation 974 // was supposed to repeat an odd number of times 975 if (mRepeatCount > 0 && (mRepeatCount & 0x01) == 1) { 976 animateValue(0f); 977 } else { 978 animateValue(1f); 979 } 980 endAnimation(); 981 } 982 983 @Override 984 public boolean isRunning() { 985 return (mPlayingState == RUNNING || mStarted); 986 } 987 988 /** 989 * Plays the ValueAnimator in reverse. If the animation is already running, 990 * it will stop itself and play backwards from the point reached when reverse was called. 991 * If the animation is not currently running, then it will start from the end and 992 * play backwards. This behavior is only set for the current animation; future playing 993 * of the animation will use the default behavior of playing forward. 994 */ 995 public void reverse() { 996 mPlayingBackwards = !mPlayingBackwards; 997 if (mPlayingState == RUNNING) { 998 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 999 long currentPlayTime = currentTime - mStartTime; 1000 long timeLeft = mDuration - currentPlayTime; 1001 mStartTime = currentTime - timeLeft; 1002 } else { 1003 start(true); 1004 } 1005 } 1006 1007 /** 1008 * Called internally to end an animation by removing it from the animations list. Must be 1009 * called on the UI thread. 1010 */ 1011 private void endAnimation() { 1012 sAnimations.get().remove(this); 1013 sPendingAnimations.get().remove(this); 1014 sDelayedAnims.get().remove(this); 1015 mPlayingState = STOPPED; 1016 if (mStarted && mListeners != null) { 1017 ArrayList<AnimatorListener> tmpListeners = 1018 (ArrayList<AnimatorListener>) mListeners.clone(); 1019 int numListeners = tmpListeners.size(); 1020 for (int i = 0; i < numListeners; ++i) { 1021 tmpListeners.get(i).onAnimationEnd(this); 1022 } 1023 } 1024 mStarted = false; 1025 } 1026 1027 /** 1028 * Called internally to start an animation by adding it to the active animations list. Must be 1029 * called on the UI thread. 1030 */ 1031 private void startAnimation() { 1032 initAnimation(); 1033 sAnimations.get().add(this); 1034 if (mStartDelay > 0 && mListeners != null) { 1035 // Listeners were already notified in start() if startDelay is 0; this is 1036 // just for delayed animations 1037 ArrayList<AnimatorListener> tmpListeners = 1038 (ArrayList<AnimatorListener>) mListeners.clone(); 1039 int numListeners = tmpListeners.size(); 1040 for (int i = 0; i < numListeners; ++i) { 1041 tmpListeners.get(i).onAnimationStart(this); 1042 } 1043 } 1044 } 1045 1046 /** 1047 * Internal function called to process an animation frame on an animation that is currently 1048 * sleeping through its <code>startDelay</code> phase. The return value indicates whether it 1049 * should be woken up and put on the active animations queue. 1050 * 1051 * @param currentTime The current animation time, used to calculate whether the animation 1052 * has exceeded its <code>startDelay</code> and should be started. 1053 * @return True if the animation's <code>startDelay</code> has been exceeded and the animation 1054 * should be added to the set of active animations. 1055 */ 1056 private boolean delayedAnimationFrame(long currentTime) { 1057 if (!mStartedDelay) { 1058 mStartedDelay = true; 1059 mDelayStartTime = currentTime; 1060 } else { 1061 long deltaTime = currentTime - mDelayStartTime; 1062 if (deltaTime > mStartDelay) { 1063 // startDelay ended - start the anim and record the 1064 // mStartTime appropriately 1065 mStartTime = currentTime - (deltaTime - mStartDelay); 1066 mPlayingState = RUNNING; 1067 return true; 1068 } 1069 } 1070 return false; 1071 } 1072 1073 /** 1074 * This internal function processes a single animation frame for a given animation. The 1075 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1076 * elapsed duration, and therefore 1077 * the elapsed fraction, of the animation. The return value indicates whether the animation 1078 * should be ended (which happens when the elapsed time of the animation exceeds the 1079 * animation's duration, including the repeatCount). 1080 * 1081 * @param currentTime The current time, as tracked by the static timing handler 1082 * @return true if the animation's duration, including any repetitions due to 1083 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1084 */ 1085 boolean animationFrame(long currentTime) { 1086 boolean done = false; 1087 1088 if (mPlayingState == STOPPED) { 1089 mPlayingState = RUNNING; 1090 if (mSeekTime < 0) { 1091 mStartTime = currentTime; 1092 } else { 1093 mStartTime = currentTime - mSeekTime; 1094 // Now that we're playing, reset the seek time 1095 mSeekTime = -1; 1096 } 1097 } 1098 switch (mPlayingState) { 1099 case RUNNING: 1100 case SEEKED: 1101 float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f; 1102 if (fraction >= 1f) { 1103 if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) { 1104 // Time to repeat 1105 if (mListeners != null) { 1106 int numListeners = mListeners.size(); 1107 for (int i = 0; i < numListeners; ++i) { 1108 mListeners.get(i).onAnimationRepeat(this); 1109 } 1110 } 1111 if (mRepeatMode == REVERSE) { 1112 mPlayingBackwards = mPlayingBackwards ? false : true; 1113 } 1114 mCurrentIteration += (int)fraction; 1115 fraction = fraction % 1f; 1116 mStartTime += mDuration; 1117 } else { 1118 done = true; 1119 fraction = Math.min(fraction, 1.0f); 1120 } 1121 } 1122 if (mPlayingBackwards) { 1123 fraction = 1f - fraction; 1124 } 1125 animateValue(fraction); 1126 break; 1127 } 1128 1129 return done; 1130 } 1131 1132 /** 1133 * Returns the current animation fraction, which is the elapsed/interpolated fraction used in 1134 * the most recent frame update on the animation. 1135 * 1136 * @return Elapsed/interpolated fraction of the animation. 1137 */ 1138 public float getAnimatedFraction() { 1139 return mCurrentFraction; 1140 } 1141 1142 /** 1143 * This method is called with the elapsed fraction of the animation during every 1144 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1145 * and then into an animated value (from the evaluator. The function is called mostly during 1146 * animation updates, but it is also called when the <code>end()</code> 1147 * function is called, to set the final value on the property. 1148 * 1149 * <p>Overrides of this method must call the superclass to perform the calculation 1150 * of the animated value.</p> 1151 * 1152 * @param fraction The elapsed fraction of the animation. 1153 */ 1154 void animateValue(float fraction) { 1155 fraction = mInterpolator.getInterpolation(fraction); 1156 mCurrentFraction = fraction; 1157 int numValues = mValues.length; 1158 for (int i = 0; i < numValues; ++i) { 1159 mValues[i].calculateValue(fraction); 1160 } 1161 if (mUpdateListeners != null) { 1162 int numListeners = mUpdateListeners.size(); 1163 for (int i = 0; i < numListeners; ++i) { 1164 mUpdateListeners.get(i).onAnimationUpdate(this); 1165 } 1166 } 1167 } 1168 1169 @Override 1170 public ValueAnimator clone() { 1171 final ValueAnimator anim = (ValueAnimator) super.clone(); 1172 if (mUpdateListeners != null) { 1173 ArrayList<AnimatorUpdateListener> oldListeners = mUpdateListeners; 1174 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 1175 int numListeners = oldListeners.size(); 1176 for (int i = 0; i < numListeners; ++i) { 1177 anim.mUpdateListeners.add(oldListeners.get(i)); 1178 } 1179 } 1180 anim.mSeekTime = -1; 1181 anim.mPlayingBackwards = false; 1182 anim.mCurrentIteration = 0; 1183 anim.mInitialized = false; 1184 anim.mPlayingState = STOPPED; 1185 anim.mStartedDelay = false; 1186 PropertyValuesHolder[] oldValues = mValues; 1187 if (oldValues != null) { 1188 int numValues = oldValues.length; 1189 anim.mValues = new PropertyValuesHolder[numValues]; 1190 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1191 for (int i = 0; i < numValues; ++i) { 1192 PropertyValuesHolder newValuesHolder = oldValues[i].clone(); 1193 anim.mValues[i] = newValuesHolder; 1194 anim.mValuesMap.put(newValuesHolder.getPropertyName(), newValuesHolder); 1195 } 1196 } 1197 return anim; 1198 } 1199 1200 /** 1201 * Implementors of this interface can add themselves as update listeners 1202 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1203 * frame, after the current frame's values have been calculated for that 1204 * <code>ValueAnimator</code>. 1205 */ 1206 public static interface AnimatorUpdateListener { 1207 /** 1208 * <p>Notifies the occurrence of another frame of the animation.</p> 1209 * 1210 * @param animation The animation which was repeated. 1211 */ 1212 void onAnimationUpdate(ValueAnimator animation); 1213 1214 } 1215 1216 /** 1217 * Return the number of animations currently running. 1218 * 1219 * Used by StrictMode internally to annotate violations. Only 1220 * called on the main thread. 1221 * 1222 * @hide 1223 */ 1224 public static int getCurrentAnimationsCount() { 1225 return sAnimations.get().size(); 1226 } 1227 1228 /** 1229 * Clear all animations on this thread, without canceling or ending them. 1230 * This should be used with caution. 1231 * 1232 * @hide 1233 */ 1234 public static void clearAllAnimations() { 1235 sAnimations.get().clear(); 1236 sPendingAnimations.get().clear(); 1237 sDelayedAnims.get().clear(); 1238 } 1239 1240 @Override 1241 public String toString() { 1242 String returnVal = "ValueAnimator@" + Integer.toHexString(hashCode()); 1243 if (mValues != null) { 1244 for (int i = 0; i < mValues.length; ++i) { 1245 returnVal += "\n " + mValues[i].toString(); 1246 } 1247 } 1248 return returnVal; 1249 } 1250} 1251