ValueAnimator.java revision 70d4ba15b1f0c1133c5aabc86de828b41e482fff
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.view.animation.AccelerateDecelerateInterpolator; 23import android.view.animation.AnimationUtils; 24 25import java.util.ArrayList; 26import java.util.HashMap; 27 28/** 29 * This class provides a simple timing engine for running animations 30 * which calculate animated values and set them on target objects. 31 * 32 * <p>There is a single timing pulse that all animations use. It runs in a 33 * custom handler to ensure that property changes happen on the UI thread.</p> 34 * 35 * <p>By default, ValueAnimator uses non-linear time interpolation, via the 36 * {@link AccelerateDecelerateInterpolator} class, which accelerates into and decelerates 37 * out of an animation. This behavior can be changed by calling 38 * {@link ValueAnimator#setInterpolator(TimeInterpolator)}.</p> 39 */ 40public class ValueAnimator extends Animator { 41 42 /** 43 * Internal constants 44 */ 45 46 /* 47 * The default amount of time in ms between animation frames 48 */ 49 private static final long DEFAULT_FRAME_DELAY = 10; 50 51 /** 52 * Messages sent to timing handler: START is sent when an animation first begins, FRAME is sent 53 * by the handler to itself to process the next animation frame 54 */ 55 private static final int ANIMATION_START = 0; 56 private static final int ANIMATION_FRAME = 1; 57 58 /** 59 * Values used with internal variable mPlayingState to indicate the current state of an 60 * animation. 61 */ 62 private static final int STOPPED = 0; // Not yet playing 63 private static final int RUNNING = 1; // Playing normally 64 private static final int CANCELED = 2; // cancel() called - need to end it 65 private static final int ENDED = 3; // end() called - need to end it 66 private static final int SEEKED = 4; // 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 private long mStartTime; 79 80 /** 81 * Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked 82 * to a value. 83 */ 84 private 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 three primitive types handled by this implementation 147 private static final TypeEvaluator sIntEvaluator = new IntEvaluator(); 148 private static final TypeEvaluator sFloatEvaluator = new FloatEvaluator(); 149 private static final TypeEvaluator sDoubleEvaluator = new DoubleEvaluator(); 150 151 /** 152 * Used to indicate whether the animation is currently playing in reverse. This causes the 153 * elapsed fraction to be inverted to calculate the appropriate values. 154 */ 155 private boolean mPlayingBackwards = false; 156 157 /** 158 * This variable tracks the current iteration that is playing. When mCurrentIteration exceeds the 159 * repeatCount (if repeatCount!=INFINITE), the animation ends 160 */ 161 private int mCurrentIteration = 0; 162 163 /** 164 * Tracks whether a startDelay'd animation has begun playing through the startDelay. 165 */ 166 private boolean mStartedDelay = false; 167 168 /** 169 * Tracks the time at which the animation began playing through its startDelay. This is 170 * different from the mStartTime variable, which is used to track when the animation became 171 * active (which is when the startDelay expired and the animation was added to the active 172 * animations list). 173 */ 174 private long mDelayStartTime; 175 176 /** 177 * Flag that represents the current state of the animation. Used to figure out when to start 178 * an animation (if state == STOPPED). Also used to end an animation that 179 * has been cancel()'d or end()'d since the last animation frame. Possible values are 180 * STOPPED, RUNNING, ENDED, CANCELED. 181 */ 182 private int mPlayingState = STOPPED; 183 184 /** 185 * Flag that denotes whether the animation is set up and ready to go. Used to 186 * set up animation that has not yet been started. 187 */ 188 boolean mInitialized = 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 198 private long mStartDelay = 0; 199 200 // The number of milliseconds between animation frames 201 private static long sFrameDelay = DEFAULT_FRAME_DELAY; 202 203 // The number of times the animation will repeat. The default is 0, which means the animation 204 // will play only once 205 private int mRepeatCount = 0; 206 207 /** 208 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 209 * animation will start from the beginning on every new cycle. REVERSE means the animation 210 * will reverse directions on each iteration. 211 */ 212 private int mRepeatMode = RESTART; 213 214 /** 215 * The time interpolator to be used. The elapsed fraction of the animation will be passed 216 * through this interpolator to calculate the interpolated fraction, which is then used to 217 * calculate the animated values. 218 */ 219 private TimeInterpolator mInterpolator = sDefaultInterpolator; 220 221 /** 222 * The set of listeners to be sent events through the life of an animation. 223 */ 224 private ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 225 226 /** 227 * The property/value sets being animated. 228 */ 229 PropertyValuesHolder[] mValues; 230 231 /** 232 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 233 * by property name during calls to getAnimatedValue(String). 234 */ 235 HashMap<String, PropertyValuesHolder> mValuesMap; 236 237 /** 238 * Public constants 239 */ 240 241 /** 242 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 243 * or a positive value, the animation restarts from the beginning. 244 */ 245 public static final int RESTART = 1; 246 /** 247 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 248 * or a positive value, the animation reverses direction on every iteration. 249 */ 250 public static final int REVERSE = 2; 251 /** 252 * This value used used with the {@link #setRepeatCount(int)} property to repeat 253 * the animation indefinitely. 254 */ 255 public static final int INFINITE = -1; 256 257 /** 258 * Creates a new ValueAnimator object. This default constructor is primarily for 259 * use internally; the factory methods which take parameters are more generally 260 * useful. 261 */ 262 public ValueAnimator() { 263 } 264 265 /** 266 * Constructs and returns a ValueAnimator that animates between int values. A single 267 * value implies that that value is the one being animated to. However, this is not typically 268 * useful in a ValueAnimator object because there is no way for the object to determine the 269 * starting value for the animation (unlike ObjectAnimator, which can derive that value 270 * from the target object and property being animated). Therefore, there should typically 271 * be two or more values. 272 * 273 * @param values A set of values that the animation will animate between over time. 274 * @return A ValueAnimator object that is set up to animate between the given values. 275 */ 276 public static ValueAnimator ofInt(int... values) { 277 ValueAnimator anim = new ValueAnimator(); 278 anim.setIntValues(values); 279 return anim; 280 } 281 282 /** 283 * Constructs and returns a ValueAnimator that animates between float values. A single 284 * value implies that that value is the one being animated to. However, this is not typically 285 * useful in a ValueAnimator object because there is no way for the object to determine the 286 * starting value for the animation (unlike ObjectAnimator, which can derive that value 287 * from the target object and property being animated). Therefore, there should typically 288 * be two or more values. 289 * 290 * @param values A set of values that the animation will animate between over time. 291 * @return A ValueAnimator object that is set up to animate between the given values. 292 */ 293 public static ValueAnimator ofFloat(float... values) { 294 ValueAnimator anim = new ValueAnimator(); 295 anim.setFloatValues(values); 296 return anim; 297 } 298 299 /** 300 * Constructs and returns a ValueAnimator that animates between double values. A single 301 * value implies that that value is the one being animated to. However, this is not typically 302 * useful in a ValueAnimator object because there is no way for the object to determine the 303 * starting value for the animation (unlike ObjectAnimator, which can derive that value 304 * from the target object and property being animated). Therefore, there should typically 305 * be two or more values. 306 * 307 * @param values A set of values that the animation will animate between over time. 308 * @return A ValueAnimator object that is set up to animate between the given values. 309 */ 310 public static ValueAnimator ofDouble(double... values) { 311 ValueAnimator anim = new ValueAnimator(); 312 anim.setDoubleValues(values); 313 return anim; 314 } 315 316 /** 317 * Constructs and returns a ValueAnimator that animates between long values. A single 318 * value implies that that value is the one being animated to. However, this is not typically 319 * useful in a ValueAnimator object because there is no way for the object to determine the 320 * starting value for the animation (unlike ObjectAnimator, which can derive that value 321 * from the target object and property being animated). Therefore, there should typically 322 * be two or more values. 323 * 324 * @param values A set of values that the animation will animate between over time. 325 * @return A ValueAnimator object that is set up to animate between the given values. 326 */ 327 public static ValueAnimator ofLong(long... values) { 328 ValueAnimator anim = new ValueAnimator(); 329 anim.setLongValues(values); 330 return anim; 331 } 332 333 /** 334 * Constructs and returns a ValueAnimator that animates between the values 335 * specified in the PropertyValuesHolder objects. 336 * 337 * @param values A set of PropertyValuesHolder objects whose values will be animated 338 * between over time. 339 * @return A ValueAnimator object that is set up to animate between the given values. 340 */ 341 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 342 ValueAnimator anim = new ValueAnimator(); 343 anim.setValues(values); 344 return anim; 345 } 346 /** 347 * Constructs and returns a ValueAnimator that animates between Object values. A single 348 * value implies that that value is the one being animated to. However, this is not typically 349 * useful in a ValueAnimator object because there is no way for the object to determine the 350 * starting value for the animation (unlike ObjectAnimator, which can derive that value 351 * from the target object and property being animated). Therefore, there should typically 352 * be two or more values. 353 * 354 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 355 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 356 * to perform that interpolation. 357 * 358 * @param evaluator A TypeEvaluator that will be called on each animation frame to 359 * provide the ncessry interpolation between the Object values to derive the animated 360 * value. 361 * @param values A set of values that the animation will animate between over time. 362 * @return A ValueAnimator object that is set up to animate between the given values. 363 */ 364 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 365 ValueAnimator anim = new ValueAnimator(); 366 anim.setObjectValues(values); 367 anim.setEvaluator(evaluator); 368 return anim; 369 } 370 371 /** 372 * Sets int values that will be animated between. A single 373 * value implies that that value is the one being animated to. However, this is not typically 374 * useful in a ValueAnimator object because there is no way for the object to determine the 375 * starting value for the animation (unlike ObjectAnimator, which can derive that value 376 * from the target object and property being animated). Therefore, there should typically 377 * be two or more values. 378 * 379 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 380 * than one PropertyValuesHolder object, this method will set the values for the first 381 * of those objects.</p> 382 * 383 * @param values A set of values that the animation will animate between over time. 384 */ 385 public void setIntValues(int... values) { 386 if (values == null || values.length == 0) { 387 return; 388 } 389 if (mValues == null || mValues.length == 0) { 390 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofInt("", values)}); 391 } else { 392 PropertyValuesHolder valuesHolder = mValues[0]; 393 valuesHolder.setIntValues(values); 394 } 395 // New property/values/target should cause re-initialization prior to starting 396 mInitialized = false; 397 } 398 399 /** 400 * Sets float values that will be animated between. A single 401 * value implies that that value is the one being animated to. However, this is not typically 402 * useful in a ValueAnimator object because there is no way for the object to determine the 403 * starting value for the animation (unlike ObjectAnimator, which can derive that value 404 * from the target object and property being animated). Therefore, there should typically 405 * be two or more values. 406 * 407 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 408 * than one PropertyValuesHolder object, this method will set the values for the first 409 * of those objects.</p> 410 * 411 * @param values A set of values that the animation will animate between over time. 412 */ 413 public void setFloatValues(float... values) { 414 if (values == null || values.length == 0) { 415 return; 416 } 417 if (mValues == null || mValues.length == 0) { 418 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofFloat("", values)}); 419 } else { 420 PropertyValuesHolder valuesHolder = mValues[0]; 421 valuesHolder.setFloatValues(values); 422 } 423 // New property/values/target should cause re-initialization prior to starting 424 mInitialized = false; 425 } 426 427 /** 428 * Sets long values that will be animated between. A single 429 * value implies that that value is the one being animated to. However, this is not typically 430 * useful in a ValueAnimator object because there is no way for the object to determine the 431 * starting value for the animation (unlike ObjectAnimator, which can derive that value 432 * from the target object and property being animated). Therefore, there should typically 433 * be two or more values. 434 * 435 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 436 * than one PropertyValuesHolder object, this method will set the values for the first 437 * of those objects.</p> 438 * 439 * @param values A set of values that the animation will animate between over time. 440 */ 441 public void setLongValues(long... values) { 442 if (values == null || values.length == 0) { 443 return; 444 } 445 if (mValues == null || mValues.length == 0) { 446 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofLong("", values)}); 447 } else { 448 PropertyValuesHolder valuesHolder = mValues[0]; 449 valuesHolder.setLongValues(values); 450 } 451 // New property/values/target should cause re-initialization prior to starting 452 mInitialized = false; 453 } 454 455 /** 456 * Sets double values that will be animated between. A single 457 * value implies that that value is the one being animated to. However, this is not typically 458 * useful in a ValueAnimator object because there is no way for the object to determine the 459 * starting value for the animation (unlike ObjectAnimator, which can derive that value 460 * from the target object and property being animated). Therefore, there should typically 461 * be two or more values. 462 * 463 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 464 * than one PropertyValuesHolder object, this method will set the values for the first 465 * of those objects.</p> 466 * 467 * @param values A set of values that the animation will animate between over time. 468 */ 469 public void setDoubleValues(double... values) { 470 if (values == null || values.length == 0) { 471 return; 472 } 473 if (mValues == null || mValues.length == 0) { 474 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofDouble("", values)}); 475 } else { 476 PropertyValuesHolder valuesHolder = mValues[0]; 477 valuesHolder.setDoubleValues(values); 478 } 479 // New property/values/target should cause re-initialization prior to starting 480 mInitialized = false; 481 } 482 483 /** 484 * Sets the values to animate between for this animation. A single 485 * value implies that that value is the one being animated to. However, this is not typically 486 * useful in a ValueAnimator object because there is no way for the object to determine the 487 * starting value for the animation (unlike ObjectAnimator, which can derive that value 488 * from the target object and property being animated). Therefore, there should typically 489 * be two or more values. 490 * 491 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 492 * than one PropertyValuesHolder object, this method will set the values for the first 493 * of those objects.</p> 494 * 495 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 496 * between these value objects. ValueAnimator only knows how to interpolate between the 497 * primitive types specified in the other setValues() methods.</p> 498 * 499 * @param values The set of values to animate between. 500 */ 501 public void setObjectValues(Object... values) { 502 if (values == null || values.length == 0) { 503 return; 504 } 505 if (mValues == null || mValues.length == 0) { 506 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofObject("", 507 (TypeEvaluator)null, values)}); 508 } else { 509 PropertyValuesHolder valuesHolder = mValues[0]; 510 valuesHolder.setObjectValues(values); 511 } 512 // New property/values/target should cause re-initialization prior to starting 513 mInitialized = false; 514 } 515 516 /** 517 * Sets the values, per property, being animated between. This function is called internally 518 * by the constructors of ValueAnimator that take a list of values. But an ValueAnimator can 519 * be constructed without values and this method can be called to set the values manually 520 * instead. 521 * 522 * @param values The set of values, per property, being animated between. 523 */ 524 public void setValues(PropertyValuesHolder... values) { 525 int numValues = values.length; 526 mValues = values; 527 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 528 for (int i = 0; i < numValues; ++i) { 529 PropertyValuesHolder valuesHolder = (PropertyValuesHolder) values[i]; 530 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 531 } 532 // New property/values/target should cause re-initialization prior to starting 533 mInitialized = false; 534 } 535 536 /** 537 * Returns the values that this ValueAnimator animates between. These values are stored in 538 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 539 * of value objects instead. 540 * 541 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 542 * values, per property, that define the animation. 543 */ 544 public PropertyValuesHolder[] getValues() { 545 return mValues; 546 } 547 548 /** 549 * This function is called immediately before processing the first animation 550 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 551 * function is called after that delay ends. 552 * It takes care of the final initialization steps for the 553 * animation. 554 * 555 * <p>Overrides of this method should call the superclass method to ensure 556 * that internal mechanisms for the animation are set up correctly.</p> 557 */ 558 void initAnimation() { 559 if (!mInitialized) { 560 int numValues = mValues.length; 561 for (int i = 0; i < numValues; ++i) { 562 mValues[i].init(); 563 } 564 mInitialized = true; 565 } 566 } 567 568 569 /** 570 * Sets the length of the animation. The default duration is 300 milliseconds. 571 * 572 * @param duration The length of the animation, in milliseconds. 573 * @return ValueAnimator The object called with setDuration(). This return 574 * value makes it easier to compose statements together that construct and then set the 575 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 576 */ 577 public ValueAnimator setDuration(long duration) { 578 mDuration = duration; 579 return this; 580 } 581 582 /** 583 * Gets the length of the animation. The default duration is 300 milliseconds. 584 * 585 * @return The length of the animation, in milliseconds. 586 */ 587 public long getDuration() { 588 return mDuration; 589 } 590 591 /** 592 * Sets the position of the animation to the specified point in time. This time should 593 * be between 0 and the total duration of the animation, including any repetition. If 594 * the animation has not yet been started, then it will not advance forward after it is 595 * set to this time; it will simply set the time to this value and perform any appropriate 596 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 597 * will set the current playing time to this value and continue playing from that point. 598 * 599 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 600 */ 601 public void setCurrentPlayTime(long playTime) { 602 initAnimation(); 603 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 604 if (mPlayingState != RUNNING) { 605 mSeekTime = playTime; 606 mPlayingState = SEEKED; 607 } 608 mStartTime = currentTime - playTime; 609 animationFrame(currentTime); 610 } 611 612 /** 613 * Gets the current position of the animation in time, which is equal to the current 614 * time minus the time that the animation started. An animation that is not yet started will 615 * return a value of zero. 616 * 617 * @return The current position in time of the animation. 618 */ 619 public long getCurrentPlayTime() { 620 if (!mInitialized || mPlayingState == STOPPED) { 621 return 0; 622 } 623 return AnimationUtils.currentAnimationTimeMillis() - mStartTime; 624 } 625 626 /** 627 * This custom, static handler handles the timing pulse that is shared by 628 * all active animations. This approach ensures that the setting of animation 629 * values will happen on the UI thread and that all animations will share 630 * the same times for calculating their values, which makes synchronizing 631 * animations possible. 632 * 633 */ 634 private static class AnimationHandler extends Handler { 635 /** 636 * There are only two messages that we care about: ANIMATION_START and 637 * ANIMATION_FRAME. The START message is sent when an animation's start() 638 * method is called. It cannot start synchronously when start() is called 639 * because the call may be on the wrong thread, and it would also not be 640 * synchronized with other animations because it would not start on a common 641 * timing pulse. So each animation sends a START message to the handler, which 642 * causes the handler to place the animation on the active animations queue and 643 * start processing frames for that animation. 644 * The FRAME message is the one that is sent over and over while there are any 645 * active animations to process. 646 */ 647 @Override 648 public void handleMessage(Message msg) { 649 boolean callAgain = true; 650 ArrayList<ValueAnimator> animations = sAnimations.get(); 651 ArrayList<ValueAnimator> delayedAnims = sDelayedAnims.get(); 652 switch (msg.what) { 653 // TODO: should we avoid sending frame message when starting if we 654 // were already running? 655 case ANIMATION_START: 656 ArrayList<ValueAnimator> pendingAnimations = sPendingAnimations.get(); 657 if (animations.size() > 0 || delayedAnims.size() > 0) { 658 callAgain = false; 659 } 660 // pendingAnims holds any animations that have requested to be started 661 // We're going to clear sPendingAnimations, but starting animation may 662 // cause more to be added to the pending list (for example, if one animation 663 // starting triggers another starting). So we loop until sPendingAnimations 664 // is empty. 665 while (pendingAnimations.size() > 0) { 666 ArrayList<ValueAnimator> pendingCopy = 667 (ArrayList<ValueAnimator>) pendingAnimations.clone(); 668 pendingAnimations.clear(); 669 int count = pendingCopy.size(); 670 for (int i = 0; i < count; ++i) { 671 ValueAnimator anim = pendingCopy.get(i); 672 // If the animation has a startDelay, place it on the delayed list 673 if (anim.mStartDelay == 0 || anim.mPlayingState == ENDED || 674 anim.mPlayingState == CANCELED) { 675 anim.startAnimation(); 676 } else { 677 delayedAnims.add(anim); 678 } 679 } 680 } 681 // fall through to process first frame of new animations 682 case ANIMATION_FRAME: 683 // currentTime holds the common time for all animations processed 684 // during this frame 685 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 686 ArrayList<ValueAnimator> readyAnims = sReadyAnims.get(); 687 ArrayList<ValueAnimator> endingAnims = sEndingAnims.get(); 688 689 // First, process animations currently sitting on the delayed queue, adding 690 // them to the active animations if they are ready 691 int numDelayedAnims = delayedAnims.size(); 692 for (int i = 0; i < numDelayedAnims; ++i) { 693 ValueAnimator anim = delayedAnims.get(i); 694 if (anim.delayedAnimationFrame(currentTime)) { 695 readyAnims.add(anim); 696 } 697 } 698 int numReadyAnims = readyAnims.size(); 699 if (numReadyAnims > 0) { 700 for (int i = 0; i < numReadyAnims; ++i) { 701 ValueAnimator anim = readyAnims.get(i); 702 anim.startAnimation(); 703 delayedAnims.remove(anim); 704 } 705 readyAnims.clear(); 706 } 707 708 // Now process all active animations. The return value from animationFrame() 709 // tells the handler whether it should now be ended 710 int numAnims = animations.size(); 711 for (int i = 0; i < numAnims; ++i) { 712 ValueAnimator anim = animations.get(i); 713 if (anim.animationFrame(currentTime)) { 714 endingAnims.add(anim); 715 } 716 } 717 if (endingAnims.size() > 0) { 718 for (int i = 0; i < endingAnims.size(); ++i) { 719 endingAnims.get(i).endAnimation(); 720 } 721 endingAnims.clear(); 722 } 723 724 // If there are still active or delayed animations, call the handler again 725 // after the frameDelay 726 if (callAgain && (!animations.isEmpty() || !delayedAnims.isEmpty())) { 727 sendEmptyMessageDelayed(ANIMATION_FRAME, Math.max(0, sFrameDelay - 728 (AnimationUtils.currentAnimationTimeMillis() - currentTime))); 729 } 730 break; 731 } 732 } 733 } 734 735 /** 736 * The amount of time, in milliseconds, to delay starting the animation after 737 * {@link #start()} is called. 738 * 739 * @return the number of milliseconds to delay running the animation 740 */ 741 public long getStartDelay() { 742 return mStartDelay; 743 } 744 745 /** 746 * The amount of time, in milliseconds, to delay starting the animation after 747 * {@link #start()} is called. 748 749 * @param startDelay The amount of the delay, in milliseconds 750 */ 751 public void setStartDelay(long startDelay) { 752 this.mStartDelay = startDelay; 753 } 754 755 /** 756 * The amount of time, in milliseconds, between each frame of the animation. This is a 757 * requested time that the animation will attempt to honor, but the actual delay between 758 * frames may be different, depending on system load and capabilities. This is a static 759 * function because the same delay will be applied to all animations, since they are all 760 * run off of a single timing loop. 761 * 762 * @return the requested time between frames, in milliseconds 763 */ 764 public static long getFrameDelay() { 765 return sFrameDelay; 766 } 767 768 /** 769 * The amount of time, in milliseconds, between each frame of the animation. This is a 770 * requested time that the animation will attempt to honor, but the actual delay between 771 * frames may be different, depending on system load and capabilities. This is a static 772 * function because the same delay will be applied to all animations, since they are all 773 * run off of a single timing loop. 774 * 775 * @param frameDelay the requested time between frames, in milliseconds 776 */ 777 public static void setFrameDelay(long frameDelay) { 778 sFrameDelay = frameDelay; 779 } 780 781 /** 782 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 783 * property being animated. This value is only sensible while the animation is running. The main 784 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 785 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 786 * is called during each animation frame, immediately after the value is calculated. 787 * 788 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 789 * the single property being animated. If there are several properties being animated 790 * (specified by several PropertyValuesHolder objects in the constructor), this function 791 * returns the animated value for the first of those objects. 792 */ 793 public Object getAnimatedValue() { 794 if (mValues != null && mValues.length > 0) { 795 return mValues[0].getAnimatedValue(); 796 } 797 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 798 return null; 799 } 800 801 /** 802 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 803 * The main purpose for this read-only property is to retrieve the value from the 804 * <code>ValueAnimator</code> during a call to 805 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 806 * is called during each animation frame, immediately after the value is calculated. 807 * 808 * @return animatedValue The value most recently calculated for the named property 809 * by this <code>ValueAnimator</code>. 810 */ 811 public Object getAnimatedValue(String propertyName) { 812 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 813 if (valuesHolder != null) { 814 return valuesHolder.getAnimatedValue(); 815 } else { 816 // At least avoid crashing if called with bogus propertyName 817 return null; 818 } 819 } 820 821 /** 822 * Sets how many times the animation should be repeated. If the repeat 823 * count is 0, the animation is never repeated. If the repeat count is 824 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 825 * into account. The repeat count is 0 by default. 826 * 827 * @param value the number of times the animation should be repeated 828 */ 829 public void setRepeatCount(int value) { 830 mRepeatCount = value; 831 } 832 /** 833 * Defines how many times the animation should repeat. The default value 834 * is 0. 835 * 836 * @return the number of times the animation should repeat, or {@link #INFINITE} 837 */ 838 public int getRepeatCount() { 839 return mRepeatCount; 840 } 841 842 /** 843 * Defines what this animation should do when it reaches the end. This 844 * setting is applied only when the repeat count is either greater than 845 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 846 * 847 * @param value {@link #RESTART} or {@link #REVERSE} 848 */ 849 public void setRepeatMode(int value) { 850 mRepeatMode = value; 851 } 852 853 /** 854 * Defines what this animation should do when it reaches the end. 855 * 856 * @return either one of {@link #REVERSE} or {@link #RESTART} 857 */ 858 public int getRepeatMode() { 859 return mRepeatMode; 860 } 861 862 /** 863 * Adds a listener to the set of listeners that are sent update events through the life of 864 * an animation. This method is called on all listeners for every frame of the animation, 865 * after the values for the animation have been calculated. 866 * 867 * @param listener the listener to be added to the current set of listeners for this animation. 868 */ 869 public void addUpdateListener(AnimatorUpdateListener listener) { 870 if (mUpdateListeners == null) { 871 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 872 } 873 mUpdateListeners.add(listener); 874 } 875 876 /** 877 * Removes all listeners from the set listening to frame updates for this animation. 878 */ 879 public void removeAllUpdateListeners() { 880 if (mUpdateListeners == null) { 881 return; 882 } 883 mUpdateListeners.clear(); 884 mUpdateListeners = null; 885 } 886 887 /** 888 * Removes a listener from the set listening to frame updates for this animation. 889 * 890 * @param listener the listener to be removed from the current set of update listeners 891 * for this animation. 892 */ 893 public void removeUpdateListener(AnimatorUpdateListener listener) { 894 if (mUpdateListeners == null) { 895 return; 896 } 897 mUpdateListeners.remove(listener); 898 if (mUpdateListeners.size() == 0) { 899 mUpdateListeners = null; 900 } 901 } 902 903 904 /** 905 * The time interpolator used in calculating the elapsed fraction of this animation. The 906 * interpolator determines whether the animation runs with linear or non-linear motion, 907 * such as acceleration and deceleration. The default value is 908 * {@link android.view.animation.AccelerateDecelerateInterpolator} 909 * 910 * @param value the interpolator to be used by this animation 911 */ 912 @Override 913 public void setInterpolator(TimeInterpolator value) { 914 if (value != null) { 915 mInterpolator = value; 916 } 917 } 918 919 /** 920 * Returns the timing interpolator that this ValueAnimator uses. 921 * 922 * @return The timing interpolator for this ValueAnimator. 923 */ 924 public TimeInterpolator getInterpolator() { 925 return mInterpolator; 926 } 927 928 /** 929 * The type evaluator to be used when calculating the animated values of this animation. 930 * The system will automatically assign a float, int, or double evaluator based on the type 931 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 932 * are not one of these primitive types, or if different evaluation is desired (such as is 933 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 934 * For example, when running an animation on color values, the {@link RGBEvaluator} 935 * should be used to get correct RGB color interpolation. 936 * 937 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 938 * will be used for that set. If there are several sets of values being animated, which is 939 * the case if PropertyValuesHOlder objects were set on the ValueAnimator, then the evaluator 940 * is assigned just to the first PropertyValuesHolder object.</p> 941 * 942 * @param value the evaluator to be used this animation 943 */ 944 public void setEvaluator(TypeEvaluator value) { 945 if (value != null && mValues != null && mValues.length > 0) { 946 mValues[0].setEvaluator(value); 947 } 948 } 949 950 /** 951 * Start the animation playing. This version of start() takes a boolean flag that indicates 952 * whether the animation should play in reverse. The flag is usually false, but may be set 953 * to true if called from the reverse() method/ 954 * 955 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 956 */ 957 private void start(boolean playBackwards) { 958 mPlayingBackwards = playBackwards; 959 Looper looper = Looper.getMainLooper(); 960 final boolean isUiThread; 961 if (looper != null) { 962 isUiThread = Thread.currentThread() == looper.getThread(); 963 } else { 964 // ignore check if we don't have a Looper (this isn't an Activity) 965 isUiThread = true; 966 } 967 if ((mStartDelay == 0) && isUiThread) { 968 if (mListeners != null) { 969 ArrayList<AnimatorListener> tmpListeners = 970 (ArrayList<AnimatorListener>) mListeners.clone(); 971 for (AnimatorListener listener : tmpListeners) { 972 listener.onAnimationStart(this); 973 } 974 } 975 // This sets the initial value of the animation, prior to actually starting it running 976 setCurrentPlayTime(getCurrentPlayTime()); 977 } 978 mCurrentIteration = 0; 979 mPlayingState = STOPPED; 980 mStartedDelay = false; 981 sPendingAnimations.get().add(this); 982 AnimationHandler animationHandler = sAnimationHandler.get(); 983 if (animationHandler == null) { 984 animationHandler = new AnimationHandler(); 985 sAnimationHandler.set(animationHandler); 986 } 987 animationHandler.sendEmptyMessage(ANIMATION_START); 988 } 989 990 @Override 991 public void start() { 992 start(false); 993 } 994 995 @Override 996 public void cancel() { 997 if (mListeners != null) { 998 ArrayList<AnimatorListener> tmpListeners = 999 (ArrayList<AnimatorListener>) mListeners.clone(); 1000 for (AnimatorListener listener : tmpListeners) { 1001 listener.onAnimationCancel(this); 1002 } 1003 } 1004 // Just set the CANCELED flag - this causes the animation to end the next time a frame 1005 // is processed. 1006 mPlayingState = CANCELED; 1007 } 1008 1009 @Override 1010 public void end() { 1011 if (!sAnimations.get().contains(this) && !sPendingAnimations.get().contains(this)) { 1012 // Special case if the animation has not yet started; get it ready for ending 1013 mStartedDelay = false; 1014 sPendingAnimations.get().add(this); 1015 AnimationHandler animationHandler = sAnimationHandler.get(); 1016 if (animationHandler == null) { 1017 animationHandler = new AnimationHandler(); 1018 sAnimationHandler.set(animationHandler); 1019 } 1020 animationHandler.sendEmptyMessage(ANIMATION_START); 1021 } 1022 // Just set the ENDED flag - this causes the animation to end the next time a frame 1023 // is processed. 1024 mPlayingState = ENDED; 1025 } 1026 1027 @Override 1028 public boolean isRunning() { 1029 // ENDED or CANCELED indicate that it has been ended or canceled, but not processed yet 1030 return (mPlayingState == RUNNING || mPlayingState == ENDED || mPlayingState == CANCELED); 1031 } 1032 1033 /** 1034 * Plays the ValueAnimator in reverse. If the animation is already running, 1035 * it will stop itself and play backwards from the point reached when reverse was called. 1036 * If the animation is not currently running, then it will start from the end and 1037 * play backwards. This behavior is only set for the current animation; future playing 1038 * of the animation will use the default behavior of playing forward. 1039 */ 1040 public void reverse() { 1041 mPlayingBackwards = !mPlayingBackwards; 1042 if (mPlayingState == RUNNING) { 1043 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 1044 long currentPlayTime = currentTime - mStartTime; 1045 long timeLeft = mDuration - currentPlayTime; 1046 mStartTime = currentTime - timeLeft; 1047 } else { 1048 start(true); 1049 } 1050 } 1051 1052 /** 1053 * Called internally to end an animation by removing it from the animations list. Must be 1054 * called on the UI thread. 1055 */ 1056 private void endAnimation() { 1057 sAnimations.get().remove(this); 1058 mPlayingState = STOPPED; 1059 if (mListeners != null) { 1060 ArrayList<AnimatorListener> tmpListeners = 1061 (ArrayList<AnimatorListener>) mListeners.clone(); 1062 for (AnimatorListener listener : tmpListeners) { 1063 listener.onAnimationEnd(this); 1064 } 1065 } 1066 } 1067 1068 /** 1069 * Called internally to start an animation by adding it to the active animations list. Must be 1070 * called on the UI thread. 1071 */ 1072 private void startAnimation() { 1073 initAnimation(); 1074 sAnimations.get().add(this); 1075 if (mStartDelay > 0 && mListeners != null) { 1076 // Listeners were already notified in start() if startDelay is 0; this is 1077 // just for delayed animations 1078 ArrayList<AnimatorListener> tmpListeners = 1079 (ArrayList<AnimatorListener>) mListeners.clone(); 1080 for (AnimatorListener listener : tmpListeners) { 1081 listener.onAnimationStart(this); 1082 } 1083 } 1084 } 1085 1086 /** 1087 * Internal function called to process an animation frame on an animation that is currently 1088 * sleeping through its <code>startDelay</code> phase. The return value indicates whether it 1089 * should be woken up and put on the active animations queue. 1090 * 1091 * @param currentTime The current animation time, used to calculate whether the animation 1092 * has exceeded its <code>startDelay</code> and should be started. 1093 * @return True if the animation's <code>startDelay</code> has been exceeded and the animation 1094 * should be added to the set of active animations. 1095 */ 1096 private boolean delayedAnimationFrame(long currentTime) { 1097 if (mPlayingState == CANCELED || mPlayingState == ENDED) { 1098 // end the delay, process an animation frame to actually cancel it 1099 return true; 1100 } 1101 if (!mStartedDelay) { 1102 mStartedDelay = true; 1103 mDelayStartTime = currentTime; 1104 } else { 1105 long deltaTime = currentTime - mDelayStartTime; 1106 if (deltaTime > mStartDelay) { 1107 // startDelay ended - start the anim and record the 1108 // mStartTime appropriately 1109 mStartTime = currentTime - (deltaTime - mStartDelay); 1110 mPlayingState = RUNNING; 1111 return true; 1112 } 1113 } 1114 return false; 1115 } 1116 1117 /** 1118 * This internal function processes a single animation frame for a given animation. The 1119 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1120 * elapsed duration, and therefore 1121 * the elapsed fraction, of the animation. The return value indicates whether the animation 1122 * should be ended (which happens when the elapsed time of the animation exceeds the 1123 * animation's duration, including the repeatCount). 1124 * 1125 * @param currentTime The current time, as tracked by the static timing handler 1126 * @return true if the animation's duration, including any repetitions due to 1127 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1128 */ 1129 private boolean animationFrame(long currentTime) { 1130 boolean done = false; 1131 1132 if (mPlayingState == STOPPED) { 1133 mPlayingState = RUNNING; 1134 if (mSeekTime < 0) { 1135 mStartTime = currentTime; 1136 } else { 1137 mStartTime = currentTime - mSeekTime; 1138 // Now that we're playing, reset the seek time 1139 mSeekTime = -1; 1140 } 1141 } 1142 switch (mPlayingState) { 1143 case RUNNING: 1144 case SEEKED: 1145 float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f; 1146 if (fraction >= 1f) { 1147 if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) { 1148 // Time to repeat 1149 if (mListeners != null) { 1150 for (AnimatorListener listener : mListeners) { 1151 listener.onAnimationRepeat(this); 1152 } 1153 } 1154 ++mCurrentIteration; 1155 if (mRepeatMode == REVERSE) { 1156 mPlayingBackwards = mPlayingBackwards ? false : true; 1157 } 1158 // TODO: doesn't account for fraction going Wayyyyy over 1, like 2+ 1159 fraction = fraction - 1f; 1160 mStartTime += mDuration; 1161 } else { 1162 done = true; 1163 fraction = Math.min(fraction, 1.0f); 1164 } 1165 } 1166 if (mPlayingBackwards) { 1167 fraction = 1f - fraction; 1168 } 1169 animateValue(fraction); 1170 break; 1171 case ENDED: 1172 // The final value set on the target varies, depending on whether the animation 1173 // was supposed to repeat an odd number of times 1174 if (mRepeatCount > 0 && (mRepeatCount & 0x01) == 1) { 1175 animateValue(0f); 1176 } else { 1177 animateValue(1f); 1178 } 1179 // Fall through to set done flag 1180 case CANCELED: 1181 done = true; 1182 mPlayingState = STOPPED; 1183 break; 1184 } 1185 1186 return done; 1187 } 1188 1189 /** 1190 * This method is called with the elapsed fraction of the animation during every 1191 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1192 * and then into an animated value (from the evaluator. The function is called mostly during 1193 * animation updates, but it is also called when the <code>end()</code> 1194 * function is called, to set the final value on the property. 1195 * 1196 * <p>Overrides of this method must call the superclass to perform the calculation 1197 * of the animated value.</p> 1198 * 1199 * @param fraction The elapsed fraction of the animation. 1200 */ 1201 void animateValue(float fraction) { 1202 fraction = mInterpolator.getInterpolation(fraction); 1203 int numValues = mValues.length; 1204 for (int i = 0; i < numValues; ++i) { 1205 mValues[i].calculateValue(fraction); 1206 } 1207 if (mUpdateListeners != null) { 1208 int numListeners = mUpdateListeners.size(); 1209 for (int i = 0; i < numListeners; ++i) { 1210 mUpdateListeners.get(i).onAnimationUpdate(this); 1211 } 1212 } 1213 } 1214 1215 @Override 1216 public ValueAnimator clone() { 1217 final ValueAnimator anim = (ValueAnimator) super.clone(); 1218 if (mUpdateListeners != null) { 1219 ArrayList<AnimatorUpdateListener> oldListeners = mUpdateListeners; 1220 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 1221 int numListeners = oldListeners.size(); 1222 for (int i = 0; i < numListeners; ++i) { 1223 anim.mUpdateListeners.add(oldListeners.get(i)); 1224 } 1225 } 1226 anim.mSeekTime = -1; 1227 anim.mPlayingBackwards = false; 1228 anim.mCurrentIteration = 0; 1229 anim.mInitialized = false; 1230 anim.mPlayingState = STOPPED; 1231 anim.mStartedDelay = false; 1232 PropertyValuesHolder[] oldValues = mValues; 1233 if (oldValues != null) { 1234 int numValues = oldValues.length; 1235 anim.mValues = new PropertyValuesHolder[numValues]; 1236 for (int i = 0; i < numValues; ++i) { 1237 anim.mValues[i] = oldValues[i].clone(); 1238 } 1239 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1240 for (int i = 0; i < numValues; ++i) { 1241 PropertyValuesHolder valuesHolder = mValues[i]; 1242 anim.mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 1243 } 1244 } 1245 return anim; 1246 } 1247 1248 /** 1249 * Implementors of this interface can add themselves as update listeners 1250 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1251 * frame, after the current frame's values have been calculated for that 1252 * <code>ValueAnimator</code>. 1253 */ 1254 public static interface AnimatorUpdateListener { 1255 /** 1256 * <p>Notifies the occurrence of another frame of the animation.</p> 1257 * 1258 * @param animation The animation which was repeated. 1259 */ 1260 void onAnimationUpdate(ValueAnimator animation); 1261 1262 } 1263 1264 /** 1265 * Return the number of animations currently running. 1266 * 1267 * Used by StrictMode internally to annotate violations. Only 1268 * called on the main thread. 1269 * 1270 * @hide 1271 */ 1272 public static int getCurrentAnimationsCount() { 1273 return sAnimations.get().size(); 1274 } 1275} 1276