ValueAnimator.java revision 51b3227c2e08143c2e3dde9d51ae5b6fff36693c
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 // The static sAnimationHandler processes the internal timing loop on which all animations 87 // are based 88 private static AnimationHandler sAnimationHandler; 89 90 // The static list of all active animations 91 private static final ArrayList<ValueAnimator> sAnimations = new ArrayList<ValueAnimator>(); 92 93 // The set of animations to be started on the next animation frame 94 private static final ArrayList<ValueAnimator> sPendingAnimations = new ArrayList<ValueAnimator>(); 95 96 // The time interpolator to be used if none is set on the animation 97 private static final TimeInterpolator sDefaultInterpolator = 98 new AccelerateDecelerateInterpolator(); 99 100 // type evaluators for the three primitive types handled by this implementation 101 private static final TypeEvaluator sIntEvaluator = new IntEvaluator(); 102 private static final TypeEvaluator sFloatEvaluator = new FloatEvaluator(); 103 private static final TypeEvaluator sDoubleEvaluator = new DoubleEvaluator(); 104 105 /** 106 * Used to indicate whether the animation is currently playing in reverse. This causes the 107 * elapsed fraction to be inverted to calculate the appropriate values. 108 */ 109 private boolean mPlayingBackwards = false; 110 111 /** 112 * This variable tracks the current iteration that is playing. When mCurrentIteration exceeds the 113 * repeatCount (if repeatCount!=INFINITE), the animation ends 114 */ 115 private int mCurrentIteration = 0; 116 117 /** 118 * Tracks whether a startDelay'd animation has begun playing through the startDelay. 119 */ 120 private boolean mStartedDelay = false; 121 122 /** 123 * Tracks the time at which the animation began playing through its startDelay. This is 124 * different from the mStartTime variable, which is used to track when the animation became 125 * active (which is when the startDelay expired and the animation was added to the active 126 * animations list). 127 */ 128 private long mDelayStartTime; 129 130 /** 131 * Flag that represents the current state of the animation. Used to figure out when to start 132 * an animation (if state == STOPPED). Also used to end an animation that 133 * has been cancel()'d or end()'d since the last animation frame. Possible values are 134 * STOPPED, RUNNING, ENDED, CANCELED. 135 */ 136 private int mPlayingState = STOPPED; 137 138 /** 139 * Internal collections used to avoid set collisions as animations start and end while being 140 * processed. 141 */ 142 private static final ArrayList<ValueAnimator> sEndingAnims = new ArrayList<ValueAnimator>(); 143 private static final ArrayList<ValueAnimator> sDelayedAnims = new ArrayList<ValueAnimator>(); 144 private static final ArrayList<ValueAnimator> sReadyAnims = new ArrayList<ValueAnimator>(); 145 146 /** 147 * Flag that denotes whether the animation is set up and ready to go. Used to 148 * set up animation that has not yet been started. 149 */ 150 boolean mInitialized = false; 151 152 // 153 // Backing variables 154 // 155 156 // How long the animation should last in ms 157 private long mDuration = 300; 158 159 // The amount of time in ms to delay starting the animation after start() is called 160 private long mStartDelay = 0; 161 162 // The number of milliseconds between animation frames 163 private static long sFrameDelay = DEFAULT_FRAME_DELAY; 164 165 // The number of times the animation will repeat. The default is 0, which means the animation 166 // will play only once 167 private int mRepeatCount = 0; 168 169 /** 170 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 171 * animation will start from the beginning on every new cycle. REVERSE means the animation 172 * will reverse directions on each iteration. 173 */ 174 private int mRepeatMode = RESTART; 175 176 /** 177 * The time interpolator to be used. The elapsed fraction of the animation will be passed 178 * through this interpolator to calculate the interpolated fraction, which is then used to 179 * calculate the animated values. 180 */ 181 private TimeInterpolator mInterpolator = sDefaultInterpolator; 182 183 /** 184 * The set of listeners to be sent events through the life of an animation. 185 */ 186 private ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 187 188 /** 189 * The property/value sets being animated. 190 */ 191 PropertyValuesHolder[] mValues; 192 193 /** 194 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 195 * by property name during calls to getAnimatedValue(String). 196 */ 197 HashMap<String, PropertyValuesHolder> mValuesMap; 198 199 /** 200 * Public constants 201 */ 202 203 /** 204 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 205 * or a positive value, the animation restarts from the beginning. 206 */ 207 public static final int RESTART = 1; 208 /** 209 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 210 * or a positive value, the animation reverses direction on every iteration. 211 */ 212 public static final int REVERSE = 2; 213 /** 214 * This value used used with the {@link #setRepeatCount(int)} property to repeat 215 * the animation indefinitely. 216 */ 217 public static final int INFINITE = -1; 218 219 /** 220 * Creates a new ValueAnimator object. This default constructor is primarily for 221 * use internally; the factory methods which take parameters are more generally 222 * useful. 223 */ 224 public ValueAnimator() { 225 } 226 227 /** 228 * Constructs and returns a ValueAnimator that animates between int values. A single 229 * value implies that that value is the one being animated to. However, this is not typically 230 * useful in a ValueAnimator object because there is no way for the object to determine the 231 * starting value for the animation (unlike ObjectAnimator, which can derive that value 232 * from the target object and property being animated). Therefore, there should typically 233 * be two or more values. 234 * 235 * @param values A set of values that the animation will animate between over time. 236 * @return A ValueAnimator object that is set up to animate between the given values. 237 */ 238 public static ValueAnimator ofInt(int... values) { 239 ValueAnimator anim = new ValueAnimator(); 240 anim.setIntValues(values); 241 return anim; 242 } 243 244 /** 245 * Constructs and returns a ValueAnimator that animates between float values. A single 246 * value implies that that value is the one being animated to. However, this is not typically 247 * useful in a ValueAnimator object because there is no way for the object to determine the 248 * starting value for the animation (unlike ObjectAnimator, which can derive that value 249 * from the target object and property being animated). Therefore, there should typically 250 * be two or more values. 251 * 252 * @param values A set of values that the animation will animate between over time. 253 * @return A ValueAnimator object that is set up to animate between the given values. 254 */ 255 public static ValueAnimator ofFloat(float... values) { 256 ValueAnimator anim = new ValueAnimator(); 257 anim.setFloatValues(values); 258 return anim; 259 } 260 261 /** 262 * Constructs and returns a ValueAnimator that animates between double values. A single 263 * value implies that that value is the one being animated to. However, this is not typically 264 * useful in a ValueAnimator object because there is no way for the object to determine the 265 * starting value for the animation (unlike ObjectAnimator, which can derive that value 266 * from the target object and property being animated). Therefore, there should typically 267 * be two or more values. 268 * 269 * @param values A set of values that the animation will animate between over time. 270 * @return A ValueAnimator object that is set up to animate between the given values. 271 */ 272 public static ValueAnimator ofDouble(double... values) { 273 ValueAnimator anim = new ValueAnimator(); 274 anim.setDoubleValues(values); 275 return anim; 276 } 277 278 /** 279 * Constructs and returns a ValueAnimator that animates between long values. A single 280 * value implies that that value is the one being animated to. However, this is not typically 281 * useful in a ValueAnimator object because there is no way for the object to determine the 282 * starting value for the animation (unlike ObjectAnimator, which can derive that value 283 * from the target object and property being animated). Therefore, there should typically 284 * be two or more values. 285 * 286 * @param values A set of values that the animation will animate between over time. 287 * @return A ValueAnimator object that is set up to animate between the given values. 288 */ 289 public static ValueAnimator ofLong(long... values) { 290 ValueAnimator anim = new ValueAnimator(); 291 anim.setLongValues(values); 292 return anim; 293 } 294 295 /** 296 * Constructs and returns a ValueAnimator that animates between the values 297 * specified in the PropertyValuesHolder objects. 298 * 299 * @param values A set of PropertyValuesHolder objects whose values will be animated 300 * between over time. 301 * @return A ValueAnimator object that is set up to animate between the given values. 302 */ 303 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 304 ValueAnimator anim = new ValueAnimator(); 305 anim.setValues(values); 306 return anim; 307 } 308 /** 309 * Constructs and returns a ValueAnimator that animates between Object values. A single 310 * value implies that that value is the one being animated to. However, this is not typically 311 * useful in a ValueAnimator object because there is no way for the object to determine the 312 * starting value for the animation (unlike ObjectAnimator, which can derive that value 313 * from the target object and property being animated). Therefore, there should typically 314 * be two or more values. 315 * 316 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 317 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 318 * to perform that interpolation. 319 * 320 * @param evaluator A TypeEvaluator that will be called on each animation frame to 321 * provide the ncessry interpolation between the Object values to derive the animated 322 * value. 323 * @param values A set of values that the animation will animate between over time. 324 * @return A ValueAnimator object that is set up to animate between the given values. 325 */ 326 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 327 ValueAnimator anim = new ValueAnimator(); 328 anim.setObjectValues(values); 329 anim.setEvaluator(evaluator); 330 return anim; 331 } 332 333 /** 334 * Sets int values that will be animated between. A single 335 * value implies that that value is the one being animated to. However, this is not typically 336 * useful in a ValueAnimator object because there is no way for the object to determine the 337 * starting value for the animation (unlike ObjectAnimator, which can derive that value 338 * from the target object and property being animated). Therefore, there should typically 339 * be two or more values. 340 * 341 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 342 * than one PropertyValuesHolder object, this method will set the values for the first 343 * of those objects.</p> 344 * 345 * @param values A set of values that the animation will animate between over time. 346 */ 347 public void setIntValues(int... values) { 348 if (values == null || values.length == 0) { 349 return; 350 } 351 if (mValues == null || mValues.length == 0) { 352 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofInt("", values)}); 353 } else { 354 PropertyValuesHolder valuesHolder = mValues[0]; 355 valuesHolder.setIntValues(values); 356 } 357 // New property/values/target should cause re-initialization prior to starting 358 mInitialized = false; 359 } 360 361 /** 362 * Sets float values that will be animated between. A single 363 * value implies that that value is the one being animated to. However, this is not typically 364 * useful in a ValueAnimator object because there is no way for the object to determine the 365 * starting value for the animation (unlike ObjectAnimator, which can derive that value 366 * from the target object and property being animated). Therefore, there should typically 367 * be two or more values. 368 * 369 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 370 * than one PropertyValuesHolder object, this method will set the values for the first 371 * of those objects.</p> 372 * 373 * @param values A set of values that the animation will animate between over time. 374 */ 375 public void setFloatValues(float... values) { 376 if (values == null || values.length == 0) { 377 return; 378 } 379 if (mValues == null || mValues.length == 0) { 380 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofFloat("", values)}); 381 } else { 382 PropertyValuesHolder valuesHolder = mValues[0]; 383 valuesHolder.setFloatValues(values); 384 } 385 // New property/values/target should cause re-initialization prior to starting 386 mInitialized = false; 387 } 388 389 /** 390 * Sets long values that will be animated between. A single 391 * value implies that that value is the one being animated to. However, this is not typically 392 * useful in a ValueAnimator object because there is no way for the object to determine the 393 * starting value for the animation (unlike ObjectAnimator, which can derive that value 394 * from the target object and property being animated). Therefore, there should typically 395 * be two or more values. 396 * 397 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 398 * than one PropertyValuesHolder object, this method will set the values for the first 399 * of those objects.</p> 400 * 401 * @param values A set of values that the animation will animate between over time. 402 */ 403 public void setLongValues(long... values) { 404 if (values == null || values.length == 0) { 405 return; 406 } 407 if (mValues == null || mValues.length == 0) { 408 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofLong("", values)}); 409 } else { 410 PropertyValuesHolder valuesHolder = mValues[0]; 411 valuesHolder.setLongValues(values); 412 } 413 // New property/values/target should cause re-initialization prior to starting 414 mInitialized = false; 415 } 416 417 /** 418 * Sets double values that will be animated between. A single 419 * value implies that that value is the one being animated to. However, this is not typically 420 * useful in a ValueAnimator object because there is no way for the object to determine the 421 * starting value for the animation (unlike ObjectAnimator, which can derive that value 422 * from the target object and property being animated). Therefore, there should typically 423 * be two or more values. 424 * 425 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 426 * than one PropertyValuesHolder object, this method will set the values for the first 427 * of those objects.</p> 428 * 429 * @param values A set of values that the animation will animate between over time. 430 */ 431 public void setDoubleValues(double... values) { 432 if (values == null || values.length == 0) { 433 return; 434 } 435 if (mValues == null || mValues.length == 0) { 436 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofDouble("", values)}); 437 } else { 438 PropertyValuesHolder valuesHolder = mValues[0]; 439 valuesHolder.setDoubleValues(values); 440 } 441 // New property/values/target should cause re-initialization prior to starting 442 mInitialized = false; 443 } 444 445 /** 446 * Sets the values to animate between for this animation. A single 447 * value implies that that value is the one being animated to. However, this is not typically 448 * useful in a ValueAnimator object because there is no way for the object to determine the 449 * starting value for the animation (unlike ObjectAnimator, which can derive that value 450 * from the target object and property being animated). Therefore, there should typically 451 * be two or more values. 452 * 453 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 454 * than one PropertyValuesHolder object, this method will set the values for the first 455 * of those objects.</p> 456 * 457 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 458 * between these value objects. ValueAnimator only knows how to interpolate between the 459 * primitive types specified in the other setValues() methods.</p> 460 * 461 * @param values The set of values to animate between. 462 */ 463 public void setObjectValues(Object... values) { 464 if (values == null || values.length == 0) { 465 return; 466 } 467 if (mValues == null || mValues.length == 0) { 468 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofObject("", 469 (TypeEvaluator)null, values)}); 470 } else { 471 PropertyValuesHolder valuesHolder = mValues[0]; 472 valuesHolder.setObjectValues(values); 473 } 474 // New property/values/target should cause re-initialization prior to starting 475 mInitialized = false; 476 } 477 478 /** 479 * Sets the values, per property, being animated between. This function is called internally 480 * by the constructors of ValueAnimator that take a list of values. But an ValueAnimator can 481 * be constructed without values and this method can be called to set the values manually 482 * instead. 483 * 484 * @param values The set of values, per property, being animated between. 485 */ 486 public void setValues(PropertyValuesHolder... values) { 487 int numValues = values.length; 488 mValues = values; 489 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 490 for (int i = 0; i < numValues; ++i) { 491 PropertyValuesHolder valuesHolder = (PropertyValuesHolder) values[i]; 492 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 493 } 494 // New property/values/target should cause re-initialization prior to starting 495 mInitialized = false; 496 } 497 498 /** 499 * Returns the values that this ValueAnimator animates between. These values are stored in 500 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 501 * of value objects instead. 502 * 503 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 504 * values, per property, that define the animation. 505 */ 506 public PropertyValuesHolder[] getValues() { 507 return mValues; 508 } 509 510 /** 511 * This function is called immediately before processing the first animation 512 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 513 * function is called after that delay ends. 514 * It takes care of the final initialization steps for the 515 * animation. 516 * 517 * <p>Overrides of this method should call the superclass method to ensure 518 * that internal mechanisms for the animation are set up correctly.</p> 519 */ 520 void initAnimation() { 521 if (!mInitialized) { 522 int numValues = mValues.length; 523 for (int i = 0; i < numValues; ++i) { 524 mValues[i].init(); 525 } 526 mCurrentIteration = 0; 527 mInitialized = true; 528 } 529 } 530 531 532 /** 533 * Sets the length of the animation. The default duration is 300 milliseconds. 534 * 535 * @param duration The length of the animation, in milliseconds. 536 * @return ValueAnimator The object called with setDuration(). This return 537 * value makes it easier to compose statements together that construct and then set the 538 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 539 */ 540 public ValueAnimator setDuration(long duration) { 541 mDuration = duration; 542 return this; 543 } 544 545 /** 546 * Gets the length of the animation. The default duration is 300 milliseconds. 547 * 548 * @return The length of the animation, in milliseconds. 549 */ 550 public long getDuration() { 551 return mDuration; 552 } 553 554 /** 555 * Sets the position of the animation to the specified point in time. This time should 556 * be between 0 and the total duration of the animation, including any repetition. If 557 * the animation has not yet been started, then it will not advance forward after it is 558 * set to this time; it will simply set the time to this value and perform any appropriate 559 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 560 * will set the current playing time to this value and continue playing from that point. 561 * 562 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 563 */ 564 public void setCurrentPlayTime(long playTime) { 565 initAnimation(); 566 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 567 if (mPlayingState != RUNNING) { 568 mSeekTime = playTime; 569 mPlayingState = SEEKED; 570 } 571 mStartTime = currentTime - playTime; 572 animationFrame(currentTime); 573 } 574 575 /** 576 * Gets the current position of the animation in time, which is equal to the current 577 * time minus the time that the animation started. An animation that is not yet started will 578 * return a value of zero. 579 * 580 * @return The current position in time of the animation. 581 */ 582 public long getCurrentPlayTime() { 583 if (!mInitialized || mPlayingState == STOPPED) { 584 return 0; 585 } 586 return AnimationUtils.currentAnimationTimeMillis() - mStartTime; 587 } 588 589 /** 590 * This custom, static handler handles the timing pulse that is shared by 591 * all active animations. This approach ensures that the setting of animation 592 * values will happen on the UI thread and that all animations will share 593 * the same times for calculating their values, which makes synchronizing 594 * animations possible. 595 * 596 */ 597 private static class AnimationHandler extends Handler { 598 /** 599 * There are only two messages that we care about: ANIMATION_START and 600 * ANIMATION_FRAME. The START message is sent when an animation's start() 601 * method is called. It cannot start synchronously when start() is called 602 * because the call may be on the wrong thread, and it would also not be 603 * synchronized with other animations because it would not start on a common 604 * timing pulse. So each animation sends a START message to the handler, which 605 * causes the handler to place the animation on the active animations queue and 606 * start processing frames for that animation. 607 * The FRAME message is the one that is sent over and over while there are any 608 * active animations to process. 609 */ 610 @Override 611 public void handleMessage(Message msg) { 612 boolean callAgain = true; 613 switch (msg.what) { 614 // TODO: should we avoid sending frame message when starting if we 615 // were already running? 616 case ANIMATION_START: 617 if (sAnimations.size() > 0 || sDelayedAnims.size() > 0) { 618 callAgain = false; 619 } 620 // pendingAnims holds any animations that have requested to be started 621 // We're going to clear sPendingAnimations, but starting animation may 622 // cause more to be added to the pending list (for example, if one animation 623 // starting triggers another starting). So we loop until sPendingAnimations 624 // is empty. 625 while (sPendingAnimations.size() > 0) { 626 ArrayList<ValueAnimator> pendingCopy = 627 (ArrayList<ValueAnimator>) sPendingAnimations.clone(); 628 sPendingAnimations.clear(); 629 int count = pendingCopy.size(); 630 for (int i = 0; i < count; ++i) { 631 ValueAnimator anim = pendingCopy.get(i); 632 // If the animation has a startDelay, place it on the delayed list 633 if (anim.mStartDelay == 0 || anim.mPlayingState == ENDED || 634 anim.mPlayingState == CANCELED) { 635 anim.startAnimation(); 636 } else { 637 sDelayedAnims.add(anim); 638 } 639 } 640 } 641 // fall through to process first frame of new animations 642 case ANIMATION_FRAME: 643 // currentTime holds the common time for all animations processed 644 // during this frame 645 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 646 647 // First, process animations currently sitting on the delayed queue, adding 648 // them to the active animations if they are ready 649 int numDelayedAnims = sDelayedAnims.size(); 650 for (int i = 0; i < numDelayedAnims; ++i) { 651 ValueAnimator anim = sDelayedAnims.get(i); 652 if (anim.delayedAnimationFrame(currentTime)) { 653 sReadyAnims.add(anim); 654 } 655 } 656 int numReadyAnims = sReadyAnims.size(); 657 if (numReadyAnims > 0) { 658 for (int i = 0; i < numReadyAnims; ++i) { 659 ValueAnimator anim = sReadyAnims.get(i); 660 anim.startAnimation(); 661 sDelayedAnims.remove(anim); 662 } 663 sReadyAnims.clear(); 664 } 665 666 // Now process all active animations. The return value from animationFrame() 667 // tells the handler whether it should now be ended 668 int numAnims = sAnimations.size(); 669 for (int i = 0; i < numAnims; ++i) { 670 ValueAnimator anim = sAnimations.get(i); 671 if (anim.animationFrame(currentTime)) { 672 sEndingAnims.add(anim); 673 } 674 } 675 if (sEndingAnims.size() > 0) { 676 for (int i = 0; i < sEndingAnims.size(); ++i) { 677 sEndingAnims.get(i).endAnimation(); 678 } 679 sEndingAnims.clear(); 680 } 681 682 // If there are still active or delayed animations, call the handler again 683 // after the frameDelay 684 if (callAgain && (!sAnimations.isEmpty() || !sDelayedAnims.isEmpty())) { 685 sendEmptyMessageDelayed(ANIMATION_FRAME, Math.max(0, sFrameDelay - 686 (AnimationUtils.currentAnimationTimeMillis() - currentTime))); 687 } 688 break; 689 } 690 } 691 } 692 693 /** 694 * The amount of time, in milliseconds, to delay starting the animation after 695 * {@link #start()} is called. 696 * 697 * @return the number of milliseconds to delay running the animation 698 */ 699 public long getStartDelay() { 700 return mStartDelay; 701 } 702 703 /** 704 * The amount of time, in milliseconds, to delay starting the animation after 705 * {@link #start()} is called. 706 707 * @param startDelay The amount of the delay, in milliseconds 708 */ 709 public void setStartDelay(long startDelay) { 710 this.mStartDelay = startDelay; 711 } 712 713 /** 714 * The amount of time, in milliseconds, between each frame of the animation. This is a 715 * requested time that the animation will attempt to honor, but the actual delay between 716 * frames may be different, depending on system load and capabilities. This is a static 717 * function because the same delay will be applied to all animations, since they are all 718 * run off of a single timing loop. 719 * 720 * @return the requested time between frames, in milliseconds 721 */ 722 public static long getFrameDelay() { 723 return sFrameDelay; 724 } 725 726 /** 727 * The amount of time, in milliseconds, between each frame of the animation. This is a 728 * requested time that the animation will attempt to honor, but the actual delay between 729 * frames may be different, depending on system load and capabilities. This is a static 730 * function because the same delay will be applied to all animations, since they are all 731 * run off of a single timing loop. 732 * 733 * @param frameDelay the requested time between frames, in milliseconds 734 */ 735 public static void setFrameDelay(long frameDelay) { 736 sFrameDelay = frameDelay; 737 } 738 739 /** 740 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 741 * property being animated. This value is only sensible while the animation is running. The main 742 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 743 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 744 * is called during each animation frame, immediately after the value is calculated. 745 * 746 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 747 * the single property being animated. If there are several properties being animated 748 * (specified by several PropertyValuesHolder objects in the constructor), this function 749 * returns the animated value for the first of those objects. 750 */ 751 public Object getAnimatedValue() { 752 if (mValues != null && mValues.length > 0) { 753 return mValues[0].getAnimatedValue(); 754 } 755 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 756 return null; 757 } 758 759 /** 760 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 761 * The main purpose for this read-only property is to retrieve the value from the 762 * <code>ValueAnimator</code> during a call to 763 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 764 * is called during each animation frame, immediately after the value is calculated. 765 * 766 * @return animatedValue The value most recently calculated for the named property 767 * by this <code>ValueAnimator</code>. 768 */ 769 public Object getAnimatedValue(String propertyName) { 770 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 771 if (valuesHolder != null) { 772 return valuesHolder.getAnimatedValue(); 773 } else { 774 // At least avoid crashing if called with bogus propertyName 775 return null; 776 } 777 } 778 779 /** 780 * Sets how many times the animation should be repeated. If the repeat 781 * count is 0, the animation is never repeated. If the repeat count is 782 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 783 * into account. The repeat count is 0 by default. 784 * 785 * @param value the number of times the animation should be repeated 786 */ 787 public void setRepeatCount(int value) { 788 mRepeatCount = value; 789 } 790 /** 791 * Defines how many times the animation should repeat. The default value 792 * is 0. 793 * 794 * @return the number of times the animation should repeat, or {@link #INFINITE} 795 */ 796 public int getRepeatCount() { 797 return mRepeatCount; 798 } 799 800 /** 801 * Defines what this animation should do when it reaches the end. This 802 * setting is applied only when the repeat count is either greater than 803 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 804 * 805 * @param value {@link #RESTART} or {@link #REVERSE} 806 */ 807 public void setRepeatMode(int value) { 808 mRepeatMode = value; 809 } 810 811 /** 812 * Defines what this animation should do when it reaches the end. 813 * 814 * @return either one of {@link #REVERSE} or {@link #RESTART} 815 */ 816 public int getRepeatMode() { 817 return mRepeatMode; 818 } 819 820 /** 821 * Adds a listener to the set of listeners that are sent update events through the life of 822 * an animation. This method is called on all listeners for every frame of the animation, 823 * after the values for the animation have been calculated. 824 * 825 * @param listener the listener to be added to the current set of listeners for this animation. 826 */ 827 public void addUpdateListener(AnimatorUpdateListener listener) { 828 if (mUpdateListeners == null) { 829 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 830 } 831 mUpdateListeners.add(listener); 832 } 833 834 /** 835 * Removes all listeners from the set listening to frame updates for this animation. 836 */ 837 public void removeAllUpdateListeners() { 838 if (mUpdateListeners == null) { 839 return; 840 } 841 mUpdateListeners.clear(); 842 mUpdateListeners = null; 843 } 844 845 /** 846 * Removes a listener from the set listening to frame updates for this animation. 847 * 848 * @param listener the listener to be removed from the current set of update listeners 849 * for this animation. 850 */ 851 public void removeUpdateListener(AnimatorUpdateListener listener) { 852 if (mUpdateListeners == null) { 853 return; 854 } 855 mUpdateListeners.remove(listener); 856 if (mUpdateListeners.size() == 0) { 857 mUpdateListeners = null; 858 } 859 } 860 861 862 /** 863 * The time interpolator used in calculating the elapsed fraction of this animation. The 864 * interpolator determines whether the animation runs with linear or non-linear motion, 865 * such as acceleration and deceleration. The default value is 866 * {@link android.view.animation.AccelerateDecelerateInterpolator} 867 * 868 * @param value the interpolator to be used by this animation 869 */ 870 @Override 871 public void setInterpolator(TimeInterpolator value) { 872 if (value != null) { 873 mInterpolator = value; 874 } 875 } 876 877 /** 878 * Returns the timing interpolator that this ValueAnimator uses. 879 * 880 * @return The timing interpolator for this ValueAnimator. 881 */ 882 public TimeInterpolator getInterpolator() { 883 return mInterpolator; 884 } 885 886 /** 887 * The type evaluator to be used when calculating the animated values of this animation. 888 * The system will automatically assign a float, int, or double evaluator based on the type 889 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 890 * are not one of these primitive types, or if different evaluation is desired (such as is 891 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 892 * For example, when running an animation on color values, the {@link RGBEvaluator} 893 * should be used to get correct RGB color interpolation. 894 * 895 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 896 * will be used for that set. If there are several sets of values being animated, which is 897 * the case if PropertyValuesHOlder objects were set on the ValueAnimator, then the evaluator 898 * is assigned just to the first PropertyValuesHolder object.</p> 899 * 900 * @param value the evaluator to be used this animation 901 */ 902 public void setEvaluator(TypeEvaluator value) { 903 if (value != null && mValues != null && mValues.length > 0) { 904 mValues[0].setEvaluator(value); 905 } 906 } 907 908 /** 909 * Start the animation playing. This version of start() takes a boolean flag that indicates 910 * whether the animation should play in reverse. The flag is usually false, but may be set 911 * to true if called from the reverse() method/ 912 * 913 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 914 */ 915 private void start(boolean playBackwards) { 916 mPlayingBackwards = playBackwards; 917 Looper looper = Looper.getMainLooper(); 918 final boolean isUiThread; 919 if (looper != null) { 920 isUiThread = Thread.currentThread() == looper.getThread(); 921 } else { 922 // ignore check if we don't have a Looper (this isn't an Activity) 923 isUiThread = true; 924 } 925 if ((mStartDelay == 0) && isUiThread) { 926 if (mListeners != null) { 927 ArrayList<AnimatorListener> tmpListeners = 928 (ArrayList<AnimatorListener>) mListeners.clone(); 929 for (AnimatorListener listener : tmpListeners) { 930 listener.onAnimationStart(this); 931 } 932 } 933 // This sets the initial value of the animation, prior to actually starting it running 934 setCurrentPlayTime(getCurrentPlayTime()); 935 } 936 mPlayingState = STOPPED; 937 mStartedDelay = false; 938 sPendingAnimations.add(this); 939 if (sAnimationHandler == null) { 940 sAnimationHandler = new AnimationHandler(); 941 } 942 // TODO: does this put too many messages on the queue if the handler 943 // is already running? 944 sAnimationHandler.sendEmptyMessage(ANIMATION_START); 945 } 946 947 @Override 948 public void start() { 949 start(false); 950 } 951 952 @Override 953 public void cancel() { 954 if (mListeners != null) { 955 ArrayList<AnimatorListener> tmpListeners = 956 (ArrayList<AnimatorListener>) mListeners.clone(); 957 for (AnimatorListener listener : tmpListeners) { 958 listener.onAnimationCancel(this); 959 } 960 } 961 // Just set the CANCELED flag - this causes the animation to end the next time a frame 962 // is processed. 963 mPlayingState = CANCELED; 964 } 965 966 @Override 967 public void end() { 968 if (!sAnimations.contains(this) && !sPendingAnimations.contains(this)) { 969 // Special case if the animation has not yet started; get it ready for ending 970 mStartedDelay = false; 971 sPendingAnimations.add(this); 972 if (sAnimationHandler == null) { 973 sAnimationHandler = new AnimationHandler(); 974 } 975 sAnimationHandler.sendEmptyMessage(ANIMATION_START); 976 } 977 // Just set the ENDED flag - this causes the animation to end the next time a frame 978 // is processed. 979 mPlayingState = ENDED; 980 } 981 982 @Override 983 public boolean isRunning() { 984 // ENDED or CANCELED indicate that it has been ended or canceled, but not processed yet 985 return (mPlayingState == RUNNING || mPlayingState == ENDED || mPlayingState == CANCELED); 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.remove(this); 1013 mPlayingState = STOPPED; 1014 if (mListeners != null) { 1015 ArrayList<AnimatorListener> tmpListeners = 1016 (ArrayList<AnimatorListener>) mListeners.clone(); 1017 for (AnimatorListener listener : tmpListeners) { 1018 listener.onAnimationEnd(this); 1019 } 1020 } 1021 } 1022 1023 /** 1024 * Called internally to start an animation by adding it to the active animations list. Must be 1025 * called on the UI thread. 1026 */ 1027 private void startAnimation() { 1028 initAnimation(); 1029 sAnimations.add(this); 1030 if (mStartDelay > 0 && mListeners != null) { 1031 // Listeners were already notified in start() if startDelay is 0; this is 1032 // just for delayed animations 1033 ArrayList<AnimatorListener> tmpListeners = 1034 (ArrayList<AnimatorListener>) mListeners.clone(); 1035 for (AnimatorListener listener : tmpListeners) { 1036 listener.onAnimationStart(this); 1037 } 1038 } 1039 } 1040 1041 /** 1042 * Internal function called to process an animation frame on an animation that is currently 1043 * sleeping through its <code>startDelay</code> phase. The return value indicates whether it 1044 * should be woken up and put on the active animations queue. 1045 * 1046 * @param currentTime The current animation time, used to calculate whether the animation 1047 * has exceeded its <code>startDelay</code> and should be started. 1048 * @return True if the animation's <code>startDelay</code> has been exceeded and the animation 1049 * should be added to the set of active animations. 1050 */ 1051 private boolean delayedAnimationFrame(long currentTime) { 1052 if (mPlayingState == CANCELED || mPlayingState == ENDED) { 1053 // end the delay, process an animation frame to actually cancel it 1054 return true; 1055 } 1056 if (!mStartedDelay) { 1057 mStartedDelay = true; 1058 mDelayStartTime = currentTime; 1059 } else { 1060 long deltaTime = currentTime - mDelayStartTime; 1061 if (deltaTime > mStartDelay) { 1062 // startDelay ended - start the anim and record the 1063 // mStartTime appropriately 1064 mStartTime = currentTime - (deltaTime - mStartDelay); 1065 mPlayingState = RUNNING; 1066 return true; 1067 } 1068 } 1069 return false; 1070 } 1071 1072 /** 1073 * This internal function processes a single animation frame for a given animation. The 1074 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1075 * elapsed duration, and therefore 1076 * the elapsed fraction, of the animation. The return value indicates whether the animation 1077 * should be ended (which happens when the elapsed time of the animation exceeds the 1078 * animation's duration, including the repeatCount). 1079 * 1080 * @param currentTime The current time, as tracked by the static timing handler 1081 * @return true if the animation's duration, including any repetitions due to 1082 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1083 */ 1084 private boolean animationFrame(long currentTime) { 1085 boolean done = false; 1086 1087 if (mPlayingState == STOPPED) { 1088 mPlayingState = RUNNING; 1089 if (mSeekTime < 0) { 1090 mStartTime = currentTime; 1091 } else { 1092 mStartTime = currentTime - mSeekTime; 1093 // Now that we're playing, reset the seek time 1094 mSeekTime = -1; 1095 } 1096 } 1097 switch (mPlayingState) { 1098 case RUNNING: 1099 case SEEKED: 1100 float fraction = (float)(currentTime - mStartTime) / mDuration; 1101 if (fraction >= 1f) { 1102 if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) { 1103 // Time to repeat 1104 if (mListeners != null) { 1105 for (AnimatorListener listener : mListeners) { 1106 listener.onAnimationRepeat(this); 1107 } 1108 } 1109 ++mCurrentIteration; 1110 if (mRepeatMode == REVERSE) { 1111 mPlayingBackwards = mPlayingBackwards ? false : true; 1112 } 1113 // TODO: doesn't account for fraction going Wayyyyy over 1, like 2+ 1114 fraction = fraction - 1f; 1115 mStartTime += mDuration; 1116 } else { 1117 done = true; 1118 fraction = Math.min(fraction, 1.0f); 1119 } 1120 } 1121 if (mPlayingBackwards) { 1122 fraction = 1f - fraction; 1123 } 1124 animateValue(fraction); 1125 break; 1126 case ENDED: 1127 // The final value set on the target varies, depending on whether the animation 1128 // was supposed to repeat an odd number of times 1129 if (mRepeatCount > 0 && (mRepeatCount & 0x01) == 1) { 1130 animateValue(0f); 1131 } else { 1132 animateValue(1f); 1133 } 1134 // Fall through to set done flag 1135 case CANCELED: 1136 done = true; 1137 mPlayingState = STOPPED; 1138 break; 1139 } 1140 1141 return done; 1142 } 1143 1144 /** 1145 * This method is called with the elapsed fraction of the animation during every 1146 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1147 * and then into an animated value (from the evaluator. The function is called mostly during 1148 * animation updates, but it is also called when the <code>end()</code> 1149 * function is called, to set the final value on the property. 1150 * 1151 * <p>Overrides of this method must call the superclass to perform the calculation 1152 * of the animated value.</p> 1153 * 1154 * @param fraction The elapsed fraction of the animation. 1155 */ 1156 void animateValue(float fraction) { 1157 fraction = mInterpolator.getInterpolation(fraction); 1158 int numValues = mValues.length; 1159 for (int i = 0; i < numValues; ++i) { 1160 mValues[i].calculateValue(fraction); 1161 } 1162 if (mUpdateListeners != null) { 1163 int numListeners = mUpdateListeners.size(); 1164 for (int i = 0; i < numListeners; ++i) { 1165 mUpdateListeners.get(i).onAnimationUpdate(this); 1166 } 1167 } 1168 } 1169 1170 @Override 1171 public ValueAnimator clone() { 1172 final ValueAnimator anim = (ValueAnimator) super.clone(); 1173 if (mUpdateListeners != null) { 1174 ArrayList<AnimatorUpdateListener> oldListeners = mUpdateListeners; 1175 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 1176 int numListeners = oldListeners.size(); 1177 for (int i = 0; i < numListeners; ++i) { 1178 anim.mUpdateListeners.add(oldListeners.get(i)); 1179 } 1180 } 1181 anim.mSeekTime = -1; 1182 anim.mPlayingBackwards = false; 1183 anim.mCurrentIteration = 0; 1184 anim.mInitialized = false; 1185 anim.mPlayingState = STOPPED; 1186 anim.mStartedDelay = false; 1187 PropertyValuesHolder[] oldValues = mValues; 1188 if (oldValues != null) { 1189 int numValues = oldValues.length; 1190 anim.mValues = new PropertyValuesHolder[numValues]; 1191 for (int i = 0; i < numValues; ++i) { 1192 anim.mValues[i] = oldValues[i].clone(); 1193 } 1194 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1195 for (int i = 0; i < numValues; ++i) { 1196 PropertyValuesHolder valuesHolder = mValues[i]; 1197 anim.mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 1198 } 1199 } 1200 return anim; 1201 } 1202 1203 /** 1204 * Implementors of this interface can add themselves as update listeners 1205 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1206 * frame, after the current frame's values have been calculated for that 1207 * <code>ValueAnimator</code>. 1208 */ 1209 public static interface AnimatorUpdateListener { 1210 /** 1211 * <p>Notifies the occurrence of another frame of the animation.</p> 1212 * 1213 * @param animation The animation which was repeated. 1214 */ 1215 void onAnimationUpdate(ValueAnimator animation); 1216 1217 } 1218}