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 17 package android.animation; 18 19 import android.os.Looper; 20 import android.os.Trace; 21 import android.util.AndroidRuntimeException; 22 import android.view.Choreographer; 23 import android.view.animation.AccelerateDecelerateInterpolator; 24 import android.view.animation.AnimationUtils; 25 import android.view.animation.LinearInterpolator; 26 27 import java.util.ArrayList; 28 import java.util.HashMap; 29 30 /** 31 * This class provides a simple timing engine for running animations 32 * which calculate animated values and set them on target objects. 33 * 34 * <p>There is a single timing pulse that all animations use. It runs in a 35 * custom handler to ensure that property changes happen on the UI thread.</p> 36 * 37 * <p>By default, ValueAnimator uses non-linear time interpolation, via the 38 * {@link AccelerateDecelerateInterpolator} class, which accelerates into and decelerates 39 * out of an animation. This behavior can be changed by calling 40 * {@link ValueAnimator#setInterpolator(TimeInterpolator)}.</p> 41 * 42 * <div class="special reference"> 43 * <h3>Developer Guides</h3> 44 * <p>For more information about animating with {@code ValueAnimator}, read the 45 * <a href="{@docRoot}guide/topics/graphics/prop-animation.html#value-animator">Property 46 * Animation</a> developer guide.</p> 47 * </div> 48 */ 49 @SuppressWarnings("unchecked") 50 public class ValueAnimator extends Animator { 51 52 /** 53 * Internal constants 54 */ 55 private static float sDurationScale = 1.0f; 56 57 /** 58 * Values used with internal variable mPlayingState to indicate the current state of an 59 * animation. 60 */ 61 static final int STOPPED = 0; // Not yet playing 62 static final int RUNNING = 1; // Playing normally 63 static final int SEEKED = 2; // Seeked to some time value 64 65 /** 66 * Internal variables 67 * NOTE: This object implements the clone() method, making a deep copy of any referenced 68 * objects. As other non-trivial fields are added to this class, make sure to add logic 69 * to clone() to make deep copies of them. 70 */ 71 72 // The first time that the animation's animateFrame() method is called. This time is used to 73 // determine elapsed time (and therefore the elapsed fraction) in subsequent calls 74 // to animateFrame() 75 long mStartTime; 76 77 /** 78 * Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked 79 * to a value. 80 */ 81 long mSeekTime = -1; 82 83 // The static sAnimationHandler processes the internal timing loop on which all animations 84 // are based 85 /** 86 * @hide 87 */ 88 protected static ThreadLocal<AnimationHandler> sAnimationHandler = 89 new ThreadLocal<AnimationHandler>(); 90 91 // The time interpolator to be used if none is set on the animation 92 private static final TimeInterpolator sDefaultInterpolator = 93 new AccelerateDecelerateInterpolator(); 94 95 /** 96 * Used to indicate whether the animation is currently playing in reverse. This causes the 97 * elapsed fraction to be inverted to calculate the appropriate values. 98 */ 99 private boolean mPlayingBackwards = false; 100 101 /** 102 * This variable tracks the current iteration that is playing. When mCurrentIteration exceeds the 103 * repeatCount (if repeatCount!=INFINITE), the animation ends 104 */ 105 private int mCurrentIteration = 0; 106 107 /** 108 * Tracks current elapsed/eased fraction, for querying in getAnimatedFraction(). 109 */ 110 private float mCurrentFraction = 0f; 111 112 /** 113 * Tracks whether a startDelay'd animation has begun playing through the startDelay. 114 */ 115 private boolean mStartedDelay = false; 116 117 /** 118 * Tracks the time at which the animation began playing through its startDelay. This is 119 * different from the mStartTime variable, which is used to track when the animation became 120 * active (which is when the startDelay expired and the animation was added to the active 121 * animations list). 122 */ 123 private long mDelayStartTime; 124 125 /** 126 * Flag that represents the current state of the animation. Used to figure out when to start 127 * an animation (if state == STOPPED). Also used to end an animation that 128 * has been cancel()'d or end()'d since the last animation frame. Possible values are 129 * STOPPED, RUNNING, SEEKED. 130 */ 131 int mPlayingState = STOPPED; 132 133 /** 134 * Additional playing state to indicate whether an animator has been start()'d. There is 135 * some lag between a call to start() and the first animation frame. We should still note 136 * that the animation has been started, even if it's first animation frame has not yet 137 * happened, and reflect that state in isRunning(). 138 * Note that delayed animations are different: they are not started until their first 139 * animation frame, which occurs after their delay elapses. 140 */ 141 private boolean mRunning = false; 142 143 /** 144 * Additional playing state to indicate whether an animator has been start()'d, whether or 145 * not there is a nonzero startDelay. 146 */ 147 private boolean mStarted = false; 148 149 /** 150 * Tracks whether we've notified listeners of the onAnimationSTart() event. This can be 151 * complex to keep track of since we notify listeners at different times depending on 152 * startDelay and whether start() was called before end(). 153 */ 154 private boolean mStartListenersCalled = false; 155 156 /** 157 * Flag that denotes whether the animation is set up and ready to go. Used to 158 * set up animation that has not yet been started. 159 */ 160 boolean mInitialized = false; 161 162 // 163 // Backing variables 164 // 165 166 // How long the animation should last in ms 167 private long mDuration = (long)(300 * sDurationScale); 168 private long mUnscaledDuration = 300; 169 170 // The amount of time in ms to delay starting the animation after start() is called 171 private long mStartDelay = 0; 172 private long mUnscaledStartDelay = 0; 173 174 // The number of times the animation will repeat. The default is 0, which means the animation 175 // will play only once 176 private int mRepeatCount = 0; 177 178 /** 179 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 180 * animation will start from the beginning on every new cycle. REVERSE means the animation 181 * will reverse directions on each iteration. 182 */ 183 private int mRepeatMode = RESTART; 184 185 /** 186 * The time interpolator to be used. The elapsed fraction of the animation will be passed 187 * through this interpolator to calculate the interpolated fraction, which is then used to 188 * calculate the animated values. 189 */ 190 private TimeInterpolator mInterpolator = sDefaultInterpolator; 191 192 /** 193 * The set of listeners to be sent events through the life of an animation. 194 */ 195 private ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 196 197 /** 198 * The property/value sets being animated. 199 */ 200 PropertyValuesHolder[] mValues; 201 202 /** 203 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 204 * by property name during calls to getAnimatedValue(String). 205 */ 206 HashMap<String, PropertyValuesHolder> mValuesMap; 207 208 /** 209 * Public constants 210 */ 211 212 /** 213 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 214 * or a positive value, the animation restarts from the beginning. 215 */ 216 public static final int RESTART = 1; 217 /** 218 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 219 * or a positive value, the animation reverses direction on every iteration. 220 */ 221 public static final int REVERSE = 2; 222 /** 223 * This value used used with the {@link #setRepeatCount(int)} property to repeat 224 * the animation indefinitely. 225 */ 226 public static final int INFINITE = -1; 227 228 229 /** 230 * @hide 231 */ 232 public static void setDurationScale(float durationScale) { 233 sDurationScale = durationScale; 234 } 235 236 /** 237 * @hide 238 */ 239 public static float getDurationScale() { 240 return sDurationScale; 241 } 242 243 /** 244 * Creates a new ValueAnimator object. This default constructor is primarily for 245 * use internally; the factory methods which take parameters are more generally 246 * useful. 247 */ 248 public ValueAnimator() { 249 } 250 251 /** 252 * Constructs and returns a ValueAnimator that animates between int values. A single 253 * value implies that that value is the one being animated to. However, this is not typically 254 * useful in a ValueAnimator object because there is no way for the object to determine the 255 * starting value for the animation (unlike ObjectAnimator, which can derive that value 256 * from the target object and property being animated). Therefore, there should typically 257 * be two or more values. 258 * 259 * @param values A set of values that the animation will animate between over time. 260 * @return A ValueAnimator object that is set up to animate between the given values. 261 */ 262 public static ValueAnimator ofInt(int... values) { 263 ValueAnimator anim = new ValueAnimator(); 264 anim.setIntValues(values); 265 return anim; 266 } 267 268 /** 269 * Constructs and returns a ValueAnimator that animates between float values. A single 270 * value implies that that value is the one being animated to. However, this is not typically 271 * useful in a ValueAnimator object because there is no way for the object to determine the 272 * starting value for the animation (unlike ObjectAnimator, which can derive that value 273 * from the target object and property being animated). Therefore, there should typically 274 * be two or more values. 275 * 276 * @param values A set of values that the animation will animate between over time. 277 * @return A ValueAnimator object that is set up to animate between the given values. 278 */ 279 public static ValueAnimator ofFloat(float... values) { 280 ValueAnimator anim = new ValueAnimator(); 281 anim.setFloatValues(values); 282 return anim; 283 } 284 285 /** 286 * Constructs and returns a ValueAnimator that animates between the values 287 * specified in the PropertyValuesHolder objects. 288 * 289 * @param values A set of PropertyValuesHolder objects whose values will be animated 290 * between over time. 291 * @return A ValueAnimator object that is set up to animate between the given values. 292 */ 293 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 294 ValueAnimator anim = new ValueAnimator(); 295 anim.setValues(values); 296 return anim; 297 } 298 /** 299 * Constructs and returns a ValueAnimator that animates between Object values. A single 300 * value implies that that value is the one being animated to. However, this is not typically 301 * useful in a ValueAnimator object because there is no way for the object to determine the 302 * starting value for the animation (unlike ObjectAnimator, which can derive that value 303 * from the target object and property being animated). Therefore, there should typically 304 * be two or more values. 305 * 306 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 307 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 308 * to perform that interpolation. 309 * 310 * @param evaluator A TypeEvaluator that will be called on each animation frame to 311 * provide the ncessry interpolation between the Object values to derive the animated 312 * value. 313 * @param values A set of values that the animation will animate between over time. 314 * @return A ValueAnimator object that is set up to animate between the given values. 315 */ 316 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 317 ValueAnimator anim = new ValueAnimator(); 318 anim.setObjectValues(values); 319 anim.setEvaluator(evaluator); 320 return anim; 321 } 322 323 /** 324 * Sets int values that will be animated between. A single 325 * value implies that that value is the one being animated to. However, this is not typically 326 * useful in a ValueAnimator object because there is no way for the object to determine the 327 * starting value for the animation (unlike ObjectAnimator, which can derive that value 328 * from the target object and property being animated). Therefore, there should typically 329 * be two or more values. 330 * 331 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 332 * than one PropertyValuesHolder object, this method will set the values for the first 333 * of those objects.</p> 334 * 335 * @param values A set of values that the animation will animate between over time. 336 */ 337 public void setIntValues(int... values) { 338 if (values == null || values.length == 0) { 339 return; 340 } 341 if (mValues == null || mValues.length == 0) { 342 setValues(PropertyValuesHolder.ofInt("", values)); 343 } else { 344 PropertyValuesHolder valuesHolder = mValues[0]; 345 valuesHolder.setIntValues(values); 346 } 347 // New property/values/target should cause re-initialization prior to starting 348 mInitialized = false; 349 } 350 351 /** 352 * Sets float values that will be animated between. A single 353 * value implies that that value is the one being animated to. However, this is not typically 354 * useful in a ValueAnimator object because there is no way for the object to determine the 355 * starting value for the animation (unlike ObjectAnimator, which can derive that value 356 * from the target object and property being animated). Therefore, there should typically 357 * be two or more values. 358 * 359 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 360 * than one PropertyValuesHolder object, this method will set the values for the first 361 * of those objects.</p> 362 * 363 * @param values A set of values that the animation will animate between over time. 364 */ 365 public void setFloatValues(float... values) { 366 if (values == null || values.length == 0) { 367 return; 368 } 369 if (mValues == null || mValues.length == 0) { 370 setValues(PropertyValuesHolder.ofFloat("", values)); 371 } else { 372 PropertyValuesHolder valuesHolder = mValues[0]; 373 valuesHolder.setFloatValues(values); 374 } 375 // New property/values/target should cause re-initialization prior to starting 376 mInitialized = false; 377 } 378 379 /** 380 * Sets the values to animate between for this animation. A single 381 * value implies that that value is the one being animated to. However, this is not typically 382 * useful in a ValueAnimator object because there is no way for the object to determine the 383 * starting value for the animation (unlike ObjectAnimator, which can derive that value 384 * from the target object and property being animated). Therefore, there should typically 385 * be two or more values. 386 * 387 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 388 * than one PropertyValuesHolder object, this method will set the values for the first 389 * of those objects.</p> 390 * 391 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 392 * between these value objects. ValueAnimator only knows how to interpolate between the 393 * primitive types specified in the other setValues() methods.</p> 394 * 395 * @param values The set of values to animate between. 396 */ 397 public void setObjectValues(Object... values) { 398 if (values == null || values.length == 0) { 399 return; 400 } 401 if (mValues == null || mValues.length == 0) { 402 setValues(PropertyValuesHolder.ofObject("", null, values)); 403 } else { 404 PropertyValuesHolder valuesHolder = mValues[0]; 405 valuesHolder.setObjectValues(values); 406 } 407 // New property/values/target should cause re-initialization prior to starting 408 mInitialized = false; 409 } 410 411 /** 412 * Sets the values, per property, being animated between. This function is called internally 413 * by the constructors of ValueAnimator that take a list of values. But a ValueAnimator can 414 * be constructed without values and this method can be called to set the values manually 415 * instead. 416 * 417 * @param values The set of values, per property, being animated between. 418 */ 419 public void setValues(PropertyValuesHolder... values) { 420 int numValues = values.length; 421 mValues = values; 422 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 423 for (int i = 0; i < numValues; ++i) { 424 PropertyValuesHolder valuesHolder = values[i]; 425 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 426 } 427 // New property/values/target should cause re-initialization prior to starting 428 mInitialized = false; 429 } 430 431 /** 432 * Returns the values that this ValueAnimator animates between. These values are stored in 433 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 434 * of value objects instead. 435 * 436 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 437 * values, per property, that define the animation. 438 */ 439 public PropertyValuesHolder[] getValues() { 440 return mValues; 441 } 442 443 /** 444 * This function is called immediately before processing the first animation 445 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 446 * function is called after that delay ends. 447 * It takes care of the final initialization steps for the 448 * animation. 449 * 450 * <p>Overrides of this method should call the superclass method to ensure 451 * that internal mechanisms for the animation are set up correctly.</p> 452 */ 453 void initAnimation() { 454 if (!mInitialized) { 455 int numValues = mValues.length; 456 for (int i = 0; i < numValues; ++i) { 457 mValues[i].init(); 458 } 459 mInitialized = true; 460 } 461 } 462 463 464 /** 465 * Sets the length of the animation. The default duration is 300 milliseconds. 466 * 467 * @param duration The length of the animation, in milliseconds. This value cannot 468 * be negative. 469 * @return ValueAnimator The object called with setDuration(). This return 470 * value makes it easier to compose statements together that construct and then set the 471 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 472 */ 473 public ValueAnimator setDuration(long duration) { 474 if (duration < 0) { 475 throw new IllegalArgumentException("Animators cannot have negative duration: " + 476 duration); 477 } 478 mUnscaledDuration = duration; 479 mDuration = (long)(duration * sDurationScale); 480 return this; 481 } 482 483 /** 484 * Gets the length of the animation. The default duration is 300 milliseconds. 485 * 486 * @return The length of the animation, in milliseconds. 487 */ 488 public long getDuration() { 489 return mUnscaledDuration; 490 } 491 492 /** 493 * Sets the position of the animation to the specified point in time. This time should 494 * be between 0 and the total duration of the animation, including any repetition. If 495 * the animation has not yet been started, then it will not advance forward after it is 496 * set to this time; it will simply set the time to this value and perform any appropriate 497 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 498 * will set the current playing time to this value and continue playing from that point. 499 * 500 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 501 */ 502 public void setCurrentPlayTime(long playTime) { 503 initAnimation(); 504 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 505 if (mPlayingState != RUNNING) { 506 mSeekTime = playTime; 507 mPlayingState = SEEKED; 508 } 509 mStartTime = currentTime - playTime; 510 doAnimationFrame(currentTime); 511 } 512 513 /** 514 * Gets the current position of the animation in time, which is equal to the current 515 * time minus the time that the animation started. An animation that is not yet started will 516 * return a value of zero. 517 * 518 * @return The current position in time of the animation. 519 */ 520 public long getCurrentPlayTime() { 521 if (!mInitialized || mPlayingState == STOPPED) { 522 return 0; 523 } 524 return AnimationUtils.currentAnimationTimeMillis() - mStartTime; 525 } 526 527 /** 528 * This custom, static handler handles the timing pulse that is shared by 529 * all active animations. This approach ensures that the setting of animation 530 * values will happen on the UI thread and that all animations will share 531 * the same times for calculating their values, which makes synchronizing 532 * animations possible. 533 * 534 * The handler uses the Choreographer for executing periodic callbacks. 535 * 536 * @hide 537 */ 538 @SuppressWarnings("unchecked") 539 protected static class AnimationHandler implements Runnable { 540 // The per-thread list of all active animations 541 /** @hide */ 542 protected final ArrayList<ValueAnimator> mAnimations = new ArrayList<ValueAnimator>(); 543 544 // Used in doAnimationFrame() to avoid concurrent modifications of mAnimations 545 private final ArrayList<ValueAnimator> mTmpAnimations = new ArrayList<ValueAnimator>(); 546 547 // The per-thread set of animations to be started on the next animation frame 548 /** @hide */ 549 protected final ArrayList<ValueAnimator> mPendingAnimations = new ArrayList<ValueAnimator>(); 550 551 /** 552 * Internal per-thread collections used to avoid set collisions as animations start and end 553 * while being processed. 554 * @hide 555 */ 556 protected final ArrayList<ValueAnimator> mDelayedAnims = new ArrayList<ValueAnimator>(); 557 private final ArrayList<ValueAnimator> mEndingAnims = new ArrayList<ValueAnimator>(); 558 private final ArrayList<ValueAnimator> mReadyAnims = new ArrayList<ValueAnimator>(); 559 560 private final Choreographer mChoreographer; 561 private boolean mAnimationScheduled; 562 563 private AnimationHandler() { 564 mChoreographer = Choreographer.getInstance(); 565 } 566 567 /** 568 * Start animating on the next frame. 569 */ 570 public void start() { 571 scheduleAnimation(); 572 } 573 574 private void doAnimationFrame(long frameTime) { 575 // mPendingAnimations holds any animations that have requested to be started 576 // We're going to clear mPendingAnimations, but starting animation may 577 // cause more to be added to the pending list (for example, if one animation 578 // starting triggers another starting). So we loop until mPendingAnimations 579 // is empty. 580 while (mPendingAnimations.size() > 0) { 581 ArrayList<ValueAnimator> pendingCopy = 582 (ArrayList<ValueAnimator>) mPendingAnimations.clone(); 583 mPendingAnimations.clear(); 584 int count = pendingCopy.size(); 585 for (int i = 0; i < count; ++i) { 586 ValueAnimator anim = pendingCopy.get(i); 587 // If the animation has a startDelay, place it on the delayed list 588 if (anim.mStartDelay == 0) { 589 anim.startAnimation(this); 590 } else { 591 mDelayedAnims.add(anim); 592 } 593 } 594 } 595 // Next, process animations currently sitting on the delayed queue, adding 596 // them to the active animations if they are ready 597 int numDelayedAnims = mDelayedAnims.size(); 598 for (int i = 0; i < numDelayedAnims; ++i) { 599 ValueAnimator anim = mDelayedAnims.get(i); 600 if (anim.delayedAnimationFrame(frameTime)) { 601 mReadyAnims.add(anim); 602 } 603 } 604 int numReadyAnims = mReadyAnims.size(); 605 if (numReadyAnims > 0) { 606 for (int i = 0; i < numReadyAnims; ++i) { 607 ValueAnimator anim = mReadyAnims.get(i); 608 anim.startAnimation(this); 609 anim.mRunning = true; 610 mDelayedAnims.remove(anim); 611 } 612 mReadyAnims.clear(); 613 } 614 615 // Now process all active animations. The return value from animationFrame() 616 // tells the handler whether it should now be ended 617 int numAnims = mAnimations.size(); 618 for (int i = 0; i < numAnims; ++i) { 619 mTmpAnimations.add(mAnimations.get(i)); 620 } 621 for (int i = 0; i < numAnims; ++i) { 622 ValueAnimator anim = mTmpAnimations.get(i); 623 if (mAnimations.contains(anim) && anim.doAnimationFrame(frameTime)) { 624 mEndingAnims.add(anim); 625 } 626 } 627 mTmpAnimations.clear(); 628 if (mEndingAnims.size() > 0) { 629 for (int i = 0; i < mEndingAnims.size(); ++i) { 630 mEndingAnims.get(i).endAnimation(this); 631 } 632 mEndingAnims.clear(); 633 } 634 635 // If there are still active or delayed animations, schedule a future call to 636 // onAnimate to process the next frame of the animations. 637 if (!mAnimations.isEmpty() || !mDelayedAnims.isEmpty()) { 638 scheduleAnimation(); 639 } 640 } 641 642 // Called by the Choreographer. 643 @Override 644 public void run() { 645 mAnimationScheduled = false; 646 doAnimationFrame(mChoreographer.getFrameTime()); 647 } 648 649 private void scheduleAnimation() { 650 if (!mAnimationScheduled) { 651 mChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, this, null); 652 mAnimationScheduled = true; 653 } 654 } 655 } 656 657 /** 658 * The amount of time, in milliseconds, to delay starting the animation after 659 * {@link #start()} is called. 660 * 661 * @return the number of milliseconds to delay running the animation 662 */ 663 public long getStartDelay() { 664 return mUnscaledStartDelay; 665 } 666 667 /** 668 * The amount of time, in milliseconds, to delay starting the animation after 669 * {@link #start()} is called. 670 671 * @param startDelay The amount of the delay, in milliseconds 672 */ 673 public void setStartDelay(long startDelay) { 674 this.mStartDelay = (long)(startDelay * sDurationScale); 675 mUnscaledStartDelay = startDelay; 676 } 677 678 /** 679 * The amount of time, in milliseconds, between each frame of the animation. This is a 680 * requested time that the animation will attempt to honor, but the actual delay between 681 * frames may be different, depending on system load and capabilities. This is a static 682 * function because the same delay will be applied to all animations, since they are all 683 * run off of a single timing loop. 684 * 685 * The frame delay may be ignored when the animation system uses an external timing 686 * source, such as the display refresh rate (vsync), to govern animations. 687 * 688 * @return the requested time between frames, in milliseconds 689 */ 690 public static long getFrameDelay() { 691 return Choreographer.getFrameDelay(); 692 } 693 694 /** 695 * The amount of time, in milliseconds, between each frame of the animation. This is a 696 * requested time that the animation will attempt to honor, but the actual delay between 697 * frames may be different, depending on system load and capabilities. This is a static 698 * function because the same delay will be applied to all animations, since they are all 699 * run off of a single timing loop. 700 * 701 * The frame delay may be ignored when the animation system uses an external timing 702 * source, such as the display refresh rate (vsync), to govern animations. 703 * 704 * @param frameDelay the requested time between frames, in milliseconds 705 */ 706 public static void setFrameDelay(long frameDelay) { 707 Choreographer.setFrameDelay(frameDelay); 708 } 709 710 /** 711 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 712 * property being animated. This value is only sensible while the animation is running. The main 713 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 714 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 715 * is called during each animation frame, immediately after the value is calculated. 716 * 717 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 718 * the single property being animated. If there are several properties being animated 719 * (specified by several PropertyValuesHolder objects in the constructor), this function 720 * returns the animated value for the first of those objects. 721 */ 722 public Object getAnimatedValue() { 723 if (mValues != null && mValues.length > 0) { 724 return mValues[0].getAnimatedValue(); 725 } 726 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 727 return null; 728 } 729 730 /** 731 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 732 * The main purpose for this read-only property is to retrieve the value from the 733 * <code>ValueAnimator</code> during a call to 734 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 735 * is called during each animation frame, immediately after the value is calculated. 736 * 737 * @return animatedValue The value most recently calculated for the named property 738 * by this <code>ValueAnimator</code>. 739 */ 740 public Object getAnimatedValue(String propertyName) { 741 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 742 if (valuesHolder != null) { 743 return valuesHolder.getAnimatedValue(); 744 } else { 745 // At least avoid crashing if called with bogus propertyName 746 return null; 747 } 748 } 749 750 /** 751 * Sets how many times the animation should be repeated. If the repeat 752 * count is 0, the animation is never repeated. If the repeat count is 753 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 754 * into account. The repeat count is 0 by default. 755 * 756 * @param value the number of times the animation should be repeated 757 */ 758 public void setRepeatCount(int value) { 759 mRepeatCount = value; 760 } 761 /** 762 * Defines how many times the animation should repeat. The default value 763 * is 0. 764 * 765 * @return the number of times the animation should repeat, or {@link #INFINITE} 766 */ 767 public int getRepeatCount() { 768 return mRepeatCount; 769 } 770 771 /** 772 * Defines what this animation should do when it reaches the end. This 773 * setting is applied only when the repeat count is either greater than 774 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 775 * 776 * @param value {@link #RESTART} or {@link #REVERSE} 777 */ 778 public void setRepeatMode(int value) { 779 mRepeatMode = value; 780 } 781 782 /** 783 * Defines what this animation should do when it reaches the end. 784 * 785 * @return either one of {@link #REVERSE} or {@link #RESTART} 786 */ 787 public int getRepeatMode() { 788 return mRepeatMode; 789 } 790 791 /** 792 * Adds a listener to the set of listeners that are sent update events through the life of 793 * an animation. This method is called on all listeners for every frame of the animation, 794 * after the values for the animation have been calculated. 795 * 796 * @param listener the listener to be added to the current set of listeners for this animation. 797 */ 798 public void addUpdateListener(AnimatorUpdateListener listener) { 799 if (mUpdateListeners == null) { 800 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 801 } 802 mUpdateListeners.add(listener); 803 } 804 805 /** 806 * Removes all listeners from the set listening to frame updates for this animation. 807 */ 808 public void removeAllUpdateListeners() { 809 if (mUpdateListeners == null) { 810 return; 811 } 812 mUpdateListeners.clear(); 813 mUpdateListeners = null; 814 } 815 816 /** 817 * Removes a listener from the set listening to frame updates for this animation. 818 * 819 * @param listener the listener to be removed from the current set of update listeners 820 * for this animation. 821 */ 822 public void removeUpdateListener(AnimatorUpdateListener listener) { 823 if (mUpdateListeners == null) { 824 return; 825 } 826 mUpdateListeners.remove(listener); 827 if (mUpdateListeners.size() == 0) { 828 mUpdateListeners = null; 829 } 830 } 831 832 833 /** 834 * The time interpolator used in calculating the elapsed fraction of this animation. The 835 * interpolator determines whether the animation runs with linear or non-linear motion, 836 * such as acceleration and deceleration. The default value is 837 * {@link android.view.animation.AccelerateDecelerateInterpolator} 838 * 839 * @param value the interpolator to be used by this animation. A value of <code>null</code> 840 * will result in linear interpolation. 841 */ 842 @Override 843 public void setInterpolator(TimeInterpolator value) { 844 if (value != null) { 845 mInterpolator = value; 846 } else { 847 mInterpolator = new LinearInterpolator(); 848 } 849 } 850 851 /** 852 * Returns the timing interpolator that this ValueAnimator uses. 853 * 854 * @return The timing interpolator for this ValueAnimator. 855 */ 856 @Override 857 public TimeInterpolator getInterpolator() { 858 return mInterpolator; 859 } 860 861 /** 862 * The type evaluator to be used when calculating the animated values of this animation. 863 * The system will automatically assign a float or int evaluator based on the type 864 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 865 * are not one of these primitive types, or if different evaluation is desired (such as is 866 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 867 * For example, when running an animation on color values, the {@link ArgbEvaluator} 868 * should be used to get correct RGB color interpolation. 869 * 870 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 871 * will be used for that set. If there are several sets of values being animated, which is 872 * the case if PropertyValuesHOlder objects were set on the ValueAnimator, then the evaluator 873 * is assigned just to the first PropertyValuesHolder object.</p> 874 * 875 * @param value the evaluator to be used this animation 876 */ 877 public void setEvaluator(TypeEvaluator value) { 878 if (value != null && mValues != null && mValues.length > 0) { 879 mValues[0].setEvaluator(value); 880 } 881 } 882 883 private void notifyStartListeners() { 884 if (mListeners != null && !mStartListenersCalled) { 885 ArrayList<AnimatorListener> tmpListeners = 886 (ArrayList<AnimatorListener>) mListeners.clone(); 887 int numListeners = tmpListeners.size(); 888 for (int i = 0; i < numListeners; ++i) { 889 tmpListeners.get(i).onAnimationStart(this); 890 } 891 } 892 mStartListenersCalled = true; 893 } 894 895 /** 896 * Start the animation playing. This version of start() takes a boolean flag that indicates 897 * whether the animation should play in reverse. The flag is usually false, but may be set 898 * to true if called from the reverse() method. 899 * 900 * <p>The animation started by calling this method will be run on the thread that called 901 * this method. This thread should have a Looper on it (a runtime exception will be thrown if 902 * this is not the case). Also, if the animation will animate 903 * properties of objects in the view hierarchy, then the calling thread should be the UI 904 * thread for that view hierarchy.</p> 905 * 906 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 907 */ 908 private void start(boolean playBackwards) { 909 if (Looper.myLooper() == null) { 910 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 911 } 912 mPlayingBackwards = playBackwards; 913 mCurrentIteration = 0; 914 mPlayingState = STOPPED; 915 mStarted = true; 916 mStartedDelay = false; 917 AnimationHandler animationHandler = getOrCreateAnimationHandler(); 918 animationHandler.mPendingAnimations.add(this); 919 if (mStartDelay == 0) { 920 // This sets the initial value of the animation, prior to actually starting it running 921 setCurrentPlayTime(0); 922 mPlayingState = STOPPED; 923 mRunning = true; 924 notifyStartListeners(); 925 } 926 animationHandler.start(); 927 } 928 929 @Override 930 public void start() { 931 start(false); 932 } 933 934 @Override 935 public void cancel() { 936 // Only cancel if the animation is actually running or has been started and is about 937 // to run 938 AnimationHandler handler = getOrCreateAnimationHandler(); 939 if (mPlayingState != STOPPED 940 || handler.mPendingAnimations.contains(this) 941 || handler.mDelayedAnims.contains(this)) { 942 // Only notify listeners if the animator has actually started 943 if ((mStarted || mRunning) && mListeners != null) { 944 if (!mRunning) { 945 // If it's not yet running, then start listeners weren't called. Call them now. 946 notifyStartListeners(); 947 } 948 ArrayList<AnimatorListener> tmpListeners = 949 (ArrayList<AnimatorListener>) mListeners.clone(); 950 for (AnimatorListener listener : tmpListeners) { 951 listener.onAnimationCancel(this); 952 } 953 } 954 endAnimation(handler); 955 } 956 } 957 958 @Override 959 public void end() { 960 AnimationHandler handler = getOrCreateAnimationHandler(); 961 if (!handler.mAnimations.contains(this) && !handler.mPendingAnimations.contains(this)) { 962 // Special case if the animation has not yet started; get it ready for ending 963 mStartedDelay = false; 964 startAnimation(handler); 965 mStarted = true; 966 } else if (!mInitialized) { 967 initAnimation(); 968 } 969 animateValue(mPlayingBackwards ? 0f : 1f); 970 endAnimation(handler); 971 } 972 973 @Override 974 public boolean isRunning() { 975 return (mPlayingState == RUNNING || mRunning); 976 } 977 978 @Override 979 public boolean isStarted() { 980 return mStarted; 981 } 982 983 /** 984 * Plays the ValueAnimator in reverse. If the animation is already running, 985 * it will stop itself and play backwards from the point reached when reverse was called. 986 * If the animation is not currently running, then it will start from the end and 987 * play backwards. This behavior is only set for the current animation; future playing 988 * of the animation will use the default behavior of playing forward. 989 */ 990 public void reverse() { 991 mPlayingBackwards = !mPlayingBackwards; 992 if (mPlayingState == RUNNING) { 993 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 994 long currentPlayTime = currentTime - mStartTime; 995 long timeLeft = mDuration - currentPlayTime; 996 mStartTime = currentTime - timeLeft; 997 } else { 998 start(true); 999 } 1000 } 1001 1002 /** 1003 * Called internally to end an animation by removing it from the animations list. Must be 1004 * called on the UI thread. 1005 */ 1006 private void endAnimation(AnimationHandler handler) { 1007 handler.mAnimations.remove(this); 1008 handler.mPendingAnimations.remove(this); 1009 handler.mDelayedAnims.remove(this); 1010 mPlayingState = STOPPED; 1011 if ((mStarted || mRunning) && mListeners != null) { 1012 if (!mRunning) { 1013 // If it's not yet running, then start listeners weren't called. Call them now. 1014 notifyStartListeners(); 1015 } 1016 ArrayList<AnimatorListener> tmpListeners = 1017 (ArrayList<AnimatorListener>) mListeners.clone(); 1018 int numListeners = tmpListeners.size(); 1019 for (int i = 0; i < numListeners; ++i) { 1020 tmpListeners.get(i).onAnimationEnd(this); 1021 } 1022 } 1023 mRunning = false; 1024 mStarted = false; 1025 mStartListenersCalled = false; 1026 mPlayingBackwards = false; 1027 Trace.asyncTraceEnd(Trace.TRACE_TAG_VIEW, "animator", 1028 System.identityHashCode(this)); 1029 } 1030 1031 /** 1032 * Called internally to start an animation by adding it to the active animations list. Must be 1033 * called on the UI thread. 1034 */ 1035 private void startAnimation(AnimationHandler handler) { 1036 Trace.asyncTraceBegin(Trace.TRACE_TAG_VIEW, "animator", 1037 System.identityHashCode(this)); 1038 initAnimation(); 1039 handler.mAnimations.add(this); 1040 if (mStartDelay > 0 && mListeners != null) { 1041 // Listeners were already notified in start() if startDelay is 0; this is 1042 // just for delayed animations 1043 notifyStartListeners(); 1044 } 1045 } 1046 1047 /** 1048 * Internal function called to process an animation frame on an animation that is currently 1049 * sleeping through its <code>startDelay</code> phase. The return value indicates whether it 1050 * should be woken up and put on the active animations queue. 1051 * 1052 * @param currentTime The current animation time, used to calculate whether the animation 1053 * has exceeded its <code>startDelay</code> and should be started. 1054 * @return True if the animation's <code>startDelay</code> has been exceeded and the animation 1055 * should be added to the set of active animations. 1056 */ 1057 private boolean delayedAnimationFrame(long currentTime) { 1058 if (!mStartedDelay) { 1059 mStartedDelay = true; 1060 mDelayStartTime = currentTime; 1061 } else { 1062 long deltaTime = currentTime - mDelayStartTime; 1063 if (deltaTime > mStartDelay) { 1064 // startDelay ended - start the anim and record the 1065 // mStartTime appropriately 1066 mStartTime = currentTime - (deltaTime - mStartDelay); 1067 mPlayingState = RUNNING; 1068 return true; 1069 } 1070 } 1071 return false; 1072 } 1073 1074 /** 1075 * This internal function processes a single animation frame for a given animation. The 1076 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1077 * elapsed duration, and therefore 1078 * the elapsed fraction, of the animation. The return value indicates whether the animation 1079 * should be ended (which happens when the elapsed time of the animation exceeds the 1080 * animation's duration, including the repeatCount). 1081 * 1082 * @param currentTime The current time, as tracked by the static timing handler 1083 * @return true if the animation's duration, including any repetitions due to 1084 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1085 */ 1086 boolean animationFrame(long currentTime) { 1087 boolean done = false; 1088 switch (mPlayingState) { 1089 case RUNNING: 1090 case SEEKED: 1091 float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f; 1092 if (fraction >= 1f) { 1093 if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) { 1094 // Time to repeat 1095 if (mListeners != null) { 1096 int numListeners = mListeners.size(); 1097 for (int i = 0; i < numListeners; ++i) { 1098 mListeners.get(i).onAnimationRepeat(this); 1099 } 1100 } 1101 if (mRepeatMode == REVERSE) { 1102 mPlayingBackwards = !mPlayingBackwards; 1103 } 1104 mCurrentIteration += (int)fraction; 1105 fraction = fraction % 1f; 1106 mStartTime += mDuration; 1107 } else { 1108 done = true; 1109 fraction = Math.min(fraction, 1.0f); 1110 } 1111 } 1112 if (mPlayingBackwards) { 1113 fraction = 1f - fraction; 1114 } 1115 animateValue(fraction); 1116 break; 1117 } 1118 1119 return done; 1120 } 1121 1122 /** 1123 * Processes a frame of the animation, adjusting the start time if needed. 1124 * 1125 * @param frameTime The frame time. 1126 * @return true if the animation has ended. 1127 */ 1128 final boolean doAnimationFrame(long frameTime) { 1129 if (mPlayingState == STOPPED) { 1130 mPlayingState = RUNNING; 1131 if (mSeekTime < 0) { 1132 mStartTime = frameTime; 1133 } else { 1134 mStartTime = frameTime - mSeekTime; 1135 // Now that we're playing, reset the seek time 1136 mSeekTime = -1; 1137 } 1138 } 1139 // The frame time might be before the start time during the first frame of 1140 // an animation. The "current time" must always be on or after the start 1141 // time to avoid animating frames at negative time intervals. In practice, this 1142 // is very rare and only happens when seeking backwards. 1143 final long currentTime = Math.max(frameTime, mStartTime); 1144 return animationFrame(currentTime); 1145 } 1146 1147 /** 1148 * Returns the current animation fraction, which is the elapsed/interpolated fraction used in 1149 * the most recent frame update on the animation. 1150 * 1151 * @return Elapsed/interpolated fraction of the animation. 1152 */ 1153 public float getAnimatedFraction() { 1154 return mCurrentFraction; 1155 } 1156 1157 /** 1158 * This method is called with the elapsed fraction of the animation during every 1159 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1160 * and then into an animated value (from the evaluator. The function is called mostly during 1161 * animation updates, but it is also called when the <code>end()</code> 1162 * function is called, to set the final value on the property. 1163 * 1164 * <p>Overrides of this method must call the superclass to perform the calculation 1165 * of the animated value.</p> 1166 * 1167 * @param fraction The elapsed fraction of the animation. 1168 */ 1169 void animateValue(float fraction) { 1170 fraction = mInterpolator.getInterpolation(fraction); 1171 mCurrentFraction = fraction; 1172 int numValues = mValues.length; 1173 for (int i = 0; i < numValues; ++i) { 1174 mValues[i].calculateValue(fraction); 1175 } 1176 if (mUpdateListeners != null) { 1177 int numListeners = mUpdateListeners.size(); 1178 for (int i = 0; i < numListeners; ++i) { 1179 mUpdateListeners.get(i).onAnimationUpdate(this); 1180 } 1181 } 1182 } 1183 1184 @Override 1185 public ValueAnimator clone() { 1186 final ValueAnimator anim = (ValueAnimator) super.clone(); 1187 if (mUpdateListeners != null) { 1188 ArrayList<AnimatorUpdateListener> oldListeners = mUpdateListeners; 1189 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 1190 int numListeners = oldListeners.size(); 1191 for (int i = 0; i < numListeners; ++i) { 1192 anim.mUpdateListeners.add(oldListeners.get(i)); 1193 } 1194 } 1195 anim.mSeekTime = -1; 1196 anim.mPlayingBackwards = false; 1197 anim.mCurrentIteration = 0; 1198 anim.mInitialized = false; 1199 anim.mPlayingState = STOPPED; 1200 anim.mStartedDelay = false; 1201 PropertyValuesHolder[] oldValues = mValues; 1202 if (oldValues != null) { 1203 int numValues = oldValues.length; 1204 anim.mValues = new PropertyValuesHolder[numValues]; 1205 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1206 for (int i = 0; i < numValues; ++i) { 1207 PropertyValuesHolder newValuesHolder = oldValues[i].clone(); 1208 anim.mValues[i] = newValuesHolder; 1209 anim.mValuesMap.put(newValuesHolder.getPropertyName(), newValuesHolder); 1210 } 1211 } 1212 return anim; 1213 } 1214 1215 /** 1216 * Implementors of this interface can add themselves as update listeners 1217 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1218 * frame, after the current frame's values have been calculated for that 1219 * <code>ValueAnimator</code>. 1220 */ 1221 public static interface AnimatorUpdateListener { 1222 /** 1223 * <p>Notifies the occurrence of another frame of the animation.</p> 1224 * 1225 * @param animation The animation which was repeated. 1226 */ 1227 void onAnimationUpdate(ValueAnimator animation); 1228 1229 } 1230 1231 /** 1232 * Return the number of animations currently running. 1233 * 1234 * Used by StrictMode internally to annotate violations. 1235 * May be called on arbitrary threads! 1236 * 1237 * @hide 1238 */ 1239 public static int getCurrentAnimationsCount() { 1240 AnimationHandler handler = sAnimationHandler.get(); 1241 return handler != null ? handler.mAnimations.size() : 0; 1242 } 1243 1244 /** 1245 * Clear all animations on this thread, without canceling or ending them. 1246 * This should be used with caution. 1247 * 1248 * @hide 1249 */ 1250 public static void clearAllAnimations() { 1251 AnimationHandler handler = sAnimationHandler.get(); 1252 if (handler != null) { 1253 handler.mAnimations.clear(); 1254 handler.mPendingAnimations.clear(); 1255 handler.mDelayedAnims.clear(); 1256 } 1257 } 1258 1259 private static AnimationHandler getOrCreateAnimationHandler() { 1260 AnimationHandler handler = sAnimationHandler.get(); 1261 if (handler == null) { 1262 handler = new AnimationHandler(); 1263 sAnimationHandler.set(handler); 1264 } 1265 return handler; 1266 } 1267 1268 @Override 1269 public String toString() { 1270 String returnVal = "ValueAnimator@" + Integer.toHexString(hashCode()); 1271 if (mValues != null) { 1272 for (int i = 0; i < mValues.length; ++i) { 1273 returnVal += "\n " + mValues[i].toString(); 1274 } 1275 } 1276 return returnVal; 1277 } 1278 } 1279