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