ValueAnimator.java revision 7ae9d5faad5816f7e567ec1ec77e78d746cf7e5c
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 * Messages sent to timing handler: START is sent when an animation first begins. 60 */ 61 static final int ANIMATION_START = 0; 62 63 /** 64 * Values used with internal variable mPlayingState to indicate the current state of an 65 * animation. 66 */ 67 static final int STOPPED = 0; // Not yet playing 68 static final int RUNNING = 1; // Playing normally 69 static final int SEEKED = 2; // Seeked to some time value 70 71 /** 72 * Internal variables 73 * NOTE: This object implements the clone() method, making a deep copy of any referenced 74 * objects. As other non-trivial fields are added to this class, make sure to add logic 75 * to clone() to make deep copies of them. 76 */ 77 78 // The first time that the animation's animateFrame() method is called. This time is used to 79 // determine elapsed time (and therefore the elapsed fraction) in subsequent calls 80 // to animateFrame() 81 long mStartTime; 82 83 /** 84 * Set when setCurrentPlayTime() is called. If negative, animation is not currently seeked 85 * to a value. 86 */ 87 long mSeekTime = -1; 88 89 // The static sAnimationHandler processes the internal timing loop on which all animations 90 // are based 91 private static ThreadLocal<AnimationHandler> sAnimationHandler = 92 new ThreadLocal<AnimationHandler>(); 93 94 // The time interpolator to be used if none is set on the animation 95 private static final TimeInterpolator sDefaultInterpolator = 96 new AccelerateDecelerateInterpolator(); 97 98 /** 99 * Used to indicate whether the animation is currently playing in reverse. This causes the 100 * elapsed fraction to be inverted to calculate the appropriate values. 101 */ 102 private boolean mPlayingBackwards = false; 103 104 /** 105 * This variable tracks the current iteration that is playing. When mCurrentIteration exceeds the 106 * repeatCount (if repeatCount!=INFINITE), the animation ends 107 */ 108 private int mCurrentIteration = 0; 109 110 /** 111 * Tracks current elapsed/eased fraction, for querying in getAnimatedFraction(). 112 */ 113 private float mCurrentFraction = 0f; 114 115 /** 116 * Tracks whether a startDelay'd animation has begun playing through the startDelay. 117 */ 118 private boolean mStartedDelay = false; 119 120 /** 121 * Tracks the time at which the animation began playing through its startDelay. This is 122 * different from the mStartTime variable, which is used to track when the animation became 123 * active (which is when the startDelay expired and the animation was added to the active 124 * animations list). 125 */ 126 private long mDelayStartTime; 127 128 /** 129 * Flag that represents the current state of the animation. Used to figure out when to start 130 * an animation (if state == STOPPED). Also used to end an animation that 131 * has been cancel()'d or end()'d since the last animation frame. Possible values are 132 * STOPPED, RUNNING, SEEKED. 133 */ 134 int mPlayingState = STOPPED; 135 136 /** 137 * Additional playing state to indicate whether an animator has been start()'d. There is 138 * some lag between a call to start() and the first animation frame. We should still note 139 * that the animation has been started, even if it's first animation frame has not yet 140 * happened, and reflect that state in isRunning(). 141 * Note that delayed animations are different: they are not started until their first 142 * animation frame, which occurs after their delay elapses. 143 */ 144 private boolean mRunning = false; 145 146 /** 147 * Additional playing state to indicate whether an animator has been start()'d, whether or 148 * not there is a nonzero startDelay. 149 */ 150 private boolean mStarted = false; 151 152 /** 153 * Flag that denotes whether the animation is set up and ready to go. Used to 154 * set up animation that has not yet been started. 155 */ 156 boolean mInitialized = false; 157 158 // 159 // Backing variables 160 // 161 162 // How long the animation should last in ms 163 private long mDuration = (long)(300 * sDurationScale); 164 private long mUnscaledDuration = 300; 165 166 // The amount of time in ms to delay starting the animation after start() is called 167 private long mStartDelay = 0; 168 private long mUnscaledStartDelay = 0; 169 170 // The number of times the animation will repeat. The default is 0, which means the animation 171 // will play only once 172 private int mRepeatCount = 0; 173 174 /** 175 * The type of repetition that will occur when repeatMode is nonzero. RESTART means the 176 * animation will start from the beginning on every new cycle. REVERSE means the animation 177 * will reverse directions on each iteration. 178 */ 179 private int mRepeatMode = RESTART; 180 181 /** 182 * The time interpolator to be used. The elapsed fraction of the animation will be passed 183 * through this interpolator to calculate the interpolated fraction, which is then used to 184 * calculate the animated values. 185 */ 186 private TimeInterpolator mInterpolator = sDefaultInterpolator; 187 188 /** 189 * The set of listeners to be sent events through the life of an animation. 190 */ 191 private ArrayList<AnimatorUpdateListener> mUpdateListeners = null; 192 193 /** 194 * The property/value sets being animated. 195 */ 196 PropertyValuesHolder[] mValues; 197 198 /** 199 * A hashmap of the PropertyValuesHolder objects. This map is used to lookup animated values 200 * by property name during calls to getAnimatedValue(String). 201 */ 202 HashMap<String, PropertyValuesHolder> mValuesMap; 203 204 /** 205 * Public constants 206 */ 207 208 /** 209 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 210 * or a positive value, the animation restarts from the beginning. 211 */ 212 public static final int RESTART = 1; 213 /** 214 * When the animation reaches the end and <code>repeatCount</code> is INFINITE 215 * or a positive value, the animation reverses direction on every iteration. 216 */ 217 public static final int REVERSE = 2; 218 /** 219 * This value used used with the {@link #setRepeatCount(int)} property to repeat 220 * the animation indefinitely. 221 */ 222 public static final int INFINITE = -1; 223 224 225 /** 226 * @hide 227 */ 228 public static void setDurationScale(float durationScale) { 229 sDurationScale = durationScale; 230 } 231 232 /** 233 * Creates a new ValueAnimator object. This default constructor is primarily for 234 * use internally; the factory methods which take parameters are more generally 235 * useful. 236 */ 237 public ValueAnimator() { 238 } 239 240 /** 241 * Constructs and returns a ValueAnimator that animates between int values. A single 242 * value implies that that value is the one being animated to. However, this is not typically 243 * useful in a ValueAnimator object because there is no way for the object to determine the 244 * starting value for the animation (unlike ObjectAnimator, which can derive that value 245 * from the target object and property being animated). Therefore, there should typically 246 * be two or more values. 247 * 248 * @param values A set of values that the animation will animate between over time. 249 * @return A ValueAnimator object that is set up to animate between the given values. 250 */ 251 public static ValueAnimator ofInt(int... values) { 252 ValueAnimator anim = new ValueAnimator(); 253 anim.setIntValues(values); 254 return anim; 255 } 256 257 /** 258 * Constructs and returns a ValueAnimator that animates between float values. A single 259 * value implies that that value is the one being animated to. However, this is not typically 260 * useful in a ValueAnimator object because there is no way for the object to determine the 261 * starting value for the animation (unlike ObjectAnimator, which can derive that value 262 * from the target object and property being animated). Therefore, there should typically 263 * be two or more values. 264 * 265 * @param values A set of values that the animation will animate between over time. 266 * @return A ValueAnimator object that is set up to animate between the given values. 267 */ 268 public static ValueAnimator ofFloat(float... values) { 269 ValueAnimator anim = new ValueAnimator(); 270 anim.setFloatValues(values); 271 return anim; 272 } 273 274 /** 275 * Constructs and returns a ValueAnimator that animates between the values 276 * specified in the PropertyValuesHolder objects. 277 * 278 * @param values A set of PropertyValuesHolder objects whose values will be animated 279 * between over time. 280 * @return A ValueAnimator object that is set up to animate between the given values. 281 */ 282 public static ValueAnimator ofPropertyValuesHolder(PropertyValuesHolder... values) { 283 ValueAnimator anim = new ValueAnimator(); 284 anim.setValues(values); 285 return anim; 286 } 287 /** 288 * Constructs and returns a ValueAnimator that animates between Object values. A single 289 * value implies that that value is the one being animated to. However, this is not typically 290 * useful in a ValueAnimator object because there is no way for the object to determine the 291 * starting value for the animation (unlike ObjectAnimator, which can derive that value 292 * from the target object and property being animated). Therefore, there should typically 293 * be two or more values. 294 * 295 * <p>Since ValueAnimator does not know how to animate between arbitrary Objects, this 296 * factory method also takes a TypeEvaluator object that the ValueAnimator will use 297 * to perform that interpolation. 298 * 299 * @param evaluator A TypeEvaluator that will be called on each animation frame to 300 * provide the ncessry interpolation between the Object values to derive the animated 301 * value. 302 * @param values A set of values that the animation will animate between over time. 303 * @return A ValueAnimator object that is set up to animate between the given values. 304 */ 305 public static ValueAnimator ofObject(TypeEvaluator evaluator, Object... values) { 306 ValueAnimator anim = new ValueAnimator(); 307 anim.setObjectValues(values); 308 anim.setEvaluator(evaluator); 309 return anim; 310 } 311 312 /** 313 * Sets int values that will be animated between. A single 314 * value implies that that value is the one being animated to. However, this is not typically 315 * useful in a ValueAnimator object because there is no way for the object to determine the 316 * starting value for the animation (unlike ObjectAnimator, which can derive that value 317 * from the target object and property being animated). Therefore, there should typically 318 * be two or more values. 319 * 320 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 321 * than one PropertyValuesHolder object, this method will set the values for the first 322 * of those objects.</p> 323 * 324 * @param values A set of values that the animation will animate between over time. 325 */ 326 public void setIntValues(int... values) { 327 if (values == null || values.length == 0) { 328 return; 329 } 330 if (mValues == null || mValues.length == 0) { 331 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofInt("", values)}); 332 } else { 333 PropertyValuesHolder valuesHolder = mValues[0]; 334 valuesHolder.setIntValues(values); 335 } 336 // New property/values/target should cause re-initialization prior to starting 337 mInitialized = false; 338 } 339 340 /** 341 * Sets float values that will be animated between. A single 342 * value implies that that value is the one being animated to. However, this is not typically 343 * useful in a ValueAnimator object because there is no way for the object to determine the 344 * starting value for the animation (unlike ObjectAnimator, which can derive that value 345 * from the target object and property being animated). Therefore, there should typically 346 * be two or more values. 347 * 348 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 349 * than one PropertyValuesHolder object, this method will set the values for the first 350 * of those objects.</p> 351 * 352 * @param values A set of values that the animation will animate between over time. 353 */ 354 public void setFloatValues(float... values) { 355 if (values == null || values.length == 0) { 356 return; 357 } 358 if (mValues == null || mValues.length == 0) { 359 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofFloat("", values)}); 360 } else { 361 PropertyValuesHolder valuesHolder = mValues[0]; 362 valuesHolder.setFloatValues(values); 363 } 364 // New property/values/target should cause re-initialization prior to starting 365 mInitialized = false; 366 } 367 368 /** 369 * Sets the values to animate between for this animation. A single 370 * value implies that that value is the one being animated to. However, this is not typically 371 * useful in a ValueAnimator object because there is no way for the object to determine the 372 * starting value for the animation (unlike ObjectAnimator, which can derive that value 373 * from the target object and property being animated). Therefore, there should typically 374 * be two or more values. 375 * 376 * <p>If there are already multiple sets of values defined for this ValueAnimator via more 377 * than one PropertyValuesHolder object, this method will set the values for the first 378 * of those objects.</p> 379 * 380 * <p>There should be a TypeEvaluator set on the ValueAnimator that knows how to interpolate 381 * between these value objects. ValueAnimator only knows how to interpolate between the 382 * primitive types specified in the other setValues() methods.</p> 383 * 384 * @param values The set of values to animate between. 385 */ 386 public void setObjectValues(Object... values) { 387 if (values == null || values.length == 0) { 388 return; 389 } 390 if (mValues == null || mValues.length == 0) { 391 setValues(new PropertyValuesHolder[]{PropertyValuesHolder.ofObject("", 392 (TypeEvaluator)null, values)}); 393 } else { 394 PropertyValuesHolder valuesHolder = mValues[0]; 395 valuesHolder.setObjectValues(values); 396 } 397 // New property/values/target should cause re-initialization prior to starting 398 mInitialized = false; 399 } 400 401 /** 402 * Sets the values, per property, being animated between. This function is called internally 403 * by the constructors of ValueAnimator that take a list of values. But an ValueAnimator can 404 * be constructed without values and this method can be called to set the values manually 405 * instead. 406 * 407 * @param values The set of values, per property, being animated between. 408 */ 409 public void setValues(PropertyValuesHolder... values) { 410 int numValues = values.length; 411 mValues = values; 412 mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 413 for (int i = 0; i < numValues; ++i) { 414 PropertyValuesHolder valuesHolder = (PropertyValuesHolder) values[i]; 415 mValuesMap.put(valuesHolder.getPropertyName(), valuesHolder); 416 } 417 // New property/values/target should cause re-initialization prior to starting 418 mInitialized = false; 419 } 420 421 /** 422 * Returns the values that this ValueAnimator animates between. These values are stored in 423 * PropertyValuesHolder objects, even if the ValueAnimator was created with a simple list 424 * of value objects instead. 425 * 426 * @return PropertyValuesHolder[] An array of PropertyValuesHolder objects which hold the 427 * values, per property, that define the animation. 428 */ 429 public PropertyValuesHolder[] getValues() { 430 return mValues; 431 } 432 433 /** 434 * This function is called immediately before processing the first animation 435 * frame of an animation. If there is a nonzero <code>startDelay</code>, the 436 * function is called after that delay ends. 437 * It takes care of the final initialization steps for the 438 * animation. 439 * 440 * <p>Overrides of this method should call the superclass method to ensure 441 * that internal mechanisms for the animation are set up correctly.</p> 442 */ 443 void initAnimation() { 444 if (!mInitialized) { 445 int numValues = mValues.length; 446 for (int i = 0; i < numValues; ++i) { 447 mValues[i].init(); 448 } 449 mInitialized = true; 450 } 451 } 452 453 454 /** 455 * Sets the length of the animation. The default duration is 300 milliseconds. 456 * 457 * @param duration The length of the animation, in milliseconds. This value cannot 458 * be negative. 459 * @return ValueAnimator The object called with setDuration(). This return 460 * value makes it easier to compose statements together that construct and then set the 461 * duration, as in <code>ValueAnimator.ofInt(0, 10).setDuration(500).start()</code>. 462 */ 463 public ValueAnimator setDuration(long duration) { 464 if (duration < 0) { 465 throw new IllegalArgumentException("Animators cannot have negative duration: " + 466 duration); 467 } 468 mUnscaledDuration = duration; 469 mDuration = (long)(duration * sDurationScale); 470 return this; 471 } 472 473 /** 474 * Gets the length of the animation. The default duration is 300 milliseconds. 475 * 476 * @return The length of the animation, in milliseconds. 477 */ 478 public long getDuration() { 479 return mUnscaledDuration; 480 } 481 482 /** 483 * Sets the position of the animation to the specified point in time. This time should 484 * be between 0 and the total duration of the animation, including any repetition. If 485 * the animation has not yet been started, then it will not advance forward after it is 486 * set to this time; it will simply set the time to this value and perform any appropriate 487 * actions based on that time. If the animation is already running, then setCurrentPlayTime() 488 * will set the current playing time to this value and continue playing from that point. 489 * 490 * @param playTime The time, in milliseconds, to which the animation is advanced or rewound. 491 */ 492 public void setCurrentPlayTime(long playTime) { 493 initAnimation(); 494 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 495 if (mPlayingState != RUNNING) { 496 mSeekTime = playTime; 497 mPlayingState = SEEKED; 498 } 499 mStartTime = currentTime - playTime; 500 animationFrame(currentTime); 501 } 502 503 /** 504 * Gets the current position of the animation in time, which is equal to the current 505 * time minus the time that the animation started. An animation that is not yet started will 506 * return a value of zero. 507 * 508 * @return The current position in time of the animation. 509 */ 510 public long getCurrentPlayTime() { 511 if (!mInitialized || mPlayingState == STOPPED) { 512 return 0; 513 } 514 return AnimationUtils.currentAnimationTimeMillis() - mStartTime; 515 } 516 517 /** 518 * This custom, static handler handles the timing pulse that is shared by 519 * all active animations. This approach ensures that the setting of animation 520 * values will happen on the UI thread and that all animations will share 521 * the same times for calculating their values, which makes synchronizing 522 * animations possible. 523 * 524 */ 525 private static class AnimationHandler extends Handler implements Runnable { 526 // The per-thread list of all active animations 527 private final ArrayList<ValueAnimator> mAnimations = new ArrayList<ValueAnimator>(); 528 529 // The per-thread set of animations to be started on the next animation frame 530 private final ArrayList<ValueAnimator> mPendingAnimations = new ArrayList<ValueAnimator>(); 531 532 /** 533 * Internal per-thread collections used to avoid set collisions as animations start and end 534 * while being processed. 535 */ 536 private final ArrayList<ValueAnimator> mDelayedAnims = new ArrayList<ValueAnimator>(); 537 private final ArrayList<ValueAnimator> mEndingAnims = new ArrayList<ValueAnimator>(); 538 private final ArrayList<ValueAnimator> mReadyAnims = new ArrayList<ValueAnimator>(); 539 540 private final Choreographer mChoreographer; 541 private boolean mAnimationScheduled; 542 543 private AnimationHandler() { 544 mChoreographer = Choreographer.getInstance(); 545 } 546 547 /** 548 * The START message is sent when an animation's start() method is called. 549 * It cannot start synchronously when start() is called 550 * because the call may be on the wrong thread, and it would also not be 551 * synchronized with other animations because it would not start on a common 552 * timing pulse. So each animation sends a START message to the handler, which 553 * causes the handler to place the animation on the active animations queue and 554 * start processing frames for that animation. 555 */ 556 @Override 557 public void handleMessage(Message msg) { 558 switch (msg.what) { 559 case ANIMATION_START: 560 doAnimationStart(); 561 break; 562 } 563 } 564 565 private void doAnimationStart() { 566 // mPendingAnimations holds any animations that have requested to be started 567 // We're going to clear mPendingAnimations, but starting animation may 568 // cause more to be added to the pending list (for example, if one animation 569 // starting triggers another starting). So we loop until mPendingAnimations 570 // is empty. 571 while (mPendingAnimations.size() > 0) { 572 ArrayList<ValueAnimator> pendingCopy = 573 (ArrayList<ValueAnimator>) mPendingAnimations.clone(); 574 mPendingAnimations.clear(); 575 int count = pendingCopy.size(); 576 for (int i = 0; i < count; ++i) { 577 ValueAnimator anim = pendingCopy.get(i); 578 // If the animation has a startDelay, place it on the delayed list 579 if (anim.mStartDelay == 0) { 580 anim.startAnimation(this); 581 } else { 582 mDelayedAnims.add(anim); 583 } 584 } 585 } 586 doAnimationFrame(); 587 } 588 589 private void doAnimationFrame() { 590 // currentTime holds the common time for all animations processed 591 // during this frame 592 long currentTime = AnimationUtils.currentAnimationTimeMillis(); 593 594 // First, process animations currently sitting on the delayed queue, adding 595 // them to the active animations if they are ready 596 int numDelayedAnims = mDelayedAnims.size(); 597 for (int i = 0; i < numDelayedAnims; ++i) { 598 ValueAnimator anim = mDelayedAnims.get(i); 599 if (anim.delayedAnimationFrame(currentTime)) { 600 mReadyAnims.add(anim); 601 } 602 } 603 int numReadyAnims = mReadyAnims.size(); 604 if (numReadyAnims > 0) { 605 for (int i = 0; i < numReadyAnims; ++i) { 606 ValueAnimator anim = mReadyAnims.get(i); 607 anim.startAnimation(this); 608 anim.mRunning = true; 609 mDelayedAnims.remove(anim); 610 } 611 mReadyAnims.clear(); 612 } 613 614 // Now process all active animations. The return value from animationFrame() 615 // tells the handler whether it should now be ended 616 int numAnims = mAnimations.size(); 617 int i = 0; 618 while (i < numAnims) { 619 ValueAnimator anim = mAnimations.get(i); 620 if (anim.animationFrame(currentTime)) { 621 mEndingAnims.add(anim); 622 } 623 if (mAnimations.size() == numAnims) { 624 ++i; 625 } else { 626 // An animation might be canceled or ended by client code 627 // during the animation frame. Check to see if this happened by 628 // seeing whether the current index is the same as it was before 629 // calling animationFrame(). Another approach would be to copy 630 // animations to a temporary list and process that list instead, 631 // but that entails garbage and processing overhead that would 632 // be nice to avoid. 633 --numAnims; 634 mEndingAnims.remove(anim); 635 } 636 } 637 if (mEndingAnims.size() > 0) { 638 for (i = 0; i < mEndingAnims.size(); ++i) { 639 mEndingAnims.get(i).endAnimation(this); 640 } 641 mEndingAnims.clear(); 642 } 643 644 // If there are still active or delayed animations, schedule a future call to 645 // onAnimate to process the next frame of the animations. 646 if (!mAnimationScheduled 647 && (!mAnimations.isEmpty() || !mDelayedAnims.isEmpty())) { 648 mChoreographer.postAnimationCallback(this, null); 649 mAnimationScheduled = true; 650 } 651 } 652 653 // Called by the Choreographer. 654 @Override 655 public void run() { 656 mAnimationScheduled = false; 657 doAnimationFrame(); 658 } 659 } 660 661 /** 662 * The amount of time, in milliseconds, to delay starting the animation after 663 * {@link #start()} is called. 664 * 665 * @return the number of milliseconds to delay running the animation 666 */ 667 public long getStartDelay() { 668 return mUnscaledStartDelay; 669 } 670 671 /** 672 * The amount of time, in milliseconds, to delay starting the animation after 673 * {@link #start()} is called. 674 675 * @param startDelay The amount of the delay, in milliseconds 676 */ 677 public void setStartDelay(long startDelay) { 678 this.mStartDelay = (long)(startDelay * sDurationScale); 679 mUnscaledStartDelay = startDelay; 680 } 681 682 /** 683 * The amount of time, in milliseconds, between each frame of the animation. This is a 684 * requested time that the animation will attempt to honor, but the actual delay between 685 * frames may be different, depending on system load and capabilities. This is a static 686 * function because the same delay will be applied to all animations, since they are all 687 * run off of a single timing loop. 688 * 689 * The frame delay may be ignored when the animation system uses an external timing 690 * source, such as the display refresh rate (vsync), to govern animations. 691 * 692 * @return the requested time between frames, in milliseconds 693 */ 694 public static long getFrameDelay() { 695 return Choreographer.getFrameDelay(); 696 } 697 698 /** 699 * The amount of time, in milliseconds, between each frame of the animation. This is a 700 * requested time that the animation will attempt to honor, but the actual delay between 701 * frames may be different, depending on system load and capabilities. This is a static 702 * function because the same delay will be applied to all animations, since they are all 703 * run off of a single timing loop. 704 * 705 * The frame delay may be ignored when the animation system uses an external timing 706 * source, such as the display refresh rate (vsync), to govern animations. 707 * 708 * @param frameDelay the requested time between frames, in milliseconds 709 */ 710 public static void setFrameDelay(long frameDelay) { 711 Choreographer.setFrameDelay(frameDelay); 712 } 713 714 /** 715 * The most recent value calculated by this <code>ValueAnimator</code> when there is just one 716 * property being animated. This value is only sensible while the animation is running. The main 717 * purpose for this read-only property is to retrieve the value from the <code>ValueAnimator</code> 718 * during a call to {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 719 * is called during each animation frame, immediately after the value is calculated. 720 * 721 * @return animatedValue The value most recently calculated by this <code>ValueAnimator</code> for 722 * the single property being animated. If there are several properties being animated 723 * (specified by several PropertyValuesHolder objects in the constructor), this function 724 * returns the animated value for the first of those objects. 725 */ 726 public Object getAnimatedValue() { 727 if (mValues != null && mValues.length > 0) { 728 return mValues[0].getAnimatedValue(); 729 } 730 // Shouldn't get here; should always have values unless ValueAnimator was set up wrong 731 return null; 732 } 733 734 /** 735 * The most recent value calculated by this <code>ValueAnimator</code> for <code>propertyName</code>. 736 * The main purpose for this read-only property is to retrieve the value from the 737 * <code>ValueAnimator</code> during a call to 738 * {@link AnimatorUpdateListener#onAnimationUpdate(ValueAnimator)}, which 739 * is called during each animation frame, immediately after the value is calculated. 740 * 741 * @return animatedValue The value most recently calculated for the named property 742 * by this <code>ValueAnimator</code>. 743 */ 744 public Object getAnimatedValue(String propertyName) { 745 PropertyValuesHolder valuesHolder = mValuesMap.get(propertyName); 746 if (valuesHolder != null) { 747 return valuesHolder.getAnimatedValue(); 748 } else { 749 // At least avoid crashing if called with bogus propertyName 750 return null; 751 } 752 } 753 754 /** 755 * Sets how many times the animation should be repeated. If the repeat 756 * count is 0, the animation is never repeated. If the repeat count is 757 * greater than 0 or {@link #INFINITE}, the repeat mode will be taken 758 * into account. The repeat count is 0 by default. 759 * 760 * @param value the number of times the animation should be repeated 761 */ 762 public void setRepeatCount(int value) { 763 mRepeatCount = value; 764 } 765 /** 766 * Defines how many times the animation should repeat. The default value 767 * is 0. 768 * 769 * @return the number of times the animation should repeat, or {@link #INFINITE} 770 */ 771 public int getRepeatCount() { 772 return mRepeatCount; 773 } 774 775 /** 776 * Defines what this animation should do when it reaches the end. This 777 * setting is applied only when the repeat count is either greater than 778 * 0 or {@link #INFINITE}. Defaults to {@link #RESTART}. 779 * 780 * @param value {@link #RESTART} or {@link #REVERSE} 781 */ 782 public void setRepeatMode(int value) { 783 mRepeatMode = value; 784 } 785 786 /** 787 * Defines what this animation should do when it reaches the end. 788 * 789 * @return either one of {@link #REVERSE} or {@link #RESTART} 790 */ 791 public int getRepeatMode() { 792 return mRepeatMode; 793 } 794 795 /** 796 * Adds a listener to the set of listeners that are sent update events through the life of 797 * an animation. This method is called on all listeners for every frame of the animation, 798 * after the values for the animation have been calculated. 799 * 800 * @param listener the listener to be added to the current set of listeners for this animation. 801 */ 802 public void addUpdateListener(AnimatorUpdateListener listener) { 803 if (mUpdateListeners == null) { 804 mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 805 } 806 mUpdateListeners.add(listener); 807 } 808 809 /** 810 * Removes all listeners from the set listening to frame updates for this animation. 811 */ 812 public void removeAllUpdateListeners() { 813 if (mUpdateListeners == null) { 814 return; 815 } 816 mUpdateListeners.clear(); 817 mUpdateListeners = null; 818 } 819 820 /** 821 * Removes a listener from the set listening to frame updates for this animation. 822 * 823 * @param listener the listener to be removed from the current set of update listeners 824 * for this animation. 825 */ 826 public void removeUpdateListener(AnimatorUpdateListener listener) { 827 if (mUpdateListeners == null) { 828 return; 829 } 830 mUpdateListeners.remove(listener); 831 if (mUpdateListeners.size() == 0) { 832 mUpdateListeners = null; 833 } 834 } 835 836 837 /** 838 * The time interpolator used in calculating the elapsed fraction of this animation. The 839 * interpolator determines whether the animation runs with linear or non-linear motion, 840 * such as acceleration and deceleration. The default value is 841 * {@link android.view.animation.AccelerateDecelerateInterpolator} 842 * 843 * @param value the interpolator to be used by this animation. A value of <code>null</code> 844 * will result in linear interpolation. 845 */ 846 @Override 847 public void setInterpolator(TimeInterpolator value) { 848 if (value != null) { 849 mInterpolator = value; 850 } else { 851 mInterpolator = new LinearInterpolator(); 852 } 853 } 854 855 /** 856 * Returns the timing interpolator that this ValueAnimator uses. 857 * 858 * @return The timing interpolator for this ValueAnimator. 859 */ 860 public TimeInterpolator getInterpolator() { 861 return mInterpolator; 862 } 863 864 /** 865 * The type evaluator to be used when calculating the animated values of this animation. 866 * The system will automatically assign a float or int evaluator based on the type 867 * of <code>startValue</code> and <code>endValue</code> in the constructor. But if these values 868 * are not one of these primitive types, or if different evaluation is desired (such as is 869 * necessary with int values that represent colors), a custom evaluator needs to be assigned. 870 * For example, when running an animation on color values, the {@link ArgbEvaluator} 871 * should be used to get correct RGB color interpolation. 872 * 873 * <p>If this ValueAnimator has only one set of values being animated between, this evaluator 874 * will be used for that set. If there are several sets of values being animated, which is 875 * the case if PropertyValuesHOlder objects were set on the ValueAnimator, then the evaluator 876 * is assigned just to the first PropertyValuesHolder object.</p> 877 * 878 * @param value the evaluator to be used this animation 879 */ 880 public void setEvaluator(TypeEvaluator value) { 881 if (value != null && mValues != null && mValues.length > 0) { 882 mValues[0].setEvaluator(value); 883 } 884 } 885 886 /** 887 * Start the animation playing. This version of start() takes a boolean flag that indicates 888 * whether the animation should play in reverse. The flag is usually false, but may be set 889 * to true if called from the reverse() method. 890 * 891 * <p>The animation started by calling this method will be run on the thread that called 892 * this method. This thread should have a Looper on it (a runtime exception will be thrown if 893 * this is not the case). Also, if the animation will animate 894 * properties of objects in the view hierarchy, then the calling thread should be the UI 895 * thread for that view hierarchy.</p> 896 * 897 * @param playBackwards Whether the ValueAnimator should start playing in reverse. 898 */ 899 private void start(boolean playBackwards) { 900 if (Looper.myLooper() == null) { 901 throw new AndroidRuntimeException("Animators may only be run on Looper threads"); 902 } 903 mPlayingBackwards = playBackwards; 904 mCurrentIteration = 0; 905 mPlayingState = STOPPED; 906 mStarted = true; 907 mStartedDelay = false; 908 AnimationHandler animationHandler = getOrCreateAnimationHandler(); 909 animationHandler.mPendingAnimations.add(this); 910 if (mStartDelay == 0) { 911 // This sets the initial value of the animation, prior to actually starting it running 912 setCurrentPlayTime(getCurrentPlayTime()); 913 mPlayingState = STOPPED; 914 mRunning = true; 915 916 if (mListeners != null) { 917 ArrayList<AnimatorListener> tmpListeners = 918 (ArrayList<AnimatorListener>) mListeners.clone(); 919 int numListeners = tmpListeners.size(); 920 for (int i = 0; i < numListeners; ++i) { 921 tmpListeners.get(i).onAnimationStart(this); 922 } 923 } 924 } 925 animationHandler.sendEmptyMessage(ANIMATION_START); 926 } 927 928 @Override 929 public void start() { 930 start(false); 931 } 932 933 @Override 934 public void cancel() { 935 // Only cancel if the animation is actually running or has been started and is about 936 // to run 937 AnimationHandler handler = getOrCreateAnimationHandler(); 938 if (mPlayingState != STOPPED 939 || handler.mPendingAnimations.contains(this) 940 || handler.mDelayedAnims.contains(this)) { 941 // Only notify listeners if the animator has actually started 942 if (mRunning && mListeners != null) { 943 ArrayList<AnimatorListener> tmpListeners = 944 (ArrayList<AnimatorListener>) mListeners.clone(); 945 for (AnimatorListener listener : tmpListeners) { 946 listener.onAnimationCancel(this); 947 } 948 } 949 endAnimation(handler); 950 } 951 } 952 953 @Override 954 public void end() { 955 AnimationHandler handler = getOrCreateAnimationHandler(); 956 if (!handler.mAnimations.contains(this) && !handler.mPendingAnimations.contains(this)) { 957 // Special case if the animation has not yet started; get it ready for ending 958 mStartedDelay = false; 959 startAnimation(handler); 960 } else if (!mInitialized) { 961 initAnimation(); 962 } 963 // The final value set on the target varies, depending on whether the animation 964 // was supposed to repeat an odd number of times 965 if (mRepeatCount > 0 && (mRepeatCount & 0x01) == 1) { 966 animateValue(0f); 967 } else { 968 animateValue(1f); 969 } 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 (mRunning && mListeners != null) { 1012 ArrayList<AnimatorListener> tmpListeners = 1013 (ArrayList<AnimatorListener>) mListeners.clone(); 1014 int numListeners = tmpListeners.size(); 1015 for (int i = 0; i < numListeners; ++i) { 1016 tmpListeners.get(i).onAnimationEnd(this); 1017 } 1018 } 1019 mRunning = false; 1020 mStarted = false; 1021 } 1022 1023 /** 1024 * Called internally to start an animation by adding it to the active animations list. Must be 1025 * called on the UI thread. 1026 */ 1027 private void startAnimation(AnimationHandler handler) { 1028 initAnimation(); 1029 handler.mAnimations.add(this); 1030 if (mStartDelay > 0 && mListeners != null) { 1031 // Listeners were already notified in start() if startDelay is 0; this is 1032 // just for delayed animations 1033 ArrayList<AnimatorListener> tmpListeners = 1034 (ArrayList<AnimatorListener>) mListeners.clone(); 1035 int numListeners = tmpListeners.size(); 1036 for (int i = 0; i < numListeners; ++i) { 1037 tmpListeners.get(i).onAnimationStart(this); 1038 } 1039 } 1040 } 1041 1042 /** 1043 * Internal function called to process an animation frame on an animation that is currently 1044 * sleeping through its <code>startDelay</code> phase. The return value indicates whether it 1045 * should be woken up and put on the active animations queue. 1046 * 1047 * @param currentTime The current animation time, used to calculate whether the animation 1048 * has exceeded its <code>startDelay</code> and should be started. 1049 * @return True if the animation's <code>startDelay</code> has been exceeded and the animation 1050 * should be added to the set of active animations. 1051 */ 1052 private boolean delayedAnimationFrame(long currentTime) { 1053 if (!mStartedDelay) { 1054 mStartedDelay = true; 1055 mDelayStartTime = currentTime; 1056 } else { 1057 long deltaTime = currentTime - mDelayStartTime; 1058 if (deltaTime > mStartDelay) { 1059 // startDelay ended - start the anim and record the 1060 // mStartTime appropriately 1061 mStartTime = currentTime - (deltaTime - mStartDelay); 1062 mPlayingState = RUNNING; 1063 return true; 1064 } 1065 } 1066 return false; 1067 } 1068 1069 /** 1070 * This internal function processes a single animation frame for a given animation. The 1071 * currentTime parameter is the timing pulse sent by the handler, used to calculate the 1072 * elapsed duration, and therefore 1073 * the elapsed fraction, of the animation. The return value indicates whether the animation 1074 * should be ended (which happens when the elapsed time of the animation exceeds the 1075 * animation's duration, including the repeatCount). 1076 * 1077 * @param currentTime The current time, as tracked by the static timing handler 1078 * @return true if the animation's duration, including any repetitions due to 1079 * <code>repeatCount</code> has been exceeded and the animation should be ended. 1080 */ 1081 boolean animationFrame(long currentTime) { 1082 boolean done = false; 1083 1084 if (mPlayingState == STOPPED) { 1085 mPlayingState = RUNNING; 1086 if (mSeekTime < 0) { 1087 mStartTime = currentTime; 1088 } else { 1089 mStartTime = currentTime - mSeekTime; 1090 // Now that we're playing, reset the seek time 1091 mSeekTime = -1; 1092 } 1093 } 1094 switch (mPlayingState) { 1095 case RUNNING: 1096 case SEEKED: 1097 float fraction = mDuration > 0 ? (float)(currentTime - mStartTime) / mDuration : 1f; 1098 if (fraction >= 1f) { 1099 if (mCurrentIteration < mRepeatCount || mRepeatCount == INFINITE) { 1100 // Time to repeat 1101 if (mListeners != null) { 1102 int numListeners = mListeners.size(); 1103 for (int i = 0; i < numListeners; ++i) { 1104 mListeners.get(i).onAnimationRepeat(this); 1105 } 1106 } 1107 if (mRepeatMode == REVERSE) { 1108 mPlayingBackwards = mPlayingBackwards ? false : true; 1109 } 1110 mCurrentIteration += (int)fraction; 1111 fraction = fraction % 1f; 1112 mStartTime += mDuration; 1113 } else { 1114 done = true; 1115 fraction = Math.min(fraction, 1.0f); 1116 } 1117 } 1118 if (mPlayingBackwards) { 1119 fraction = 1f - fraction; 1120 } 1121 animateValue(fraction); 1122 break; 1123 } 1124 1125 return done; 1126 } 1127 1128 /** 1129 * Returns the current animation fraction, which is the elapsed/interpolated fraction used in 1130 * the most recent frame update on the animation. 1131 * 1132 * @return Elapsed/interpolated fraction of the animation. 1133 */ 1134 public float getAnimatedFraction() { 1135 return mCurrentFraction; 1136 } 1137 1138 /** 1139 * This method is called with the elapsed fraction of the animation during every 1140 * animation frame. This function turns the elapsed fraction into an interpolated fraction 1141 * and then into an animated value (from the evaluator. The function is called mostly during 1142 * animation updates, but it is also called when the <code>end()</code> 1143 * function is called, to set the final value on the property. 1144 * 1145 * <p>Overrides of this method must call the superclass to perform the calculation 1146 * of the animated value.</p> 1147 * 1148 * @param fraction The elapsed fraction of the animation. 1149 */ 1150 void animateValue(float fraction) { 1151 fraction = mInterpolator.getInterpolation(fraction); 1152 mCurrentFraction = fraction; 1153 int numValues = mValues.length; 1154 for (int i = 0; i < numValues; ++i) { 1155 mValues[i].calculateValue(fraction); 1156 } 1157 if (mUpdateListeners != null) { 1158 int numListeners = mUpdateListeners.size(); 1159 for (int i = 0; i < numListeners; ++i) { 1160 mUpdateListeners.get(i).onAnimationUpdate(this); 1161 } 1162 } 1163 } 1164 1165 @Override 1166 public ValueAnimator clone() { 1167 final ValueAnimator anim = (ValueAnimator) super.clone(); 1168 if (mUpdateListeners != null) { 1169 ArrayList<AnimatorUpdateListener> oldListeners = mUpdateListeners; 1170 anim.mUpdateListeners = new ArrayList<AnimatorUpdateListener>(); 1171 int numListeners = oldListeners.size(); 1172 for (int i = 0; i < numListeners; ++i) { 1173 anim.mUpdateListeners.add(oldListeners.get(i)); 1174 } 1175 } 1176 anim.mSeekTime = -1; 1177 anim.mPlayingBackwards = false; 1178 anim.mCurrentIteration = 0; 1179 anim.mInitialized = false; 1180 anim.mPlayingState = STOPPED; 1181 anim.mStartedDelay = false; 1182 PropertyValuesHolder[] oldValues = mValues; 1183 if (oldValues != null) { 1184 int numValues = oldValues.length; 1185 anim.mValues = new PropertyValuesHolder[numValues]; 1186 anim.mValuesMap = new HashMap<String, PropertyValuesHolder>(numValues); 1187 for (int i = 0; i < numValues; ++i) { 1188 PropertyValuesHolder newValuesHolder = oldValues[i].clone(); 1189 anim.mValues[i] = newValuesHolder; 1190 anim.mValuesMap.put(newValuesHolder.getPropertyName(), newValuesHolder); 1191 } 1192 } 1193 return anim; 1194 } 1195 1196 /** 1197 * Implementors of this interface can add themselves as update listeners 1198 * to an <code>ValueAnimator</code> instance to receive callbacks on every animation 1199 * frame, after the current frame's values have been calculated for that 1200 * <code>ValueAnimator</code>. 1201 */ 1202 public static interface AnimatorUpdateListener { 1203 /** 1204 * <p>Notifies the occurrence of another frame of the animation.</p> 1205 * 1206 * @param animation The animation which was repeated. 1207 */ 1208 void onAnimationUpdate(ValueAnimator animation); 1209 1210 } 1211 1212 /** 1213 * Return the number of animations currently running. 1214 * 1215 * Used by StrictMode internally to annotate violations. 1216 * May be called on arbitrary threads! 1217 * 1218 * @hide 1219 */ 1220 public static int getCurrentAnimationsCount() { 1221 AnimationHandler handler = sAnimationHandler.get(); 1222 return handler != null ? handler.mAnimations.size() : 0; 1223 } 1224 1225 /** 1226 * Clear all animations on this thread, without canceling or ending them. 1227 * This should be used with caution. 1228 * 1229 * @hide 1230 */ 1231 public static void clearAllAnimations() { 1232 AnimationHandler handler = sAnimationHandler.get(); 1233 if (handler != null) { 1234 handler.mAnimations.clear(); 1235 handler.mPendingAnimations.clear(); 1236 handler.mDelayedAnims.clear(); 1237 } 1238 } 1239 1240 private AnimationHandler getOrCreateAnimationHandler() { 1241 AnimationHandler handler = sAnimationHandler.get(); 1242 if (handler == null) { 1243 handler = new AnimationHandler(); 1244 sAnimationHandler.set(handler); 1245 } 1246 return handler; 1247 } 1248 1249 @Override 1250 public String toString() { 1251 String returnVal = "ValueAnimator@" + Integer.toHexString(hashCode()); 1252 if (mValues != null) { 1253 for (int i = 0; i < mValues.length; ++i) { 1254 returnVal += "\n " + mValues[i].toString(); 1255 } 1256 } 1257 return returnVal; 1258 } 1259} 1260