AnimatorSet.java revision 7c608f25d494c8a0a671e7373efbb47ca635367e
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 java.util.ArrayList; 20import java.util.HashMap; 21 22/** 23 * This class plays a set of {@link Animator} objects in the specified order. Animations 24 * can be set up to play together, in sequence, or after a specified delay. 25 * 26 * <p>There are two different approaches to adding animations to a <code>AnimatorSet</code>: 27 * either the {@link AnimatorSet#playTogether(Animator[]) playTogether()} or 28 * {@link AnimatorSet#playSequentially(Animator[]) playSequentially()} methods can be called to add 29 * a set of animations all at once, or the {@link AnimatorSet#play(Animator)} can be 30 * used in conjunction with methods in the {@link AnimatorSet.Builder Builder} 31 * class to add animations 32 * one by one.</p> 33 * 34 * <p>It is possible to set up a <code>AnimatorSet</code> with circular dependencies between 35 * its animations. For example, an animation a1 could be set up to start before animation a2, a2 36 * before a3, and a3 before a1. The results of this configuration are undefined, but will typically 37 * result in none of the affected animations being played. Because of this (and because 38 * circular dependencies do not make logical sense anyway), circular dependencies 39 * should be avoided, and the dependency flow of animations should only be in one direction. 40 */ 41public final class AnimatorSet extends Animator { 42 43 /** 44 * Internal variables 45 * NOTE: This object implements the clone() method, making a deep copy of any referenced 46 * objects. As other non-trivial fields are added to this class, make sure to add logic 47 * to clone() to make deep copies of them. 48 */ 49 50 /** 51 * Tracks animations currently being played, so that we know what to 52 * cancel or end when cancel() or end() is called on this AnimatorSet 53 */ 54 private ArrayList<Animator> mPlayingSet = new ArrayList<Animator>(); 55 56 /** 57 * Contains all nodes, mapped to their respective Animators. When new 58 * dependency information is added for an Animator, we want to add it 59 * to a single node representing that Animator, not create a new Node 60 * if one already exists. 61 */ 62 private HashMap<Animator, Node> mNodeMap = new HashMap<Animator, Node>(); 63 64 /** 65 * Set of all nodes created for this AnimatorSet. This list is used upon 66 * starting the set, and the nodes are placed in sorted order into the 67 * sortedNodes collection. 68 */ 69 private ArrayList<Node> mNodes = new ArrayList<Node>(); 70 71 /** 72 * The sorted list of nodes. This is the order in which the animations will 73 * be played. The details about when exactly they will be played depend 74 * on the dependency relationships of the nodes. 75 */ 76 private ArrayList<Node> mSortedNodes = new ArrayList<Node>(); 77 78 /** 79 * Flag indicating whether the nodes should be sorted prior to playing. This 80 * flag allows us to cache the previous sorted nodes so that if the sequence 81 * is replayed with no changes, it does not have to re-sort the nodes again. 82 */ 83 private boolean mNeedsSort = true; 84 85 private AnimatorSetListener mSetListener = null; 86 87 /** 88 * Flag indicating that the AnimatorSet has been canceled (by calling cancel() or end()). 89 * This flag is used to avoid starting other animations when currently-playing 90 * child animations of this AnimatorSet end. 91 */ 92 boolean mCanceled = false; 93 94 // The amount of time in ms to delay starting the animation after start() is called 95 private long mStartDelay = 0; 96 97 98 // How long the child animations should last in ms. The default value is negative, which 99 // simply means that there is no duration set on the AnimatorSet. When a real duration is 100 // set, it is passed along to the child animations. 101 private long mDuration = -1; 102 103 104 /** 105 * Sets up this AnimatorSet to play all of the supplied animations at the same time. 106 * 107 * @param items The animations that will be started simultaneously. 108 */ 109 public void playTogether(Animator... items) { 110 if (items != null) { 111 mNeedsSort = true; 112 Builder builder = play(items[0]); 113 for (int i = 1; i < items.length; ++i) { 114 builder.with(items[i]); 115 } 116 } 117 } 118 119 /** 120 * Sets up this AnimatorSet to play each of the supplied animations when the 121 * previous animation ends. 122 * 123 * @param items The aniamtions that will be started one after another. 124 */ 125 public void playSequentially(Animator... items) { 126 if (items != null) { 127 mNeedsSort = true; 128 if (items.length == 1) { 129 play(items[0]); 130 } else { 131 for (int i = 0; i < items.length - 1; ++i) { 132 play(items[i]).before(items[i+1]); 133 } 134 } 135 } 136 } 137 138 /** 139 * Returns the current list of child Animator objects controlled by this 140 * AnimatorSet. This is a copy of the internal list; modifications to the returned list 141 * will not affect the AnimatorSet, although changes to the underlying Animator objects 142 * will affect those objects being managed by the AnimatorSet. 143 * 144 * @return ArrayList<Animator> The list of child animations of this AnimatorSet. 145 */ 146 public ArrayList<Animator> getChildAnimations() { 147 ArrayList<Animator> childList = new ArrayList<Animator>(); 148 for (Node node : mNodes) { 149 childList.add(node.animation); 150 } 151 return childList; 152 } 153 154 /** 155 * Sets the target object for all current {@link #getChildAnimations() child animations} 156 * of this AnimatorSet that take targets ({@link ObjectAnimator} and 157 * AnimatorSet). 158 * 159 * @param target The object being animated 160 */ 161 @Override 162 public void setTarget(Object target) { 163 for (Node node : mNodes) { 164 Animator animation = node.animation; 165 if (animation instanceof AnimatorSet) { 166 ((AnimatorSet)animation).setTarget(target); 167 } else if (animation instanceof ObjectAnimator) { 168 ((ObjectAnimator)animation).setTarget(target); 169 } 170 } 171 } 172 173 /** 174 * Sets the TimeInterpolator for all current {@link #getChildAnimations() child animations} 175 * of this AnimatorSet. 176 * 177 * @param interpolator the interpolator to be used by each child animation of this AnimatorSet 178 */ 179 @Override 180 public void setInterpolator(TimeInterpolator interpolator) { 181 for (Node node : mNodes) { 182 node.animation.setInterpolator(interpolator); 183 } 184 } 185 186 /** 187 * This method creates a <code>Builder</code> object, which is used to 188 * set up playing constraints. This initial <code>play()</code> method 189 * tells the <code>Builder</code> the animation that is the dependency for 190 * the succeeding commands to the <code>Builder</code>. For example, 191 * calling <code>play(a1).with(a2)</code> sets up the AnimatorSet to play 192 * <code>a1</code> and <code>a2</code> at the same time, 193 * <code>play(a1).before(a2)</code> sets up the AnimatorSet to play 194 * <code>a1</code> first, followed by <code>a2</code>, and 195 * <code>play(a1).after(a2)</code> sets up the AnimatorSet to play 196 * <code>a2</code> first, followed by <code>a1</code>. 197 * 198 * <p>Note that <code>play()</code> is the only way to tell the 199 * <code>Builder</code> the animation upon which the dependency is created, 200 * so successive calls to the various functions in <code>Builder</code> 201 * will all refer to the initial parameter supplied in <code>play()</code> 202 * as the dependency of the other animations. For example, calling 203 * <code>play(a1).before(a2).before(a3)</code> will play both <code>a2</code> 204 * and <code>a3</code> when a1 ends; it does not set up a dependency between 205 * <code>a2</code> and <code>a3</code>.</p> 206 * 207 * @param anim The animation that is the dependency used in later calls to the 208 * methods in the returned <code>Builder</code> object. A null parameter will result 209 * in a null <code>Builder</code> return value. 210 * @return Builder The object that constructs the AnimatorSet based on the dependencies 211 * outlined in the calls to <code>play</code> and the other methods in the 212 * <code>Builder</code object. 213 */ 214 public Builder play(Animator anim) { 215 if (anim != null) { 216 mNeedsSort = true; 217 return new Builder(anim); 218 } 219 return null; 220 } 221 222 /** 223 * {@inheritDoc} 224 * 225 * <p>Note that canceling a <code>AnimatorSet</code> also cancels all of the animations that it is 226 * responsible for.</p> 227 */ 228 @SuppressWarnings("unchecked") 229 @Override 230 public void cancel() { 231 mCanceled = true; 232 if (mListeners != null) { 233 ArrayList<AnimatorListener> tmpListeners = 234 (ArrayList<AnimatorListener>) mListeners.clone(); 235 for (AnimatorListener listener : tmpListeners) { 236 listener.onAnimationCancel(this); 237 } 238 } 239 if (mSortedNodes.size() > 0) { 240 for (Node node : mSortedNodes) { 241 node.animation.cancel(); 242 } 243 } 244 } 245 246 /** 247 * {@inheritDoc} 248 * 249 * <p>Note that ending a <code>AnimatorSet</code> also ends all of the animations that it is 250 * responsible for.</p> 251 */ 252 @Override 253 public void end() { 254 mCanceled = true; 255 if (mSortedNodes.size() != mNodes.size()) { 256 // hasn't been started yet - sort the nodes now, then end them 257 sortNodes(); 258 for (Node node : mSortedNodes) { 259 if (mSetListener == null) { 260 mSetListener = new AnimatorSetListener(this); 261 } 262 node.animation.addListener(mSetListener); 263 } 264 } 265 if (mSortedNodes.size() > 0) { 266 for (Node node : mSortedNodes) { 267 node.animation.end(); 268 } 269 } 270 } 271 272 /** 273 * Returns true if any of the child animations of this AnimatorSet have been started and have not 274 * yet ended. 275 * @return Whether this AnimatorSet has been started and has not yet ended. 276 */ 277 @Override 278 public boolean isRunning() { 279 for (Node node : mNodes) { 280 if (node.animation.isRunning()) { 281 return true; 282 } 283 } 284 return false; 285 } 286 287 /** 288 * The amount of time, in milliseconds, to delay starting the animation after 289 * {@link #start()} is called. 290 * 291 * @return the number of milliseconds to delay running the animation 292 */ 293 @Override 294 public long getStartDelay() { 295 return mStartDelay; 296 } 297 298 /** 299 * The amount of time, in milliseconds, to delay starting the animation after 300 * {@link #start()} is called. 301 302 * @param startDelay The amount of the delay, in milliseconds 303 */ 304 @Override 305 public void setStartDelay(long startDelay) { 306 mStartDelay = startDelay; 307 } 308 309 /** 310 * Gets the length of each of the child animations of this AnimatorSet. This value may 311 * be less than 0, which indicates that no duration has been set on this AnimatorSet 312 * and each of the child animations will use their own duration. 313 * 314 * @return The length of the animation, in milliseconds, of each of the child 315 * animations of this AnimatorSet. 316 */ 317 @Override 318 public long getDuration() { 319 return mDuration; 320 } 321 322 /** 323 * Sets the length of each of the current child animations of this AnimatorSet. By default, 324 * each child animation will use its own duration. If the duration is set on the AnimatorSet, 325 * then each child animation inherits this duration. 326 * 327 * @param duration The length of the animation, in milliseconds, of each of the child 328 * animations of this AnimatorSet. 329 */ 330 @Override 331 public AnimatorSet setDuration(long duration) { 332 if (duration < 0) { 333 throw new IllegalArgumentException("duration must be a value of zero or greater"); 334 } 335 for (Node node : mNodes) { 336 // TODO: don't set the duration of the timing-only nodes created by AnimatorSet to 337 // insert "play-after" delays 338 node.animation.setDuration(duration); 339 } 340 mDuration = duration; 341 return this; 342 } 343 344 /** 345 * {@inheritDoc} 346 * 347 * <p>Starting this <code>AnimatorSet</code> will, in turn, start the animations for which 348 * it is responsible. The details of when exactly those animations are started depends on 349 * the dependency relationships that have been set up between the animations. 350 */ 351 @SuppressWarnings("unchecked") 352 @Override 353 public void start() { 354 mCanceled = false; 355 356 // First, sort the nodes (if necessary). This will ensure that sortedNodes 357 // contains the animation nodes in the correct order. 358 sortNodes(); 359 360 // nodesToStart holds the list of nodes to be started immediately. We don't want to 361 // start the animations in the loop directly because we first need to set up 362 // dependencies on all of the nodes. For example, we don't want to start an animation 363 // when some other animation also wants to start when the first animation begins. 364 final ArrayList<Node> nodesToStart = new ArrayList<Node>(); 365 int numSortedNodes = mSortedNodes.size(); 366 for (int i = 0; i < numSortedNodes; ++i) { 367 Node node = mSortedNodes.get(i); 368 if (mSetListener == null) { 369 mSetListener = new AnimatorSetListener(this); 370 } 371 if (node.dependencies == null || node.dependencies.size() == 0) { 372 nodesToStart.add(node); 373 } else { 374 int numDependencies = node.dependencies.size(); 375 for (int j = 0; j < numDependencies; ++j) { 376 Dependency dependency = node.dependencies.get(j); 377 dependency.node.animation.addListener( 378 new DependencyListener(this, node, dependency.rule)); 379 } 380 node.tmpDependencies = (ArrayList<Dependency>) node.dependencies.clone(); 381 } 382 node.animation.addListener(mSetListener); 383 } 384 // Now that all dependencies are set up, start the animations that should be started. 385 if (mStartDelay <= 0) { 386 for (Node node : nodesToStart) { 387 node.animation.start(); 388 mPlayingSet.add(node.animation); 389 } 390 } else { 391 // TODO: Need to cancel out of the delay appropriately 392 ValueAnimator delayAnim = ValueAnimator.ofFloat(0f, 1f); 393 delayAnim.setDuration(mStartDelay); 394 delayAnim.addListener(new AnimatorListenerAdapter() { 395 public void onAnimationEnd(Animator anim) { 396 int numNodes = nodesToStart.size(); 397 for (int i = 0; i < numNodes; ++i) { 398 Node node = nodesToStart.get(i); 399 node.animation.start(); 400 mPlayingSet.add(node.animation); 401 } 402 } 403 }); 404 } 405 if (mListeners != null) { 406 ArrayList<AnimatorListener> tmpListeners = 407 (ArrayList<AnimatorListener>) mListeners.clone(); 408 int numListeners = tmpListeners.size(); 409 for (int i = 0; i < numListeners; ++i) { 410 tmpListeners.get(i).onAnimationStart(this); 411 } 412 } 413 } 414 415 @Override 416 public AnimatorSet clone() { 417 final AnimatorSet anim = (AnimatorSet) super.clone(); 418 /* 419 * The basic clone() operation copies all items. This doesn't work very well for 420 * AnimatorSet, because it will copy references that need to be recreated and state 421 * that may not apply. What we need to do now is put the clone in an uninitialized 422 * state, with fresh, empty data structures. Then we will build up the nodes list 423 * manually, as we clone each Node (and its animation). The clone will then be sorted, 424 * and will populate any appropriate lists, when it is started. 425 */ 426 anim.mNeedsSort = true; 427 anim.mCanceled = false; 428 anim.mPlayingSet = new ArrayList<Animator>(); 429 anim.mNodeMap = new HashMap<Animator, Node>(); 430 anim.mNodes = new ArrayList<Node>(); 431 anim.mSortedNodes = new ArrayList<Node>(); 432 433 // Walk through the old nodes list, cloning each node and adding it to the new nodemap. 434 // One problem is that the old node dependencies point to nodes in the old AnimatorSet. 435 // We need to track the old/new nodes in order to reconstruct the dependencies in the clone. 436 HashMap<Node, Node> nodeCloneMap = new HashMap<Node, Node>(); // <old, new> 437 for (Node node : mNodes) { 438 Node nodeClone = node.clone(); 439 nodeCloneMap.put(node, nodeClone); 440 anim.mNodes.add(nodeClone); 441 anim.mNodeMap.put(nodeClone.animation, nodeClone); 442 // Clear out the dependencies in the clone; we'll set these up manually later 443 nodeClone.dependencies = null; 444 nodeClone.tmpDependencies = null; 445 nodeClone.nodeDependents = null; 446 nodeClone.nodeDependencies = null; 447 // clear out any listeners that were set up by the AnimatorSet; these will 448 // be set up when the clone's nodes are sorted 449 ArrayList<AnimatorListener> cloneListeners = nodeClone.animation.getListeners(); 450 if (cloneListeners != null) { 451 ArrayList<AnimatorListener> listenersToRemove = null; 452 for (AnimatorListener listener : cloneListeners) { 453 if (listener instanceof AnimatorSetListener) { 454 if (listenersToRemove == null) { 455 listenersToRemove = new ArrayList<AnimatorListener>(); 456 } 457 listenersToRemove.add(listener); 458 } 459 } 460 if (listenersToRemove != null) { 461 for (AnimatorListener listener : listenersToRemove) { 462 cloneListeners.remove(listener); 463 } 464 } 465 } 466 } 467 // Now that we've cloned all of the nodes, we're ready to walk through their 468 // dependencies, mapping the old dependencies to the new nodes 469 for (Node node : mNodes) { 470 Node nodeClone = nodeCloneMap.get(node); 471 if (node.dependencies != null) { 472 for (Dependency dependency : node.dependencies) { 473 Node clonedDependencyNode = nodeCloneMap.get(dependency.node); 474 Dependency cloneDependency = new Dependency(clonedDependencyNode, 475 dependency.rule); 476 nodeClone.addDependency(cloneDependency); 477 } 478 } 479 } 480 481 return anim; 482 } 483 484 /** 485 * This class is the mechanism by which animations are started based on events in other 486 * animations. If an animation has multiple dependencies on other animations, then 487 * all dependencies must be satisfied before the animation is started. 488 */ 489 private static class DependencyListener implements AnimatorListener { 490 491 private AnimatorSet mAnimatorSet; 492 493 // The node upon which the dependency is based. 494 private Node mNode; 495 496 // The Dependency rule (WITH or AFTER) that the listener should wait for on 497 // the node 498 private int mRule; 499 500 public DependencyListener(AnimatorSet animatorSet, Node node, int rule) { 501 this.mAnimatorSet = animatorSet; 502 this.mNode = node; 503 this.mRule = rule; 504 } 505 506 /** 507 * Ignore cancel events for now. We may want to handle this eventually, 508 * to prevent follow-on animations from running when some dependency 509 * animation is canceled. 510 */ 511 public void onAnimationCancel(Animator animation) { 512 } 513 514 /** 515 * An end event is received - see if this is an event we are listening for 516 */ 517 public void onAnimationEnd(Animator animation) { 518 if (mRule == Dependency.AFTER) { 519 startIfReady(animation); 520 } 521 } 522 523 /** 524 * Ignore repeat events for now 525 */ 526 public void onAnimationRepeat(Animator animation) { 527 } 528 529 /** 530 * A start event is received - see if this is an event we are listening for 531 */ 532 public void onAnimationStart(Animator animation) { 533 if (mRule == Dependency.WITH) { 534 startIfReady(animation); 535 } 536 } 537 538 /** 539 * Check whether the event received is one that the node was waiting for. 540 * If so, mark it as complete and see whether it's time to start 541 * the animation. 542 * @param dependencyAnimation the animation that sent the event. 543 */ 544 private void startIfReady(Animator dependencyAnimation) { 545 if (mAnimatorSet.mCanceled) { 546 // if the parent AnimatorSet was canceled, then don't start any dependent anims 547 return; 548 } 549 Dependency dependencyToRemove = null; 550 int numDependencies = mNode.tmpDependencies.size(); 551 for (int i = 0; i < numDependencies; ++i) { 552 Dependency dependency = mNode.tmpDependencies.get(i); 553 if (dependency.rule == mRule && 554 dependency.node.animation == dependencyAnimation) { 555 // rule fired - remove the dependency and listener and check to 556 // see whether it's time to start the animation 557 dependencyToRemove = dependency; 558 dependencyAnimation.removeListener(this); 559 break; 560 } 561 } 562 mNode.tmpDependencies.remove(dependencyToRemove); 563 if (mNode.tmpDependencies.size() == 0) { 564 // all dependencies satisfied: start the animation 565 mNode.animation.start(); 566 mAnimatorSet.mPlayingSet.add(mNode.animation); 567 } 568 } 569 570 } 571 572 private class AnimatorSetListener implements AnimatorListener { 573 574 private AnimatorSet mAnimatorSet; 575 576 AnimatorSetListener(AnimatorSet animatorSet) { 577 mAnimatorSet = animatorSet; 578 } 579 580 public void onAnimationCancel(Animator animation) { 581 if (mPlayingSet.size() == 0) { 582 if (mListeners != null) { 583 int numListeners = mListeners.size(); 584 for (int i = 0; i < numListeners; ++i) { 585 mListeners.get(i).onAnimationCancel(mAnimatorSet); 586 } 587 } 588 } 589 } 590 591 @SuppressWarnings("unchecked") 592 public void onAnimationEnd(Animator animation) { 593 animation.removeListener(this); 594 mPlayingSet.remove(animation); 595 Node animNode = mAnimatorSet.mNodeMap.get(animation); 596 animNode.done = true; 597 ArrayList<Node> sortedNodes = mAnimatorSet.mSortedNodes; 598 boolean allDone = true; 599 int numSortedNodes = sortedNodes.size(); 600 for (int i = 0; i < numSortedNodes; ++i) { 601 if (!sortedNodes.get(i).done) { 602 allDone = false; 603 break; 604 } 605 } 606 if (allDone) { 607 // If this was the last child animation to end, then notify listeners that this 608 // AnimatorSet has ended 609 if (mListeners != null) { 610 ArrayList<AnimatorListener> tmpListeners = 611 (ArrayList<AnimatorListener>) mListeners.clone(); 612 int numListeners = tmpListeners.size(); 613 for (int i = 0; i < numListeners; ++i) { 614 tmpListeners.get(i).onAnimationEnd(mAnimatorSet); 615 } 616 } 617 } 618 } 619 620 // Nothing to do 621 public void onAnimationRepeat(Animator animation) { 622 } 623 624 // Nothing to do 625 public void onAnimationStart(Animator animation) { 626 } 627 628 } 629 630 /** 631 * This method sorts the current set of nodes, if needed. The sort is a simple 632 * DependencyGraph sort, which goes like this: 633 * - All nodes without dependencies become 'roots' 634 * - while roots list is not null 635 * - for each root r 636 * - add r to sorted list 637 * - remove r as a dependency from any other node 638 * - any nodes with no dependencies are added to the roots list 639 */ 640 private void sortNodes() { 641 if (mNeedsSort) { 642 mSortedNodes.clear(); 643 ArrayList<Node> roots = new ArrayList<Node>(); 644 int numNodes = mNodes.size(); 645 for (int i = 0; i < numNodes; ++i) { 646 Node node = mNodes.get(i); 647 if (node.dependencies == null || node.dependencies.size() == 0) { 648 roots.add(node); 649 } 650 } 651 ArrayList<Node> tmpRoots = new ArrayList<Node>(); 652 while (roots.size() > 0) { 653 int numRoots = roots.size(); 654 for (int i = 0; i < numRoots; ++i) { 655 Node root = roots.get(i); 656 mSortedNodes.add(root); 657 if (root.nodeDependents != null) { 658 int numDependents = root.nodeDependents.size(); 659 for (int j = 0; j < numDependents; ++j) { 660 Node node = root.nodeDependents.get(j); 661 node.nodeDependencies.remove(root); 662 if (node.nodeDependencies.size() == 0) { 663 tmpRoots.add(node); 664 } 665 } 666 } 667 } 668 roots.clear(); 669 roots.addAll(tmpRoots); 670 tmpRoots.clear(); 671 } 672 mNeedsSort = false; 673 if (mSortedNodes.size() != mNodes.size()) { 674 throw new IllegalStateException("Circular dependencies cannot exist" 675 + " in AnimatorSet"); 676 } 677 } else { 678 // Doesn't need sorting, but still need to add in the nodeDependencies list 679 // because these get removed as the event listeners fire and the dependencies 680 // are satisfied 681 int numNodes = mNodes.size(); 682 for (int i = 0; i < numNodes; ++i) { 683 Node node = mNodes.get(i); 684 if (node.dependencies != null && node.dependencies.size() > 0) { 685 int numDependencies = node.dependencies.size(); 686 for (int j = 0; j < numDependencies; ++j) { 687 Dependency dependency = node.dependencies.get(j); 688 if (node.nodeDependencies == null) { 689 node.nodeDependencies = new ArrayList<Node>(); 690 } 691 if (!node.nodeDependencies.contains(dependency.node)) { 692 node.nodeDependencies.add(dependency.node); 693 } 694 } 695 } 696 node.done = false; 697 } 698 } 699 } 700 701 /** 702 * Dependency holds information about the node that some other node is 703 * dependent upon and the nature of that dependency. 704 * 705 */ 706 private static class Dependency { 707 static final int WITH = 0; // dependent node must start with this dependency node 708 static final int AFTER = 1; // dependent node must start when this dependency node finishes 709 710 // The node that the other node with this Dependency is dependent upon 711 public Node node; 712 713 // The nature of the dependency (WITH or AFTER) 714 public int rule; 715 716 public Dependency(Node node, int rule) { 717 this.node = node; 718 this.rule = rule; 719 } 720 } 721 722 /** 723 * A Node is an embodiment of both the Animator that it wraps as well as 724 * any dependencies that are associated with that Animation. This includes 725 * both dependencies upon other nodes (in the dependencies list) as 726 * well as dependencies of other nodes upon this (in the nodeDependents list). 727 */ 728 private static class Node implements Cloneable { 729 public Animator animation; 730 731 /** 732 * These are the dependencies that this node's animation has on other 733 * nodes. For example, if this node's animation should begin with some 734 * other animation ends, then there will be an item in this node's 735 * dependencies list for that other animation's node. 736 */ 737 public ArrayList<Dependency> dependencies = null; 738 739 /** 740 * tmpDependencies is a runtime detail. We use the dependencies list for sorting. 741 * But we also use the list to keep track of when multiple dependencies are satisfied, 742 * but removing each dependency as it is satisfied. We do not want to remove 743 * the dependency itself from the list, because we need to retain that information 744 * if the AnimatorSet is launched in the future. So we create a copy of the dependency 745 * list when the AnimatorSet starts and use this tmpDependencies list to track the 746 * list of satisfied dependencies. 747 */ 748 public ArrayList<Dependency> tmpDependencies = null; 749 750 /** 751 * nodeDependencies is just a list of the nodes that this Node is dependent upon. 752 * This information is used in sortNodes(), to determine when a node is a root. 753 */ 754 public ArrayList<Node> nodeDependencies = null; 755 756 /** 757 * nodeDepdendents is the list of nodes that have this node as a dependency. This 758 * is a utility field used in sortNodes to facilitate removing this node as a 759 * dependency when it is a root node. 760 */ 761 public ArrayList<Node> nodeDependents = null; 762 763 /** 764 * Flag indicating whether the animation in this node is finished. This flag 765 * is used by AnimatorSet to check, as each animation ends, whether all child animations 766 * are done and it's time to send out an end event for the entire AnimatorSet. 767 */ 768 public boolean done = false; 769 770 /** 771 * Constructs the Node with the animation that it encapsulates. A Node has no 772 * dependencies by default; dependencies are added via the addDependency() 773 * method. 774 * 775 * @param animation The animation that the Node encapsulates. 776 */ 777 public Node(Animator animation) { 778 this.animation = animation; 779 } 780 781 /** 782 * Add a dependency to this Node. The dependency includes information about the 783 * node that this node is dependency upon and the nature of the dependency. 784 * @param dependency 785 */ 786 public void addDependency(Dependency dependency) { 787 if (dependencies == null) { 788 dependencies = new ArrayList<Dependency>(); 789 nodeDependencies = new ArrayList<Node>(); 790 } 791 dependencies.add(dependency); 792 if (!nodeDependencies.contains(dependency.node)) { 793 nodeDependencies.add(dependency.node); 794 } 795 Node dependencyNode = dependency.node; 796 if (dependencyNode.nodeDependents == null) { 797 dependencyNode.nodeDependents = new ArrayList<Node>(); 798 } 799 dependencyNode.nodeDependents.add(this); 800 } 801 802 @Override 803 public Node clone() { 804 try { 805 Node node = (Node) super.clone(); 806 node.animation = (Animator) animation.clone(); 807 return node; 808 } catch (CloneNotSupportedException e) { 809 throw new AssertionError(); 810 } 811 } 812 } 813 814 /** 815 * The <code>Builder</code> object is a utility class to facilitate adding animations to a 816 * <code>AnimatorSet</code> along with the relationships between the various animations. The 817 * intention of the <code>Builder</code> methods, along with the {@link 818 * AnimatorSet#play(Animator) play()} method of <code>AnimatorSet</code> is to make it possible to 819 * express the dependency relationships of animations in a natural way. Developers can also use 820 * the {@link AnimatorSet#playTogether(Animator[]) playTogether()} and {@link 821 * AnimatorSet#playSequentially(Animator[]) playSequentially()} methods if these suit the need, 822 * but it might be easier in some situations to express the AnimatorSet of animations in pairs. 823 * <p/> 824 * <p>The <code>Builder</code> object cannot be constructed directly, but is rather constructed 825 * internally via a call to {@link AnimatorSet#play(Animator)}.</p> 826 * <p/> 827 * <p>For example, this sets up a AnimatorSet to play anim1 and anim2 at the same time, anim3 to 828 * play when anim2 finishes, and anim4 to play when anim3 finishes:</p> 829 * <pre> 830 * AnimatorSet s = new AnimatorSet(); 831 * s.play(anim1).with(anim2); 832 * s.play(anim2).before(anim3); 833 * s.play(anim4).after(anim3); 834 * </pre> 835 * <p/> 836 * <p>Note in the example that both {@link Builder#before(Animator)} and {@link 837 * Builder#after(Animator)} are used. These are just different ways of expressing the same 838 * relationship and are provided to make it easier to say things in a way that is more natural, 839 * depending on the situation.</p> 840 * <p/> 841 * <p>It is possible to make several calls into the same <code>Builder</code> object to express 842 * multiple relationships. However, note that it is only the animation passed into the initial 843 * {@link AnimatorSet#play(Animator)} method that is the dependency in any of the successive 844 * calls to the <code>Builder</code> object. For example, the following code starts both anim2 845 * and anim3 when anim1 ends; there is no direct dependency relationship between anim2 and 846 * anim3: 847 * <pre> 848 * AnimatorSet s = new AnimatorSet(); 849 * s.play(anim1).before(anim2).before(anim3); 850 * </pre> 851 * If the desired result is to play anim1 then anim2 then anim3, this code expresses the 852 * relationship correctly:</p> 853 * <pre> 854 * AnimatorSet s = new AnimatorSet(); 855 * s.play(anim1).before(anim2); 856 * s.play(anim2).before(anim3); 857 * </pre> 858 * <p/> 859 * <p>Note that it is possible to express relationships that cannot be resolved and will not 860 * result in sensible results. For example, <code>play(anim1).after(anim1)</code> makes no 861 * sense. In general, circular dependencies like this one (or more indirect ones where a depends 862 * on b, which depends on c, which depends on a) should be avoided. Only create AnimatorSets 863 * that can boil down to a simple, one-way relationship of animations starting with, before, and 864 * after other, different, animations.</p> 865 */ 866 public class Builder { 867 868 /** 869 * This tracks the current node being processed. It is supplied to the play() method 870 * of AnimatorSet and passed into the constructor of Builder. 871 */ 872 private Node mCurrentNode; 873 874 /** 875 * package-private constructor. Builders are only constructed by AnimatorSet, when the 876 * play() method is called. 877 * 878 * @param anim The animation that is the dependency for the other animations passed into 879 * the other methods of this Builder object. 880 */ 881 Builder(Animator anim) { 882 mCurrentNode = mNodeMap.get(anim); 883 if (mCurrentNode == null) { 884 mCurrentNode = new Node(anim); 885 mNodeMap.put(anim, mCurrentNode); 886 mNodes.add(mCurrentNode); 887 } 888 } 889 890 /** 891 * Sets up the given animation to play at the same time as the animation supplied in the 892 * {@link AnimatorSet#play(Animator)} call that created this <code>Builder</code> object. 893 * 894 * @param anim The animation that will play when the animation supplied to the 895 * {@link AnimatorSet#play(Animator)} method starts. 896 */ 897 public void with(Animator anim) { 898 Node node = mNodeMap.get(anim); 899 if (node == null) { 900 node = new Node(anim); 901 mNodeMap.put(anim, node); 902 mNodes.add(node); 903 } 904 Dependency dependency = new Dependency(mCurrentNode, Dependency.WITH); 905 node.addDependency(dependency); 906 } 907 908 /** 909 * Sets up the given animation to play when the animation supplied in the 910 * {@link AnimatorSet#play(Animator)} call that created this <code>Builder</code> object 911 * ends. 912 * 913 * @param anim The animation that will play when the animation supplied to the 914 * {@link AnimatorSet#play(Animator)} method ends. 915 */ 916 public void before(Animator anim) { 917 Node node = mNodeMap.get(anim); 918 if (node == null) { 919 node = new Node(anim); 920 mNodeMap.put(anim, node); 921 mNodes.add(node); 922 } 923 Dependency dependency = new Dependency(mCurrentNode, Dependency.AFTER); 924 node.addDependency(dependency); 925 } 926 927 /** 928 * Sets up the given animation to play when the animation supplied in the 929 * {@link AnimatorSet#play(Animator)} call that created this <code>Builder</code> object 930 * to start when the animation supplied in this method call ends. 931 * 932 * @param anim The animation whose end will cause the animation supplied to the 933 * {@link AnimatorSet#play(Animator)} method to play. 934 */ 935 public void after(Animator anim) { 936 Node node = mNodeMap.get(anim); 937 if (node == null) { 938 node = new Node(anim); 939 mNodeMap.put(anim, node); 940 mNodes.add(node); 941 } 942 Dependency dependency = new Dependency(node, Dependency.AFTER); 943 mCurrentNode.addDependency(dependency); 944 } 945 946 /** 947 * Sets up the animation supplied in the 948 * {@link AnimatorSet#play(Animator)} call that created this <code>Builder</code> object 949 * to play when the given amount of time elapses. 950 * 951 * @param delay The number of milliseconds that should elapse before the 952 * animation starts. 953 */ 954 public void after(long delay) { 955 // setup dummy ValueAnimator just to run the clock 956 ValueAnimator anim = ValueAnimator.ofFloat(0f, 1f); 957 anim.setDuration(delay); 958 after(anim); 959 } 960 961 } 962 963} 964