Android animations go reactive

RxMagic + Android Animations

Transcript

1. Mihael Franceković, Five 9.12.2016@Krakow #droidconpl Mihael Francković ANDROID ANIMATIONS GO REACTIVE
2. Design Driven App Development @fivenyc five.agency
3. RxJava?
4. Before we start • Not a rxJava course • Will talk about ◦ ValueAnimators, ViewPropertyAnimators • Will not talk about ◦ Transitons, ObjectAnimator and such
5. A journey to rxZation
6. The problem
7. The problem ViewPager Fading in image Dynamic username text Rotating view Page indicator
8. Background • MVP ◦ Keep presenters !android • Separation of concerns ◦ View handles how to animate ◦ Presenter handles when to animate • Nice looking code
9. What is actually going on
10. Lets do this • LayoutAnimations for ViewGroups • ViewPropertyAnimator for View
11. Source // Pre transform username.setAlpha(TRANSPARENT); username.setTranslationX(-TRANSLATION); // Create animator ViewPropertyAnimator animator = username.animate().setDuration(DURATION) .alpha(OPAQUE).translationXBy(TRANSLATION); // Wire animators together animator.withEndAction(() -> anotherAnimator.start()); animator.start();
12. Lets not do this • Boolean flags for synchronization ◦ withEndAction(...) hell ◦ Canceling animation ◦ Username and colors data are asynchronous ( data in general ) ◦ View notifies presenter when animation is over • Not a nice looking code, there must be a nicer way
13. • Helps with synchronization • What our presenter cares about? ◦ start/stop animation Reactive?
14. • Helps with synchronization • What our presenter cares about? ◦ start/stop animation • Completable ? Reactive?
15. Completable Completable.fromAction(() -> triggerLayoutAnimation()); Completable.create(new Completable.CompletableOnSubscribe() {..})
16. CompletableOnSubscribe public final class CompletableAction implements Completable.CompletableOnSubscribe { @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { completableSubscriber.onSubscribe(subscription); completableSubscriber.onError(throwable); completableSubscriber.onCompleted(); } }
17. Completable ViewPropertyAnimator public final class AnimateOnSubscribe implements Completable.CompletableOnSubscribe { private final ViewPropertyAnimator propertyAnimator; public static from(final ViewPropertyAnimator propertyAnimator) { return new AnimateOnSubscribe(propertyAnimator); } @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { propertyAnimator.withEndAction(completableSubscriber::onCompleted); propertyAnimator.start(); } }
18. Completable ViewPropertyAnimator Activity/Fragment // Pre transform … // Create animators ... // Wire animators Completable.create(AnimateOnSubscribe.from(firstPropertyAnimator)) .concatWith(Completable.create(AnimateOnSubscribe.from(secondPropertyAnimator))); Pros: - Animators do not know of each other Cons: - We still have to create animator for every view and pre transform that view
19. Can we remove that animator creation from the view?
20. Removing animator creation public final class AnimateFadeInOnSubscribe implements Completable.CompletableOnSubscribe { private final WeakReference<View> viewWeakRef; public AnimateOnSubscribe(final View view) { this.viewWeakRef = new WeakReference<>(view); } @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { final View view = viewWeakRef.get(); if (view == null) { completableSubscriber.onCompleted(); return; } final ViewPropertyAnimatorCompat animator = ViewCompat.animate(view); animator.setDuration(DURATION).alpha(OPAQUE); animator.withEndAction(() -> completableSubscriber.onCompleted()); animator.start(); } }
21. Removing animator creation - Activity/Fragment // Wire animations Completable.create(AnimateFadeInOnSubscribe.animate(welcomeMessage)) .concatWith(Completable.create(AnimateFadeInOnSubscribe.animate(username))); Pros: - View is not creating animators directly Cons: - Transformations?
22. Removing animator creation public final class AnimateFadeInOnSubscribe implements Completable.CompletableOnSubscribe { private final WeakReference<View> viewWeakRef; public AnimateOnSubscribe(final View view) { this.viewWeakRef = new WeakReference<>(view); } @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { final View view = viewWeakRef.get(); if (view == null) { completableSubscriber.onCompleted(); return; } final ViewPropertyAnimatorCompat animator = ViewCompat.animate(view); animator.setDuration(DURATION).alpha(OPAQUE); animator.withEndAction(() -> completableSubscriber.onCompleted()); animator.start(); } }
23. Removing animator creation public final class AnimateFadeInOnSubscribe implements Completable.CompletableOnSubscribe { private final WeakReference<View> viewWeakRef; public AnimateOnSubscribe(final View view) { this.viewWeakRef = new WeakReference<>(view); } @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { final View view = viewWeakRef.get(); if (view == null) { completableSubscriber.onCompleted(); return; } preTransformView(view); final ViewPropertyAnimatorCompat animator = ViewCompat.animate(view); animator.setDuration(DURATION).alpha(OPAQUE); animator.withEndAction(() -> completableSubscriber.onCompleted()); animator.start(); } }
24. Removing animator creation - Activity/Fragment // Wire animations Completable.create(AnimateFadeInOnSubscribe.animate(welcomeMessage)) .concatWith(Completable.create(AnimateFadeInOnSubscribe.animate(username))); Pros: - View is not creating animators directly - View does not need to pre transform views it animates Cons: - Many classes
25. Removing animator creation - Activity/Fragment // Wire animations Completable.create(AnimateFadeInOnSubscribe.animate(welcomeMessage)) .concatWith(Completable.create(AnimateFadeInOnSubscribe.animate(username))); Pros: - View is not creating animators directly - View does not need to pre transform views it animates Cons: - Many classes Are we really satisfied?
26. WE NEED TO GO DEEPER
27. The builder • ViewPropertyAnimator is builder • Idea - RxAnimationBuilder
28. Builder creation public final class RxAnimationBuilder { public static RxAnimationBuilder animate(final View view) { return new RxAnimationBuilder(view, DEFAULT_DURATION, DEFAULT_DELAY, defaultInterpolator()); } private RxAnimationBuilder(final View view, final int duration, final int delay, final Interpolator interpolator) { this.viewWeakRef = new WeakReference<>(view); .... } }
29. The builder
30. The builder
31. The builder
32. The builder
33. The builder
34. The builder
35. Animations actions public final class RxAnimationBuilder { final List<Action1<ViewPropertyAnimator>> preTransformActions; final List<Action1<ViewPropertyAnimator>> animateActions; }
36. Animations actions public final class RxAnimationBuilder { private static final float OPAQUE = 1f; private static final float TRANSPARENT = 0f; final List<Action1<ViewPropertyAnimator>> preTransformActions; final List<Action1<ViewPropertyAnimator>> animateActions; public RxAnimationBuilder fadeIn() { preTransformActions.add(preTransform -> preTransform.alpha(TRANSPARENT)); animateActions.add(animate -> animate.alpha(OPAQUE)); return this; } }
37. Animations actions public final class RxAnimationBuilder { private static final float OPAQUE = 1f; private static final float TRANSPARENT = 0f; final List<Action1<ViewPropertyAnimator>> preTransformActions; final List<Action1<ViewPropertyAnimator>> animateActions; public RxAnimationBuilder fadeIn() { preTransformActions.add(preTransform -> preTransform.alpha(TRANSPARENT)); animateActions.add(animate -> animate.alpha(OPAQUE)); return this; } public RxAnimationBuilder translateBy(final int x, final int y) { preTransformActions.add(preTransform -> preTransform.xBy(-x).yBy(-y)); animateActions.add(animate -> animate.xBy(x).yBy(y)); return this; } }
38. The builder
39. Animation actions public final class AnimateOnSubscribe implements Completable.CompletableOnSubscribe { private final WeakReference<View> viewWeakRef; private final List<Action1<ViewPropertyAnimator>> preTransformActions; private final List<Action1<ViewPropertyAnimator>> animationActions; public AnimateOnSubscribe(final WeakReference<View> viewWeakRef, @Nullable final List<Action1<ViewPropertyAnimator>> preTransformActions, final List<Action1<ViewPropertyAnimator>> animationActions) { this.viewWeakRef = viewWeakRef; this.preTransformActions = preTransformActions; this.animationActions = animationActions; }
40. Animation actions public final class AnimateOnSubscribe implements Completable.CompletableOnSubscribe { @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { final View view = viewWeakRef.get(); if ( view == null ) { completableSubscriber.onCompleted(); return; } final ViewPropertyAnimator animator = view.animate(); applyActions(preTransformActions, animator); // Shared animator.setDuration(0).setStartDelay(0) .withEndAction(() -> runAnimation(completableSubscriber, animator)) .start(); }
41. Animation actions public final class AnimateOnSubscribe implements Completable.CompletableOnSubscribe { private void applyActions(final List<Action1<ViewPropertyAnimator>> actions, final ViewPropertyAnimato animator) { If ( actions == null ) return; for (final Action1<ViewPropertyAnimator> action : actions) { action.call(animator); } } private void runAnimation(final Completable.CompletableSubscriber completableSubscriber, final ViewPropertyAnimator animator) { applyActions(animationActions, animator); animator.withEndAction(completableSubscriber::onCompleted) .start(); }
42. Animations actions public final class RxAnimationBuilder { public Completable schedule() { return Completable.create(new AnimateOnSubscribe(viewWeakRef, preTransformActions, animateActions)); } }
43. The builder
44. ALMOST THERE
45. Static wrapper public final class RxAnimations { public static Completable hide(final View view) { return animate(view, IMMEDIATE).fadeOut().schedule(); } } }
46. Static wrapper public final class RxAnimations { public static Completable hide(final View view) { return animate(view, IMMEDIATE).fadeOut().schedule(); } public static Completable fadeIn(final View view) { return animate(view).fadeIn().schedule(); } } }
47. Static wrapper public final class RxAnimations { public static Completable hide(final View view) { return animate(view, IMMEDIATE).fadeOut().schedule(); } public static Completable fadeIn(final View view) { return animate(view).fadeIn().schedule(); } public static Completable enter(final View view, final int xOffset, final int yOffset) { return animate(view, new DecelerateInterpolator()).fadeIn().translateBy(xOffset, yOffset).schedule(); } } }
48. Static wrapper public final class RxAnimations { public static Completable hide(final View view) { return animate(view, IMMEDIATE).fadeOut().schedule(); } public static Completable fadeIn(final View view) { return animate(view).fadeIn().schedule(); } public static Completable enter(final View view, final int xOffset, final int yOffset) { return animate(view, new DecelerateInterpolator()).fadeIn().translateBy(xOffset, yOffset).schedule(); } public static Completable enterViewsWithDelay(final int initialDelay, final int delay, final int duration, final int xOffset, final int yOffset, final View... views) { return Observable.range(0, views.length) .flatMap(i -> enter(views[i], duration, xOffset, yOffset, i * delay + initialDelay).toObservable()) .toCompletable(); } }
49. The animation - Activity/Fragment @Override public Completable startInitialAnimation() { return animateTogether( fadeIn (...), slideIn(...) ) .concatWith( enterViewsWithDelay(...) ) .concatWith( rotate(...) ) }
50. The animation - Activity/Fragment @Override public Completable setupInitialAnimation() { return animateTogether(hideViewGroupChildren(helloTextContainer, languageContainer), hide(paletteBackground, paletteViewPager, palettePageIndicator, settingsIcon)); } @Override public Completable startInitialAnimation() { return animateTogether( fadeIn(paletteBackground, LANGUAGE_ICON_ANIMATION_DURATION), doAfterDelay(VIEW_PAGER_ITEMS_ANIMATION_DELAY, this::animateViewPagerItems), enterViewsWithDelay(WELCOME_TEXT_INITIAL_DELAY, WELCOME_TEXT_DELAY, WELCOME_TEXT_DELAY, ITEMS_HORIZONTAL_OFFSET, userWelcomeMessage, username), doAfterDelay(LEVELS_INITIAL_DELAY, this::animatePageIndicator), enterViewsWithDelay(LE_COLORS_GROUP_INITIAL_DELAY, LANGUAGE_DETAILS_DELAY, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, leColorsLabel, seeMoreColorsButton), enterWithRotation(settingsIcon, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, 0, SETTINGS_ICON_DELAY, SETTINGS_ICON_ROTATION))); }
51. The animation - Activity/Fragment private static final float OPAQUE = 1.f; private static final int LANGUAGE_ICON_ANIMATION_DURATION = 800; private static final int ICONS_ANIMATION_DURATION = 600; private static final int ITEMS_HORIZONTAL_OFFSET = -48; private static final int SETTINGS_ICON_ROTATION = 60; private static final int VIEW_PAGER_ITEMS_ANIMATION_DELAY = 600; private static final int LEVELS_INITIAL_DELAY = 800; private static final int LE_COLORS_GROUP_INITIAL_DELAY = 1000; private static final int LANGUAGE_DETAILS_DELAY = 200; private static final int WELCOME_TEXT_INITIAL_DELAY = 500; private static final int WELCOME_TEXT_DELAY = 600; private static final int SETTINGS_ICON_DELAY = 600;
52. The animation - Presenter final Subscription animationSubscription = view.setupInitialAnimation() .concatWith(view.startInitialAnimation()) .subscribe(Throwable::printStackTrace, this::onAnimationEnd);
53. The animation - Presenter final Subscription animationSubscription = view.setupInitialAnimation() .concatWith(view.startInitialAnimation()) .subscribe(Throwable::printStackTrace, this::onAnimationEnd); Animation cancellation?
54. Completable subscriber - cancellation public interface CompletableSubscriber { void onCompleted(); void onError(Throwable e); /** * Called once by the Completable to set a Subscription on this instance which * then can be used to cancel the subscription at any time. * @param d the Subscription instance to call dispose on for cancellation, not null */ void onSubscribe(Subscription d); }
55. Completable subscriber - cancellation public final class ClearSubscription implements Subscription { private boolean isUnsubscribed = false; private final Action0 clearAction; public ClearSubscription(final Action0 clearAction) { this.clearAction = clearAction; } @Override public void unsubscribe() { isUnsubscribed = true; clearAction.call(); } } @Override public boolean isUnsubscribed() { return isUnsubscribed; }
56. Completable subscriber - cancellation public final class ClearSubscription implements Subscription { private boolean isUnsubscribed = false; private final Action0 clearAction; public ClearSubscription(final Action0 clearAction) { this.clearAction = clearAction; } @Override public void unsubscribe() { isUnsubscribed = true; clearAction.call(); } } @Override public boolean isUnsubscribed() { return isUnsubscribed; }
57. Completable subscriber - cancellation public final class AnimateOnSubscribe implements Completable.CompletableOnSubscribe { @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { final View view = viewWeakRef.get(); if ( view == null ) { completableSubscriber.onCompleted(); return; } final ViewPropertyAnimator animator = view.animate(); applyActions(preTransformActions, animator); animator.setDuration(0).setStartDelay(0) .withEndAction(() -> runAnimation(completableSubscriber, animator)) .start(); }
58. Animation actions public final class AnimateOnSubscribe implements Completable.CompletableOnSubscribe { @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { final View view = viewWeakRef.get(); if ( view == null ) { completableSubscriber.onCompleted(); return; } final ViewPropertyAnimator animator = view.animate(); completableSubscriber.onSubscribe(new ClearSubscription(animator::cancel)); applyActions(preTransformActions, animator); animator.setDuration(0).setStartDelay(0) .withEndAction(() -> runAnimation(completableSubscriber, animator)) .start(); }
59. View throttle ?
60. What is actually going on
61. The animation - Activity/Fragment @Override public Completable startInitialAnimation() { animateTogether( fadeIn(paletteBackground, LANGUAGE_ICON_ANIMATION_DURATION), doAfterDelay(VIEW_PAGER_ITEMS_ANIMATION_DELAY, this::animateViewPagerItems), enterViewsWithDelay(WELCOME_TEXT_INITIAL_DELAY, WELCOME_TEXT_DELAY, WELCOME_TEXT_DELAY, ITEMS_HORIZONTAL_OFFSET, userWelcomeMessage, username), doAfterDelay(LEVELS_INITIAL_DELAY, this::animatePageIndicator), enterViewsWithDelay(LE_COLORS_GROUP_INITIAL_DELAY, LANGUAGE_DETAILS_DELAY, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, leColorsLabel, seeMoreColorsButton), enterWithRotation(settingsIcon, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, 0, SETTINGS_ICON_DELAY, SETTINGS_ICON_ROTATION))); }
62. The animation - Activity/Fragment private BehaviorSubject<Boolean> viewReadySignal = BehaviorSubject.create(false); @Override public Completable startInitialAnimation() { return viewReadySignal.toCompletable().concatWith( animateTogether( fadeIn(paletteBackground, LANGUAGE_ICON_ANIMATION_DURATION), doAfterDelay(VIEW_PAGER_ITEMS_ANIMATION_DELAY, this::animateViewPagerItems), enterViewsWithDelay(WELCOME_TEXT_INITIAL_DELAY, WELCOME_TEXT_DELAY, WELCOME_TEXT_DELAY, ITEMS_HORIZONTAL_OFFSET, userWelcomeMessage, username), doAfterDelay(LEVELS_INITIAL_DELAY, this::animatePageIndicator), enterViewsWithDelay(LE_COLORS_GROUP_INITIAL_DELAY, LANGUAGE_DETAILS_DELAY, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, leColorsLabel, seeMoreColorsButton), enterWithRotation(settingsIcon, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, 0, SETTINGS_ICON_DELAY, SETTINGS_ICON_ROTATION))); }
63. The animation - Activity/Fragment private BehaviorSubject<Boolean> viewReadySignal = BehaviorSubject.create(false); ... viewReadySignal.onCompleted(); ... @Override public Completable startInitialAnimation() { return viewReadySignal.toCompletable().concatWith( animateTogether( fadeIn(paletteBackground, LANGUAGE_ICON_ANIMATION_DURATION), doAfterDelay(VIEW_PAGER_ITEMS_ANIMATION_DELAY, this::animateViewPagerItems), enterViewsWithDelay(WELCOME_TEXT_INITIAL_DELAY, WELCOME_TEXT_DELAY, WELCOME_TEXT_DELAY, ITEMS_HORIZONTAL_OFFSET, userWelcomeMessage, username), doAfterDelay(LEVELS_INITIAL_DELAY, this::animatePageIndicator), enterViewsWithDelay(LE_COLORS_GROUP_INITIAL_DELAY, LANGUAGE_DETAILS_DELAY, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, leColorsLabel, seeMoreColorsButton), enterWithRotation(settingsIcon, ICONS_ANIMATION_DURATION, ITEMS_HORIZONTAL_OFFSET, 0, SETTINGS_ICON_DELAY, SETTINGS_ICON_ROTATION))); }
64. ? ?
65. Designers at it, again
66. Designers at it, again
67. Designers at it, again
68. Path animation?
69. Path animation? • ViewPropertyAnimators?
70. Path animation? • ViewPropertyAnimators? • ValueAnimator?
71. ValueAnimator rxZation final ValueAnimator valueAnimator = ValueAnimator.ofFloat(startValue, endValue); valueAnimator.addUpdateListener(animator -> updateView(animator.getAnimatedValue())); Observable?
72. ValueAnimator rxZation public final class RxObservableValueAnimator { private final ValueAnimator valueAnimator;
73. ValueAnimator rxZation public final class RxObservableValueAnimator { private final ValueAnimator valueAnimator; private BehaviorSubject<Object> valueUpdateSubject;
74. ValueAnimator rxZation public final class RxObservableValueAnimator { private final ValueAnimator valueAnimator; private BehaviorSubject<Object> valueUpdateSubject; public static RxObservableValueAnimator from(final ValueAnimator valueAnimator) { return new RxObservableValueAnimator(valueAnimator); }
75. ValueAnimator rxZation public final class RxObservableValueAnimator { private RxObservableValueAnimator(final ValueAnimator valueAnimator) { this.valueAnimator = valueAnimator; this.valueUpdateSubject = BehaviorSubject.create(); this.valueAnimator.addUpdateListener(animation -> valueUpdateSubject.onNext(animation.getAnimatedValue())); this.valueAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(final Animator animation) { valueUpdateSubject.onCompleted(); } }); }
76. ValueAnimator rxZation public final class RxObservableValueAnimator { public Observable<Object> schedule() { valueAnimator.start(); return valueUpdateSubject; }
77. Reveal animation: Activity/Fragment private void setupAnimation() { final ValueAnimator xAnimator = ValueAnimator.ofFloat(clickPoint.x, center.x); xAnimator.setDuration(DURATION).setInterpolator(new AccelerateInterpolator()); final ValueAnimator yAnimator = ValueAnimator.ofFloat(clickPoint.y, center.y); yAnimator.setDuration(DURATION).setInterpolator(new DecelerateInterpolator()); xObservableAnimator = RxObservableValueAnimator.from(xAnimator); yObservableAnimator = RxObservableValueAnimator.from(yAnimator); }
78. Reveal animation: Activity/Fragment public Subscription revealAnimation() { return Observable.combineLatest(xObservableAnimator.schedule(), yObservableAnimator.schedule(), this::zipAnimationData) .subscribe(this::updateRevealView, Throwable::printStackTrace, () -> presenter.onRevealAnimationEnd()); }
79. ValueAnimator rxZation public final class RxObservableValueAnimator { public Observable<Object> scheduleReversed() { valueAnimator.reverse(); return valueUpdateSubject; }
80. ValueAnimator rxZation, Completable ?
81. ValueAnimator rxZation, Completable public final class RxValueAnimator implements Completable.CompletableOnSubscribe { private final ValueAnimator valueAnimator;
82. ValueAnimator rxZation, Completable public final class RxValueAnimator implements Completable.CompletableOnSubscribe { private final ValueAnimator valueAnimator; private final Action1<ValueAnimator> valueUpdateAction; public static RxValueAnimator from(final ValueAnimator valueAnimator, final Action1<ValueAnimator> valueUpdateAction) { return new RxValueAnimator(valueAnimator, valueUpdateAction); } private RxValueAnimator(final ValueAnimator valueAnimator, final Action1<ValueAnimator> valueUpdateAction) { this.valueAnimator = valueAnimator; this.valueAnimator.addUpdateListener(valueUpdateAction::call); this.valueUpdateAction = valueUpdateAction; }
83. ValueAnimator rxZation, Completable public final class RxValueAnimator implements Completable.CompletableOnSubscribe { private final ValueAnimator valueAnimator; private final Action1<ValueAnimator> valueUpdateAction; public static RxValueAnimator from(final ValueAnimator valueAnimator, final Action1<ValueAnimator> valueUpdateAction) { return new RxValueAnimator(valueAnimator, valueUpdateAction); } private RxValueAnimator(final ValueAnimator valueAnimator, final Action1<ValueAnimator> valueUpdateAction) { this.valueAnimator = valueAnimator; this.valueAnimator.addUpdateListener(valueUpdateAction::call); this.valueUpdateAction = valueUpdateAction; }
84. ValueAnimator rxZation, Completable public final class RxValueAnimator implements Completable.CompletableOnSubscribe { @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { valueAnimator.start(); valueAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(final Animator animation) { valueAnimator.removeAllListeners(); completableSubscriber.onCompleted(); } }); } }
85. ValueAnimator rxZation, Completable public final class RxValueAnimator implements Completable.CompletableOnSubscribe { @Override public void call(final Completable.CompletableSubscriber completableSubscriber) { completableSubscriber.onSubscribe(new ClearSubscription(valueAnimator::end)); valueAnimator.start(); valueAnimator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(final Animator animation) { valueAnimator.removeAllListeners(); completableSubscriber.onCompleted(); } }); } }
86. RxValueAnimator - Activity/Fragment public Completable animateWidget() { final ValueAnimator widgetAnimator = ValueAnimator.ofFloat(startValue, endValue); widgetAnimator.setDuration(DURATION); return Completable.create(RxValueAnimator.from(widgetAnimator, this::updateWidget)); } private void updateWidget(final ValueAnimator animator) { // Update view }
87. Q&A