| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.animation; |
| |
| import android.view.View; |
| import android.view.ViewGroup; |
| import android.view.ViewTreeObserver; |
| import android.view.animation.AccelerateDecelerateInterpolator; |
| import android.view.animation.DecelerateInterpolator; |
| import android.view.animation.Interpolator; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.List; |
| |
| /** |
| * This class enables automatic animations on layout changes in ViewGroup objects. To enable |
| * transitions for a layout container, create a LayoutTransition object and set it on any |
| * ViewGroup by calling {@link ViewGroup#setLayoutTransition(LayoutTransition)}. This will cause |
| * default animations to run whenever items are added to or removed from that container. To specify |
| * custom animations, use the {@link LayoutTransition#setAnimator(int, Animator) |
| * setAnimator()} method. |
| * |
| * <p>One of the core concepts of these transition animations is that there are two core |
| * changes that cause the transition and four different animations that run because of |
| * those changes. The changes that trigger the transition are items being added to a container |
| * (referred to as an "appearing" transition) or removed from a container (also known as |
| * "disappearing"). The animations that run due to those events are one that animates |
| * items being added, one that animates items being removed, and two that animate the other |
| * items in the container that change due to the add/remove occurrence. Users of |
| * the transition may want different animations for the changing items depending on whether |
| * they are changing due to anappearing or disappearing event, so there is one animation for |
| * each of these variations of the changing event. Most of the API of this class is concerned |
| * with setting up the basic properties of the animations used in these four situations, |
| * or with setting up custom animations for any or all of the four.</p> |
| * |
| * <p>The animations specified for the transition, both the defaults and any custom animations |
| * set on the transition object, are templates only. That is, these animations exist to hold the |
| * basic animation properties, such as the duration, start delay, and properties being animated. |
| * But the actual target object, as well as the start and end values for those properties, are |
| * set automatically in the process of setting up the transition each time it runs. Each of the |
| * animations is cloned from the original copy and the clone is then populated with the dynamic |
| * values of the target being animated (such as one of the items in a layout container that is |
| * moving as a result of the layout event) as well as the values that are changing (such as the |
| * position and size of that object). The actual values that are pushed to each animation |
| * depends on what properties are specified for the animation. For example, the default |
| * CHANGE_APPEARING animation animates <code>left</code>, <code>top</code>, <code>right</code>, |
| * and <code>bottom</code>. Values for these properties are updated with the pre- and post-layout |
| * values when the transition begins. Custom animations will be similarly populated with |
| * the target and values being animated, assuming they use ObjectAnimator objects with |
| * property names that are known on the target object.</p> |
| */ |
| public class LayoutTransition { |
| |
| /** |
| * A flag indicating the animation that runs on those items that are changing |
| * due to a new item appearing in the container. |
| */ |
| public static final int CHANGE_APPEARING = 0; |
| |
| /** |
| * A flag indicating the animation that runs on those items that are changing |
| * due to a new item disappearing from the container. |
| */ |
| public static final int CHANGE_DISAPPEARING = 1; |
| |
| /** |
| * A flag indicating the animation that runs on those items that are changing |
| * due to a new item appearing in the container. |
| */ |
| public static final int APPEARING = 2; |
| |
| /** |
| * A flag indicating the animation that runs on those items that are changing |
| * due to a new item appearing in the container. |
| */ |
| public static final int DISAPPEARING = 3; |
| |
| /** |
| * These variables hold the animations that are currently used to run the transition effects. |
| * These animations are set to defaults, but can be changed to custom animations by |
| * calls to setAnimator(). |
| */ |
| private Animator mDisappearingAnim = null; |
| private Animator mAppearingAnim = null; |
| private Animator mChangingAppearingAnim = null; |
| private Animator mChangingDisappearingAnim = null; |
| |
| /** |
| * These are the default animations, defined in the constructor, that will be used |
| * unless the user specifies custom animations. |
| */ |
| private static ObjectAnimator defaultChangeIn; |
| private static ObjectAnimator defaultChangeOut; |
| private static ObjectAnimator defaultFadeIn; |
| private static ObjectAnimator defaultFadeOut; |
| |
| /** |
| * The default duration used by all animations. |
| */ |
| private static long DEFAULT_DURATION = 300; |
| |
| /** |
| * The durations of the four different animations |
| */ |
| private long mChangingAppearingDuration = DEFAULT_DURATION; |
| private long mChangingDisappearingDuration = DEFAULT_DURATION; |
| private long mAppearingDuration = DEFAULT_DURATION; |
| private long mDisappearingDuration = DEFAULT_DURATION; |
| |
| /** |
| * The start delays of the four different animations. Note that the default behavior of |
| * the appearing item is the default duration, since it should wait for the items to move |
| * before fading it. Same for the changing animation when disappearing; it waits for the item |
| * to fade out before moving the other items. |
| */ |
| private long mAppearingDelay = DEFAULT_DURATION; |
| private long mDisappearingDelay = 0; |
| private long mChangingAppearingDelay = 0; |
| private long mChangingDisappearingDelay = DEFAULT_DURATION; |
| |
| /** |
| * The inter-animation delays used on the two changing animations |
| */ |
| private long mChangingAppearingStagger = 0; |
| private long mChangingDisappearingStagger = 0; |
| |
| /** |
| * The default interpolators used for the animations |
| */ |
| private Interpolator mAppearingInterpolator = new AccelerateDecelerateInterpolator(); |
| private Interpolator mDisappearingInterpolator = new AccelerateDecelerateInterpolator(); |
| private Interpolator mChangingAppearingInterpolator = new DecelerateInterpolator(); |
| private Interpolator mChangingDisappearingInterpolator = new DecelerateInterpolator(); |
| |
| /** |
| * This hashmap is used to store the animations that are currently running as part of |
| * the transition. The reason for this is that a further layout event should cause |
| * existing animations to stop where they are prior to starting new animations. So |
| * we cache all of the current animations in this map for possible cancellation on |
| * another layout event. |
| */ |
| private HashMap<View, Animator> currentAnimations = new HashMap<View, Animator>(); |
| |
| /** |
| * This hashmap is used to track the listeners that have been added to the children of |
| * a container. When a layout change occurs, an animation is created for each View, so that |
| * the pre-layout values can be cached in that animation. Then a listener is added to the |
| * view to see whether the layout changes the bounds of that view. If so, the animation |
| * is set with the final values and then run. If not, the animation is not started. When |
| * the process of setting up and running all appropriate animations is done, we need to |
| * remove these listeners and clear out the map. |
| */ |
| private HashMap<View, View.OnLayoutChangeListener> layoutChangeListenerMap = |
| new HashMap<View, View.OnLayoutChangeListener>(); |
| |
| /** |
| * Used to track the current delay being assigned to successive animations as they are |
| * started. This value is incremented for each new animation, then zeroed before the next |
| * transition begins. |
| */ |
| private long staggerDelay; |
| |
| /** |
| * The set of listeners that should be notified when APPEARING/DISAPPEARING transitions |
| * start and end. |
| */ |
| private ArrayList<TransitionListener> mListeners; |
| |
| |
| /** |
| * Constructs a LayoutTransition object. By default, the object will listen to layout |
| * events on any ViewGroup that it is set on and will run default animations for each |
| * type of layout event. |
| */ |
| public LayoutTransition() { |
| if (defaultChangeIn == null) { |
| // "left" is just a placeholder; we'll put real properties/values in when needed |
| PropertyValuesHolder<Integer> pvhLeft = new PropertyValuesHolder<Integer>("left", 0, 1); |
| PropertyValuesHolder<Integer> pvhTop = new PropertyValuesHolder<Integer>("top", 0, 1); |
| PropertyValuesHolder<Integer> pvhRight = new PropertyValuesHolder<Integer>("right", 0, 1); |
| PropertyValuesHolder<Integer> pvhBottom = new PropertyValuesHolder<Integer>("bottom", 0, 1); |
| defaultChangeIn = new ObjectAnimator<PropertyValuesHolder>(DEFAULT_DURATION, this, |
| pvhLeft, pvhTop, pvhRight, pvhBottom); |
| defaultChangeIn.setStartDelay(mChangingAppearingDelay); |
| defaultChangeIn.setInterpolator(mChangingAppearingInterpolator); |
| defaultChangeOut = defaultChangeIn.clone(); |
| defaultChangeOut.setStartDelay(mChangingDisappearingDelay); |
| defaultChangeOut.setInterpolator(mChangingDisappearingInterpolator); |
| defaultFadeIn = |
| new ObjectAnimator<Float>(DEFAULT_DURATION, this, "alpha", 0f, 1f); |
| defaultFadeIn.setStartDelay(mAppearingDelay); |
| defaultFadeIn.setInterpolator(mAppearingInterpolator); |
| defaultFadeOut = |
| new ObjectAnimator<Float>(DEFAULT_DURATION, this, "alpha", 1f, 0f); |
| defaultFadeOut.setStartDelay(mDisappearingDelay); |
| defaultFadeOut.setInterpolator(mDisappearingInterpolator); |
| } |
| mChangingAppearingAnim = defaultChangeIn; |
| mChangingDisappearingAnim = defaultChangeOut; |
| mAppearingAnim = defaultFadeIn; |
| mDisappearingAnim = defaultFadeOut; |
| } |
| |
| /** |
| * Sets the duration to be used by all animations of this transition object. If you want to |
| * set the duration of just one of the animations in particular, use the |
| * {@link #setDuration(int, long)} method. |
| * |
| * @param duration The length of time, in milliseconds, that the transition animations |
| * should last. |
| */ |
| public void setDuration(long duration) { |
| mChangingAppearingDuration = duration; |
| mChangingDisappearingDuration = duration; |
| mAppearingDuration = duration; |
| mDisappearingDuration = duration; |
| } |
| |
| /** |
| * Sets the start delay on one of the animation objects used by this transition. The |
| * <code>transitionType</code> parameter determines the animation whose start delay |
| * is being set. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose start |
| * delay is being set. |
| * @param delay The length of time, in milliseconds, to delay before starting the animation. |
| * @see Animator#setStartDelay(long) |
| */ |
| public void setStartDelay(int transitionType, long delay) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| mChangingAppearingDelay = delay; |
| break; |
| case CHANGE_DISAPPEARING: |
| mChangingDisappearingDelay = delay; |
| break; |
| case APPEARING: |
| mAppearingDelay = delay; |
| break; |
| case DISAPPEARING: |
| mDisappearingDelay = delay; |
| break; |
| } |
| } |
| |
| /** |
| * Gets the start delay on one of the animation objects used by this transition. The |
| * <code>transitionType</code> parameter determines the animation whose start delay |
| * is returned. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose start |
| * delay is returned. |
| * @return long The start delay of the specified animation. |
| * @see Animator#getStartDelay() |
| */ |
| public long getStartDelay(int transitionType) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| return mChangingAppearingDuration; |
| case CHANGE_DISAPPEARING: |
| return mChangingDisappearingDuration; |
| case APPEARING: |
| return mAppearingDuration; |
| case DISAPPEARING: |
| return mDisappearingDuration; |
| } |
| // shouldn't reach here |
| return 0; |
| } |
| |
| /** |
| * Sets the duration on one of the animation objects used by this transition. The |
| * <code>transitionType</code> parameter determines the animation whose duration |
| * is being set. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose |
| * duration is being set. |
| * @param duration The length of time, in milliseconds, that the specified animation should run. |
| * @see Animator#setDuration(long) |
| */ |
| public void setDuration(int transitionType, long duration) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| mChangingAppearingDuration = duration; |
| break; |
| case CHANGE_DISAPPEARING: |
| mChangingDisappearingDuration = duration; |
| break; |
| case APPEARING: |
| mAppearingDuration = duration; |
| break; |
| case DISAPPEARING: |
| mDisappearingDuration = duration; |
| break; |
| } |
| } |
| |
| /** |
| * Gets the duration on one of the animation objects used by this transition. The |
| * <code>transitionType</code> parameter determines the animation whose duration |
| * is returned. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose |
| * duration is returned. |
| * @return long The duration of the specified animation. |
| * @see Animator#getDuration() |
| */ |
| public long getDuration(int transitionType) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| return mChangingAppearingDuration; |
| case CHANGE_DISAPPEARING: |
| return mChangingDisappearingDuration; |
| case APPEARING: |
| return mAppearingDuration; |
| case DISAPPEARING: |
| return mDisappearingDuration; |
| } |
| // shouldn't reach here |
| return 0; |
| } |
| |
| /** |
| * Sets the length of time to delay between starting each animation during one of the |
| * CHANGE animations. |
| * |
| * @param transitionType A value of {@link #CHANGE_APPEARING} or @link #CHANGE_DISAPPEARING}. |
| * @param duration The length of time, in milliseconds, to delay before launching the next |
| * animation in the sequence. |
| */ |
| public void setStagger(int transitionType, long duration) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| mChangingAppearingStagger = duration; |
| break; |
| case CHANGE_DISAPPEARING: |
| mChangingDisappearingStagger = duration; |
| break; |
| // noop other cases |
| } |
| } |
| |
| /** |
| * Tets the length of time to delay between starting each animation during one of the |
| * CHANGE animations. |
| * |
| * @param transitionType A value of {@link #CHANGE_APPEARING} or @link #CHANGE_DISAPPEARING}. |
| * @return long The length of time, in milliseconds, to delay before launching the next |
| * animation in the sequence. |
| */ |
| public long getStagger(int transitionType) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| return mChangingAppearingStagger; |
| case CHANGE_DISAPPEARING: |
| return mChangingDisappearingStagger; |
| } |
| // shouldn't reach here |
| return 0; |
| } |
| |
| /** |
| * Sets the interpolator on one of the animation objects used by this transition. The |
| * <code>transitionType</code> parameter determines the animation whose interpolator |
| * is being set. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose |
| * duration is being set. |
| * @param interpolator The interpolator that the specified animation should use. |
| * @see Animator#setInterpolator(android.view.animation.Interpolator) |
| */ |
| public void setInterpolator(int transitionType, Interpolator interpolator) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| mChangingAppearingInterpolator = interpolator; |
| break; |
| case CHANGE_DISAPPEARING: |
| mChangingDisappearingInterpolator = interpolator; |
| break; |
| case APPEARING: |
| mAppearingInterpolator = interpolator; |
| break; |
| case DISAPPEARING: |
| mDisappearingInterpolator = interpolator; |
| break; |
| } |
| } |
| |
| /** |
| * Gets the interpolator on one of the animation objects used by this transition. The |
| * <code>transitionType</code> parameter determines the animation whose interpolator |
| * is returned. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose |
| * duration is being set. |
| * @return Interpolator The interpolator that the specified animation uses. |
| * @see Animator#setInterpolator(android.view.animation.Interpolator) |
| */ |
| public Interpolator getInterpolator(int transitionType) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| return mChangingAppearingInterpolator; |
| case CHANGE_DISAPPEARING: |
| return mChangingDisappearingInterpolator; |
| case APPEARING: |
| return mAppearingInterpolator; |
| case DISAPPEARING: |
| return mDisappearingInterpolator; |
| } |
| // shouldn't reach here |
| return null; |
| } |
| |
| /** |
| * Sets the animation used during one of the transition types that may run. Any |
| * Animator object can be used, but to be most useful in the context of layout |
| * transitions, the animation should either be a ObjectAnimator or a AnimatorSet |
| * of animations including PropertyAnimators. Also, these ObjectAnimator objects |
| * should be able to get and set values on their target objects automatically. For |
| * example, a ObjectAnimator that animates the property "left" is able to set and get the |
| * <code>left</code> property from the View objects being animated by the layout |
| * transition. The transition works by setting target objects and properties |
| * dynamically, according to the pre- and post-layoout values of those objects, so |
| * having animations that can handle those properties appropriately will work best |
| * for custom animation. The dynamic setting of values is only the case for the |
| * CHANGE animations; the APPEARING and DISAPPEARING animations are simply run with |
| * the values they have. |
| * |
| * <p>It is also worth noting that any and all animations (and their underlying |
| * PropertyValuesHolder objects) will have their start and end values set according |
| * to the pre- and post-layout values. So, for example, a custom animation on "alpha" |
| * as the CHANGE_APPEARING animation will inherit the real value of alpha on the target |
| * object (presumably 1) as its starting and ending value when the animation begins. |
| * Animations which need to use values at the beginning and end that may not match the |
| * values queried when the transition begins may need to use a different mechanism |
| * than a standard ObjectAnimator object.</p> |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose |
| * duration is being set. |
| * @param animator The animation being assigned. A value of <code>null</code> means that no |
| * animation will be run for the specified transitionType. |
| */ |
| public void setAnimator(int transitionType, Animator animator) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| mChangingAppearingAnim = animator; |
| break; |
| case CHANGE_DISAPPEARING: |
| mChangingDisappearingAnim = animator; |
| break; |
| case APPEARING: |
| mAppearingAnim = animator; |
| break; |
| case DISAPPEARING: |
| mDisappearingAnim = animator; |
| break; |
| } |
| } |
| |
| /** |
| * Gets the animation used during one of the transition types that may run. |
| * |
| * @param transitionType one of {@link #CHANGE_APPEARING}, {@link #CHANGE_DISAPPEARING}, |
| * {@link #APPEARING}, or {@link #DISAPPEARING}, which determines the animation whose |
| * duration is being set. |
| * @return Animator The animation being used for the given transition type. |
| * @see #setAnimator(int, Animator) |
| */ |
| public Animator getAnimator(int transitionType) { |
| switch (transitionType) { |
| case CHANGE_APPEARING: |
| return mChangingAppearingAnim; |
| case CHANGE_DISAPPEARING: |
| return mChangingDisappearingAnim; |
| case APPEARING: |
| return mAppearingAnim; |
| case DISAPPEARING: |
| return mDisappearingAnim; |
| } |
| // shouldn't reach here |
| return null; |
| } |
| |
| /** |
| * This function sets up runs animations on all of the views that change during layout. |
| * For every child in the parent, we create a change animation of the appropriate |
| * type (appearing or disappearing) and ask it to populate its start values from its |
| * target view. We add layout listeners to all child views and listen for changes. For |
| * those views that change, we populate the end values for those animations and start them. |
| * Animations are not run on unchanging views. |
| * |
| * @param parent The container which is undergoing an appearing or disappearing change. |
| * @param newView The view being added to or removed from the parent. |
| * @param changeReason A value of APPEARING or DISAPPEARING, indicating whether the |
| * transition is occuring because an item is being added to or removed from the parent. |
| */ |
| private void runChangeTransition(final ViewGroup parent, View newView, final int changeReason) { |
| |
| Animator baseAnimator = (changeReason == APPEARING) ? |
| mChangingAppearingAnim : mChangingDisappearingAnim; |
| // If the animation is null, there's nothing to do |
| if (baseAnimator == null) { |
| return; |
| } |
| |
| // reset the inter-animation delay, in case we use it later |
| staggerDelay = 0; |
| |
| final ViewTreeObserver observer = parent.getViewTreeObserver(); // used for later cleanup |
| if (!observer.isAlive()) { |
| // If the observer's not in a good state, skip the transition |
| return; |
| } |
| int numChildren = parent.getChildCount(); |
| |
| for (int i = 0; i < numChildren; ++i) { |
| final View child = parent.getChildAt(i); |
| |
| // only animate the views not being added or removed |
| if (child != newView) { |
| |
| // If there's an animation running on this view already, cancel it |
| Animator currentAnimation = currentAnimations.get(child); |
| if (currentAnimation != null) { |
| currentAnimation.cancel(); |
| currentAnimations.remove(child); |
| } |
| |
| // Make a copy of the appropriate animation |
| final Animator anim = baseAnimator.clone(); |
| |
| // Cache the animation in case we need to cancel it later |
| currentAnimations.put(child, anim); |
| |
| // Set the target object for the animation |
| anim.setTarget(child); |
| |
| // A ObjectAnimator (or AnimatorSet of them) can extract start values from |
| // its target object |
| anim.setupStartValues(); |
| |
| // Add a listener to track layout changes on this view. If we don't get a callback, |
| // then there's nothing to animate. |
| final View.OnLayoutChangeListener listener = new View.OnLayoutChangeListener() { |
| public void onLayoutChange(View v, int left, int top, int right, int bottom, |
| int oldLeft, int oldTop, int oldRight, int oldBottom) { |
| |
| // Tell the animation to extract end values from the changed object |
| anim.setupEndValues(); |
| |
| long startDelay; |
| long duration; |
| if (changeReason == APPEARING) { |
| startDelay = mChangingAppearingDelay + staggerDelay; |
| staggerDelay += mChangingAppearingStagger; |
| duration = mChangingAppearingDuration; |
| } else { |
| startDelay = mChangingDisappearingDelay + staggerDelay; |
| staggerDelay += mChangingDisappearingStagger; |
| duration = mChangingDisappearingDuration; |
| } |
| anim.setStartDelay(startDelay); |
| anim.setDuration(duration); |
| |
| if (anim instanceof ObjectAnimator) { |
| ((ObjectAnimator) anim).setCurrentPlayTime(0); |
| } |
| anim.start(); |
| |
| // this only removes listeners whose views changed - must clear the |
| // other listeners later |
| child.removeOnLayoutChangeListener(this); |
| layoutChangeListenerMap.remove(child); |
| } |
| }; |
| // Remove the animation from the cache when it ends |
| anim.addListener(new AnimatorListenerAdapter() { |
| private boolean canceled = false; |
| public void onAnimationCancel(Animator animator) { |
| // we remove canceled animations immediately, not here |
| canceled = true; |
| child.removeOnLayoutChangeListener(listener); |
| layoutChangeListenerMap.remove(child); |
| } |
| public void onAnimationEnd(Animator animator) { |
| if (!canceled) { |
| currentAnimations.remove(child); |
| } |
| } |
| }); |
| |
| child.addOnLayoutChangeListener(listener); |
| // cache the listener for later removal |
| layoutChangeListenerMap.put(child, listener); |
| } |
| } |
| // This is the cleanup step. When we get this rendering event, we know that all of |
| // the appropriate animations have been set up and run. Now we can clear out the |
| // layout listeners. |
| observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() { |
| public boolean onPreDraw() { |
| parent.getViewTreeObserver().removeOnPreDrawListener(this); |
| int numChildren = parent.getChildCount(); |
| for (int i = 0; i < numChildren; ++i) { |
| final View child = parent.getChildAt(i); |
| child.removeOnLayoutChangeListener(layoutChangeListenerMap.get(child)); |
| } |
| layoutChangeListenerMap.clear(); |
| return true; |
| } |
| }); |
| } |
| |
| /** |
| * This method runs the animation that makes an added item appear. |
| * |
| * @param parent The ViewGroup to which the View is being added. |
| * @param child The View being added to the ViewGroup. |
| */ |
| private void runAppearingTransition(final ViewGroup parent, final View child) { |
| if (mAppearingAnim == null) { |
| if (mListeners != null) { |
| for (TransitionListener listener : mListeners) { |
| listener.endTransition(LayoutTransition.this, parent, child, APPEARING); |
| } |
| } |
| return; |
| } |
| Animator anim = mAppearingAnim.clone(); |
| anim.setTarget(child); |
| anim.setStartDelay(mAppearingDelay); |
| anim.setDuration(mAppearingDuration); |
| if (anim instanceof ObjectAnimator) { |
| ((ObjectAnimator) anim).setCurrentPlayTime(0); |
| } |
| if (mListeners != null) { |
| anim.addListener(new AnimatorListenerAdapter() { |
| public void onAnimationEnd() { |
| for (TransitionListener listener : mListeners) { |
| listener.endTransition(LayoutTransition.this, parent, child, APPEARING); |
| } |
| } |
| }); |
| } |
| anim.start(); |
| } |
| |
| /** |
| * This method runs the animation that makes a removed item disappear. |
| * |
| * @param parent The ViewGroup from which the View is being removed. |
| * @param child The View being removed from the ViewGroup. |
| */ |
| private void runDisappearingTransition(final ViewGroup parent, final View child) { |
| if (mDisappearingAnim == null) { |
| if (mListeners != null) { |
| for (TransitionListener listener : mListeners) { |
| listener.endTransition(LayoutTransition.this, parent, child, DISAPPEARING); |
| } |
| } |
| return; |
| } |
| Animator anim = mDisappearingAnim.clone(); |
| anim.setStartDelay(mDisappearingDelay); |
| anim.setDuration(mDisappearingDuration); |
| anim.setTarget(child); |
| if (mListeners != null) { |
| anim.addListener(new AnimatorListenerAdapter() { |
| @Override |
| public void onAnimationEnd(Animator anim) { |
| for (TransitionListener listener : mListeners) { |
| listener.endTransition(LayoutTransition.this, parent, child, DISAPPEARING); |
| } |
| } |
| }); |
| } |
| if (anim instanceof ObjectAnimator) { |
| ((ObjectAnimator) anim).setCurrentPlayTime(0); |
| } |
| anim.start(); |
| } |
| |
| /** |
| * This method is called by ViewGroup when a child view is about to be added to the |
| * container. This callback starts the process of a transition; we grab the starting |
| * values, listen for changes to all of the children of the container, and start appropriate |
| * animations. |
| * |
| * @param parent The ViewGroup to which the View is being added. |
| * @param child The View being added to the ViewGroup. |
| */ |
| public void addChild(ViewGroup parent, View child) { |
| if (mListeners != null) { |
| for (TransitionListener listener : mListeners) { |
| listener.startTransition(this, parent, child, APPEARING); |
| } |
| } |
| runChangeTransition(parent, child, APPEARING); |
| runAppearingTransition(parent, child); |
| } |
| |
| /** |
| * This method is called by ViewGroup when a child view is about to be added to the |
| * container. This callback starts the process of a transition; we grab the starting |
| * values, listen for changes to all of the children of the container, and start appropriate |
| * animations. |
| * |
| * @param parent The ViewGroup to which the View is being added. |
| * @param child The View being added to the ViewGroup. |
| */ |
| public void showChild(ViewGroup parent, View child) { |
| addChild(parent, child); |
| } |
| |
| /** |
| * This method is called by ViewGroup when a child view is about to be removed from the |
| * container. This callback starts the process of a transition; we grab the starting |
| * values, listen for changes to all of the children of the container, and start appropriate |
| * animations. |
| * |
| * @param parent The ViewGroup from which the View is being removed. |
| * @param child The View being removed from the ViewGroup. |
| */ |
| public void removeChild(ViewGroup parent, View child) { |
| if (mListeners != null) { |
| for (TransitionListener listener : mListeners) { |
| listener.startTransition(this, parent, child, DISAPPEARING); |
| } |
| } |
| runChangeTransition(parent, child, DISAPPEARING); |
| runDisappearingTransition(parent, child); |
| } |
| |
| /** |
| * This method is called by ViewGroup when a child view is about to be removed from the |
| * container. This callback starts the process of a transition; we grab the starting |
| * values, listen for changes to all of the children of the container, and start appropriate |
| * animations. |
| * |
| * @param parent The ViewGroup from which the View is being removed. |
| * @param child The View being removed from the ViewGroup. |
| */ |
| public void hideChild(ViewGroup parent, View child) { |
| removeChild(parent, child); |
| } |
| |
| /** |
| * Add a listener that will be called when the bounds of the view change due to |
| * layout processing. |
| * |
| * @param listener The listener that will be called when layout bounds change. |
| */ |
| public void addTransitionListener(TransitionListener listener) { |
| if (mListeners == null) { |
| mListeners = new ArrayList<TransitionListener>(); |
| } |
| mListeners.add(listener); |
| } |
| |
| /** |
| * Remove a listener for layout changes. |
| * |
| * @param listener The listener for layout bounds change. |
| */ |
| public void removeTransitionListener(TransitionListener listener) { |
| if (mListeners == null) { |
| return; |
| } |
| mListeners.remove(listener); |
| } |
| |
| /** |
| * Gets the current list of listeners for layout changes. |
| * @return |
| */ |
| public List<TransitionListener> getTransitionListeners() { |
| return mListeners; |
| } |
| |
| /** |
| * This interface is used for listening to starting and ending events for transitions. |
| */ |
| public interface TransitionListener { |
| |
| /** |
| * This event is sent to listeners when an APPEARING or DISAPPEARING transition |
| * begins. |
| * |
| * @param transition The LayoutTransition sending out the event. |
| * @param container The ViewGroup on which the transition is playing. |
| * @param view The View object being added or removed from its parent. |
| * @param transitionType The type of transition that is beginning, either |
| * {@link android.animation.LayoutTransition#APPEARING} or |
| * {@link android.animation.LayoutTransition#DISAPPEARING}. |
| */ |
| public void startTransition(LayoutTransition transition, ViewGroup container, |
| View view, int transitionType); |
| |
| /** |
| * This event is sent to listeners when an APPEARING or DISAPPEARING transition ends. |
| * |
| * @param transition The LayoutTransition sending out the event. |
| * @param container The ViewGroup on which the transition is playing. |
| * @param view The View object being added or removed from its parent. |
| * @param transitionType The type of transition that is ending, either |
| * {@link android.animation.LayoutTransition#APPEARING} or |
| * {@link android.animation.LayoutTransition#DISAPPEARING}. |
| */ |
| public void endTransition(LayoutTransition transition, ViewGroup container, |
| View view, int transitionType); |
| } |
| |
| } |