/*
* Copyright (C) 2014 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.support.v7.widget;
import android.support.v4.animation.AnimatorCompatHelper;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.ViewPropertyAnimatorCompat;
import android.support.v4.view.ViewPropertyAnimatorListener;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
/**
* This implementation of {@link RecyclerView.ItemAnimator} provides basic
* animations on remove, add, and move events that happen to the items in
* a RecyclerView. RecyclerView uses a DefaultItemAnimator by default.
*
* @see RecyclerView#setItemAnimator(RecyclerView.ItemAnimator)
*/
public class DefaultItemAnimator extends RecyclerView.ItemAnimator {
private static final boolean DEBUG = false;
private ArrayList<ViewHolder> mPendingRemovals = new ArrayList<ViewHolder>();
private ArrayList<ViewHolder> mPendingAdditions = new ArrayList<ViewHolder>();
private ArrayList<MoveInfo> mPendingMoves = new ArrayList<MoveInfo>();
private ArrayList<ChangeInfo> mPendingChanges = new ArrayList<ChangeInfo>();
private ArrayList<ArrayList<ViewHolder>> mAdditionsList =
new ArrayList<ArrayList<ViewHolder>>();
private ArrayList<ArrayList<MoveInfo>> mMovesList = new ArrayList<ArrayList<MoveInfo>>();
private ArrayList<ArrayList<ChangeInfo>> mChangesList = new ArrayList<ArrayList<ChangeInfo>>();
private ArrayList<ViewHolder> mAddAnimations = new ArrayList<ViewHolder>();
private ArrayList<ViewHolder> mMoveAnimations = new ArrayList<ViewHolder>();
private ArrayList<ViewHolder> mRemoveAnimations = new ArrayList<ViewHolder>();
private ArrayList<ViewHolder> mChangeAnimations = new ArrayList<ViewHolder>();
private static class MoveInfo {
public ViewHolder holder;
public int fromX, fromY, toX, toY;
private MoveInfo(ViewHolder holder, int fromX, int fromY, int toX, int toY) {
this.holder = holder;
this.fromX = fromX;
this.fromY = fromY;
this.toX = toX;
this.toY = toY;
}
}
private static class ChangeInfo {
public ViewHolder oldHolder, newHolder;
public int fromX, fromY, toX, toY;
private ChangeInfo(ViewHolder oldHolder, ViewHolder newHolder) {
this.oldHolder = oldHolder;
this.newHolder = newHolder;
}
private ChangeInfo(ViewHolder oldHolder, ViewHolder newHolder,
int fromX, int fromY, int toX, int toY) {
this(oldHolder, newHolder);
this.fromX = fromX;
this.fromY = fromY;
this.toX = toX;
this.toY = toY;
}
@Override
public String toString() {
return "ChangeInfo{" +
"oldHolder=" + oldHolder +
", newHolder=" + newHolder +
", fromX=" + fromX +
", fromY=" + fromY +
", toX=" + toX +
", toY=" + toY +
'}';
}
}
@Override
public void runPendingAnimations() {
boolean removalsPending = !mPendingRemovals.isEmpty();
boolean movesPending = !mPendingMoves.isEmpty();
boolean changesPending = !mPendingChanges.isEmpty();
boolean additionsPending = !mPendingAdditions.isEmpty();
if (!removalsPending && !movesPending && !additionsPending && !changesPending) {
// nothing to animate
return;
}
// First, remove stuff
for (ViewHolder holder : mPendingRemovals) {
animateRemoveImpl(holder);
}
mPendingRemovals.clear();
// Next, move stuff
if (movesPending) {
final ArrayList<MoveInfo> moves = new ArrayList<MoveInfo>();
moves.addAll(mPendingMoves);
mMovesList.add(moves);
mPendingMoves.clear();
Runnable mover = new Runnable() {
@Override
public void run() {
for (MoveInfo moveInfo : moves) {
animateMoveImpl(moveInfo.holder, moveInfo.fromX, moveInfo.fromY,
moveInfo.toX, moveInfo.toY);
}
moves.clear();
mMovesList.remove(moves);
}
};
if (removalsPending) {
View view = moves.get(0).holder.itemView;
ViewCompat.postOnAnimationDelayed(view, mover, getRemoveDuration());
} else {
mover.run();
}
}
// Next, change stuff, to run in parallel with move animations
if (changesPending) {
final ArrayList<ChangeInfo> changes = new ArrayList<ChangeInfo>();
changes.addAll(mPendingChanges);
mChangesList.add(changes);
mPendingChanges.clear();
Runnable changer = new Runnable() {
@Override
public void run() {
for (ChangeInfo change : changes) {
animateChangeImpl(change);
}
changes.clear();
mChangesList.remove(changes);
}
};
if (removalsPending) {
ViewHolder holder = changes.get(0).oldHolder;
ViewCompat.postOnAnimationDelayed(holder.itemView, changer, getRemoveDuration());
} else {
changer.run();
}
}
// Next, add stuff
if (additionsPending) {
final ArrayList<ViewHolder> additions = new ArrayList<ViewHolder>();
additions.addAll(mPendingAdditions);
mAdditionsList.add(additions);
mPendingAdditions.clear();
Runnable adder = new Runnable() {
public void run() {
for (ViewHolder holder : additions) {
animateAddImpl(holder);
}
additions.clear();
mAdditionsList.remove(additions);
}
};
if (removalsPending || movesPending || changesPending) {
long removeDuration = removalsPending ? getRemoveDuration() : 0;
long moveDuration = movesPending ? getMoveDuration() : 0;
long changeDuration = changesPending ? getChangeDuration() : 0;
long totalDelay = removeDuration + Math.max(moveDuration, changeDuration);
View view = additions.get(0).itemView;
ViewCompat.postOnAnimationDelayed(view, adder, totalDelay);
} else {
adder.run();
}
}
}
@Override
public boolean animateRemove(final ViewHolder holder) {
resetAnimation(holder);
mPendingRemovals.add(holder);
return true;
}
private void animateRemoveImpl(final ViewHolder holder) {
final View view = holder.itemView;
final ViewPropertyAnimatorCompat animation = ViewCompat.animate(view);
mRemoveAnimations.add(holder);
animation.setDuration(getRemoveDuration())
.alpha(0).setListener(new VpaListenerAdapter() {
@Override
public void onAnimationStart(View view) {
dispatchRemoveStarting(holder);
}
@Override
public void onAnimationEnd(View view) {
animation.setListener(null);
ViewCompat.setAlpha(view, 1);
dispatchRemoveFinished(holder);
mRemoveAnimations.remove(holder);
dispatchFinishedWhenDone();
}
}).start();
}
@Override
public boolean animateAdd(final ViewHolder holder) {
resetAnimation(holder);
ViewCompat.setAlpha(holder.itemView, 0);
mPendingAdditions.add(holder);
return true;
}
private void animateAddImpl(final ViewHolder holder) {
final View view = holder.itemView;
final ViewPropertyAnimatorCompat animation = ViewCompat.animate(view);
mAddAnimations.add(holder);
animation.alpha(1).setDuration(getAddDuration()).
setListener(new VpaListenerAdapter() {
@Override
public void onAnimationStart(View view) {
dispatchAddStarting(holder);
}
@Override
public void onAnimationCancel(View view) {
ViewCompat.setAlpha(view, 1);
}
@Override
public void onAnimationEnd(View view) {
animation.setListener(null);
dispatchAddFinished(holder);
mAddAnimations.remove(holder);
dispatchFinishedWhenDone();
}
}).start();
}
@Override
public boolean animateMove(final ViewHolder holder, int fromX, int fromY,
int toX, int toY) {
final View view = holder.itemView;
fromX += ViewCompat.getTranslationX(holder.itemView);
fromY += ViewCompat.getTranslationY(holder.itemView);
resetAnimation(holder);
int deltaX = toX - fromX;
int deltaY = toY - fromY;
if (deltaX == 0 && deltaY == 0) {
dispatchMoveFinished(holder);
return false;
}
if (deltaX != 0) {
ViewCompat.setTranslationX(view, -deltaX);
}
if (deltaY != 0) {
ViewCompat.setTranslationY(view, -deltaY);
}
mPendingMoves.add(new MoveInfo(holder, fromX, fromY, toX, toY));
return true;
}
private void animateMoveImpl(final ViewHolder holder, int fromX, int fromY, int toX, int toY) {
final View view = holder.itemView;
final int deltaX = toX - fromX;
final int deltaY = toY - fromY;
if (deltaX != 0) {
ViewCompat.animate(view).translationX(0);
}
if (deltaY != 0) {
ViewCompat.animate(view).translationY(0);
}
// TODO: make EndActions end listeners instead, since end actions aren't called when
// vpas are canceled (and can't end them. why?)
// need listener functionality in VPACompat for this. Ick.
final ViewPropertyAnimatorCompat animation = ViewCompat.animate(view);
mMoveAnimations.add(holder);
animation.setDuration(getMoveDuration()).setListener(new VpaListenerAdapter() {
@Override
public void onAnimationStart(View view) {
dispatchMoveStarting(holder);
}
@Override
public void onAnimationCancel(View view) {
if (deltaX != 0) {
ViewCompat.setTranslationX(view, 0);
}
if (deltaY != 0) {
ViewCompat.setTranslationY(view, 0);
}
}
@Override
public void onAnimationEnd(View view) {
animation.setListener(null);
dispatchMoveFinished(holder);
mMoveAnimations.remove(holder);
dispatchFinishedWhenDone();
}
}).start();
}
@Override
public boolean animateChange(ViewHolder oldHolder, ViewHolder newHolder,
int fromX, int fromY, int toX, int toY) {
final float prevTranslationX = ViewCompat.getTranslationX(oldHolder.itemView);
final float prevTranslationY = ViewCompat.getTranslationY(oldHolder.itemView);
final float prevAlpha = ViewCompat.getAlpha(oldHolder.itemView);
resetAnimation(oldHolder);
int deltaX = (int) (toX - fromX - prevTranslationX);
int deltaY = (int) (toY - fromY - prevTranslationY);
// recover prev translation state after ending animation
ViewCompat.setTranslationX(oldHolder.itemView, prevTranslationX);
ViewCompat.setTranslationY(oldHolder.itemView, prevTranslationY);
ViewCompat.setAlpha(oldHolder.itemView, prevAlpha);
if (newHolder != null && newHolder.itemView != null) {
// carry over translation values
resetAnimation(newHolder);
ViewCompat.setTranslationX(newHolder.itemView, -deltaX);
ViewCompat.setTranslationY(newHolder.itemView, -deltaY);
ViewCompat.setAlpha(newHolder.itemView, 0);
}
mPendingChanges.add(new ChangeInfo(oldHolder, newHolder, fromX, fromY, toX, toY));
return true;
}
private void animateChangeImpl(final ChangeInfo changeInfo) {
final ViewHolder holder = changeInfo.oldHolder;
final View view = holder == null ? null : holder.itemView;
final ViewHolder newHolder = changeInfo.newHolder;
final View newView = newHolder != null ? newHolder.itemView : null;
if (view != null) {
final ViewPropertyAnimatorCompat oldViewAnim = ViewCompat.animate(view).setDuration(
getChangeDuration());
mChangeAnimations.add(changeInfo.oldHolder);
oldViewAnim.translationX(changeInfo.toX - changeInfo.fromX);
oldViewAnim.translationY(changeInfo.toY - changeInfo.fromY);
oldViewAnim.alpha(0).setListener(new VpaListenerAdapter() {
@Override
public void onAnimationStart(View view) {
dispatchChangeStarting(changeInfo.oldHolder, true);
}
@Override
public void onAnimationEnd(View view) {
oldViewAnim.setListener(null);
ViewCompat.setAlpha(view, 1);
ViewCompat.setTranslationX(view, 0);
ViewCompat.setTranslationY(view, 0);
dispatchChangeFinished(changeInfo.oldHolder, true);
mChangeAnimations.remove(changeInfo.oldHolder);
dispatchFinishedWhenDone();
}
}).start();
}
if (newView != null) {
final ViewPropertyAnimatorCompat newViewAnimation = ViewCompat.animate(newView);
mChangeAnimations.add(changeInfo.newHolder);
newViewAnimation.translationX(0).translationY(0).setDuration(getChangeDuration()).
alpha(1).setListener(new VpaListenerAdapter() {
@Override
public void onAnimationStart(View view) {
dispatchChangeStarting(changeInfo.newHolder, false);
}
@Override
public void onAnimationEnd(View view) {
newViewAnimation.setListener(null);
ViewCompat.setAlpha(newView, 1);
ViewCompat.setTranslationX(newView, 0);
ViewCompat.setTranslationY(newView, 0);
dispatchChangeFinished(changeInfo.newHolder, false);
mChangeAnimations.remove(changeInfo.newHolder);
dispatchFinishedWhenDone();
}
}).start();
}
}
private void endChangeAnimation(List<ChangeInfo> infoList, ViewHolder item) {
for (int i = infoList.size() - 1; i >= 0; i--) {
ChangeInfo changeInfo = infoList.get(i);
if (endChangeAnimationIfNecessary(changeInfo, item)) {
if (changeInfo.oldHolder == null && changeInfo.newHolder == null) {
infoList.remove(changeInfo);
}
}
}
}
private void endChangeAnimationIfNecessary(ChangeInfo changeInfo) {
if (changeInfo.oldHolder != null) {
endChangeAnimationIfNecessary(changeInfo, changeInfo.oldHolder);
}
if (changeInfo.newHolder != null) {
endChangeAnimationIfNecessary(changeInfo, changeInfo.newHolder);
}
}
private boolean endChangeAnimationIfNecessary(ChangeInfo changeInfo, ViewHolder item) {
boolean oldItem = false;
if (changeInfo.newHolder == item) {
changeInfo.newHolder = null;
} else if (changeInfo.oldHolder == item) {
changeInfo.oldHolder = null;
oldItem = true;
} else {
return false;
}
ViewCompat.setAlpha(item.itemView, 1);
ViewCompat.setTranslationX(item.itemView, 0);
ViewCompat.setTranslationY(item.itemView, 0);
dispatchChangeFinished(item, oldItem);
return true;
}
@Override
public void endAnimation(ViewHolder item) {
final View view = item.itemView;
// this will trigger end callback which should set properties to their target values.
ViewCompat.animate(view).cancel();
// TODO if some other animations are chained to end, how do we cancel them as well?
for (int i = mPendingMoves.size() - 1; i >= 0; i--) {
MoveInfo moveInfo = mPendingMoves.get(i);
if (moveInfo.holder == item) {
ViewCompat.setTranslationY(view, 0);
ViewCompat.setTranslationX(view, 0);
dispatchMoveFinished(item);
mPendingMoves.remove(i);
}
}
endChangeAnimation(mPendingChanges, item);
if (mPendingRemovals.remove(item)) {
ViewCompat.setAlpha(view, 1);
dispatchRemoveFinished(item);
}
if (mPendingAdditions.remove(item)) {
ViewCompat.setAlpha(view, 1);
dispatchAddFinished(item);
}
for (int i = mChangesList.size() - 1; i >= 0; i--) {
ArrayList<ChangeInfo> changes = mChangesList.get(i);
endChangeAnimation(changes, item);
if (changes.isEmpty()) {
mChangesList.remove(i);
}
}
for (int i = mMovesList.size() - 1; i >= 0; i--) {
ArrayList<MoveInfo> moves = mMovesList.get(i);
for (int j = moves.size() - 1; j >= 0; j--) {
MoveInfo moveInfo = moves.get(j);
if (moveInfo.holder == item) {
ViewCompat.setTranslationY(view, 0);
ViewCompat.setTranslationX(view, 0);
dispatchMoveFinished(item);
moves.remove(j);
if (moves.isEmpty()) {
mMovesList.remove(i);
}
break;
}
}
}
for (int i = mAdditionsList.size() - 1; i >= 0; i--) {
ArrayList<ViewHolder> additions = mAdditionsList.get(i);
if (additions.remove(item)) {
ViewCompat.setAlpha(view, 1);
dispatchAddFinished(item);
if (additions.isEmpty()) {
mAdditionsList.remove(i);
}
}
}
// animations should be ended by the cancel above.
if (mRemoveAnimations.remove(item) && DEBUG) {
throw new IllegalStateException("after animation is cancelled, item should not be in "
+ "mRemoveAnimations list");
}
if (mAddAnimations.remove(item) && DEBUG) {
throw new IllegalStateException("after animation is cancelled, item should not be in "
+ "mAddAnimations list");
}
if (mChangeAnimations.remove(item) && DEBUG) {
throw new IllegalStateException("after animation is cancelled, item should not be in "
+ "mChangeAnimations list");
}
if (mMoveAnimations.remove(item) && DEBUG) {
throw new IllegalStateException("after animation is cancelled, item should not be in "
+ "mMoveAnimations list");
}
dispatchFinishedWhenDone();
}
private void resetAnimation(ViewHolder holder) {
AnimatorCompatHelper.clearInterpolator(holder.itemView);
endAnimation(holder);
}
@Override
public boolean isRunning() {
return (!mPendingAdditions.isEmpty() ||
!mPendingChanges.isEmpty() ||
!mPendingMoves.isEmpty() ||
!mPendingRemovals.isEmpty() ||
!mMoveAnimations.isEmpty() ||
!mRemoveAnimations.isEmpty() ||
!mAddAnimations.isEmpty() ||
!mChangeAnimations.isEmpty() ||
!mMovesList.isEmpty() ||
!mAdditionsList.isEmpty() ||
!mChangesList.isEmpty());
}
/**
* Check the state of currently pending and running animations. If there are none
* pending/running, call {@link #dispatchAnimationsFinished()} to notify any
* listeners.
*/
private void dispatchFinishedWhenDone() {
if (!isRunning()) {
dispatchAnimationsFinished();
}
}
@Override
public void endAnimations() {
int count = mPendingMoves.size();
for (int i = count - 1; i >= 0; i--) {
MoveInfo item = mPendingMoves.get(i);
View view = item.holder.itemView;
ViewCompat.setTranslationY(view, 0);
ViewCompat.setTranslationX(view, 0);
dispatchMoveFinished(item.holder);
mPendingMoves.remove(i);
}
count = mPendingRemovals.size();
for (int i = count - 1; i >= 0; i--) {
ViewHolder item = mPendingRemovals.get(i);
dispatchRemoveFinished(item);
mPendingRemovals.remove(i);
}
count = mPendingAdditions.size();
for (int i = count - 1; i >= 0; i--) {
ViewHolder item = mPendingAdditions.get(i);
View view = item.itemView;
ViewCompat.setAlpha(view, 1);
dispatchAddFinished(item);
mPendingAdditions.remove(i);
}
count = mPendingChanges.size();
for (int i = count - 1; i >= 0; i--) {
endChangeAnimationIfNecessary(mPendingChanges.get(i));
}
mPendingChanges.clear();
if (!isRunning()) {
return;
}
int listCount = mMovesList.size();
for (int i = listCount - 1; i >= 0; i--) {
ArrayList<MoveInfo> moves = mMovesList.get(i);
count = moves.size();
for (int j = count - 1; j >= 0; j--) {
MoveInfo moveInfo = moves.get(j);
ViewHolder item = moveInfo.holder;
View view = item.itemView;
ViewCompat.setTranslationY(view, 0);
ViewCompat.setTranslationX(view, 0);
dispatchMoveFinished(moveInfo.holder);
moves.remove(j);
if (moves.isEmpty()) {
mMovesList.remove(moves);
}
}
}
listCount = mAdditionsList.size();
for (int i = listCount - 1; i >= 0; i--) {
ArrayList<ViewHolder> additions = mAdditionsList.get(i);
count = additions.size();
for (int j = count - 1; j >= 0; j--) {
ViewHolder item = additions.get(j);
View view = item.itemView;
ViewCompat.setAlpha(view, 1);
dispatchAddFinished(item);
additions.remove(j);
if (additions.isEmpty()) {
mAdditionsList.remove(additions);
}
}
}
listCount = mChangesList.size();
for (int i = listCount - 1; i >= 0; i--) {
ArrayList<ChangeInfo> changes = mChangesList.get(i);
count = changes.size();
for (int j = count - 1; j >= 0; j--) {
endChangeAnimationIfNecessary(changes.get(j));
if (changes.isEmpty()) {
mChangesList.remove(changes);
}
}
}
cancelAll(mRemoveAnimations);
cancelAll(mMoveAnimations);
cancelAll(mAddAnimations);
cancelAll(mChangeAnimations);
dispatchAnimationsFinished();
}
void cancelAll(List<ViewHolder> viewHolders) {
for (int i = viewHolders.size() - 1; i >= 0; i--) {
ViewCompat.animate(viewHolders.get(i).itemView).cancel();
}
}
private static class VpaListenerAdapter implements ViewPropertyAnimatorListener {
@Override
public void onAnimationStart(View view) {}
@Override
public void onAnimationEnd(View view) {}
@Override
public void onAnimationCancel(View view) {}
};
}