BaseItemAnimator

package com.ivy.recyclerviewitemanimator;import android.support.annotation.NonNull;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.support.v7.widget.SimpleItemAnimator;import android.view.View;import java.util.ArrayList;import java.util.List;public abstract class BaseItemAnimator extends SimpleItemAnimator {    private static final boolean DEBUG = false;    private ArrayList<ViewHolder> mPendingRemovals = new ArrayList<>();    private ArrayList<ViewHolder> mPendingAdditions = new ArrayList<>();    private ArrayList<MoveInfo> mPendingMoves = new ArrayList<>();    private ArrayList<ChangeInfo> mPendingChanges = new ArrayList<>();    ArrayList<ArrayList<ViewHolder>> mAdditionsList = new ArrayList<>();    ArrayList<ArrayList<MoveInfo>> mMovesList = new ArrayList<>();    ArrayList<ArrayList<ChangeInfo>> mChangesList = new ArrayList<>();    ArrayList<ViewHolder> mAddAnimations = new ArrayList<>();    ArrayList<ViewHolder> mMoveAnimations = new ArrayList<>();    ArrayList<ViewHolder> mRemoveAnimations = new ArrayList<>();    ArrayList<ViewHolder> mChangeAnimations = new ArrayList<>();    private static class MoveInfo {        public ViewHolder holder;        public int fromX, fromY, toX, toY;        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;        }        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) {            return;        }        // First, remove stuff        for (ViewHolder holder : mPendingRemovals) {            animateRemoveImpl(holder);        }        mPendingRemovals.clear();        // Next, move stuff        if (movesPending) {            final ArrayList<MoveInfo> moves = new ArrayList<>();            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<>();            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<>();            additions.addAll(mPendingAdditions);            mAdditionsList.add(additions);            mPendingAdditions.clear();            Runnable adder = new Runnable() {                @Override                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);        setRemoveAnimation(holder,animation);        animation.setDuration(getRemoveDuration())                .setListener(new VpaListenerAdapter() {            @Override            public void onAnimationStart(View view) {                dispatchRemoveStarting(holder);            }            @Override            public void onAnimationEnd(View view) {                animation.setListener(null);                removeAnimationEnd(holder);                dispatchRemoveFinished(holder);                mRemoveAnimations.remove(holder);                dispatchFinishedWhenDone();            }        }).start();    }    @Override    public boolean animateAdd(final ViewHolder holder) {        resetAnimation(holder);        addAnimationInit(holder);        mPendingAdditions.add(holder);        return true;    }    void animateAddImpl(final ViewHolder holder) {        final View view = holder.itemView;        final ViewPropertyAnimatorCompat animation = ViewCompat.animate(view);        mAddAnimations.add(holder);        setAddAnimation(holder,animation);        animation.setDuration(getAddDuration()).                setListener(new VpaListenerAdapter() {                    @Override                    public void onAnimationStart(View view) {                        dispatchAddStarting(holder);                    }                    @Override                    public void onAnimationCancel(View view) {                        addAnimationCancel(holder);                    }                    @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;    }    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) {        if (oldHolder == newHolder) {            // Don't know how to run change animations when the same view holder is re-used.            // run a move animation to handle position changes.            return animateMove(oldHolder, fromX, fromY, toX, 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) {            // carry over translation values            resetAnimation(newHolder);            ViewCompat.setTranslationX(newHolder.itemView, -deltaX);            ViewCompat.setTranslationY(newHolder.itemView, -deltaY);            newChangeAnimationInit(newHolder);        }        mPendingChanges.add(new ChangeInfo(oldHolder, newHolder, fromX, fromY, toX, toY));        return true;    }    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);            setOldChangeAnimation(holder,oldViewAnim);            oldViewAnim.setListener(new VpaListenerAdapter() {                @Override                public void onAnimationStart(View view) {                    dispatchChangeStarting(changeInfo.oldHolder, true);                }                @Override                public void onAnimationEnd(View view) {                    oldViewAnim.setListener(null);                    oldChangeAnimationEnd(holder);                    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);            setNewChangeAnimation(newHolder,newViewAnimation);            newViewAnimation.translationX(0).translationY(0).setDuration(getChangeDuration()).                    setListener(new VpaListenerAdapter() {                @Override                public void onAnimationStart(View view) {                    dispatchChangeStarting(changeInfo.newHolder, false);                }                @Override                public void onAnimationEnd(View view) {                    newViewAnimation.setListener(null);                    newChangeAnimationEnd(newHolder);                    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;        }        newChangeAnimationEnd(item);        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)) {            removeAnimationEnd(item);            dispatchRemoveFinished(item);        }        if (mPendingAdditions.remove(item)) {            addAnimationCancel(item);            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)) {                addAnimationCancel(item);                dispatchAddFinished(item);                if (additions.isEmpty()) {                    mAdditionsList.remove(i);                }            }        }        // animations should be ended by the cancel above.        //noinspection PointlessBooleanExpression,ConstantConditions        if (mRemoveAnimations.remove(item) && DEBUG) {            throw new IllegalStateException("after animation is cancelled, item should not be in "                    + "mRemoveAnimations list");        }        //noinspection PointlessBooleanExpression,ConstantConditions        if (mAddAnimations.remove(item) && DEBUG) {            throw new IllegalStateException("after animation is cancelled, item should not be in "                    + "mAddAnimations list");        }        //noinspection PointlessBooleanExpression,ConstantConditions        if (mChangeAnimations.remove(item) && DEBUG) {            throw new IllegalStateException("after animation is cancelled, item should not be in "                    + "mChangeAnimations list");        }        //noinspection PointlessBooleanExpression,ConstantConditions        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.     */    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;            addAnimationCancel(item);            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;                addAnimationCancel(item);                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();        }    }    /**     * {@inheritDoc}     * <p>     * If the payload list is not empty, BaseItemAnimator returns <code>true</code>.     * When this is the case:     * <ul>     * <li>If you override {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)}, both     * ViewHolder arguments will be the same instance.     * </li>     * <li>     * If you are not overriding {@link #animateChange(ViewHolder, ViewHolder, int, int, int, int)},     * then BaseItemAnimator will call {@link #animateMove(ViewHolder, int, int, int, int)} and     * run a move animation instead.     * </li>     * </ul>     */    @Override    public boolean canReuseUpdatedViewHolder(@NonNull ViewHolder viewHolder,                                             @NonNull List<Object> payloads) {        return !payloads.isEmpty() || super.canReuseUpdatedViewHolder(viewHolder, payloads);    }    private static class VpaListenerAdapter implements ViewPropertyAnimatorListener {        VpaListenerAdapter() {        }        @Override        public void onAnimationStart(View view) {}        @Override        public void onAnimationEnd(View view) {}        @Override        public void onAnimationCancel(View view) {}    }    /**     * 执行移除动画     * @param holder 被移除的ViewHolder     * @param animator 被移动的ViewHolder对应动画对象     */    public abstract void setRemoveAnimation(ViewHolder holder,ViewPropertyAnimatorCompat animator);    /**     * 执行移除动画结束，执行还原，因为该ViewHolder会被复用     * @param holder 被移除的ViewHolder     */    public abstract void removeAnimationEnd(ViewHolder holder);    /**     * 执行添加动画初始化 这里设置透明为0添加时就会有渐变效果当然你可以在执行动画代码之前执行     * @param holder 添加的ViewHolder     */    public abstract void addAnimationInit(ViewHolder holder);    /**     * 执行添加动画     * @param holder 添加的ViewHolder     * @param animator 添加的ViewHolder对应动画对象     */    public abstract void setAddAnimation(ViewHolder holder,ViewPropertyAnimatorCompat animator);    /**     * 取消添加还原状态以复用     * @param holder 添加的ViewHolder     */    public abstract void addAnimationCancel(ViewHolder holder);    /**     * 更新时旧的ViewHolder动画     * @param holder 旧的ViewHolder     * @param animator ViewHolder对应动画对象     */    public abstract void setOldChangeAnimation(ViewHolder holder,ViewPropertyAnimatorCompat animator);    /**     * 更新时旧的ViewHolder动画结束，执行还原     * @param holder     */    public abstract void oldChangeAnimationEnd(ViewHolder holder);    /**     * 更新时新的ViewHolder初始化     * @param holder 更新时新的ViewHolder     */    public abstract void newChangeAnimationInit(ViewHolder holder);    /**     * 更新时新的ViewHolder动画     * @param holder 新的ViewHolder     * @param animator ViewHolder对应动画对象     */    public abstract void setNewChangeAnimation(ViewHolder holder,ViewPropertyAnimatorCompat animator);    /**     * 更新时新的ViewHolder动画结束，执行还原     * @param holder     */    public abstract void newChangeAnimationEnd(ViewHolder holder);}