Java tutorial
/* * 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 com.kozhevin.example.carousel; import java.util.ArrayList; import android.support.v4.view.ViewCompat; import android.support.v4.view.ViewPropertyAnimatorCompat; import android.support.v4.view.ViewPropertyAnimatorListener; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.RecyclerView.ViewHolder; import android.view.View; /** * 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 CarouselItemAnimator extends RecyclerView.ItemAnimator { private ArrayList<ViewHolder> mPendingRemovals = new ArrayList<ViewHolder>(); private ArrayList<ViewHolder> mPendingAdditions = new ArrayList<ViewHolder>(); private ArrayList<MoveInfo> mPendingMoves = new ArrayList<MoveInfo>(); private ArrayList<ViewHolder> mAdditions = new ArrayList<ViewHolder>(); private ArrayList<MoveInfo> mMoves = new ArrayList<MoveInfo>(); private ArrayList<ViewHolder> mAddAnimations = new ArrayList<ViewHolder>(); private ArrayList<ViewHolder> mMoveAnimations = new ArrayList<ViewHolder>(); private ArrayList<ViewHolder> mRemoveAnimations = new ArrayList<ViewHolder>(); private float mTranslationValueY; private volatile boolean mIsUseTranslationAnimation; 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; } } @Override public void runPendingAnimations() { boolean removalsPending = !mPendingRemovals.isEmpty(); boolean movesPending = !mPendingMoves.isEmpty(); boolean additionsPending = !mPendingAdditions.isEmpty(); if (!removalsPending && !movesPending && !additionsPending) { // nothing to animate return; } // First, remove stuff for (ViewHolder holder : mPendingRemovals) { animateRemoveImpl(holder); } mPendingRemovals.clear(); // Next, move stuff if (movesPending) { mMoves.addAll(mPendingMoves); mPendingMoves.clear(); Runnable mover = new Runnable() { @Override public void run() { for (MoveInfo moveInfo : mMoves) { animateMoveImpl(moveInfo.holder, moveInfo.fromX, moveInfo.fromY, moveInfo.toX, moveInfo.toY); } mMoves.clear(); } }; if (removalsPending) { View view = mMoves.get(0).holder.itemView; ViewCompat.postOnAnimationDelayed(view, mover, getRemoveDuration()); } else { mover.run(); } } // Next, add stuff if (additionsPending) { mAdditions.addAll(mPendingAdditions); mPendingAdditions.clear(); Runnable adder = new Runnable() { public void run() { for (ViewHolder holder : mAdditions) { animateAddImpl(holder); } mAdditions.clear(); } }; if (removalsPending || movesPending) { View view = mAdditions.get(0).itemView; ViewCompat.postOnAnimationDelayed(view, adder, (removalsPending ? getRemoveDuration() : 0) + (movesPending ? getMoveDuration() : 0)); } else { adder.run(); } } } @Override public boolean animateRemove(final ViewHolder holder) { mPendingRemovals.add(holder); return true; } private void animateRemoveImpl(final ViewHolder pHolder) { final View view = pHolder.itemView; ViewCompat.animate(view).cancel(); if (getTranslationValueY() != 0 && mIsUseTranslationAnimation) { ViewPropertyAnimatorCompat lViewPropertyAnimatorCompat = ViewCompat.animate(view); lViewPropertyAnimatorCompat.setDuration(350); lViewPropertyAnimatorCompat.translationY(getTranslationValueY()); lViewPropertyAnimatorCompat.setListener(new ViewPropertyAnimatorListener() { @Override public void onAnimationStart(View arg0) { } @Override public void onAnimationEnd(View arg0) { animateAlhaRemove(view, pHolder); } @Override public void onAnimationCancel(View arg0) { } }); ViewCompat.animate(view).start(); } else { if (mIsUseTranslationAnimation) { view.setAlpha(0f); mIsUseTranslationAnimation = true; } animateAlhaRemove(view, pHolder); } mRemoveAnimations.add(pHolder); } private void animateAlhaRemove(final View pView, final ViewHolder pHolder) { if (pView.getAlpha() > 0.8f) { ViewCompat.animate(pView).setDuration(getRemoveDuration()).alpha(0) .setListener(new VpaListenerAdapter() { @Override public void onAnimationEnd(View pView) { afterAnimatedAlfaRemove(pView, pHolder); } }).start(); } else { afterAnimatedAlfaRemove(pView, pHolder); } } private void afterAnimatedAlfaRemove(final View pView, final ViewHolder pHolder) { ViewCompat.setAlpha(pView, 1); dispatchRemoveFinished(pHolder); mRemoveAnimations.remove(pHolder); dispatchFinishedWhenDone(); } @Override public boolean animateAdd(final ViewHolder holder) { ViewCompat.setAlpha(holder.itemView, 0); mPendingAdditions.add(holder); return true; } private void animateAddImpl(final ViewHolder holder) { final View view = holder.itemView; ViewCompat.animate(view).cancel(); ViewCompat.animate(view).alpha(1).setDuration(getAddDuration()).setListener(new VpaListenerAdapter() { @Override public void onAnimationCancel(View view) { ViewCompat.setAlpha(view, 1); } @Override public void onAnimationEnd(View view) { dispatchAddFinished(holder); mAddAnimations.remove(holder); dispatchFinishedWhenDone(); } }).start(); mAddAnimations.add(holder); } @Override public boolean animateMove(final ViewHolder holder, int fromX, int fromY, int toX, int toY) { final View view = holder.itemView; 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; ViewCompat.animate(view).cancel(); 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. ViewCompat.animate(view).setDuration(getMoveDuration()).setListener(new VpaListenerAdapter() { @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) { dispatchMoveFinished(holder); mMoveAnimations.remove(holder); dispatchFinishedWhenDone(); } }).start(); mMoveAnimations.add(holder); } @Override public void endAnimation(ViewHolder item) { final View view = item.itemView; ViewCompat.animate(view).cancel(); if (mPendingMoves.contains(item)) { ViewCompat.setTranslationY(view, 0); ViewCompat.setTranslationX(view, 0); dispatchMoveFinished(item); mPendingMoves.remove(item); } if (mPendingRemovals.contains(item)) { dispatchRemoveFinished(item); mPendingRemovals.remove(item); } if (mPendingAdditions.contains(item)) { ViewCompat.setAlpha(view, 1); dispatchAddFinished(item); mPendingAdditions.remove(item); } if (mMoveAnimations.contains(item)) { ViewCompat.setTranslationY(view, 0); ViewCompat.setTranslationX(view, 0); dispatchMoveFinished(item); mMoveAnimations.remove(item); } if (mRemoveAnimations.contains(item)) { ViewCompat.setAlpha(view, 1); dispatchRemoveFinished(item); mRemoveAnimations.remove(item); } if (mAddAnimations.contains(item)) { ViewCompat.setAlpha(view, 1); dispatchAddFinished(item); mAddAnimations.remove(item); } dispatchFinishedWhenDone(); } @Override public boolean isRunning() { return (!mMoveAnimations.isEmpty() || !mRemoveAnimations.isEmpty() || !mAddAnimations.isEmpty() || !mMoves.isEmpty() || !mAdditions.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.animate(view).cancel(); ViewCompat.setTranslationY(view, 0); ViewCompat.setTranslationX(view, 0); dispatchMoveFinished(item.holder); mPendingMoves.remove(item); } count = mPendingRemovals.size(); for (int i = count - 1; i >= 0; i--) { ViewHolder item = mPendingRemovals.get(i); dispatchRemoveFinished(item); mPendingRemovals.remove(item); } 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(item); } if (!isRunning()) { return; } count = mMoveAnimations.size(); for (int i = count - 1; i >= 0; i--) { ViewHolder item = mMoveAnimations.get(i); View view = item.itemView; ViewCompat.animate(view).cancel(); ViewCompat.setTranslationY(view, 0); ViewCompat.setTranslationX(view, 0); dispatchMoveFinished(item); mMoveAnimations.remove(item); } count = mRemoveAnimations.size(); for (int i = count - 1; i >= 0; i--) { ViewHolder item = mRemoveAnimations.get(i); View view = item.itemView; ViewCompat.animate(view).cancel(); ViewCompat.setAlpha(view, 1); dispatchRemoveFinished(item); mRemoveAnimations.remove(item); } count = mAddAnimations.size(); for (int i = count - 1; i >= 0; i--) { ViewHolder item = mAddAnimations.get(i); View view = item.itemView; ViewCompat.animate(view).cancel(); ViewCompat.setAlpha(view, 1); dispatchAddFinished(item); mAddAnimations.remove(item); } mMoves.clear(); mAdditions.clear(); dispatchAnimationsFinished(); } public float getTranslationValueY() { return mTranslationValueY; } public void setTranslationValueY(float pTranslationValueY) { mTranslationValueY = pTranslationValueY; } public boolean isUseTranslationAnimation() { return mIsUseTranslationAnimation; } public void setIsUseTranslationAnimation(boolean mIsUseTranslationAnimation) { this.mIsUseTranslationAnimation = mIsUseTranslationAnimation; } private static class VpaListenerAdapter implements ViewPropertyAnimatorListener { @Override public void onAnimationStart(View view) { } @Override public void onAnimationEnd(View view) { } @Override public void onAnimationCancel(View view) { } }; }