Java tutorial
/* * Copyright (c) 2015 Ushahidi Inc * * This program is free software: you can redistribute it and/or modify it under * the terms of the GNU Affero General Public License as published by the Free * Software Foundation, either version 3 of the License, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program in the file LICENSE-AGPL. If not, see * https://www.gnu.org/licenses/agpl-3.0.html */ package com.ushahidi.android.presentation.view.ui.animators; 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; /** * Credits: https://goo.gl/O5ao2V */ public abstract class BaseItemAnimator extends SimpleItemAnimator { private static final boolean DEBUG = false; protected ArrayList<ViewHolder> mAddAnimations = new ArrayList<>(); protected ArrayList<ViewHolder> mRemoveAnimations = new ArrayList<>(); private ArrayList<ViewHolder> mPendingRemovals = new ArrayList<>(); private ArrayList<ViewHolder> mPendingAdditions = new ArrayList<>(); private ArrayList<MoveInfo> mPendingMoves = new ArrayList<>(); private ArrayList<ChangeInfo> mPendingChanges = new ArrayList<>(); private ArrayList<ArrayList<ViewHolder>> mAdditionsList = new ArrayList<>(); private ArrayList<ArrayList<MoveInfo>> mMovesList = new ArrayList<>(); private ArrayList<ArrayList<ChangeInfo>> mChangesList = new ArrayList<>(); private ArrayList<ViewHolder> mMoveAnimations = new ArrayList<>(); private ArrayList<ViewHolder> mChangeAnimations = new ArrayList<>(); @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<>(); moves.addAll(mPendingMoves); mMovesList.add(moves); mPendingMoves.clear(); Runnable mover = () -> { 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 = () -> { 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 = () -> { 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(); } } } protected abstract void animateRemoveImpl(final ViewHolder holder); protected abstract void animateAddImpl(final ViewHolder holder); protected void preAnimateRemove(final ViewHolder holder) { ViewHelper.clear(holder.itemView); } protected void preAnimateAdd(final ViewHolder holder) { ViewHelper.clear(holder.itemView); } @Override public boolean animateRemove(final ViewHolder holder) { endAnimation(holder); preAnimateRemove(holder); mPendingRemovals.add(holder); return true; } @Override public boolean animateAdd(final ViewHolder holder) { endAnimation(holder); preAnimateAdd(holder); mPendingAdditions.add(holder); return true; } @Override public boolean animateMove(final ViewHolder holder, int x, int y, int toX, int toY) { final View view = holder.itemView; int fromX = x; int fromY = y; fromX += ViewCompat.getTranslationX(holder.itemView); fromY += ViewCompat.getTranslationY(holder.itemView); endAnimation(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. mMoveAnimations.add(holder); final ViewPropertyAnimatorCompat animation = ViewCompat.animate(view); 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); endAnimation(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 endAnimation(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) { mChangeAnimations.add(changeInfo.oldHolder); final ViewPropertyAnimatorCompat oldViewAnim = ViewCompat.animate(view) .setDuration(getChangeDuration()); 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) { mChangeAnimations.add(changeInfo.newHolder); final ViewPropertyAnimatorCompat newViewAnimation = ViewCompat.animate(newView); 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)) { ViewHelper.clear(item.itemView); dispatchRemoveFinished(item); } if (mPendingAdditions.remove(item)) { ViewHelper.clear(item.itemView); 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)) { ViewHelper.clear(item.itemView); 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(); } @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 #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); ViewHelper.clear(item.itemView); 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 MoveInfo { public ViewHolder holder; public int fromX; public int fromY; public int toX; public int toY; public 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; public ViewHolder newHolder; public int fromX; public int fromY; public int toX; public int toY; public 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 + '}'; } } private static class VpaListenerAdapter implements ViewPropertyAnimatorListener { @Override public void onAnimationStart(View view) { } @Override public void onAnimationEnd(View view) { } @Override public void onAnimationCancel(View view) { } } protected class DefaultAddVpaListener extends VpaListenerAdapter { ViewHolder mViewHolder; public DefaultAddVpaListener(final ViewHolder holder) { mViewHolder = holder; } @Override public void onAnimationStart(View view) { dispatchAddStarting(mViewHolder); } @Override public void onAnimationCancel(View view) { ViewHelper.clear(view); } @Override public void onAnimationEnd(View view) { ViewHelper.clear(view); dispatchAddFinished(mViewHolder); mAddAnimations.remove(mViewHolder); dispatchFinishedWhenDone(); } } protected class DefaultRemoveVpaListener extends VpaListenerAdapter { ViewHolder mViewHolder; public DefaultRemoveVpaListener(final ViewHolder holder) { mViewHolder = holder; } @Override public void onAnimationStart(View view) { dispatchRemoveStarting(mViewHolder); } @Override public void onAnimationCancel(View view) { ViewHelper.clear(view); } @Override public void onAnimationEnd(View view) { ViewHelper.clear(view); dispatchRemoveFinished(mViewHolder); mRemoveAnimations.remove(mViewHolder); dispatchFinishedWhenDone(); } } }