Add animators

11 files changed, 970 insertions, 26 deletions

diff --git a/library/src/main/kotlin/ca/allanwang/kau/about/AboutActivityBase.kt b/library/src/main/kotlin/ca/allanwang/kau/about/AboutActivityBase.kt
index f469028..4690718 100644
--- a/library/src/main/kotlin/ca/allanwang/kau/about/AboutActivityBase.kt
+++ b/library/src/main/kotlin/ca/allanwang/kau/about/AboutActivityBase.kt
@@ -1,20 +1,18 @@
 package ca.allanwang.kau.about
 
 import android.os.Bundle
-import android.os.PersistableBundle
 import android.support.v7.app.AppCompatActivity
 import android.support.v7.widget.RecyclerView
 import android.support.v7.widget.Toolbar
 import ca.allanwang.kau.R
 import ca.allanwang.kau.adapters.ChainedAdapters
-import ca.allanwang.kau.logging.KL
+import ca.allanwang.kau.adapters.SectionAdapter
+import ca.allanwang.kau.animators.SlideUpAlphaAnimator
 import ca.allanwang.kau.utils.bindView
 import ca.allanwang.kau.utils.string
 import ca.allanwang.kau.views.KauTextSlider
 import com.mikepenz.aboutlibraries.Libs
 import com.mikepenz.aboutlibraries.entity.Library
-import com.mikepenz.fastadapter.adapters.HeaderAdapter
-import com.mikepenz.fastadapter.adapters.ItemAdapter
 import org.jetbrains.anko.doAsync
 import org.jetbrains.anko.uiThread
 
@@ -38,17 +36,14 @@ open class AboutActivityBase(val rClass: Class<*>) : AppCompatActivity() {
     val toolbar: Toolbar by bindView(R.id.kau_toolbar)
     val toolbarText: KauTextSlider by bindView(R.id.kau_toolbar_text)
     val recycler: RecyclerView by bindView(R.id.kau_recycler)
-    val libSection: Pair<String, HeaderAdapter<LibraryItem>> by lazy { string(R.string.kau_dependencies_used) to HeaderAdapter<LibraryItem>() }
+    val libSection: Pair<String, SectionAdapter<LibraryItem>> by lazy { string(R.string.kau_dependencies_used) to SectionAdapter<LibraryItem>() }
     val sectionsChain: ChainedAdapters<String> = ChainedAdapters()
 
     fun addLibsAsync() {
         doAsync {
             val libs = Libs(this@AboutActivityBase, Libs.toStringArray(rClass.fields))
             val items = getLibraries(libs)
-            uiThread {
-                KL.e("Coun ${items.count()}")
-                libSection.second.add(items.map { LibraryItem(it) })
-            }
+            uiThread { libSection.second.add(items.map { LibraryItem(it) }) }
         }
     }
 
@@ -69,12 +64,15 @@ open class AboutActivityBase(val rClass: Class<*>) : AppCompatActivity() {
             if (dy > 0) toolbarText.setNextText(item)
             else toolbarText.setPrevText()
         }
+        recycler.itemAnimator = SlideUpAlphaAnimator()
         toolbarText.setCurrentText(sectionsChain[0].first)
+        onPostCreate()
+        addLibsAsync()
     }
 
-    override fun onPostCreate(savedInstanceState: Bundle?, persistentState: PersistableBundle?) {
-        super.onPostCreate(savedInstanceState, persistentState)
-        addLibsAsync()
+
+    open fun onPostCreate() {
+
     }
 
     /**
@@ -82,5 +80,5 @@ open class AboutActivityBase(val rClass: Class<*>) : AppCompatActivity() {
      * The adapters should be listed in the order that they appear,
      * and if the [libSection] shouldn't be at the end, it should be added in this list
      */
-    open fun onCreateSections(): List<Pair<String, HeaderAdapter<*>>> = listOf(libSection)
+    open fun onCreateSections(): List<Pair<String, SectionAdapter<*>>> = listOf(libSection)
 }
\ No newline at end of file
diff --git a/library/src/main/kotlin/ca/allanwang/kau/about/LibraryItem.kt b/library/src/main/kotlin/ca/allanwang/kau/about/LibraryItem.kt
index 560eb82..0dd4973 100644
--- a/library/src/main/kotlin/ca/allanwang/kau/about/LibraryItem.kt
+++ b/library/src/main/kotlin/ca/allanwang/kau/about/LibraryItem.kt
@@ -54,6 +54,14 @@ class LibraryItem(val lib: Library) : AbstractItem<LibraryItem, LibraryItem.View
         }
     }
 
+    override fun unbindView(holder: ViewHolder) {
+        super.unbindView(holder)
+        with (holder) {
+            name.text = null
+            creator.text = null
+            description.text = null
+        }
+    }
 
     override fun getViewHolder(v: View): ViewHolder = ViewHolder(v)
 
diff --git a/library/src/main/kotlin/ca/allanwang/kau/about/MainItem.kt b/library/src/main/kotlin/ca/allanwang/kau/about/MainItem.kt
index decacfc..3edad32 100644
--- a/library/src/main/kotlin/ca/allanwang/kau/about/MainItem.kt
+++ b/library/src/main/kotlin/ca/allanwang/kau/about/MainItem.kt
@@ -36,7 +36,7 @@ class MainItem(builder: Config.() -> Unit) : AbstractItem<MainItem, MainItem.Vie
 
     override fun bindView(holder: ViewHolder, payloads: MutableList<Any>?) {
         super.bindView(holder, payloads)
-        with (holder) {
+        with(holder) {
             title.text = configs.title
             creator.text = configs.author
             description.text = configs.description
@@ -44,6 +44,15 @@ class MainItem(builder: Config.() -> Unit) : AbstractItem<MainItem, MainItem.Vie
         }
     }
 
+    override fun unbindView(holder: ViewHolder) {
+        super.unbindView(holder)
+        with(holder) {
+            title.text = null
+            creator.text = null
+            description.text = null
+        }
+    }
+
     class ViewHolder(v: View) : RecyclerView.ViewHolder(v) {
         val card: CardView by bindView(R.id.container)
         val title: TextView by bindView(R.id.title)
diff --git a/library/src/main/kotlin/ca/allanwang/kau/adapters/ChainedAdapters.kt b/library/src/main/kotlin/ca/allanwang/kau/adapters/ChainedAdapters.kt
index aaa0fb0..e1c5c18 100644
--- a/library/src/main/kotlin/ca/allanwang/kau/adapters/ChainedAdapters.kt
+++ b/library/src/main/kotlin/ca/allanwang/kau/adapters/ChainedAdapters.kt
@@ -2,7 +2,6 @@ package ca.allanwang.kau.adapters
 
 import android.support.v7.widget.LinearLayoutManager
 import android.support.v7.widget.RecyclerView
-import ca.allanwang.kau.logging.KL
 import com.mikepenz.fastadapter.IItem
 import com.mikepenz.fastadapter.adapters.HeaderAdapter
 import com.mikepenz.fastadapter.commons.adapters.FastItemAdapter
@@ -17,18 +16,19 @@ import java.util.*
  * - Add a [LinearLayoutManager] to the recycler
  * - Add a listener for when a new adapter segment is being used
  */
-class ChainedAdapters<T>(vararg items: Pair<T, HeaderAdapter<*>>) {
-    private val chain: MutableList<Pair<T, HeaderAdapter<*>>> = mutableListOf(*items)
+class ChainedAdapters<T>(vararg items: Pair<T, SectionAdapter<*>>) {
+    private val chain: MutableList<Pair<T, SectionAdapter<*>>> = mutableListOf(*items)
     val baseAdapter: FastItemAdapter<IItem<*, *>> = FastItemAdapter()
     private val indexStack = Stack<Int>()
     var recycler: RecyclerView? = null
     val firstVisibleItemPosition: Int
         get() = (recycler?.layoutManager as LinearLayoutManager?)?.findFirstVisibleItemPosition() ?: throw IllegalArgumentException("No recyclerview was bounded to the chain adapters")
 
-    fun add(vararg items: Pair<T, HeaderAdapter<*>>) = add(items.toList())
+    fun add(vararg items: Pair<T, SectionAdapter<*>>) = add(items.toList())
 
-    fun add(items: Collection<Pair<T, HeaderAdapter<*>>>): ChainedAdapters<T> {
+    fun add(items: Collection<Pair<T, SectionAdapter<*>>>): ChainedAdapters<T> {
         if (recycler != null) throw IllegalAccessException("Chain adapter is already bounded to a recycler; cannot add directly.")
+        items.map { it.second }.forEachIndexed { index, sectionAdapter -> sectionAdapter.sectionOrder = chain.size + 1 + index }
         chain.addAll(items)
         return this
     }
@@ -51,7 +51,6 @@ class ChainedAdapters<T>(vararg items: Pair<T, HeaderAdapter<*>>) {
         chain.map { it.second }.forEachReversedWithIndex { i, headerAdapter ->
             if (i == chain.size - 1) headerAdapter.wrap(baseAdapter)
             else headerAdapter.wrap(chain[i + 1].second)
-            if (i < chain.size - 1) KL.e("${chain[i].first} ${chain[i + 1].first}")
         }
         recycler = recyclerView
         indexStack.push(0)
@@ -68,10 +67,8 @@ class ChainedAdapters<T>(vararg items: Pair<T, HeaderAdapter<*>>) {
                         val nextAdapterIndex = (currentAdapterIndex until chain.size).asSequence()
                                 .firstOrNull {
                                     val adapter = chain[it].second
-                                    KL.e("A $it ${adapter.adapterItemCount} ${adapter.getGlobalPosition(0)} $topPosition $currentAdapterIndex")
-                                    adapter.adapterItemCount > 0 && adapter.getGlobalPosition(0) >= topPosition
+                                    adapter.adapterItemCount > 0 && adapter.getGlobalPosition(adapter.adapterItemCount - 1) >= topPosition
                                 } ?: currentAdapterIndex
-                        KL.e("Next $nextAdapterIndex")
                         if (nextAdapterIndex == currentAdapterIndex) return
                         indexStack.push(nextAdapterIndex)
                         onAdapterSectionChanged(chain[indexStack.peek()].first, indexStack.peek(), dy)
diff --git a/library/src/main/kotlin/ca/allanwang/kau/adapters/SectionAdapter.kt b/library/src/main/kotlin/ca/allanwang/kau/adapters/SectionAdapter.kt
new file mode 100644
index 0000000..cf7205a
--- /dev/null
+++ b/library/src/main/kotlin/ca/allanwang/kau/adapters/SectionAdapter.kt
@@ -0,0 +1,13 @@
+package ca.allanwang.kau.adapters
+
+import com.mikepenz.fastadapter.IItem
+import com.mikepenz.fastadapter.adapters.HeaderAdapter
+
+/**
+ * Created by Allan Wang on 2017-06-27.
+ *
+ * Extension of [HeaderAdapter] where we can define the order
+ */
+class SectionAdapter<Item : IItem<*, *>>(var sectionOrder: Int = 100) : HeaderAdapter<Item>() {
+    override fun getOrder(): Int = sectionOrder
+}
\ No newline at end of file
diff --git a/library/src/main/kotlin/ca/allanwang/kau/animators/BaseItemAnimator.java b/library/src/main/kotlin/ca/allanwang/kau/animators/BaseItemAnimator.java
new file mode 100644
index 0000000..f25678f
--- /dev/null
+++ b/library/src/main/kotlin/ca/allanwang/kau/animators/BaseItemAnimator.java
@@ -0,0 +1,764 @@
+package ca.allanwang.kau.animators;
+
+/*
+ * Created by Allan Wang on 2017-06-27.
+ *
+ * Based on Item Animator by {@author Mike Penz}
+ * Rewritten to match with the updated compat dependencies
+ */
+/*
+ * 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.
+ */
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.TimeInterpolator;
+import android.animation.ValueAnimator;
+import android.support.annotation.NonNull;
+import android.support.v4.view.ViewCompat;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.support.v7.widget.SimpleItemAnimator;
+import android.view.View;
+import android.view.ViewPropertyAnimator;
+import android.view.animation.Interpolator;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * This implementation of {@link android.support.v7.widget.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 android.support.v7.widget.RecyclerView#setItemAnimator(android.support.v7.widget.RecyclerView.ItemAnimator)
+ */
+public abstract class BaseItemAnimator extends SimpleItemAnimator {
+    private static final boolean DEBUG = false;
+
+    private static TimeInterpolator sDefaultInterpolator;
+
+    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<>();
+
+    Interpolator interpolator;
+
+    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;
+        }
+    }
+
+    public 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) {
+            // 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 = 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, 0);
+            } 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;
+                long moveDuration = movesPending ? getMoveDuration() : 0;
+                ViewCompat.postOnAnimationDelayed(holder.itemView, changer, getRemoveDelay(getRemoveDuration(), moveDuration, getChangeDuration()));
+            } 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;
+                View view = additions.get(0).itemView;
+                ViewCompat.postOnAnimationDelayed(view, adder, getAddDelay(removeDuration, moveDuration, changeDuration));
+            } else {
+                adder.run();
+            }
+        }
+    }
+
+    /**
+     * used to calculated the delay until the remove animation should start
+     *
+     * @param remove the remove duration
+     * @param move   the move duration
+     * @param change the change duration
+     * @return the calculated delay for the remove items animation
+     */
+    public long getRemoveDelay(long remove, long move, long change) {
+        return remove + Math.max(move, change);
+    }
+
+    /**
+     * used to calculated the delay until the add animation should start
+     *
+     * @param remove the remove duration
+     * @param move   the move duration
+     * @param change the change duration
+     * @return the calculated delay for the add items animation
+     */
+    public long getAddDelay(long remove, long move, long change) {
+        return remove + Math.max(move, change);
+    }
+
+    @Override
+    public boolean animateRemove(final ViewHolder holder) {
+        resetAnimation(holder);
+        mPendingRemovals.add(holder);
+        return true;
+    }
+
+    private void animateRemoveImpl(final ViewHolder holder) {
+        final ViewPropertyAnimator animation = removeAnimation(holder);
+        mRemoveAnimations.add(holder);
+        animation.setListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animator) {
+                dispatchRemoveStarting(holder);
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animator) {
+                animation.setListener(null);
+                removeAnimationCleanup(holder);
+                dispatchRemoveFinished(holder);
+                mRemoveAnimations.remove(holder);
+                dispatchFinishedWhenDone();
+            }
+        }).start();
+    }
+
+    abstract public ViewPropertyAnimator removeAnimation(ViewHolder holder);
+
+    abstract public void removeAnimationCleanup(ViewHolder holder);
+
+    @Override
+    public boolean animateAdd(final ViewHolder holder) {
+        resetAnimation(holder);
+        addAnimationPrepare(holder);
+        mPendingAdditions.add(holder);
+        return true;
+    }
+
+    void animateAddImpl(final ViewHolder holder) {
+        final ViewPropertyAnimator animation = addAnimation(holder);
+        mAddAnimations.add(holder);
+        animation.setListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animator) {
+                dispatchAddStarting(holder);
+            }
+
+            @Override
+            public void onAnimationCancel(Animator animator) {
+                addAnimationCleanup(holder);
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animator) {
+                animation.setListener(null);
+                dispatchAddFinished(holder);
+                mAddAnimations.remove(holder);
+                dispatchFinishedWhenDone();
+                addAnimationCleanup(holder);
+            }
+        }).start();
+    }
+
+    /**
+     * the animation to prepare the view before the add animation is run
+     *
+     * @param holder
+     */
+    public abstract void addAnimationPrepare(ViewHolder holder);
+
+    /**
+     * the animation for adding a view
+     *
+     * @param holder
+     * @return
+     */
+    public abstract ViewPropertyAnimator addAnimation(ViewHolder holder);
+
+    /**
+     * the cleanup method if the animation needs to be stopped. and tro prepare for the next view
+     *
+     * @param holder
+     */
+    abstract void addAnimationCleanup(ViewHolder holder);
+
+    @Override
+    public boolean animateMove(final ViewHolder holder, int fromX, int fromY,
+                               int toX, int toY) {
+        final View view = holder.itemView;
+        fromX += (int) holder.itemView.getTranslationX();
+        fromY += (int) holder.itemView.getTranslationY();
+        resetAnimation(holder);
+        int deltaX = toX - fromX;
+        int deltaY = toY - fromY;
+        if (deltaX == 0 && deltaY == 0) {
+            dispatchMoveFinished(holder);
+            return false;
+        }
+        if (deltaX != 0) {
+            view.setTranslationX(-deltaX);
+        }
+        if (deltaY != 0) {
+            view.setTranslationY(-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) {
+            view.animate().translationX(0);
+        }
+        if (deltaY != 0) {
+            view.animate().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 ViewPropertyAnimator animation = view.animate();
+        mMoveAnimations.add(holder);
+        animation.setDuration(getMoveDuration()).setListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animator) {
+                dispatchMoveStarting(holder);
+            }
+
+            @Override
+            public void onAnimationCancel(Animator animator) {
+                if (deltaX != 0) {
+                    view.setTranslationX(0);
+                }
+                if (deltaY != 0) {
+                    view.setTranslationY(0);
+                }
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animator) {
+                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);
+        }
+        changeAnimation(oldHolder, newHolder,
+                fromX, fromY, toX, toY);
+        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 ViewPropertyAnimator oldViewAnim = changeOldAnimation(holder, changeInfo);
+            mChangeAnimations.add(changeInfo.oldHolder);
+            oldViewAnim.setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationStart(Animator animator) {
+                    dispatchChangeStarting(changeInfo.oldHolder, true);
+                }
+
+                @Override
+                public void onAnimationEnd(Animator animator) {
+                    oldViewAnim.setListener(null);
+                    changeAnimationCleanup(holder);
+                    view.setTranslationX(0);
+                    view.setTranslationY(0);
+                    dispatchChangeFinished(changeInfo.oldHolder, true);
+                    mChangeAnimations.remove(changeInfo.oldHolder);
+                    dispatchFinishedWhenDone();
+                }
+            }).start();
+        }
+        if (newView != null) {
+            final ViewPropertyAnimator newViewAnimation = changeNewAnimation(newHolder);
+            mChangeAnimations.add(changeInfo.newHolder);
+            newViewAnimation.setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationStart(Animator animator) {
+                    dispatchChangeStarting(changeInfo.newHolder, false);
+                }
+
+                @Override
+                public void onAnimationEnd(Animator animator) {
+                    newViewAnimation.setListener(null);
+                    changeAnimationCleanup(newHolder);
+                    newView.setTranslationX(0);
+                    newView.setTranslationY(0);
+                    dispatchChangeFinished(changeInfo.newHolder, false);
+                    mChangeAnimations.remove(changeInfo.newHolder);
+                    dispatchFinishedWhenDone();
+                }
+            }).start();
+        }
+    }
+
+    /**
+     * the whole change animation if we have to cross animate two views
+     *
+     * @param oldHolder
+     * @param newHolder
+     * @param fromX
+     * @param fromY
+     * @param toX
+     * @param toY
+     */
+    public void changeAnimation(ViewHolder oldHolder, ViewHolder newHolder, int fromX, int fromY, int toX, int toY) {
+        final float prevTranslationX = oldHolder.itemView.getTranslationX();
+        final float prevTranslationY = oldHolder.itemView.getTranslationY();
+        final float prevValue = oldHolder.itemView.getAlpha();
+        resetAnimation(oldHolder);
+        int deltaX = (int) (toX - fromX - prevTranslationX);
+        int deltaY = (int) (toY - fromY - prevTranslationY);
+        // recover prev translation state after ending animation
+        oldHolder.itemView.setTranslationX(prevTranslationX);
+        oldHolder.itemView.setTranslationY(prevTranslationY);
+
+        oldHolder.itemView.setAlpha(prevValue);
+        if (newHolder != null) {
+            // carry over translation values
+            resetAnimation(newHolder);
+            newHolder.itemView.setTranslationX(-deltaX);
+            newHolder.itemView.setTranslationY(-deltaY);
+            newHolder.itemView.setAlpha(0);
+        }
+    }
+
+    /**
+     * the animation for removing the old view
+     *
+     * @param holder
+     * @return
+     */
+    public abstract ViewPropertyAnimator changeOldAnimation(ViewHolder holder, ChangeInfo changeInfo);
+
+    /**
+     * the animation for changing the new view
+     *
+     * @param holder
+     * @return
+     */
+    public abstract ViewPropertyAnimator changeNewAnimation(ViewHolder holder);
+
+    /**
+     * the cleanup method if the animation needs to be stopped. and tro prepare for the next view
+     *
+     * @param holder
+     */
+    public abstract void changeAnimationCleanup(ViewHolder holder);
+
+    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;
+        }
+        changeAnimationCleanup(item);
+        item.itemView.setTranslationX(0);
+        item.itemView.setTranslationY(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.
+        view.animate().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) {
+                view.setTranslationY(0);
+                view.setTranslationX(0);
+                dispatchMoveFinished(item);
+                mPendingMoves.remove(i);
+            }
+        }
+        endChangeAnimation(mPendingChanges, item);
+        if (mPendingRemovals.remove(item)) {
+            removeAnimationCleanup(item);
+            dispatchRemoveFinished(item);
+        }
+        if (mPendingAdditions.remove(item)) {
+            addAnimationCleanup(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) {
+                    view.setTranslationY(0);
+                    view.setTranslationX(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)) {
+                addAnimationCleanup(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) {
+
+        if (sDefaultInterpolator == null) {
+            sDefaultInterpolator = new ValueAnimator().getInterpolator();
+        }
+        holder.itemView.animate().setInterpolator(sDefaultInterpolator);
+        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;
+            view.setTranslationY(0);
+            view.setTranslationX(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);
+            addAnimationCleanup(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;
+                view.setTranslationY(0);
+                view.setTranslationX(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;
+                addAnimationCleanup(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--) {
+            viewHolders.get(i).itemView.animate().cancel();
+        }
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p>
+     * If the payload list is not empty, DefaultItemAnimator 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 DefaultItemAnimator 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);
+    }
+}
diff --git a/library/src/main/kotlin/ca/allanwang/kau/animators/DefaultAnimator.kt b/library/src/main/kotlin/ca/allanwang/kau/animators/DefaultAnimator.kt
new file mode 100644
index 0000000..abb22c8
--- /dev/null
+++ b/library/src/main/kotlin/ca/allanwang/kau/animators/DefaultAnimator.kt
@@ -0,0 +1,62 @@
+package ca.allanwang.kau.animators
+
+import android.support.v7.widget.RecyclerView
+import android.view.ViewPropertyAnimator
+
+/**
+ * Created by Allan Wang on 2017-06-27.
+ */
+open class DefaultAnimator : BaseItemAnimator() {
+    override fun removeAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator {
+        return holder.itemView.animate().apply {
+            alpha(0f)
+            duration = this@DefaultAnimator.removeDuration
+            interpolator = this@DefaultAnimator.interpolator
+        }
+    }
+
+    override fun removeAnimationCleanup(holder: RecyclerView.ViewHolder) {
+        holder.itemView.alpha = 1f
+    }
+
+    override fun addAnimationPrepare(holder: RecyclerView.ViewHolder) {
+        holder.itemView.alpha = 0f
+    }
+
+    override fun addAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator {
+        return holder.itemView.animate().apply {
+            alpha(1f)
+            duration = this@DefaultAnimator.addDuration
+            interpolator = this@DefaultAnimator.interpolator
+        }
+    }
+
+    override fun addAnimationCleanup(holder: RecyclerView.ViewHolder) {
+        holder.itemView.alpha = 1f
+    }
+
+    override fun changeOldAnimation(holder: RecyclerView.ViewHolder, changeInfo: ChangeInfo): ViewPropertyAnimator {
+        return holder.itemView.animate().apply {
+            alpha(0f)
+            translationX(changeInfo.toX.toFloat() - changeInfo.fromX)
+            translationY(changeInfo.toY.toFloat() - changeInfo.fromY)
+            duration = this@DefaultAnimator.changeDuration
+            interpolator = this@DefaultAnimator.interpolator
+        }
+    }
+
+    override fun changeNewAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator {
+        return holder.itemView.animate().apply {
+            alpha(1f)
+            translationX(0f)
+            translationY(0f)
+            duration = this@DefaultAnimator.changeDuration
+            interpolator = this@DefaultAnimator.interpolator
+        }
+    }
+
+    override fun changeAnimationCleanup(holder: RecyclerView.ViewHolder) {
+        holder.itemView.alpha = 1f
+    }
+
+}
\ No newline at end of file
diff --git a/library/src/main/kotlin/ca/allanwang/kau/animators/NoAnimator.kt b/library/src/main/kotlin/ca/allanwang/kau/animators/NoAnimator.kt
new file mode 100644
index 0000000..244287b
--- /dev/null
+++ b/library/src/main/kotlin/ca/allanwang/kau/animators/NoAnimator.kt
@@ -0,0 +1,41 @@
+package ca.allanwang.kau.animators
+
+import android.support.v7.widget.RecyclerView
+import android.view.ViewPropertyAnimator
+
+/**
+ * Created by Allan Wang on 2017-06-27.
+ *
+ * Truly have no animation
+ */
+class NoAnimator : DefaultAnimator() {
+    override fun addAnimationPrepare(holder: RecyclerView.ViewHolder) {}
+
+    override fun addAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator = holder.itemView.animate().apply { duration = 0 }
+
+    override fun addAnimationCleanup(holder: RecyclerView.ViewHolder) {}
+
+    override fun changeOldAnimation(holder: RecyclerView.ViewHolder, changeInfo: ChangeInfo): ViewPropertyAnimator = holder.itemView.animate().apply { duration = 0 }
+
+    override fun changeNewAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator = holder.itemView.animate().apply { duration = 0 }
+
+    override fun changeAnimationCleanup(holder: RecyclerView.ViewHolder) {}
+
+    override fun changeAnimation(oldHolder: RecyclerView.ViewHolder, newHolder: RecyclerView.ViewHolder?, fromX: Int, fromY: Int, toX: Int, toY: Int) {}
+
+    override fun getAddDelay(remove: Long, move: Long, change: Long): Long = 0
+
+    override fun getAddDuration(): Long = 0
+
+    override fun getMoveDuration(): Long = 0
+
+    override fun getRemoveDuration(): Long = 0
+
+    override fun getChangeDuration(): Long = 0
+
+    override fun getRemoveDelay(remove: Long, move: Long, change: Long): Long = 0
+
+    override fun removeAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator = holder.itemView.animate().apply { duration = 0 }
+
+    override fun removeAnimationCleanup(holder: RecyclerView.ViewHolder) {}
+}
\ No newline at end of file
diff --git a/library/src/main/kotlin/ca/allanwang/kau/animators/SlideUpAlphaAnimator.kt b/library/src/main/kotlin/ca/allanwang/kau/animators/SlideUpAlphaAnimator.kt
new file mode 100644
index 0000000..3b1b223
--- /dev/null
+++ b/library/src/main/kotlin/ca/allanwang/kau/animators/SlideUpAlphaAnimator.kt
@@ -0,0 +1,52 @@
+package ca.allanwang.kau.animators
+
+import android.support.v7.widget.RecyclerView
+import android.view.ViewPropertyAnimator
+
+/**
+ * Created by Allan Wang on 2017-06-27.
+ */
+class SlideUpAlphaAnimator : DefaultAnimator() {
+    override fun addAnimationPrepare(holder: RecyclerView.ViewHolder) {
+        with(holder.itemView) {
+            translationY = height.toFloat()
+            alpha = 0f
+        }
+    }
+
+    override fun addAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator {
+        return holder.itemView.animate().apply {
+            translationY(0f)
+            alpha(0f)
+            duration = this@SlideUpAlphaAnimator.addDuration
+            interpolator = this@SlideUpAlphaAnimator.interpolator
+        }
+    }
+
+    public override fun addAnimationCleanup(holder: RecyclerView.ViewHolder) {
+        with(holder.itemView) {
+            translationY = 0f
+            alpha = 1f
+        }
+    }
+
+    override fun getAddDelay(remove: Long, move: Long, change: Long): Long = 0
+
+    override fun getRemoveDelay(remove: Long, move: Long, change: Long): Long = 0
+
+    override fun removeAnimation(holder: RecyclerView.ViewHolder): ViewPropertyAnimator {
+        return holder.itemView.animate().apply {
+            duration = this@SlideUpAlphaAnimator.removeDuration
+            alpha(0f)
+            translationY(holder.itemView.height.toFloat())
+            interpolator = this@SlideUpAlphaAnimator.interpolator
+        }
+    }
+
+    override fun removeAnimationCleanup(holder: RecyclerView.ViewHolder) {
+        with(holder.itemView) {
+            translationY = 0f
+            alpha = 1f
+        }
+    }
+}
\ No newline at end of file
diff --git a/library/src/main/kotlin/ca/allanwang/kau/searchview/SearchView.kt b/library/src/main/kotlin/ca/allanwang/kau/searchview/SearchView.kt
index 29c2223..b2490ac 100644
--- a/library/src/main/kotlin/ca/allanwang/kau/searchview/SearchView.kt
+++ b/library/src/main/kotlin/ca/allanwang/kau/searchview/SearchView.kt
@@ -11,13 +11,13 @@ import android.support.transition.AutoTransition
 import android.support.v7.widget.AppCompatEditText
 import android.support.v7.widget.LinearLayoutManager
 import android.support.v7.widget.RecyclerView
-import android.support.v7.widget.SimpleItemAnimator
 import android.util.AttributeSet
 import android.view.*
 import android.widget.FrameLayout
 import android.widget.ImageView
 import android.widget.ProgressBar
 import ca.allanwang.kau.R
+import ca.allanwang.kau.animators.NoAnimator
 import ca.allanwang.kau.kotlin.nonReadable
 import ca.allanwang.kau.searchview.SearchView.Configs
 import ca.allanwang.kau.utils.*
@@ -247,7 +247,7 @@ class SearchView @JvmOverloads constructor(
                 }
             })
             adapter = this@SearchView.adapter
-            (itemAnimator as SimpleItemAnimator).supportsChangeAnimations = false //clear the fade between item changes
+            itemAnimator = NoAnimator()
         }
         with(adapter) {
             withSelectable(true)
diff --git a/library/src/main/res/layout/kau_about_item_library.xml b/library/src/main/res/layout/kau_about_item_library.xml
index 5730d67..0ae4d3c 100644
--- a/library/src/main/res/layout/kau_about_item_library.xml
+++ b/library/src/main/res/layout/kau_about_item_library.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
-    android:id="@id/rippleForegroundListenerView"
+    android:id="@+id/rippleForegroundListenerView"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:layout_marginBottom="8dp"