Merge changes from topic "notification_messaging"

* changes:
  Fixed measuring of messages with excess space
  Fixed the handling of oneToOne conversations for certain apps
  Improved the messaging transformation
  Implemented animations for messaging changes
  Refactored clipping util to be used in core
  Improved the headsup notification for messages
  Redesigned the messaging style
  Fixed a bug where images weren't transforming properly

9 files changed, 1672 insertions, 303 deletions

diff --git a/core/java/android/app/Notification.java b/core/java/android/app/Notification.java
index 8226e0fb4e71..d5d95fb85a6a 100644
--- a/core/java/android/app/Notification.java
+++ b/core/java/android/app/Notification.java
@@ -22,6 +22,7 @@ import android.annotation.ColorInt;
 import android.annotation.DrawableRes;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
 import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
@@ -3900,7 +3901,7 @@ public class Notification implements Parcelable
             final Bundle ex = mN.extras;
             updateBackgroundColor(contentView);
             bindNotificationHeader(contentView, p.ambient);
-            bindLargeIcon(contentView);
+            bindLargeIcon(contentView, p.hideLargeIcon, p.alwaysShowReply);
             boolean showProgress = handleProgressBar(p.hasProgress, contentView, ex);
             if (p.title != null) {
                 contentView.setViewVisibility(R.id.title, View.VISIBLE);
@@ -4110,11 +4111,13 @@ public class Notification implements Parcelable
             }
         }
 
-        private void bindLargeIcon(RemoteViews contentView) {
+        private void bindLargeIcon(RemoteViews contentView, boolean hideLargeIcon,
+                boolean alwaysShowReply) {
             if (mN.mLargeIcon == null && mN.largeIcon != null) {
                 mN.mLargeIcon = Icon.createWithBitmap(mN.largeIcon);
             }
-            if (mN.mLargeIcon != null) {
+            boolean showLargeIcon = mN.mLargeIcon != null && !hideLargeIcon;
+            if (showLargeIcon) {
                 contentView.setViewVisibility(R.id.right_icon, View.VISIBLE);
                 contentView.setImageViewIcon(R.id.right_icon, mN.mLargeIcon);
                 processLargeLegacyIcon(mN.mLargeIcon, contentView);
@@ -4122,32 +4125,45 @@ public class Notification implements Parcelable
                 contentView.setViewLayoutMarginEndDimen(R.id.line1, endMargin);
                 contentView.setViewLayoutMarginEndDimen(R.id.text, endMargin);
                 contentView.setViewLayoutMarginEndDimen(R.id.progress, endMargin);
-                // Bind the reply action
-                Action action = findReplyAction();
-                contentView.setViewVisibility(R.id.reply_icon_action, action != null
-                        ? View.VISIBLE
-                        : View.GONE);
-
-                if (action != null) {
-                    int contrastColor = resolveContrastColor();
+            }
+            // Bind the reply action
+            Action action = findReplyAction();
+
+            boolean actionVisible = action != null && (showLargeIcon || alwaysShowReply);
+            int replyId = showLargeIcon ? R.id.reply_icon_action : R.id.right_icon;
+            if (actionVisible) {
+                // We're only showing the icon as big if we're hiding the large icon
+                int contrastColor = resolveContrastColor();
+                int iconColor;
+                if (showLargeIcon) {
                     contentView.setDrawableTint(R.id.reply_icon_action,
                             true /* targetBackground */,
                             contrastColor, PorterDuff.Mode.SRC_ATOP);
-                    int iconColor = NotificationColorUtil.isColorLight(contrastColor)
-                            ? Color.BLACK : Color.WHITE;
-                    contentView.setDrawableTint(R.id.reply_icon_action,
-                            false /* targetBackground */,
-                            iconColor, PorterDuff.Mode.SRC_ATOP);
                     contentView.setOnClickPendingIntent(R.id.right_icon,
                             action.actionIntent);
-                    contentView.setOnClickPendingIntent(R.id.reply_icon_action,
-                            action.actionIntent);
                     contentView.setRemoteInputs(R.id.right_icon, action.mRemoteInputs);
-                    contentView.setRemoteInputs(R.id.reply_icon_action, action.mRemoteInputs);
-
+                    iconColor = NotificationColorUtil.isColorLight(contrastColor)
+                            ? Color.BLACK : Color.WHITE;
+                } else {
+                    contentView.setImageViewResource(R.id.right_icon,
+                            R.drawable.ic_reply_notification_large);
+                    contentView.setViewVisibility(R.id.right_icon, View.VISIBLE);
+                    iconColor = contrastColor;
                 }
+                contentView.setDrawableTint(replyId,
+                        false /* targetBackground */,
+                        iconColor,
+                        PorterDuff.Mode.SRC_ATOP);
+                contentView.setOnClickPendingIntent(replyId,
+                        action.actionIntent);
+                contentView.setRemoteInputs(replyId, action.mRemoteInputs);
+            } else {
+                contentView.setRemoteInputs(R.id.right_icon, null);
             }
-            contentView.setViewVisibility(R.id.right_icon_container, mN.mLargeIcon != null
+            contentView.setViewVisibility(R.id.reply_icon_action, actionVisible && showLargeIcon
+                    ? View.VISIBLE
+                    : View.GONE);
+            contentView.setViewVisibility(R.id.right_icon_container, actionVisible || showLargeIcon
                     ? View.VISIBLE
                     : View.GONE);
         }
@@ -6055,18 +6071,12 @@ public class Notification implements Parcelable
         protected void restoreFromExtras(Bundle extras) {
             super.restoreFromExtras(extras);
 
-            mMessages.clear();
-            mHistoricMessages.clear();
             mUserDisplayName = extras.getCharSequence(EXTRA_SELF_DISPLAY_NAME);
             mConversationTitle = extras.getCharSequence(EXTRA_CONVERSATION_TITLE);
             Parcelable[] messages = extras.getParcelableArray(EXTRA_MESSAGES);
-            if (messages != null && messages instanceof Parcelable[]) {
-                mMessages = Message.getMessagesFromBundleArray(messages);
-            }
+            mMessages = Message.getMessagesFromBundleArray(messages);
             Parcelable[] histMessages = extras.getParcelableArray(EXTRA_HISTORIC_MESSAGES);
-            if (histMessages != null && histMessages instanceof Parcelable[]) {
-                mHistoricMessages = Message.getMessagesFromBundleArray(histMessages);
-            }
+            mHistoricMessages = Message.getMessagesFromBundleArray(histMessages);
         }
 
         /**
@@ -6074,38 +6084,34 @@ public class Notification implements Parcelable
          */
         @Override
         public RemoteViews makeContentView(boolean increasedHeight) {
-            if (!increasedHeight) {
-                Message m = findLatestIncomingMessage();
-                CharSequence title = mConversationTitle != null
-                        ? mConversationTitle
-                        : (m == null) ? null : m.mSender;
-                CharSequence text = (m == null)
-                        ? null
-                        : mConversationTitle != null ? makeMessageLine(m, mBuilder) : m.mText;
-
-                return mBuilder.applyStandardTemplate(mBuilder.getBaseLayoutResource(),
-                        mBuilder.mParams.reset().hasProgress(false).title(title).text(text));
-            } else {
-                mBuilder.mOriginalActions = mBuilder.mActions;
-                mBuilder.mActions = new ArrayList<>();
-                RemoteViews remoteViews = makeBigContentView();
-                mBuilder.mActions = mBuilder.mOriginalActions;
-                mBuilder.mOriginalActions = null;
-                return remoteViews;
-            }
+            mBuilder.mOriginalActions = mBuilder.mActions;
+            mBuilder.mActions = new ArrayList<>();
+            RemoteViews remoteViews = makeBigContentView();
+            mBuilder.mActions = mBuilder.mOriginalActions;
+            mBuilder.mOriginalActions = null;
+            return remoteViews;
         }
 
         private Message findLatestIncomingMessage() {
-            for (int i = mMessages.size() - 1; i >= 0; i--) {
-                Message m = mMessages.get(i);
+            return findLatestIncomingMessage(mMessages);
+        }
+
+        /**
+         * @hide
+         */
+        @Nullable
+        public static Message findLatestIncomingMessage(
+                List<Message> messages) {
+            for (int i = messages.size() - 1; i >= 0; i--) {
+                Message m = messages.get(i);
                 // Incoming messages have a non-empty sender.
                 if (!TextUtils.isEmpty(m.mSender)) {
                     return m;
                 }
             }
-            if (!mMessages.isEmpty()) {
+            if (!messages.isEmpty()) {
                 // No incoming messages, fall back to outgoing message
-                return mMessages.get(mMessages.size() - 1);
+                return messages.get(messages.size() - 1);
             }
             return null;
         }
@@ -6115,118 +6121,82 @@ public class Notification implements Parcelable
          */
         @Override
         public RemoteViews makeBigContentView() {
-            CharSequence title = !TextUtils.isEmpty(super.mBigContentTitle)
+            CharSequence conversationTitle = !TextUtils.isEmpty(super.mBigContentTitle)
                     ? super.mBigContentTitle
                     : mConversationTitle;
-            boolean hasTitle = !TextUtils.isEmpty(title);
-
-            if (mMessages.size() == 1) {
-                // Special case for a single message: Use the big text style
-                // so the collapsed and expanded versions match nicely.
-                CharSequence bigTitle;
-                CharSequence text;
-                if (hasTitle) {
-                    bigTitle = title;
-                    text = makeMessageLine(mMessages.get(0), mBuilder);
-                } else {
-                    bigTitle = mMessages.get(0).mSender;
-                    text = mMessages.get(0).mText;
-                }
-                RemoteViews contentView = mBuilder.applyStandardTemplateWithActions(
-                        mBuilder.getBigTextLayoutResource(),
-                        mBuilder.mParams.reset().hasProgress(false).title(bigTitle).text(null));
-                BigTextStyle.applyBigTextContentView(mBuilder, contentView, text);
-                return contentView;
-            }
-
+            boolean isOneToOne = TextUtils.isEmpty(conversationTitle);
+            if (isOneToOne) {
+                // Let's add the conversationTitle in case we didn't have one before and all
+                // messages are from the same sender
+                conversationTitle = createConversationTitleFromMessages();
+            } else if (hasOnlyWhiteSpaceSenders()) {
+                isOneToOne = true;
+            }
+            boolean hasTitle = !TextUtils.isEmpty(conversationTitle);
             RemoteViews contentView = mBuilder.applyStandardTemplateWithActions(
                     mBuilder.getMessagingLayoutResource(),
-                    mBuilder.mParams.reset().hasProgress(false).title(title).text(null));
-
-            int[] rowIds = {R.id.inbox_text0, R.id.inbox_text1, R.id.inbox_text2, R.id.inbox_text3,
-                    R.id.inbox_text4, R.id.inbox_text5, R.id.inbox_text6};
-
-            // Make sure all rows are gone in case we reuse a view.
-            for (int rowId : rowIds) {
-                contentView.setViewVisibility(rowId, View.GONE);
-            }
+                    mBuilder.mParams.reset().hasProgress(false).title(conversationTitle).text(null)
+                            .hideLargeIcon(isOneToOne).alwaysShowReply(true));
+            addExtras(mBuilder.mN.extras);
+            contentView.setInt(R.id.status_bar_latest_event_content, "setLayoutColor",
+                    mBuilder.resolveContrastColor());
+            contentView.setIcon(R.id.status_bar_latest_event_content, "setLargeIcon",
+                    mBuilder.mN.mLargeIcon);
+            contentView.setBoolean(R.id.status_bar_latest_event_content, "setIsOneToOne",
+                    isOneToOne);
+            contentView.setBundle(R.id.status_bar_latest_event_content, "setData",
+                    mBuilder.mN.extras);
+            return contentView;
+        }
 
-            int i=0;
-            contentView.setViewLayoutMarginBottomDimen(R.id.line1,
-                    hasTitle ? R.dimen.notification_messaging_spacing : 0);
-            contentView.setInt(R.id.notification_messaging, "setNumIndentLines",
-                    !mBuilder.mN.hasLargeIcon() ? 0 : (hasTitle ? 1 : 2));
-
-            int contractedChildId = View.NO_ID;
-            Message contractedMessage = findLatestIncomingMessage();
-            int firstHistoricMessage = Math.max(0, mHistoricMessages.size()
-                    - (rowIds.length - mMessages.size()));
-            while (firstHistoricMessage + i < mHistoricMessages.size() && i < rowIds.length) {
-                Message m = mHistoricMessages.get(firstHistoricMessage + i);
-                int rowId = rowIds[i];
-
-                contentView.setTextViewText(rowId, makeMessageLine(m, mBuilder));
-
-                if (contractedMessage == m) {
-                    contractedChildId = rowId;
+        private boolean hasOnlyWhiteSpaceSenders() {
+            for (int i = 0; i < mMessages.size(); i++) {
+                Message m = mMessages.get(i);
+                CharSequence sender = m.getSender();
+                if (!isWhiteSpace(sender)) {
+                    return false;
                 }
-
-                i++;
             }
+            return true;
+        }
 
-            int firstMessage = Math.max(0, mMessages.size() - rowIds.length);
-            while (firstMessage + i < mMessages.size() && i < rowIds.length) {
-                Message m = mMessages.get(firstMessage + i);
-                int rowId = rowIds[i];
-
-                contentView.setViewVisibility(rowId, View.VISIBLE);
-                contentView.setTextViewText(rowId, mBuilder.processTextSpans(
-                        makeMessageLine(m, mBuilder)));
-                mBuilder.setTextViewColorSecondary(contentView, rowId);
-
-                if (contractedMessage == m) {
-                    contractedChildId = rowId;
-                }
-
-                i++;
+        private boolean isWhiteSpace(CharSequence sender) {
+            if (TextUtils.isEmpty(sender)) {
+                return true;
             }
-            // Clear the remaining views for reapply. Ensures that historic message views can
-            // reliably be identified as being GONE and having non-null text.
-            while (i < rowIds.length) {
-                int rowId = rowIds[i];
-                contentView.setTextViewText(rowId, null);
-                i++;
+            if (sender.toString().matches("^\\s*$")) {
+                return true;
             }
-
-            // Record this here to allow transformation between the contracted and expanded views.
-            contentView.setInt(R.id.notification_messaging, "setContractedChildId",
-                    contractedChildId);
-            return contentView;
+            // Let's check if we only have 0 whitespace chars. Some apps did this as a workaround
+            // For the presentation that we had.
+            for (int i = 0; i < sender.length(); i++) {
+                char c = sender.charAt(i);
+                if (c != '\u200B') {
+                    return false;
+                }
+            }
+            return true;
         }
 
-        private CharSequence makeMessageLine(Message m, Builder builder) {
-            BidiFormatter bidi = BidiFormatter.getInstance();
-            SpannableStringBuilder sb = new SpannableStringBuilder();
-            boolean colorize = builder.isColorized();
-            TextAppearanceSpan colorSpan;
-            CharSequence messageName;
-            if (TextUtils.isEmpty(m.mSender)) {
-                CharSequence replyName = mUserDisplayName == null ? "" : mUserDisplayName;
-                sb.append(bidi.unicodeWrap(replyName),
-                        makeFontColorSpan(colorize
-                                ? builder.getPrimaryTextColor()
-                                : mBuilder.resolveContrastColor()),
-                        0 /* flags */);
-            } else {
-                sb.append(bidi.unicodeWrap(m.mSender),
-                        makeFontColorSpan(colorize
-                                ? builder.getPrimaryTextColor()
-                                : Color.BLACK),
-                        0 /* flags */);
+        private CharSequence createConversationTitleFromMessages() {
+            ArraySet<CharSequence> names = new ArraySet<>();
+            for (int i = 0; i < mMessages.size(); i++) {
+                Message m = mMessages.get(i);
+                CharSequence sender = m.getSender();
+                if (sender != null) {
+                    names.add(sender);
+                }
+            }
+            SpannableStringBuilder title = new SpannableStringBuilder();
+            int size = names.size();
+            for (int i = 0; i < size; i++) {
+                CharSequence name = names.valueAt(i);
+                if (!TextUtils.isEmpty(title)) {
+                    title.append(", ");
+                }
+                title.append(BidiFormatter.getInstance().unicodeWrap(name));
             }
-            CharSequence text = m.mText == null ? "" : m.mText;
-            sb.append("  ").append(bidi.unicodeWrap(text));
-            return sb;
+            return title;
         }
 
         /**
@@ -6234,19 +6204,9 @@ public class Notification implements Parcelable
          */
         @Override
         public RemoteViews makeHeadsUpContentView(boolean increasedHeight) {
-            if (increasedHeight) {
-                return makeBigContentView();
-            }
-            Message m = findLatestIncomingMessage();
-            CharSequence title = mConversationTitle != null
-                    ? mConversationTitle
-                    : (m == null) ? null : m.mSender;
-            CharSequence text = (m == null)
-                    ? null
-                    : mConversationTitle != null ? makeMessageLine(m, mBuilder) : m.mText;
-
-            return mBuilder.applyStandardTemplateWithActions(mBuilder.getBigBaseLayoutResource(),
-                    mBuilder.mParams.reset().hasProgress(false).title(title).text(text));
+            RemoteViews remoteViews = makeBigContentView();
+            remoteViews.setInt(R.id.notification_messaging, "setMaxDisplayedLines", 1);
+            return remoteViews;
         }
 
         private static TextAppearanceSpan makeFontColorSpan(int color) {
@@ -6394,7 +6354,15 @@ public class Notification implements Parcelable
                 return bundles;
             }
 
-            static List<Message> getMessagesFromBundleArray(Parcelable[] bundles) {
+            /**
+             * @return A list of messages read from the bundles.
+             *
+             * @hide
+             */
+            public static List<Message> getMessagesFromBundleArray(Parcelable[] bundles) {
+                if (bundles == null) {
+                    return new ArrayList<>();
+                }
                 List<Message> messages = new ArrayList<>(bundles.length);
                 for (int i = 0; i < bundles.length; i++) {
                     if (bundles[i] instanceof Bundle) {
@@ -8487,6 +8455,8 @@ public class Notification implements Parcelable
         boolean ambient = false;
         CharSequence title;
         CharSequence text;
+        boolean hideLargeIcon;
+        public boolean alwaysShowReply;
 
         final StandardTemplateParams reset() {
             hasProgress = true;
@@ -8511,6 +8481,16 @@ public class Notification implements Parcelable
             return this;
         }
 
+        final StandardTemplateParams alwaysShowReply(boolean alwaysShowReply) {
+            this.alwaysShowReply = alwaysShowReply;
+            return this;
+        }
+
+        final StandardTemplateParams hideLargeIcon(boolean hideLargeIcon) {
+            this.hideLargeIcon = hideLargeIcon;
+            return this;
+        }
+
         final StandardTemplateParams ambient(boolean ambient) {
             Preconditions.checkState(title == null && text == null, "must set ambient before text");
             this.ambient = ambient;
@@ -8527,7 +8507,6 @@ public class Notification implements Parcelable
                 text = extras.getCharSequence(EXTRA_TEXT);
             }
             this.text = b.processLegacyText(text, ambient);
-
             return this;
         }
     }
diff --git a/core/java/com/android/internal/widget/ImageFloatingTextView.java b/core/java/com/android/internal/widget/ImageFloatingTextView.java
index 7870333cd82d..09f7282f097a 100644
--- a/core/java/com/android/internal/widget/ImageFloatingTextView.java
+++ b/core/java/com/android/internal/widget/ImageFloatingTextView.java
@@ -176,8 +176,4 @@ public class ImageFloatingTextView extends TextView {
         }
         return false;
     }
-
-    public int getLayoutHeight() {
-        return getLayout().getHeight();
-    }
 }
diff --git a/core/java/com/android/internal/widget/MessagingGroup.java b/core/java/com/android/internal/widget/MessagingGroup.java
new file mode 100644
index 000000000000..792f9212d93e
--- /dev/null
+++ b/core/java/com/android/internal/widget/MessagingGroup.java
@@ -0,0 +1,393 @@
+/*
+ * Copyright (C) 2017 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.android.internal.widget;
+
+import android.annotation.AttrRes;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.StyleRes;
+import android.content.Context;
+import android.graphics.Color;
+import android.graphics.ColorFilter;
+import android.graphics.PorterDuff;
+import android.graphics.PorterDuffColorFilter;
+import android.graphics.drawable.Drawable;
+import android.graphics.drawable.Icon;
+import android.text.TextUtils;
+import android.util.AttributeSet;
+import android.util.Pools;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+import android.view.ViewTreeObserver;
+import android.widget.ImageView;
+import android.widget.LinearLayout;
+import android.widget.RemoteViews;
+
+import com.android.internal.R;
+import com.android.internal.util.NotificationColorUtil;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A message of a {@link MessagingLayout}.
+ */
+@RemoteViews.RemoteView
+public class MessagingGroup extends LinearLayout implements MessagingLinearLayout.MessagingChild {
+    private static Pools.SimplePool<MessagingGroup> sInstancePool
+            = new Pools.SynchronizedPool<>(10);
+    private MessagingLinearLayout mMessageContainer;
+    private ImageFloatingTextView mSenderName;
+    private ImageView mAvatarView;
+    private String mAvatarSymbol = "";
+    private int mLayoutColor;
+    private CharSequence mAvatarName = "";
+    private Icon mAvatarIcon;
+    private ColorFilter mMessageBackgroundFilter;
+    private int mTextColor;
+    private List<MessagingMessage> mMessages;
+    private ArrayList<MessagingMessage> mAddedMessages = new ArrayList<>();
+    private boolean mFirstLayout;
+    private boolean mIsHidingAnimated;
+
+    public MessagingGroup(@NonNull Context context) {
+        super(context);
+    }
+
+    public MessagingGroup(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public MessagingGroup(@NonNull Context context, @Nullable AttributeSet attrs,
+            @AttrRes int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public MessagingGroup(@NonNull Context context, @Nullable AttributeSet attrs,
+            @AttrRes int defStyleAttr, @StyleRes int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        mMessageContainer = findViewById(R.id.group_message_container);
+        mSenderName = findViewById(R.id.message_name);
+        mSenderName.addOnLayoutChangeListener(MessagingLayout.MESSAGING_PROPERTY_ANIMATOR);
+        mAvatarView = findViewById(R.id.message_icon);
+    }
+
+    public void setSender(CharSequence sender) {
+        if (sender == null) {
+            mAvatarView.setVisibility(GONE);
+            mSenderName.setVisibility(GONE);
+            setGravity(Gravity.END);
+            mMessageBackgroundFilter = new PorterDuffColorFilter(mLayoutColor,
+                    PorterDuff.Mode.SRC_ATOP);
+            mTextColor = NotificationColorUtil.isColorLight(mLayoutColor) ? getNormalTextColor()
+                    : Color.WHITE;
+        } else {
+            mSenderName.setText(sender);
+            mAvatarView.setVisibility(VISIBLE);
+            mSenderName.setVisibility(VISIBLE);
+            setGravity(Gravity.START);
+            mMessageBackgroundFilter = null;
+            mTextColor = getNormalTextColor();
+        }
+    }
+
+    private int getNormalTextColor() {
+        return mContext.getColor(R.color.notification_primary_text_color_light);
+    }
+
+    public void setAvatar(Icon icon) {
+        mAvatarIcon = icon;
+        mAvatarView.setImageIcon(icon);
+        mAvatarSymbol = "";
+        mLayoutColor = 0;
+        mAvatarName = "";
+    }
+
+    static MessagingGroup createGroup(MessagingLinearLayout layout) {;
+        MessagingGroup createdGroup = sInstancePool.acquire();
+        if (createdGroup == null) {
+            createdGroup = (MessagingGroup) LayoutInflater.from(layout.getContext()).inflate(
+                    R.layout.notification_template_messaging_group, layout,
+                    false);
+            createdGroup.addOnLayoutChangeListener(MessagingLayout.MESSAGING_PROPERTY_ANIMATOR);
+        }
+        layout.addView(createdGroup);
+        return createdGroup;
+    }
+
+    public void removeMessage(MessagingMessage messagingMessage) {
+        mMessageContainer.removeView(messagingMessage);
+        Runnable recycleRunnable = () -> {
+            mMessageContainer.removeTransientView(messagingMessage);
+            messagingMessage.recycle();
+            if (mMessageContainer.getChildCount() == 0
+                    && mMessageContainer.getTransientViewCount() == 0) {
+                ViewParent parent = getParent();
+                if (parent instanceof ViewGroup) {
+                    ((ViewGroup) parent).removeView(MessagingGroup.this);
+                }
+                setAvatar(null);
+                mAvatarView.setAlpha(1.0f);
+                mAvatarView.setTranslationY(0.0f);
+                mSenderName.setAlpha(1.0f);
+                mSenderName.setTranslationY(0.0f);
+                sInstancePool.release(MessagingGroup.this);
+            }
+        };
+        if (isShown()) {
+            mMessageContainer.addTransientView(messagingMessage, 0);
+            performRemoveAnimation(messagingMessage, recycleRunnable);
+            if (mMessageContainer.getChildCount() == 0) {
+                removeGroupAnimated(null);
+            }
+        } else {
+            recycleRunnable.run();
+        }
+
+    }
+
+    private void removeGroupAnimated(Runnable endAction) {
+        MessagingPropertyAnimator.fadeOut(mAvatarView, null);
+        MessagingPropertyAnimator.startLocalTranslationTo(mAvatarView,
+                (int) (-getHeight() * 0.5f), MessagingLayout.FAST_OUT_LINEAR_IN);
+        MessagingPropertyAnimator.fadeOut(mSenderName, null);
+        MessagingPropertyAnimator.startLocalTranslationTo(mSenderName,
+                (int) (-getHeight() * 0.5f), MessagingLayout.FAST_OUT_LINEAR_IN);
+        boolean endActionTriggered = false;
+        for (int i = mMessageContainer.getChildCount() - 1; i >= 0; i--) {
+            View child = mMessageContainer.getChildAt(i);
+            if (child.getVisibility() == View.GONE) {
+                continue;
+            }
+            final ViewGroup.LayoutParams lp = child.getLayoutParams();
+            if (lp instanceof MessagingLinearLayout.LayoutParams
+                    && ((MessagingLinearLayout.LayoutParams) lp).hide
+                    && !((MessagingLinearLayout.LayoutParams) lp).visibleBefore) {
+                continue;
+            }
+            Runnable childEndAction = endActionTriggered ? null : endAction;
+            performRemoveAnimation(child, childEndAction);
+            endActionTriggered = true;
+        }
+        if (!endActionTriggered && endAction != null) {
+            endAction.run();
+        }
+    }
+
+    public void performRemoveAnimation(View message,
+            Runnable recycleRunnable) {
+        MessagingPropertyAnimator.fadeOut(message, recycleRunnable);
+        MessagingPropertyAnimator.startLocalTranslationTo(message,
+                (int) (-getHeight() * 0.5f), MessagingLayout.FAST_OUT_LINEAR_IN);
+    }
+
+    public CharSequence getSenderName() {
+        return mSenderName.getText();
+    }
+
+    public void setSenderVisible(boolean visible) {
+        mSenderName.setVisibility(visible ? VISIBLE : GONE);
+    }
+
+    public static void dropCache() {
+        sInstancePool = new Pools.SynchronizedPool<>(10);
+    }
+
+    @Override
+    public int getMeasuredType() {
+        boolean hasNormal = false;
+        for (int i = mMessageContainer.getChildCount() - 1; i >= 0; i--) {
+            View child = mMessageContainer.getChildAt(i);
+            if (child instanceof MessagingLinearLayout.MessagingChild) {
+                int type = ((MessagingLinearLayout.MessagingChild) child).getMeasuredType();
+                if (type == MEASURED_TOO_SMALL) {
+                    if (hasNormal) {
+                        return MEASURED_SHORTENED;
+                    } else {
+                        return MEASURED_TOO_SMALL;
+                    }
+                } else if (type == MEASURED_SHORTENED) {
+                    return MEASURED_SHORTENED;
+                } else {
+                    hasNormal = true;
+                }
+            }
+        }
+        return MEASURED_NORMAL;
+    }
+
+    @Override
+    public int getConsumedLines() {
+        int result = 0;
+        for (int i = 0; i < mMessageContainer.getChildCount(); i++) {
+            View child = mMessageContainer.getChildAt(i);
+            if (child instanceof MessagingLinearLayout.MessagingChild) {
+                result += ((MessagingLinearLayout.MessagingChild) child).getConsumedLines();
+            }
+        }
+        // A group is usually taking up quite some space with the padding and the name, let's add 1
+        return result + 1;
+    }
+
+    @Override
+    public void setMaxDisplayedLines(int lines) {
+        mMessageContainer.setMaxDisplayedLines(lines);
+    }
+
+    @Override
+    public void hideAnimated() {
+        setIsHidingAnimated(true);
+        removeGroupAnimated(() -> setIsHidingAnimated(false));
+    }
+
+    @Override
+    public boolean isHidingAnimated() {
+        return mIsHidingAnimated;
+    }
+
+    private void setIsHidingAnimated(boolean isHiding) {
+        ViewParent parent = getParent();
+        mIsHidingAnimated = isHiding;
+        invalidate();
+        if (parent instanceof ViewGroup) {
+            ((ViewGroup) parent).invalidate();
+        }
+    }
+
+    public Icon getAvatarSymbolIfMatching(CharSequence avatarName, String avatarSymbol,
+            int layoutColor) {
+        if (mAvatarName.equals(avatarName) && mAvatarSymbol.equals(avatarSymbol)
+                && layoutColor == mLayoutColor) {
+            return mAvatarIcon;
+        }
+        return null;
+    }
+
+    public void setCreatedAvatar(Icon cachedIcon, CharSequence avatarName, String avatarSymbol,
+            int layoutColor) {
+        if (!mAvatarName.equals(avatarName) || !mAvatarSymbol.equals(avatarSymbol)
+                || layoutColor != mLayoutColor) {
+            setAvatar(cachedIcon);
+            mAvatarSymbol = avatarSymbol;
+            mLayoutColor = layoutColor;
+            mAvatarName = avatarName;
+        }
+    }
+
+    public void setLayoutColor(int layoutColor) {
+        mLayoutColor = layoutColor;
+    }
+
+    public void setMessages(List<MessagingMessage> group) {
+        // Let's now make sure all children are added and in the correct order
+        for (int messageIndex = 0; messageIndex < group.size(); messageIndex++) {
+            MessagingMessage message = group.get(messageIndex);
+            if (message.getGroup() != this) {
+                message.setMessagingGroup(this);
+                ViewParent parent = mMessageContainer.getParent();
+                if (parent instanceof ViewGroup) {
+                    ((ViewGroup) parent).removeView(message);
+                }
+                mMessageContainer.addView(message, messageIndex);
+                mAddedMessages.add(message);
+            }
+            if (messageIndex != mMessageContainer.indexOfChild(message)) {
+                mMessageContainer.removeView(message);
+                mMessageContainer.addView(message, messageIndex);
+            }
+            // Let's make sure the message color is correct
+            Drawable targetDrawable = message.getBackground();
+
+            if (targetDrawable != null) {
+                targetDrawable.mutate().setColorFilter(mMessageBackgroundFilter);
+            }
+            message.setTextColor(mTextColor);
+        }
+        mMessages = group;
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        super.onLayout(changed, left, top, right, bottom);
+        if (!mAddedMessages.isEmpty()) {
+            getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+                @Override
+                public boolean onPreDraw() {
+                    for (MessagingMessage message : mAddedMessages) {
+                        if (!message.isShown()) {
+                            continue;
+                        }
+                        MessagingPropertyAnimator.fadeIn(message);
+                        if (!mFirstLayout) {
+                            MessagingPropertyAnimator.startLocalTranslationFrom(message,
+                                    message.getHeight(), MessagingLayout.LINEAR_OUT_SLOW_IN);
+                        }
+                    }
+                    mAddedMessages.clear();
+                    getViewTreeObserver().removeOnPreDrawListener(this);
+                    return true;
+                }
+            });
+        }
+        mFirstLayout = false;
+    }
+
+    /**
+     * Calculates the group compatibility between this and another group.
+     *
+     * @param otherGroup the other group to compare it with
+     *
+     * @return 0 if the groups are totally incompatible or 1 + the number of matching messages if
+     *         they match.
+     */
+    public int calculateGroupCompatibility(MessagingGroup otherGroup) {
+        if (TextUtils.equals(getSenderName(),otherGroup.getSenderName())) {
+            int result = 1;
+            for (int i = 0; i < mMessages.size() && i < otherGroup.mMessages.size(); i++) {
+                MessagingMessage ownMessage = mMessages.get(mMessages.size() - 1 - i);
+                MessagingMessage otherMessage = otherGroup.mMessages.get(
+                        otherGroup.mMessages.size() - 1 - i);
+                if (!ownMessage.sameAs(otherMessage)) {
+                    return result;
+                }
+                result++;
+            }
+            return result;
+        }
+        return 0;
+    }
+
+    public View getSender() {
+        return mSenderName;
+    }
+
+    public View getAvatar() {
+        return mAvatarView;
+    }
+
+    public MessagingLinearLayout getMessageContainer() {
+        return mMessageContainer;
+    }
+}
diff --git a/core/java/com/android/internal/widget/MessagingLayout.java b/core/java/com/android/internal/widget/MessagingLayout.java
new file mode 100644
index 000000000000..2acdc015f8ef
--- /dev/null
+++ b/core/java/com/android/internal/widget/MessagingLayout.java
@@ -0,0 +1,444 @@
+/*
+ * Copyright (C) 2017 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.android.internal.widget;
+
+import android.annotation.AttrRes;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.StyleRes;
+import android.app.Notification;
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.graphics.Rect;
+import android.graphics.drawable.Icon;
+import android.os.Bundle;
+import android.os.Parcelable;
+import android.text.TextUtils;
+import android.util.ArrayMap;
+import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.view.RemotableViewMethod;
+import android.view.View;
+import android.view.ViewTreeObserver;
+import android.view.animation.Interpolator;
+import android.view.animation.PathInterpolator;
+import android.widget.FrameLayout;
+import android.widget.RemoteViews;
+import android.widget.TextView;
+
+import com.android.internal.R;
+import com.android.internal.graphics.ColorUtils;
+import com.android.internal.util.NotificationColorUtil;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+/**
+ * A custom-built layout for the Notification.MessagingStyle allows dynamic addition and removal
+ * messages and adapts the layout accordingly.
+ */
+@RemoteViews.RemoteView
+public class MessagingLayout extends FrameLayout {
+
+    private static final float COLOR_SHIFT_AMOUNT = 60;
+    private static final Consumer<MessagingMessage> REMOVE_MESSAGE
+            = MessagingMessage::removeMessage;
+    public static final Interpolator LINEAR_OUT_SLOW_IN = new PathInterpolator(0f, 0f, 0.2f, 1f);
+    public static final Interpolator FAST_OUT_LINEAR_IN = new PathInterpolator(0.4f, 0f, 1f, 1f);
+    public static final Interpolator FAST_OUT_SLOW_IN = new PathInterpolator(0.4f, 0f, 0.2f, 1f);
+    public static final OnLayoutChangeListener MESSAGING_PROPERTY_ANIMATOR
+            = new MessagingPropertyAnimator();
+    private List<MessagingMessage> mMessages = new ArrayList<>();
+    private List<MessagingMessage> mHistoricMessages = new ArrayList<>();
+    private MessagingLinearLayout mMessagingLinearLayout;
+    private View mContractedMessage;
+    private boolean mShowHistoricMessages;
+    private ArrayList<MessagingGroup> mGroups = new ArrayList<>();
+    private TextView mTitleView;
+    private int mLayoutColor;
+    private int mAvatarSize;
+    private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
+    private Paint mTextPaint = new Paint();
+    private CharSequence mConversationTitle;
+    private Icon mLargeIcon;
+    private boolean mIsOneToOne;
+    private ArrayList<MessagingGroup> mAddedGroups = new ArrayList<>();
+
+    public MessagingLayout(@NonNull Context context) {
+        super(context);
+    }
+
+    public MessagingLayout(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public MessagingLayout(@NonNull Context context, @Nullable AttributeSet attrs,
+            @AttrRes int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public MessagingLayout(@NonNull Context context, @Nullable AttributeSet attrs,
+            @AttrRes int defStyleAttr, @StyleRes int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        mMessagingLinearLayout = findViewById(R.id.notification_messaging);
+        mMessagingLinearLayout.setMessagingLayout(this);
+        // We still want to clip, but only on the top, since views can temporarily out of bounds
+        // during transitions.
+        DisplayMetrics displayMetrics = getResources().getDisplayMetrics();
+        Rect rect = new Rect(0, 0, displayMetrics.widthPixels, displayMetrics.heightPixels);
+        mMessagingLinearLayout.setClipBounds(rect);
+        mTitleView = findViewById(R.id.title);
+        mAvatarSize = getResources().getDimensionPixelSize(R.dimen.messaging_avatar_size);
+        mTextPaint.setTextAlign(Paint.Align.CENTER);
+        mTextPaint.setAntiAlias(true);
+    }
+
+    @RemotableViewMethod
+    public void setLargeIcon(Icon icon) {
+        mLargeIcon = icon;
+    }
+
+    @RemotableViewMethod
+    public void setData(Bundle extras) {
+        Parcelable[] messages = extras.getParcelableArray(Notification.EXTRA_MESSAGES);
+        List<Notification.MessagingStyle.Message> newMessages
+                = Notification.MessagingStyle.Message.getMessagesFromBundleArray(messages);
+        Parcelable[] histMessages = extras.getParcelableArray(Notification.EXTRA_HISTORIC_MESSAGES);
+        List<Notification.MessagingStyle.Message> newHistoricMessages
+                = Notification.MessagingStyle.Message.getMessagesFromBundleArray(histMessages);
+        mConversationTitle = null;
+        TextView headerText = findViewById(R.id.header_text);
+        if (headerText != null) {
+            mConversationTitle = headerText.getText();
+        }
+        bind(newMessages, newHistoricMessages);
+    }
+
+    private void bind(List<Notification.MessagingStyle.Message> newMessages,
+            List<Notification.MessagingStyle.Message> newHistoricMessages) {
+
+        List<MessagingMessage> historicMessages = createMessages(newHistoricMessages,
+                true /* isHistoric */);
+        List<MessagingMessage> messages = createMessages(newMessages, false /* isHistoric */);
+        addMessagesToGroups(historicMessages, messages);
+
+        // Let's remove the remaining messages
+        mMessages.forEach(REMOVE_MESSAGE);
+        mHistoricMessages.forEach(REMOVE_MESSAGE);
+
+        mMessages = messages;
+        mHistoricMessages = historicMessages;
+
+        updateContractedMessage();
+        updateHistoricMessageVisibility();
+        updateTitleAndNamesDisplay();
+    }
+
+    private void updateTitleAndNamesDisplay() {
+        ArrayMap<CharSequence, String> uniqueNames = new ArrayMap<>();
+        ArrayMap<Character, CharSequence> uniqueCharacters = new ArrayMap<>();
+        for (int i = 0; i < mGroups.size(); i++) {
+            MessagingGroup group = mGroups.get(i);
+            CharSequence senderName = group.getSenderName();
+            if (TextUtils.isEmpty(senderName)) {
+                continue;
+            }
+            boolean visible = !mIsOneToOne;
+            group.setSenderVisible(visible);
+            if ((visible || mLargeIcon == null) && !uniqueNames.containsKey(senderName)) {
+                char c = senderName.charAt(0);
+                if (uniqueCharacters.containsKey(c)) {
+                    // this character was already used, lets make it more unique. We first need to
+                    // resolve the existing character if it exists
+                    CharSequence existingName = uniqueCharacters.get(c);
+                    if (existingName != null) {
+                        uniqueNames.put(existingName, findNameSplit((String) existingName));
+                        uniqueCharacters.put(c, null);
+                    }
+                    uniqueNames.put(senderName, findNameSplit((String) senderName));
+                } else {
+                    uniqueNames.put(senderName, Character.toString(c));
+                    uniqueCharacters.put(c, senderName);
+                }
+            }
+        }
+
+        // Now that we have the correct symbols, let's look what we have cached
+        ArrayMap<CharSequence, Icon> cachedAvatars = new ArrayMap<>();
+        for (int i = 0; i < mGroups.size(); i++) {
+            // Let's now set the avatars
+            MessagingGroup group = mGroups.get(i);
+            CharSequence senderName = group.getSenderName();
+            if (TextUtils.isEmpty(senderName) || (mIsOneToOne && mLargeIcon != null)) {
+                continue;
+            }
+            String symbol = uniqueNames.get(senderName);
+            Icon cachedIcon = group.getAvatarSymbolIfMatching(senderName,
+                    symbol, mLayoutColor);
+            if (cachedIcon != null) {
+                cachedAvatars.put(senderName, cachedIcon);
+            }
+        }
+
+        for (int i = 0; i < mGroups.size(); i++) {
+            // Let's now set the avatars
+            MessagingGroup group = mGroups.get(i);
+            CharSequence senderName = group.getSenderName();
+            if (TextUtils.isEmpty(senderName)) {
+                continue;
+            }
+            if (mIsOneToOne && mLargeIcon != null) {
+                group.setAvatar(mLargeIcon);
+            } else {
+                Icon cachedIcon = cachedAvatars.get(senderName);
+                if (cachedIcon == null) {
+                    cachedIcon = createAvatarSymbol(senderName, uniqueNames.get(senderName),
+                            mLayoutColor);
+                    cachedAvatars.put(senderName, cachedIcon);
+                }
+                group.setCreatedAvatar(cachedIcon, senderName, uniqueNames.get(senderName),
+                        mLayoutColor);
+            }
+        }
+    }
+
+    public Icon createAvatarSymbol(CharSequence senderName, String symbol, int layoutColor) {
+        Bitmap bitmap = Bitmap.createBitmap(mAvatarSize, mAvatarSize, Bitmap.Config.ARGB_8888);
+        Canvas canvas = new Canvas(bitmap);
+        float radius = mAvatarSize / 2.0f;
+        int color = findColor(senderName, layoutColor);
+        mPaint.setColor(color);
+        canvas.drawCircle(radius, radius, radius, mPaint);
+        boolean needDarkText  = ColorUtils.calculateLuminance(color) > 0.5f;
+        mTextPaint.setColor(needDarkText ? Color.BLACK : Color.WHITE);
+        mTextPaint.setTextSize(symbol.length() == 1 ? mAvatarSize * 0.75f : mAvatarSize * 0.4f);
+        int yPos = (int) (radius - ((mTextPaint.descent() + mTextPaint.ascent()) / 2)) ;
+        canvas.drawText(symbol, radius, yPos, mTextPaint);
+        return Icon.createWithBitmap(bitmap);
+    }
+
+    private int findColor(CharSequence senderName, int layoutColor) {
+        double luminance = NotificationColorUtil.calculateLuminance(layoutColor);
+        float shift = Math.abs(senderName.hashCode()) % 5 / 4.0f - 0.5f;
+
+        // we need to offset the range if the luminance is too close to the borders
+        shift += Math.max(COLOR_SHIFT_AMOUNT / 2.0f / 100 - luminance, 0);
+        shift -= Math.max(COLOR_SHIFT_AMOUNT / 2.0f / 100 - (1.0f - luminance), 0);
+        return NotificationColorUtil.getShiftedColor(layoutColor,
+                (int) (shift * COLOR_SHIFT_AMOUNT));
+    }
+
+    private String findNameSplit(String existingName) {
+        String[] split = existingName.split(" ");
+        if (split.length > 1) {
+            return Character.toString(split[0].charAt(0))
+                    + Character.toString(split[1].charAt(0));
+        }
+        return existingName.substring(0, 1);
+    }
+
+    @RemotableViewMethod
+    public void setLayoutColor(int color) {
+        mLayoutColor = color;
+    }
+
+    @RemotableViewMethod
+    public void setIsOneToOne(boolean oneToOne) {
+        mIsOneToOne = oneToOne;
+    }
+
+    private void addMessagesToGroups(List<MessagingMessage> historicMessages,
+            List<MessagingMessage> messages) {
+        // Let's first find our groups!
+        List<List<MessagingMessage>> groups = new ArrayList<>();
+        List<CharSequence> senders = new ArrayList<>();
+
+        // Lets first find the groups
+        findGroups(historicMessages, messages, groups, senders);
+
+        // Let's now create the views and reorder them accordingly
+        createGroupViews(groups, senders);
+    }
+
+    private void createGroupViews(List<List<MessagingMessage>> groups, List<CharSequence> senders) {
+        mGroups.clear();
+        for (int groupIndex = 0; groupIndex < groups.size(); groupIndex++) {
+            List<MessagingMessage> group = groups.get(groupIndex);
+            MessagingGroup newGroup = null;
+            // we'll just take the first group that exists or create one there is none
+            for (int messageIndex = group.size() - 1; messageIndex >= 0; messageIndex--) {
+                MessagingMessage message = group.get(messageIndex);
+                newGroup = message.getGroup();
+                if (newGroup != null) {
+                    break;
+                }
+            }
+            if (newGroup == null) {
+                newGroup = MessagingGroup.createGroup(mMessagingLinearLayout);
+                mAddedGroups.add(newGroup);
+            }
+            newGroup.setLayoutColor(mLayoutColor);
+            newGroup.setSender(senders.get(groupIndex));
+            mGroups.add(newGroup);
+
+            if (mMessagingLinearLayout.indexOfChild(newGroup) != groupIndex) {
+                mMessagingLinearLayout.removeView(newGroup);
+                mMessagingLinearLayout.addView(newGroup, groupIndex);
+            }
+            newGroup.setMessages(group);
+        }
+    }
+
+    private void findGroups(List<MessagingMessage> historicMessages,
+            List<MessagingMessage> messages, List<List<MessagingMessage>> groups,
+            List<CharSequence> senders) {
+        CharSequence currentSender = null;
+        List<MessagingMessage> currentGroup = null;
+        int histSize = historicMessages.size();
+        for (int i = 0; i < histSize + messages.size(); i++) {
+            MessagingMessage message;
+            if (i < histSize) {
+                message = historicMessages.get(i);
+            } else {
+                message = messages.get(i - histSize);
+            }
+            boolean isNewGroup = currentGroup == null;
+            CharSequence sender = message.getMessage().getSender();
+            isNewGroup |= !TextUtils.equals(sender, currentSender);
+            if (isNewGroup) {
+                currentGroup = new ArrayList<>();
+                groups.add(currentGroup);
+                senders.add(sender);
+                currentSender = sender;
+            }
+            currentGroup.add(message);
+        }
+    }
+
+    private void updateContractedMessage() {
+        for (int i = mMessages.size() - 1; i >= 0; i--) {
+            MessagingMessage m = mMessages.get(i);
+            // Incoming messages have a non-empty sender.
+            if (!TextUtils.isEmpty(m.getMessage().getSender())) {
+                mContractedMessage = m;
+                return;
+            }
+        }
+        if (!mMessages.isEmpty()) {
+            // No incoming messages, fall back to outgoing message
+            mContractedMessage = mMessages.get(mMessages.size() - 1);
+            return;
+        }
+        mContractedMessage = null;
+    }
+
+    /**
+     * Creates new messages, reusing existing ones if they are available.
+     *
+     * @param newMessages the messages to parse.
+     */
+    private List<MessagingMessage> createMessages(
+            List<Notification.MessagingStyle.Message> newMessages, boolean historic) {
+        List<MessagingMessage> result = new ArrayList<>();;
+        for (int i = 0; i < newMessages.size(); i++) {
+            Notification.MessagingStyle.Message m = newMessages.get(i);
+            MessagingMessage message = findAndRemoveMatchingMessage(m);
+            if (message == null) {
+                message = MessagingMessage.createMessage(this, m);
+                message.addOnLayoutChangeListener(MESSAGING_PROPERTY_ANIMATOR);
+            }
+            message.setIsHistoric(historic);
+            result.add(message);
+        }
+        return result;
+    }
+
+    private MessagingMessage findAndRemoveMatchingMessage(Notification.MessagingStyle.Message m) {
+        for (int i = 0; i < mMessages.size(); i++) {
+            MessagingMessage existing = mMessages.get(i);
+            if (existing.sameAs(m)) {
+                mMessages.remove(i);
+                return existing;
+            }
+        }
+        for (int i = 0; i < mHistoricMessages.size(); i++) {
+            MessagingMessage existing = mHistoricMessages.get(i);
+            if (existing.sameAs(m)) {
+                mHistoricMessages.remove(i);
+                return existing;
+            }
+        }
+        return null;
+    }
+
+    public void showHistoricMessages(boolean show) {
+        mShowHistoricMessages = show;
+        updateHistoricMessageVisibility();
+    }
+
+    private void updateHistoricMessageVisibility() {
+        for (int i = 0; i < mHistoricMessages.size(); i++) {
+            MessagingMessage existing = mHistoricMessages.get(i);
+            existing.setVisibility(mShowHistoricMessages ? VISIBLE : GONE);
+        }
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
+        super.onLayout(changed, left, top, right, bottom);
+        if (!mAddedGroups.isEmpty()) {
+            getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+                @Override
+                public boolean onPreDraw() {
+                    for (MessagingGroup group : mAddedGroups) {
+                        if (!group.isShown()) {
+                            continue;
+                        }
+                        MessagingPropertyAnimator.fadeIn(group.getAvatar());
+                        MessagingPropertyAnimator.fadeIn(group.getSender());
+                        MessagingPropertyAnimator.startLocalTranslationFrom(group,
+                                group.getHeight(), LINEAR_OUT_SLOW_IN);
+                    }
+                    mAddedGroups.clear();
+                    getViewTreeObserver().removeOnPreDrawListener(this);
+                    return true;
+                }
+            });
+        }
+    }
+
+    public View getContractedMessage() {
+        return mContractedMessage;
+    }
+
+    public MessagingLinearLayout getMessagingLinearLayout() {
+        return mMessagingLinearLayout;
+    }
+
+    public ArrayList<MessagingGroup> getMessagingGroups() {
+        return mGroups;
+    }
+}
diff --git a/core/java/com/android/internal/widget/MessagingLinearLayout.java b/core/java/com/android/internal/widget/MessagingLinearLayout.java
index 70473a014c0d..f0ef37076618 100644
--- a/core/java/com/android/internal/widget/MessagingLinearLayout.java
+++ b/core/java/com/android/internal/widget/MessagingLinearLayout.java
@@ -36,28 +36,14 @@ import com.android.internal.R;
 @RemoteViews.RemoteView
 public class MessagingLinearLayout extends ViewGroup {
 
-    private static final int NOT_MEASURED_BEFORE = -1;
     /**
      * Spacing to be applied between views.
      */
     private int mSpacing;
 
-    /**
-     * The maximum height allowed.
-     */
-    private int mMaxHeight;
+    private int mMaxDisplayedLines = Integer.MAX_VALUE;
 
-    private int mIndentLines;
-
-    /**
-     * Id of the child that's also visible in the contracted layout.
-     */
-    private int mContractedChildId;
-    /**
-     * The last measured with in a layout pass if it was measured before or
-     * {@link #NOT_MEASURED_BEFORE} if this is the first layout pass.
-     */
-    private int mLastMeasuredWidth = NOT_MEASURED_BEFORE;
+    private MessagingLayout mMessagingLayout;
 
     public MessagingLinearLayout(Context context, @Nullable AttributeSet attrs) {
         super(context, attrs);
@@ -79,7 +65,6 @@ public class MessagingLinearLayout extends ViewGroup {
         a.recycle();
     }
 
-
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         // This is essentially a bottom-up linear layout that only adds children that fit entirely
@@ -91,118 +76,67 @@ public class MessagingLinearLayout extends ViewGroup {
                 break;
         }
         int widthSize = MeasureSpec.getSize(widthMeasureSpec);
-        boolean recalculateVisibility = mLastMeasuredWidth == NOT_MEASURED_BEFORE
-                || getMeasuredHeight() != targetHeight
-                || mLastMeasuredWidth != widthSize;
-
-        final int count = getChildCount();
-        if (recalculateVisibility) {
-            // We only need to recalculate the view visibilities if the view wasn't measured already
-            // in this pass, otherwise we may drop messages here already since we are measured
-            // exactly with what we returned before, which was optimized already with the
-            // line-indents.
-            for (int i = 0; i < count; ++i) {
-                final View child = getChildAt(i);
-                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
-                lp.hide = true;
-            }
-
-            int totalHeight = mPaddingTop + mPaddingBottom;
-            boolean first = true;
-
-            // Starting from the bottom: we measure every view as if it were the only one. If it still
-
-            // fits, we take it, otherwise we stop there.
-            for (int i = count - 1; i >= 0 && totalHeight < targetHeight; i--) {
-                if (getChildAt(i).getVisibility() == GONE) {
-                    continue;
-                }
-                final View child = getChildAt(i);
-                LayoutParams lp = (LayoutParams) getChildAt(i).getLayoutParams();
-                ImageFloatingTextView textChild = null;
-                if (child instanceof ImageFloatingTextView) {
-                    // Pretend we need the image padding for all views, we don't know which
-                    // one will end up needing to do this (might end up not using all the space,
-                    // but calculating this exactly would be more expensive).
-                    textChild = (ImageFloatingTextView) child;
-                    textChild.setNumIndentLines(mIndentLines == 2 ? 3 : mIndentLines);
-                }
-
-                int spacing = first ? 0 : mSpacing;
-                measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, totalHeight
-                        - mPaddingTop - mPaddingBottom + spacing);
-
-                final int childHeight = child.getMeasuredHeight();
-                int newHeight = Math.max(totalHeight, totalHeight + childHeight + lp.topMargin +
-                        lp.bottomMargin + spacing);
-                first = false;
-                boolean measuredTooSmall = false;
-                if (textChild != null) {
-                    measuredTooSmall = childHeight < textChild.getLayoutHeight()
-                            + textChild.getPaddingTop() + textChild.getPaddingBottom();
-                }
-
-                if (newHeight <= targetHeight && !measuredTooSmall) {
-                    totalHeight = newHeight;
-                    lp.hide = false;
-                } else {
-                    break;
-                }
-            }
-        }
 
         // Now that we know which views to take, fix up the indents and see what width we get.
         int measuredWidth = mPaddingLeft + mPaddingRight;
-        int imageLines = mIndentLines;
-        // Need to redo the height because it may change due to changing indents.
-        int totalHeight = mPaddingTop + mPaddingBottom;
-        boolean first = true;
-        for (int i = 0; i < count; i++) {
+        final int count = getChildCount();
+        int totalHeight;
+        for (int i = 0; i < count; ++i) {
             final View child = getChildAt(i);
             final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+            lp.hide = true;
+        }
+
+        totalHeight = mPaddingTop + mPaddingBottom;
+        boolean first = true;
+        int linesRemaining = mMaxDisplayedLines;
 
-            if (child.getVisibility() == GONE || lp.hide) {
+        // Starting from the bottom: we measure every view as if it were the only one. If it still
+        // fits, we take it, otherwise we stop there.
+        for (int i = count - 1; i >= 0 && totalHeight < targetHeight; i--) {
+            if (getChildAt(i).getVisibility() == GONE) {
                 continue;
             }
-
-            if (child instanceof ImageFloatingTextView) {
-                ImageFloatingTextView textChild = (ImageFloatingTextView) child;
-                if (imageLines == 2 && textChild.getLineCount() > 2) {
-                    // HACK: If we need indent for two lines, and they're coming from the same
-                    // view, we need extra spacing to compensate for the lack of margins,
-                    // so add an extra line of indent.
-                    imageLines = 3;
-                }
-                boolean changed = textChild.setNumIndentLines(Math.max(0, imageLines));
-                if (changed || !recalculateVisibility) {
-                    final int childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
-                            mPaddingLeft + mPaddingRight + lp.leftMargin + lp.rightMargin,
-                            lp.width);
-                    // we want to measure it at most as high as it is currently, otherwise we'll
-                    // drop later lines
-                    final int childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec,
-                            targetHeight - child.getMeasuredHeight(), lp.height);
-
-                    child.measure(childWidthMeasureSpec, childHeightMeasureSpec);;
-                }
-                imageLines -= textChild.getLineCount();
+            final View child = getChildAt(i);
+            LayoutParams lp = (LayoutParams) getChildAt(i).getLayoutParams();
+            MessagingChild messagingChild = null;
+            if (child instanceof MessagingChild) {
+                messagingChild = (MessagingChild) child;
+                messagingChild.setMaxDisplayedLines(linesRemaining);
             }
+            int spacing = first ? 0 : mSpacing;
+            measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, totalHeight
+                    - mPaddingTop - mPaddingBottom + spacing);
 
-            measuredWidth = Math.max(measuredWidth,
-                    child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin
-                            + mPaddingLeft + mPaddingRight);
-            totalHeight = Math.max(totalHeight, totalHeight + child.getMeasuredHeight() +
-                    lp.topMargin + lp.bottomMargin + (first ? 0 : mSpacing));
+            final int childHeight = child.getMeasuredHeight();
+            int newHeight = Math.max(totalHeight, totalHeight + childHeight + lp.topMargin +
+                    lp.bottomMargin + spacing);
             first = false;
+            int measureType = MessagingChild.MEASURED_NORMAL;
+            if (messagingChild != null) {
+                measureType = messagingChild.getMeasuredType();
+                linesRemaining -= messagingChild.getConsumedLines();
+            }
+            boolean isShortened = measureType == MessagingChild.MEASURED_SHORTENED;
+            boolean isTooSmall = measureType == MessagingChild.MEASURED_TOO_SMALL;
+            if (newHeight <= targetHeight && !isTooSmall) {
+                totalHeight = newHeight;
+                measuredWidth = Math.max(measuredWidth,
+                        child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin
+                                + mPaddingLeft + mPaddingRight);
+                lp.hide = false;
+                if (isShortened || linesRemaining <= 0) {
+                    break;
+                }
+            } else {
+                break;
+            }
         }
 
-
         setMeasuredDimension(
                 resolveSize(Math.max(getSuggestedMinimumWidth(), measuredWidth),
                         widthMeasureSpec),
-                resolveSize(Math.max(getSuggestedMinimumHeight(), totalHeight),
-                        heightMeasureSpec));
-        mLastMeasuredWidth = widthSize;
+                Math.max(getSuggestedMinimumHeight(), totalHeight));
     }
 
     @Override
@@ -221,13 +155,22 @@ public class MessagingLinearLayout extends ViewGroup {
         childTop = mPaddingTop;
 
         boolean first = true;
-
+        final boolean shown = isShown();
         for (int i = 0; i < count; i++) {
             final View child = getChildAt(i);
+            if (child.getVisibility() == GONE) {
+                continue;
+            }
             final LayoutParams lp = (LayoutParams) child.getLayoutParams();
-
-            if (child.getVisibility() == GONE || lp.hide) {
+            MessagingChild messagingChild = (MessagingChild) child;
+            if (lp.hide) {
+                if (shown && lp.visibleBefore) {
+                    messagingChild.hideAnimated();
+                }
+                lp.visibleBefore = false;
                 continue;
+            } else {
+                lp.visibleBefore = true;
             }
 
             final int childWidth = child.getMeasuredWidth();
@@ -251,14 +194,16 @@ public class MessagingLinearLayout extends ViewGroup {
 
             first = false;
         }
-        mLastMeasuredWidth = NOT_MEASURED_BEFORE;
     }
 
     @Override
     protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
         final LayoutParams lp = (LayoutParams) child.getLayoutParams();
         if (lp.hide) {
-            return true;
+            MessagingChild messagingChild = (MessagingChild) child;
+            if (!messagingChild.isHidingAnimated()) {
+                return true;
+            }
         }
         return super.drawChild(canvas, child, drawingTime);
     }
@@ -284,31 +229,37 @@ public class MessagingLinearLayout extends ViewGroup {
     }
 
     /**
-     * Sets how many lines should be indented to avoid a floating image.
+     * Sets how many lines should be displayed at most
      */
     @RemotableViewMethod
-    public void setNumIndentLines(int numberLines) {
-        mIndentLines = numberLines;
+    public void setMaxDisplayedLines(int numberLines) {
+        mMaxDisplayedLines = numberLines;
     }
 
-    /**
-     * Set id of the child that's also visible in the contracted layout.
-     */
-    @RemotableViewMethod
-    public void setContractedChildId(int contractedChildId) {
-        mContractedChildId = contractedChildId;
+    public void setMessagingLayout(MessagingLayout layout) {
+        mMessagingLayout = layout;
     }
 
-    /**
-     * Get id of the child that's also visible in the contracted layout.
-     */
-    public int getContractedChildId() {
-        return mContractedChildId;
+    public MessagingLayout getMessagingLayout() {
+        return mMessagingLayout;
+    }
+
+    public interface MessagingChild {
+        int MEASURED_NORMAL = 0;
+        int MEASURED_SHORTENED = 1;
+        int MEASURED_TOO_SMALL = 2;
+
+        int getMeasuredType();
+        int getConsumedLines();
+        void setMaxDisplayedLines(int lines);
+        void hideAnimated();
+        boolean isHidingAnimated();
     }
 
     public static class LayoutParams extends MarginLayoutParams {
 
-        boolean hide = false;
+        public boolean hide = false;
+        public boolean visibleBefore = false;
 
         public LayoutParams(Context c, AttributeSet attrs) {
             super(c, attrs);
diff --git a/core/java/com/android/internal/widget/MessagingMessage.java b/core/java/com/android/internal/widget/MessagingMessage.java
new file mode 100644
index 000000000000..f09621f544bc
--- /dev/null
+++ b/core/java/com/android/internal/widget/MessagingMessage.java
@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2017 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.android.internal.widget;
+
+import android.annotation.AttrRes;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.StyleRes;
+import android.app.Notification;
+import android.content.Context;
+import android.text.Layout;
+import android.util.AttributeSet;
+import android.util.Pools;
+import android.view.LayoutInflater;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+import android.widget.RemoteViews;
+
+import com.android.internal.R;
+
+import java.util.Objects;
+
+/**
+ * A message of a {@link MessagingLayout}.
+ */
+@RemoteViews.RemoteView
+public class MessagingMessage extends ImageFloatingTextView implements
+        MessagingLinearLayout.MessagingChild {
+
+    private static Pools.SimplePool<MessagingMessage> sInstancePool
+            = new Pools.SynchronizedPool<>(10);
+    private Notification.MessagingStyle.Message mMessage;
+    private MessagingGroup mGroup;
+    private boolean mIsHistoric;
+    private boolean mIsHidingAnimated;
+
+    public MessagingMessage(@NonNull Context context) {
+        super(context);
+    }
+
+    public MessagingMessage(@NonNull Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public MessagingMessage(@NonNull Context context, @Nullable AttributeSet attrs,
+            @AttrRes int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public MessagingMessage(@NonNull Context context, @Nullable AttributeSet attrs,
+            @AttrRes int defStyleAttr, @StyleRes int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    private void setMessage(Notification.MessagingStyle.Message message) {
+        mMessage = message;
+        setText(message.getText());
+    }
+
+    public Notification.MessagingStyle.Message getMessage() {
+        return mMessage;
+    }
+
+    boolean sameAs(Notification.MessagingStyle.Message message) {
+        if (!Objects.equals(message.getText(), mMessage.getText())) {
+            return false;
+        }
+        if (!Objects.equals(message.getSender(), mMessage.getSender())) {
+            return false;
+        }
+        if (!Objects.equals(message.getTimestamp(), mMessage.getTimestamp())) {
+            return false;
+        }
+        return true;
+    }
+
+    boolean sameAs(MessagingMessage message) {
+        return sameAs(message.getMessage());
+    }
+
+    static MessagingMessage createMessage(MessagingLayout layout,
+            Notification.MessagingStyle.Message m) {
+        MessagingLinearLayout messagingLinearLayout = layout.getMessagingLinearLayout();
+        MessagingMessage createdMessage = sInstancePool.acquire();
+        if (createdMessage == null) {
+            createdMessage = (MessagingMessage) LayoutInflater.from(layout.getContext()).inflate(
+                    R.layout.notification_template_messaging_message, messagingLinearLayout,
+                    false);
+        }
+        createdMessage.setMessage(m);
+        return createdMessage;
+    }
+
+    public void removeMessage() {
+        mGroup.removeMessage(this);
+    }
+
+    public void recycle() {
+        mGroup = null;
+        mMessage = null;
+        setAlpha(1.0f);
+        setTranslationY(0);
+        sInstancePool.release(this);
+    }
+
+    public void setMessagingGroup(MessagingGroup group) {
+        mGroup = group;
+    }
+
+    public static void dropCache() {
+        sInstancePool = new Pools.SynchronizedPool<>(10);
+    }
+
+    public void setIsHistoric(boolean isHistoric) {
+        mIsHistoric = isHistoric;
+    }
+
+    public MessagingGroup getGroup() {
+        return mGroup;
+    }
+
+    @Override
+    public int getMeasuredType() {
+        boolean measuredTooSmall = getMeasuredHeight()
+                < getLayoutHeight() + getPaddingTop() + getPaddingBottom();
+        if (measuredTooSmall) {
+            return MEASURED_TOO_SMALL;
+        } else {
+            Layout layout = getLayout();
+            if (layout == null) {
+                return MEASURED_TOO_SMALL;
+            }
+            if (layout.getEllipsisCount(layout.getLineCount() - 1) > 0) {
+                return MEASURED_SHORTENED;
+            } else {
+                return MEASURED_NORMAL;
+            }
+        }
+    }
+
+    @Override
+    public void hideAnimated() {
+        setIsHidingAnimated(true);
+        mGroup.performRemoveAnimation(this, () -> setIsHidingAnimated(false));
+    }
+
+    private void setIsHidingAnimated(boolean isHiding) {
+        ViewParent parent = getParent();
+        mIsHidingAnimated = isHiding;
+        invalidate();
+        if (parent instanceof ViewGroup) {
+            ((ViewGroup) parent).invalidate();
+        }
+    }
+
+    @Override
+    public boolean isHidingAnimated() {
+        return mIsHidingAnimated;
+    }
+
+    @Override
+    public void setMaxDisplayedLines(int lines) {
+        setMaxLines(lines);
+    }
+
+    @Override
+    public int getConsumedLines() {
+        return getLineCount();
+    }
+
+    public int getLayoutHeight() {
+        Layout layout = getLayout();
+        if (layout == null) {
+            return 0;
+        }
+        return layout.getHeight();
+    }
+
+    @Override
+    public boolean hasOverlappingRendering() {
+        return false;
+    }
+}
diff --git a/core/java/com/android/internal/widget/MessagingPropertyAnimator.java b/core/java/com/android/internal/widget/MessagingPropertyAnimator.java
new file mode 100644
index 000000000000..7c3ab7f9547f
--- /dev/null
+++ b/core/java/com/android/internal/widget/MessagingPropertyAnimator.java
@@ -0,0 +1,233 @@
+/*
+ * Copyright (C) 2017 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.android.internal.widget;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ObjectAnimator;
+import android.util.IntProperty;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.animation.Interpolator;
+import android.view.animation.PathInterpolator;
+
+import com.android.internal.R;
+
+/**
+ * A listener that automatically starts animations when the layout bounds change.
+ */
+public class MessagingPropertyAnimator implements View.OnLayoutChangeListener {
+    static final long APPEAR_ANIMATION_LENGTH = 210;
+    private static final Interpolator ALPHA_IN = new PathInterpolator(0.4f, 0f, 1f, 1f);
+    public static final Interpolator ALPHA_OUT = new PathInterpolator(0f, 0f, 0.8f, 1f);
+    private static final int TAG_LOCAL_TRANSLATION_ANIMATOR = R.id.tag_local_translation_y_animator;
+    private static final int TAG_LOCAL_TRANSLATION_Y = R.id.tag_local_translation_y;
+    private static final int TAG_LAYOUT_TOP = R.id.tag_layout_top;
+    private static final int TAG_ALPHA_ANIMATOR = R.id.tag_alpha_animator;
+    private static final ViewClippingUtil.ClippingParameters CLIPPING_PARAMETERS =
+            view -> view.getId() == com.android.internal.R.id.notification_messaging;
+    private static final IntProperty<View> LOCAL_TRANSLATION_Y =
+            new IntProperty<View>("localTranslationY") {
+                @Override
+                public void setValue(View object, int value) {
+                    setLocalTranslationY(object, value);
+                }
+
+                @Override
+                public Integer get(View object) {
+                    return getLocalTranslationY(object);
+                }
+            };
+
+    @Override
+    public void onLayoutChange(View v, int left, int top, int right, int bottom, int oldLeft,
+            int oldTop, int oldRight, int oldBottom) {
+        int oldHeight = oldBottom - oldTop;
+        Integer layoutTop = (Integer) v.getTag(TAG_LAYOUT_TOP);
+        if (layoutTop != null) {
+            oldTop = layoutTop;
+        }
+        int topChange = oldTop - top;
+        if (oldHeight == 0 || topChange == 0 || !v.isShown() || isGone(v)) {
+            // First layout
+            return;
+        }
+        if (layoutTop != null) {
+            v.setTagInternal(TAG_LAYOUT_TOP, top);
+        }
+        int newHeight = bottom - top;
+        int heightDifference = oldHeight - newHeight;
+        // Only add the difference if the height changes and it's getting smaller
+        heightDifference = Math.max(heightDifference, 0);
+        startLocalTranslationFrom(v, topChange + heightDifference + getLocalTranslationY(v));
+    }
+
+    private boolean isGone(View view) {
+        if (view.getVisibility() == View.GONE) {
+            return true;
+        }
+        final ViewGroup.LayoutParams lp = view.getLayoutParams();
+        if (lp instanceof MessagingLinearLayout.LayoutParams
+                && ((MessagingLinearLayout.LayoutParams) lp).hide) {
+            return true;
+        }
+        return false;
+    }
+
+    public static void startLocalTranslationFrom(View v, int startTranslation) {
+        startLocalTranslationFrom(v, startTranslation, MessagingLayout.FAST_OUT_SLOW_IN);
+    }
+
+    public static void startLocalTranslationFrom(View v, int startTranslation,
+            Interpolator interpolator) {
+        startLocalTranslation(v, startTranslation, 0, interpolator);
+    }
+
+    public static void startLocalTranslationTo(View v, int endTranslation,
+            Interpolator interpolator) {
+        startLocalTranslation(v, getLocalTranslationY(v), endTranslation, interpolator);
+    }
+
+    public static int getLocalTranslationY(View v) {
+        Integer tag = (Integer) v.getTag(TAG_LOCAL_TRANSLATION_Y);
+        if (tag == null) {
+            return 0;
+        }
+        return tag;
+    }
+
+    private static void setLocalTranslationY(View v, int value) {
+        v.setTagInternal(TAG_LOCAL_TRANSLATION_Y, value);
+        updateTopAndBottom(v);
+    }
+
+    private static void updateTopAndBottom(View v) {
+        int layoutTop = (int) v.getTag(TAG_LAYOUT_TOP);
+        int localTranslation = getLocalTranslationY(v);
+        int height = v.getHeight();
+        v.setTop(layoutTop + localTranslation);
+        v.setBottom(layoutTop + height + localTranslation);
+    }
+
+    private static void startLocalTranslation(final View v, int start, int end,
+            Interpolator interpolator) {
+        ObjectAnimator existing = (ObjectAnimator) v.getTag(TAG_LOCAL_TRANSLATION_ANIMATOR);
+        if (existing != null) {
+            existing.cancel();
+        }
+        ObjectAnimator animator = ObjectAnimator.ofInt(v, LOCAL_TRANSLATION_Y, start, end);
+        Integer layoutTop = (Integer) v.getTag(TAG_LAYOUT_TOP);
+        if (layoutTop == null) {
+            layoutTop = v.getTop();
+            v.setTagInternal(TAG_LAYOUT_TOP, layoutTop);
+        }
+        setLocalTranslationY(v, start);
+        animator.setInterpolator(interpolator);
+        animator.setDuration(APPEAR_ANIMATION_LENGTH);
+        animator.addListener(new AnimatorListenerAdapter() {
+            public boolean mCancelled;
+
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                v.setTagInternal(TAG_LOCAL_TRANSLATION_ANIMATOR, null);
+                setClippingDeactivated(v, false);
+                if (!mCancelled) {
+                    setLocalTranslationY(v, 0);
+                    v.setTagInternal(TAG_LAYOUT_TOP, null);
+                }
+            }
+
+            @Override
+            public void onAnimationCancel(Animator animation) {
+                mCancelled = true;
+            }
+        });
+        setClippingDeactivated(v, true);
+        v.setTagInternal(TAG_LOCAL_TRANSLATION_ANIMATOR, animator);
+        animator.start();
+    }
+
+    public static void fadeIn(final View v) {
+        ObjectAnimator existing = (ObjectAnimator) v.getTag(TAG_ALPHA_ANIMATOR);
+        if (existing != null) {
+            existing.cancel();
+        }
+        if (v.getVisibility() == View.INVISIBLE) {
+            v.setVisibility(View.VISIBLE);
+        }
+        ObjectAnimator animator = ObjectAnimator.ofFloat(v, View.ALPHA,
+                0.0f, 1.0f);
+        v.setAlpha(0.0f);
+        animator.setInterpolator(ALPHA_IN);
+        animator.setDuration(APPEAR_ANIMATION_LENGTH);
+        animator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                v.setTagInternal(TAG_ALPHA_ANIMATOR, null);
+                updateLayerType(v, false /* animating */);
+            }
+        });
+        updateLayerType(v, true /* animating */);
+        v.setTagInternal(TAG_ALPHA_ANIMATOR, animator);
+        animator.start();
+    }
+
+    private static void updateLayerType(View view, boolean animating) {
+        if (view.hasOverlappingRendering() && animating) {
+            view.setLayerType(View.LAYER_TYPE_HARDWARE, null);
+        } else if (view.getLayerType() == View.LAYER_TYPE_HARDWARE) {
+            view.setLayerType(View.LAYER_TYPE_NONE, null);
+        }
+    }
+
+    public static void fadeOut(final View view, Runnable endAction) {
+        ObjectAnimator existing = (ObjectAnimator) view.getTag(TAG_ALPHA_ANIMATOR);
+        if (existing != null) {
+            existing.cancel();
+        }
+        ObjectAnimator animator = ObjectAnimator.ofFloat(view, View.ALPHA,
+                view.getAlpha(), 0.0f);
+        animator.setInterpolator(ALPHA_OUT);
+        animator.setDuration(APPEAR_ANIMATION_LENGTH);
+        animator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                view.setTagInternal(TAG_ALPHA_ANIMATOR, null);
+                updateLayerType(view, false /* animating */);
+                if (endAction != null) {
+                    endAction.run();
+                }
+            }
+        });
+        updateLayerType(view, true /* animating */);
+        view.setTagInternal(TAG_ALPHA_ANIMATOR, animator);
+        animator.start();
+    }
+
+    public static void setClippingDeactivated(final View transformedView, boolean deactivated) {
+        ViewClippingUtil.setClippingDeactivated(transformedView, deactivated,
+                CLIPPING_PARAMETERS);
+    }
+
+    public static boolean isAnimatingTranslation(View v) {
+        return v.getTag(TAG_LOCAL_TRANSLATION_ANIMATOR) != null;
+    }
+
+    public static boolean isAnimatingAlpha(View v) {
+        return v.getTag(TAG_ALPHA_ANIMATOR) != null;
+    }
+}
diff --git a/core/java/com/android/internal/widget/RemeasuringLinearLayout.java b/core/java/com/android/internal/widget/RemeasuringLinearLayout.java
new file mode 100644
index 000000000000..e352b45ef413
--- /dev/null
+++ b/core/java/com/android/internal/widget/RemeasuringLinearLayout.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2017 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.android.internal.widget;
+
+import android.annotation.Nullable;
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.LinearLayout;
+import android.widget.RemoteViews;
+
+/**
+ * A LinearLayout that sets it's height again after the last measure pass. This is needed for
+ * MessagingLayouts where groups need to be able to snap it's height to.
+ */
+@RemoteViews.RemoteView
+public class RemeasuringLinearLayout extends LinearLayout {
+
+    public RemeasuringLinearLayout(Context context) {
+        super(context);
+    }
+
+    public RemeasuringLinearLayout(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public RemeasuringLinearLayout(Context context, @Nullable AttributeSet attrs,
+            int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public RemeasuringLinearLayout(Context context, AttributeSet attrs, int defStyleAttr,
+            int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        int count = getChildCount();
+        int height = 0;
+        for (int i = 0; i < count; ++i) {
+            final View child = getChildAt(i);
+            if (child == null || child.getVisibility() == View.GONE) {
+                continue;
+            }
+
+            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
+            height = Math.max(height, height + child.getMeasuredHeight() + lp.topMargin +
+                    lp.bottomMargin);
+        }
+        setMeasuredDimension(getMeasuredWidth(), height);
+    }
+}
diff --git a/core/java/com/android/internal/widget/ViewClippingUtil.java b/core/java/com/android/internal/widget/ViewClippingUtil.java
new file mode 100644
index 000000000000..59bbed443193
--- /dev/null
+++ b/core/java/com/android/internal/widget/ViewClippingUtil.java
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2017 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.android.internal.widget;
+
+import android.util.ArraySet;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewParent;
+
+import com.android.internal.R;
+
+/**
+ * A utility class that allows to clip views and their parents to allow for better transitions
+ */
+public class ViewClippingUtil {
+    private static final int CLIP_CLIPPING_SET = R.id.clip_children_set_tag;
+    private static final int CLIP_CHILDREN_TAG = R.id.clip_children_tag;
+    private static final int CLIP_TO_PADDING = R.id.clip_to_padding_tag;
+
+    public static void setClippingDeactivated(final View transformedView, boolean deactivated,
+        ClippingParameters clippingParameters) {
+        if (!deactivated && !clippingParameters.isClippingEnablingAllowed(transformedView)) {
+            return;
+        }
+        if (!(transformedView.getParent() instanceof ViewGroup)) {
+            return;
+        }
+        ViewGroup parent = (ViewGroup) transformedView.getParent();
+        while (true) {
+            if (!deactivated && !clippingParameters.isClippingEnablingAllowed(transformedView)) {
+                return;
+            }
+            ArraySet<View> clipSet = (ArraySet<View>) parent.getTag(CLIP_CLIPPING_SET);
+            if (clipSet == null) {
+                clipSet = new ArraySet<>();
+                parent.setTagInternal(CLIP_CLIPPING_SET, clipSet);
+            }
+            Boolean clipChildren = (Boolean) parent.getTag(CLIP_CHILDREN_TAG);
+            if (clipChildren == null) {
+                clipChildren = parent.getClipChildren();
+                parent.setTagInternal(CLIP_CHILDREN_TAG, clipChildren);
+            }
+            Boolean clipToPadding = (Boolean) parent.getTag(CLIP_TO_PADDING);
+            if (clipToPadding == null) {
+                clipToPadding = parent.getClipToPadding();
+                parent.setTagInternal(CLIP_TO_PADDING, clipToPadding);
+            }
+            if (!deactivated) {
+                clipSet.remove(transformedView);
+                if (clipSet.isEmpty()) {
+                    parent.setClipChildren(clipChildren);
+                    parent.setClipToPadding(clipToPadding);
+                    parent.setTagInternal(CLIP_CLIPPING_SET, null);
+                    clippingParameters.onClippingStateChanged(parent, true);
+                }
+            } else {
+                clipSet.add(transformedView);
+                parent.setClipChildren(false);
+                parent.setClipToPadding(false);
+                clippingParameters.onClippingStateChanged(parent, false);
+            }
+            if (clippingParameters.shouldFinish(parent)) {
+                return;
+            }
+            final ViewParent viewParent = parent.getParent();
+            if (viewParent instanceof ViewGroup) {
+                parent = (ViewGroup) viewParent;
+            } else {
+                return;
+            }
+        }
+    }
+
+    public interface ClippingParameters {
+        /**
+         * Should we stop clipping at this view? If true is returned, {@param view} is the last view
+         * where clipping is activated / deactivated.
+         */
+        boolean shouldFinish(View view);
+
+        /**
+         * Is it allowed to enable clipping on this view.
+         */
+        default boolean isClippingEnablingAllowed(View view) {
+            return !MessagingPropertyAnimator.isAnimatingTranslation(view);
+        }
+
+        /**
+         * A method that is called whenever the view starts clipping again / stops clipping to the
+         * children and padding.
+         */
+        default void onClippingStateChanged(View view, boolean isClipping) {};
+    }
+}