diff --git a/AndroidManifest-common.xml b/AndroidManifest-common.xml
index 23ea195..86ae73e 100644
--- a/AndroidManifest-common.xml
+++ b/AndroidManifest-common.xml
@@ -76,6 +76,14 @@
             android:process=":wallpaper_chooser">
         </service>
 
+        <service android:name="com.android.launcher3.notification.NotificationListener"
+                 android:enabled="@bool/notification_badging_enabled"
+                 android:permission="android.permission.BIND_NOTIFICATION_LISTENER_SERVICE">
+            <intent-filter>
+                <action android:name="android.service.notification.NotificationListenerService" />
+            </intent-filter>
+        </service>
+
         <meta-data android:name="android.nfc.disable_beam_default"
                        android:value="true" />
 
diff --git a/res/values-bn-rBD/strings.xml b/res/values-bn-rBD/strings.xml
index 6137f03..2e0f926 100644
--- a/res/values-bn-rBD/strings.xml
+++ b/res/values-bn-rBD/strings.xml
@@ -98,7 +98,7 @@
     <string name="action_move_screen_left" msgid="8854216831569401665">"স্ক্রীন বাঁ দিকে সরান"</string>
     <string name="action_move_screen_right" msgid="329334910274311123">"স্ক্রীন ডান দিকে সরান"</string>
     <string name="screen_moved" msgid="266230079505650577">"স্ক্রীন সরানো হয়েছে"</string>
-    <string name="action_resize" msgid="1802976324781771067">"আবার আকার দিন"</string>
+    <string name="action_resize" msgid="1802976324781771067">"পুনরায় আকার দিন"</string>
     <string name="action_increase_width" msgid="8773715375078513326">"প্রস্থ বাড়ান"</string>
     <string name="action_increase_height" msgid="459390020612501122">"উচ্চতা বাড়ান"</string>
     <string name="action_decrease_width" msgid="1374549771083094654">"প্রস্থ কমান"</string>
diff --git a/res/values-ko/strings.xml b/res/values-ko/strings.xml
index 85b50c8..bcc1699 100644
--- a/res/values-ko/strings.xml
+++ b/res/values-ko/strings.xml
@@ -27,7 +27,7 @@
     <string name="safemode_shortcut_error" msgid="9160126848219158407">"다운로드한 앱은 안전 모드에서 사용할 수 없습니다."</string>
     <string name="safemode_widget_error" msgid="4863470563535682004">"안전 모드에서 위젯 사용 중지됨"</string>
     <string name="shortcut_not_available" msgid="2536503539825726397">"바로가기를 사용할 수 없음"</string>
-    <string name="home_screen" msgid="806512411299847073">"홈 화면"</string>
+    <string name="home_screen" msgid="806512411299847073">"메인 스크린"</string>
     <string name="custom_actions" msgid="3747508247759093328">"맞춤 작업"</string>
     <string name="long_press_widget_to_add" msgid="7699152356777458215">"위젯을 선택하려면 길게 터치하세요."</string>
     <string name="long_accessible_way_to_add" msgid="4289502106628154155">"위젯을 선택하려면 두 번 탭한 다음 길게 터치하거나 맞춤 액션을 사용합니다."</string>
@@ -58,7 +58,7 @@
     <string name="disabled_app_label" msgid="6673129024321402780">"<xliff:g id="APP_NAME">%1$s</xliff:g> 사용 안함"</string>
     <string name="default_scroll_format" msgid="7475544710230993317">"페이지 %1$d/%2$d"</string>
     <string name="workspace_scroll_format" msgid="8458889198184077399">"홈 화면 %1$d/%2$d"</string>
-    <string name="workspace_new_page" msgid="257366611030256142">"새로운 홈 화면 페이지"</string>
+    <string name="workspace_new_page" msgid="257366611030256142">"새로운 메인 스크린 페이지"</string>
     <string name="folder_opened" msgid="94695026776264709">"폴더 열림(<xliff:g id="WIDTH">%1$d</xliff:g>X<xliff:g id="HEIGHT">%2$d</xliff:g>)"</string>
     <string name="folder_tap_to_close" msgid="4625795376335528256">"탭하여 폴더 닫기"</string>
     <string name="folder_tap_to_rename" msgid="4017685068016979677">"탭하여 변경된 이름 저장"</string>
@@ -70,7 +70,7 @@
     <string name="settings_button_text" msgid="8119458837558863227">"설정"</string>
     <string name="msg_disabled_by_admin" msgid="6898038085516271325">"관리자가 사용 중지함"</string>
     <string name="accessibility_action_overview" msgid="6257665857640347026">"개요"</string>
-    <string name="allow_rotation_title" msgid="7728578836261442095">"홈 화면 회전 허용"</string>
+    <string name="allow_rotation_title" msgid="7728578836261442095">"메인 스크린 회전 허용"</string>
     <string name="allow_rotation_desc" msgid="8662546029078692509">"휴대전화 회전 시"</string>
     <string name="allow_rotation_blocked_desc" msgid="3212602545192996253">"현재 표시 설정에는 회전 기능이 허용되지 않습니다."</string>
     <string name="package_state_unknown" msgid="7592128424511031410">"알 수 없음"</string>
@@ -80,9 +80,9 @@
     <string name="abandoned_promise_explanation" msgid="3990027586878167529">"이 아이콘의 앱이 설치되어 있지 않습니다. 아이콘을 삭제하거나 앱을 검색하여 수동으로 설치하세요."</string>
     <string name="app_downloading_title" msgid="8336702962104482644">"<xliff:g id="NAME">%1$s</xliff:g> 다운로드 중, <xliff:g id="PROGRESS">%2$s</xliff:g> 완료"</string>
     <string name="app_waiting_download_title" msgid="7053938513995617849">"<xliff:g id="NAME">%1$s</xliff:g> 설치 대기 중"</string>
-    <string name="action_add_to_workspace" msgid="8902165848117513641">"홈 화면에 추가"</string>
+    <string name="action_add_to_workspace" msgid="8902165848117513641">"메인 스크린에 추가"</string>
     <string name="action_move_here" msgid="2170188780612570250">"여기에 항목을 이동"</string>
-    <string name="item_added_to_workspace" msgid="4211073925752213539">"홈 화면에 항목 추가됨"</string>
+    <string name="item_added_to_workspace" msgid="4211073925752213539">"메인 스크린에 항목 추가됨"</string>
     <string name="item_removed" msgid="851119963877842327">"항목 삭제됨"</string>
     <string name="action_move" msgid="4339390619886385032">"항목 이동"</string>
     <string name="move_to_empty_cell" msgid="2833711483015685619">"<xliff:g id="NUMBER_0">%1$s</xliff:g>행 <xliff:g id="NUMBER_1">%2$s</xliff:g>열로 이동"</string>
@@ -94,7 +94,7 @@
     <string name="added_to_folder" msgid="4793259502305558003">"항목이 폴더에 추가되었습니다."</string>
     <string name="create_folder_with" msgid="4050141361160214248">"다음이 포함된 폴더 만들기: <xliff:g id="NAME">%1$s</xliff:g>"</string>
     <string name="folder_created" msgid="6409794597405184510">"폴더를 만들었습니다."</string>
-    <string name="action_move_to_workspace" msgid="1603837886334246317">"홈 화면으로 이동"</string>
+    <string name="action_move_to_workspace" msgid="1603837886334246317">"메인 스크린으로 이동"</string>
     <string name="action_move_screen_left" msgid="8854216831569401665">"화면을 왼쪽으로 이동"</string>
     <string name="action_move_screen_right" msgid="329334910274311123">"화면을 오른쪽으로 이동"</string>
     <string name="screen_moved" msgid="266230079505650577">"화면 이동됨"</string>
diff --git a/res/values-ne-rNP/strings.xml b/res/values-ne-rNP/strings.xml
index c97eaa2..4589450 100644
--- a/res/values-ne-rNP/strings.xml
+++ b/res/values-ne-rNP/strings.xml
@@ -77,7 +77,7 @@
     <string name="abandoned_clean_this" msgid="7610119707847920412">"हटाउनुहोस्"</string>
     <string name="abandoned_search" msgid="891119232568284442">"खोजी गर्नुहोस्"</string>
     <string name="abandoned_promises_title" msgid="7096178467971716750">"यो अनुप्रयोग स्थापित छैन"</string>
-    <string name="abandoned_promise_explanation" msgid="3990027586878167529">"यो प्रतिमाका लागि अनुप्रयोगलाई स्थापना गरिएको छैन। तपाईं यसलाई हटाउन, वा अनुप्रयोग खोजी र स्वयं यो स्थापित गर्न सक्नुहुन्छ।"</string>
+    <string name="abandoned_promise_explanation" msgid="3990027586878167529">"यो प्रतिमाका लागि अनुप्रयोगलाई स्थापना गरिएको छैन। तपाईँ यसलाई हटाउन, वा अनुप्रयोग खोजी र स्वयं यो स्थापित गर्न सक्नुहुन्छ।"</string>
     <string name="app_downloading_title" msgid="8336702962104482644">"<xliff:g id="NAME">%1$s</xliff:g> डाउनलोड गर्दै, <xliff:g id="PROGRESS">%2$s</xliff:g> सम्पन्‍न"</string>
     <string name="app_waiting_download_title" msgid="7053938513995617849">"<xliff:g id="NAME">%1$s</xliff:g> स्थापना गर्न प्रतीक्षा गर्दै"</string>
     <string name="action_add_to_workspace" msgid="8902165848117513641">"गृह स्क्रिनमा थप्नुहोस्"</string>
diff --git a/res/values-sv/strings.xml b/res/values-sv/strings.xml
index bedef80..907de79 100644
--- a/res/values-sv/strings.xml
+++ b/res/values-sv/strings.xml
@@ -60,8 +60,8 @@
     <string name="workspace_scroll_format" msgid="8458889198184077399">"Startskärmen %1$d av %2$d"</string>
     <string name="workspace_new_page" msgid="257366611030256142">"Ny sida på startskärmen"</string>
     <string name="folder_opened" msgid="94695026776264709">"Mappen är öppen, <xliff:g id="WIDTH">%1$d</xliff:g> gånger <xliff:g id="HEIGHT">%2$d</xliff:g>"</string>
-    <string name="folder_tap_to_close" msgid="4625795376335528256">"Tryck för att stänga mappen"</string>
-    <string name="folder_tap_to_rename" msgid="4017685068016979677">"Tryck för att spara namnändringen"</string>
+    <string name="folder_tap_to_close" msgid="4625795376335528256">"Tryck om du vill stänga mappen"</string>
+    <string name="folder_tap_to_rename" msgid="4017685068016979677">"Tryck om du vill spara namnändringen"</string>
     <string name="folder_closed" msgid="4100806530910930934">"Mappen är stängd"</string>
     <string name="folder_renamed" msgid="1794088362165669656">"Mappen har bytt namn till <xliff:g id="NAME">%1$s</xliff:g>"</string>
     <string name="folder_name_format" msgid="6629239338071103179">"Mapp: <xliff:g id="NAME">%1$s</xliff:g>"</string>
diff --git a/res/values-v25/bools.xml b/res/values-v25/bools.xml
new file mode 100644
index 0000000..6f7ecd9
--- /dev/null
+++ b/res/values-v25/bools.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/* Copyright 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.
+*/
+-->
+
+<resources>
+    <!-- TODO(b/35443111): remove from v25 and keep in v26 -->
+    <bool name="notification_badging_enabled">true</bool>
+</resources>
\ No newline at end of file
diff --git a/res/values-v26/bools.xml b/res/values-v26/bools.xml
new file mode 100644
index 0000000..1093f78
--- /dev/null
+++ b/res/values-v26/bools.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/* Copyright 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.
+*/
+-->
+
+<resources>
+    <bool name="notification_badging_enabled">true</bool>
+</resources>
\ No newline at end of file
diff --git a/res/values/bools.xml b/res/values/bools.xml
new file mode 100644
index 0000000..cc4a7ba
--- /dev/null
+++ b/res/values/bools.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/* Copyright 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.
+*/
+-->
+
+<resources>
+    <bool name="notification_badging_enabled">false</bool>
+</resources>
\ No newline at end of file
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 70f5b32..f6bb3ad 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -89,6 +89,7 @@
     <dimen name="widget_preview_key_shadow_distance">1dp</dimen>
     <dimen name="widget_preview_corner_radius">2dp</dimen>
     <dimen name="widget_preview_cell_divider_width">0.5dp</dimen>
+    <dimen name="widget_preview_shortcut_padding">8dp</dimen>
 
     <dimen name="widget_section_height">56dp</dimen>
     <dimen name="widget_section_icon_size">40dp</dimen>
diff --git a/src/com/android/launcher3/CellLayout.java b/src/com/android/launcher3/CellLayout.java
index 0df8e5a..e0fcbf0 100644
--- a/src/com/android/launcher3/CellLayout.java
+++ b/src/com/android/launcher3/CellLayout.java
@@ -50,6 +50,7 @@
 import com.android.launcher3.accessibility.DragAndDropAccessibilityDelegate;
 import com.android.launcher3.accessibility.FolderAccessibilityHelper;
 import com.android.launcher3.accessibility.WorkspaceAccessibilityHelper;
+import com.android.launcher3.anim.PropertyListBuilder;
 import com.android.launcher3.config.ProviderConfig;
 import com.android.launcher3.folder.FolderIcon;
 import com.android.launcher3.graphics.DragPreviewProvider;
@@ -2097,12 +2098,13 @@
             }
 
             setInitialAnimationValues(true);
-            a = new LauncherViewPropertyAnimator(child)
-                .scaleX(initScale)
-                .scaleY(initScale)
-                .translationX(initDeltaX)
-                .translationY(initDeltaY)
-                .setDuration(REORDER_ANIMATION_DURATION);
+            a = LauncherAnimUtils.ofPropertyValuesHolder(child,
+                    new PropertyListBuilder()
+                            .scale(initScale)
+                            .translationX(initDeltaX)
+                            .translationY(initDeltaY)
+                            .build())
+                    .setDuration(REORDER_ANIMATION_DURATION);
             a.setInterpolator(new android.view.animation.DecelerateInterpolator(1.5f));
             a.start();
         }
@@ -2144,7 +2146,7 @@
                 info.spanY = lp.cellVSpan;
 
                 if (requiresDbUpdate) {
-                    LauncherModel.modifyItemInDatabase(getContext(), info, container, screenId,
+                    mLauncher.getModelWriter().modifyItemInDatabase(info, container, screenId,
                             info.cellX, info.cellY, info.spanX, info.spanY);
                 }
             }
diff --git a/src/com/android/launcher3/FolderInfo.java b/src/com/android/launcher3/FolderInfo.java
index 5fff2e7..2c69d0a 100644
--- a/src/com/android/launcher3/FolderInfo.java
+++ b/src/com/android/launcher3/FolderInfo.java
@@ -16,9 +16,9 @@
 
 package com.android.launcher3;
 
-import android.content.Context;
 import android.os.Process;
 
+import com.android.launcher3.model.ModelWriter;
 import com.android.launcher3.util.ContentWriter;
 
 import java.util.ArrayList;
@@ -128,17 +128,17 @@
     /**
      * @param option flag to set or clear
      * @param isEnabled whether to set or clear the flag
-     * @param context if not null, save changes to the db.
+     * @param writer if not null, save changes to the db.
      */
-    public void setOption(int option, boolean isEnabled, Context context) {
+    public void setOption(int option, boolean isEnabled, ModelWriter writer) {
         int oldOptions = options;
         if (isEnabled) {
             options |= option;
         } else {
             options &= ~option;
         }
-        if (context != null && oldOptions != options) {
-            LauncherModel.updateItemInDatabase(context, this);
+        if (writer != null && oldOptions != options) {
+            writer.updateItemInDatabase(this);
         }
     }
 }
diff --git a/src/com/android/launcher3/InvariantDeviceProfile.java b/src/com/android/launcher3/InvariantDeviceProfile.java
index e3c6965..8aeab87 100644
--- a/src/com/android/launcher3/InvariantDeviceProfile.java
+++ b/src/com/android/launcher3/InvariantDeviceProfile.java
@@ -29,6 +29,7 @@
 
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.config.ProviderConfig;
+import com.android.launcher3.logging.FileLog;
 import com.android.launcher3.util.Thunk;
 
 import org.xmlpull.v1.XmlPullParser;
@@ -187,6 +188,23 @@
         }
     }
 
+    public void dumpDisplayInfo(Context context) {
+        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
+        Display display = wm.getDefaultDisplay();
+        DisplayMetrics dm = new DisplayMetrics();
+        display.getMetrics(dm);
+
+        Point smallestSize = new Point();
+        Point largestSize = new Point();
+        display.getCurrentSizeRange(smallestSize, largestSize);
+
+        FileLog.e("DisplayInfo", "Default Density: " + DisplayMetrics.DENSITY_DEFAULT);
+        FileLog.e("DisplayInfo", "Density: " + dm.densityDpi);
+        FileLog.e("DisplayInfo", "Smallest size: " + smallestSize);
+        FileLog.e("DisplayInfo", "Largest size: " + largestSize);
+        FileLog.e("DisplayInfo", "minWidth/Height DPS: " + minWidthDps + ", " + minHeightDps);
+    }
+
     ArrayList<InvariantDeviceProfile> getPredefinedDeviceProfiles(Context context) {
         ArrayList<InvariantDeviceProfile> profiles = new ArrayList<>();
         try (XmlResourceParser parser = context.getResources().getXml(R.xml.device_profiles)) {
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index a160c41..14b9c82 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -85,6 +85,7 @@
 import com.android.launcher3.allapps.AllAppsTransitionController;
 import com.android.launcher3.allapps.DefaultAppSearchController;
 import com.android.launcher3.anim.AnimationLayerSet;
+import com.android.launcher3.model.ModelWriter;
 import com.android.launcher3.notification.NotificationListener;
 import com.android.launcher3.popup.PopupDataProvider;
 import com.android.launcher3.compat.AppWidgetManagerCompat;
@@ -254,6 +255,7 @@
     private ViewOnDrawExecutor mPendingExecutor;
 
     private LauncherModel mModel;
+    private ModelWriter mModelWriter;
     private IconCache mIconCache;
     private ExtractedColors mExtractedColors;
     private LauncherAccessibilityDelegate mAccessibilityDelegate;
@@ -371,6 +373,7 @@
         mSharedPrefs = Utilities.getPrefs(this);
         mIsSafeModeEnabled = getPackageManager().isSafeMode();
         mModel = app.setLauncher(this);
+        mModelWriter = mModel.getWriter(mDeviceProfile.isVerticalBarLayout());
         mIconCache = app.getIconCache();
         mAccessibilityDelegate = new LauncherAccessibilityDelegate(this);
 
@@ -1498,7 +1501,7 @@
             return;
         }
 
-        LauncherModel.addItemToDatabase(this, info, container, screenId, cellXY[0], cellXY[1]);
+        getModelWriter().addItemToDatabase(info, container, screenId, cellXY[0], cellXY[1]);
         mWorkspace.addInScreen(view, info);
     }
 
@@ -1526,7 +1529,7 @@
         launcherInfo.minSpanY = itemInfo.minSpanY;
         launcherInfo.user = appWidgetInfo.getUser();
 
-        LauncherModel.addItemToDatabase(this, launcherInfo,
+        getModelWriter().addItemToDatabase(launcherInfo,
                 itemInfo.container, itemInfo.screenId, itemInfo.cellX, itemInfo.cellY);
 
         if (hostView == null) {
@@ -1686,6 +1689,10 @@
         return mModel;
     }
 
+    public ModelWriter getModelWriter() {
+        return mModelWriter;
+    }
+
     public SharedPreferences getSharedPrefs() {
         return mSharedPrefs;
     }
@@ -2127,8 +2134,7 @@
         folderInfo.title = getText(R.string.folder_name);
 
         // Update the model
-        LauncherModel.addItemToDatabase(Launcher.this, folderInfo, container, screenId,
-                cellX, cellY);
+        getModelWriter().addItemToDatabase(folderInfo, container, screenId, cellX, cellY);
 
         // Create the view
         FolderIcon newFolder = FolderIcon.fromXml(R.layout.folder_icon, this, layout, folderInfo);
@@ -2156,7 +2162,7 @@
                 mWorkspace.removeWorkspaceItem(v);
             }
             if (deleteFromDb) {
-                LauncherModel.deleteItemFromDatabase(this, itemInfo);
+                getModelWriter().deleteItemFromDatabase(itemInfo);
             }
         } else if (itemInfo instanceof FolderInfo) {
             final FolderInfo folderInfo = (FolderInfo) itemInfo;
@@ -2165,7 +2171,7 @@
             }
             mWorkspace.removeWorkspaceItem(v);
             if (deleteFromDb) {
-                LauncherModel.deleteFolderAndContentsFromDatabase(this, folderInfo);
+                getModelWriter().deleteFolderAndContentsFromDatabase(folderInfo);
             }
         } else if (itemInfo instanceof LauncherAppWidgetInfo) {
             final LauncherAppWidgetInfo widgetInfo = (LauncherAppWidgetInfo) itemInfo;
@@ -2194,7 +2200,7 @@
                 }
             }.executeOnExecutor(Utilities.THREAD_POOL_EXECUTOR);
         }
-        LauncherModel.deleteItemFromDatabase(this, widgetInfo);
+        getModelWriter().deleteItemFromDatabase(widgetInfo);
     }
 
     @Override
@@ -3373,7 +3379,7 @@
                         throw (new RuntimeException(desc));
                     } else {
                         Log.d(TAG, desc);
-                        LauncherModel.deleteItemFromDatabase(this, item);
+                        getModelWriter().deleteItemFromDatabase(item);
                         continue;
                     }
                 }
@@ -3470,7 +3476,7 @@
                             + " belongs to component " + item.providerName
                             + ", as the provider is null");
                 }
-                LauncherModel.deleteItemFromDatabase(this, item);
+                getModelWriter().deleteItemFromDatabase(item);
                 return;
             }
 
@@ -3517,14 +3523,14 @@
                                 : LauncherAppWidgetInfo.FLAG_UI_NOT_READY;
                     }
 
-                    LauncherModel.updateItemInDatabase(this, item);
+                    getModelWriter().updateItemInDatabase(item);
                 }
             } else if (item.hasRestoreFlag(LauncherAppWidgetInfo.FLAG_UI_NOT_READY)
                     && (appWidgetInfo.configure == null)) {
                 // The widget was marked as UI not ready, but there is no configure activity to
                 // update the UI.
                 item.restoreStatus = LauncherAppWidgetInfo.RESTORE_COMPLETED;
-                LauncherModel.updateItemInDatabase(this, item);
+                getModelWriter().updateItemInDatabase(item);
             }
         }
 
@@ -3574,7 +3580,7 @@
         info.restoreStatus = finalRestoreFlag;
 
         mWorkspace.reinflateWidgetsIfNecessary();
-        LauncherModel.updateItemInDatabase(this, info);
+        getModelWriter().updateItemInDatabase(info);
         return info;
     }
 
diff --git a/src/com/android/launcher3/LauncherAppState.java b/src/com/android/launcher3/LauncherAppState.java
index 55c3703..e0e53a6 100644
--- a/src/com/android/launcher3/LauncherAppState.java
+++ b/src/com/android/launcher3/LauncherAppState.java
@@ -28,6 +28,7 @@
 import com.android.launcher3.compat.UserManagerCompat;
 import com.android.launcher3.config.ProviderConfig;
 import com.android.launcher3.dynamicui.ExtractionUtils;
+import com.android.launcher3.model.GridSizeMigrationTask;
 import com.android.launcher3.util.ConfigMonitor;
 import com.android.launcher3.util.Preconditions;
 import com.android.launcher3.util.TestingUtils;
@@ -53,6 +54,8 @@
         if (INSTANCE == null) {
             if (Looper.myLooper() == Looper.getMainLooper()) {
                 INSTANCE = new LauncherAppState(context.getApplicationContext());
+                GridSizeMigrationTask.logDeviceProfileIfChanged(
+                        INSTANCE.getInvariantDeviceProfile(), context);
             } else {
                 try {
                     return new MainThreadExecutor().submit(new Callable<LauncherAppState>() {
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index 9ad8433..34d576d 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -57,6 +57,7 @@
 import com.android.launcher3.model.ExtendedModelTask;
 import com.android.launcher3.model.GridSizeMigrationTask;
 import com.android.launcher3.model.LoaderCursor;
+import com.android.launcher3.model.ModelWriter;
 import com.android.launcher3.model.PackageInstallStateChangedTask;
 import com.android.launcher3.model.PackageItemInfo;
 import com.android.launcher3.model.PackageUpdatedTask;
@@ -266,19 +267,8 @@
         enqueueModelUpdateTask(new AddWorkspaceItemsTask(appsProvider));
     }
 
-    /**
-     * Adds an item to the DB if it was not created previously, or move it to a new
-     * <container, screen, cellX, cellY>
-     */
-    public static void addOrMoveItemInDatabase(Context context, ItemInfo item, long container,
-            long screenId, int cellX, int cellY) {
-        if (item.container == ItemInfo.NO_ID) {
-            // From all apps
-            addItemToDatabase(context, item, container, screenId, cellX, cellY);
-        } else {
-            // From somewhere else
-            moveItemInDatabase(context, item, container, screenId, cellX, cellY);
-        }
+    public ModelWriter getWriter(boolean hasVerticalHotseat) {
+        return new ModelWriter(mApp.getContext(), sBgDataModel, hasVerticalHotseat);
     }
 
     static void checkItemInfoLocked(
@@ -332,281 +322,6 @@
         runOnWorkerThread(r);
     }
 
-    static void updateItemInDatabaseHelper(Context context, final ContentWriter writer,
-            final ItemInfo item, final String callingFunction) {
-        final long itemId = item.id;
-        final Uri uri = LauncherSettings.Favorites.getContentUri(itemId);
-        final ContentResolver cr = context.getContentResolver();
-
-        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
-        final Context appContext = context.getApplicationContext();
-        Runnable r = new Runnable() {
-            public void run() {
-                cr.update(uri, writer.getValues(appContext), null, null);
-                updateItemArrays(item, itemId, stackTrace);
-            }
-        };
-        runOnWorkerThread(r);
-    }
-
-    static void updateItemsInDatabaseHelper(Context context, final ArrayList<ContentValues> valuesList,
-            final ArrayList<ItemInfo> items, final String callingFunction) {
-        final ContentResolver cr = context.getContentResolver();
-
-        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
-        Runnable r = new Runnable() {
-            public void run() {
-                ArrayList<ContentProviderOperation> ops =
-                        new ArrayList<ContentProviderOperation>();
-                int count = items.size();
-                for (int i = 0; i < count; i++) {
-                    ItemInfo item = items.get(i);
-                    final long itemId = item.id;
-                    final Uri uri = LauncherSettings.Favorites.getContentUri(itemId);
-                    ContentValues values = valuesList.get(i);
-
-                    ops.add(ContentProviderOperation.newUpdate(uri).withValues(values).build());
-                    updateItemArrays(item, itemId, stackTrace);
-
-                }
-                try {
-                    cr.applyBatch(LauncherProvider.AUTHORITY, ops);
-                } catch (Exception e) {
-                    e.printStackTrace();
-                }
-            }
-        };
-        runOnWorkerThread(r);
-    }
-
-    static void updateItemArrays(ItemInfo item, long itemId, StackTraceElement[] stackTrace) {
-        // Lock on mBgLock *after* the db operation
-        synchronized (sBgDataModel) {
-            checkItemInfoLocked(itemId, item, stackTrace);
-
-            if (item.container != LauncherSettings.Favorites.CONTAINER_DESKTOP &&
-                    item.container != LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
-                // Item is in a folder, make sure this folder exists
-                if (!sBgDataModel.folders.containsKey(item.container)) {
-                    // An items container is being set to a that of an item which is not in
-                    // the list of Folders.
-                    String msg = "item: " + item + " container being set to: " +
-                            item.container + ", not in the list of folders";
-                    Log.e(TAG, msg);
-                }
-            }
-
-            // Items are added/removed from the corresponding FolderInfo elsewhere, such
-            // as in Workspace.onDrop. Here, we just add/remove them from the list of items
-            // that are on the desktop, as appropriate
-            ItemInfo modelItem = sBgDataModel.itemsIdMap.get(itemId);
-            if (modelItem != null &&
-                    (modelItem.container == LauncherSettings.Favorites.CONTAINER_DESKTOP ||
-                     modelItem.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT)) {
-                switch (modelItem.itemType) {
-                    case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
-                    case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
-                    case LauncherSettings.Favorites.ITEM_TYPE_DEEP_SHORTCUT:
-                    case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
-                        if (!sBgDataModel.workspaceItems.contains(modelItem)) {
-                            sBgDataModel.workspaceItems.add(modelItem);
-                        }
-                        break;
-                    default:
-                        break;
-                }
-            } else {
-                sBgDataModel.workspaceItems.remove(modelItem);
-            }
-        }
-    }
-
-    /**
-     * Move an item in the DB to a new <container, screen, cellX, cellY>
-     */
-    public static void moveItemInDatabase(Context context, final ItemInfo item, final long container,
-            final long screenId, final int cellX, final int cellY) {
-        item.container = container;
-        item.cellX = cellX;
-        item.cellY = cellY;
-
-        // We store hotseat items in canonical form which is this orientation invariant position
-        // in the hotseat
-        if (context instanceof Launcher && screenId < 0 &&
-                container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
-            item.screenId = Launcher.getLauncher(context).getHotseat()
-                    .getOrderInHotseat(cellX, cellY);
-        } else {
-            item.screenId = screenId;
-        }
-
-        final ContentWriter writer = new ContentWriter(context)
-                .put(LauncherSettings.Favorites.CONTAINER, item.container)
-                .put(LauncherSettings.Favorites.CELLX, item.cellX)
-                .put(LauncherSettings.Favorites.CELLY, item.cellY)
-                .put(LauncherSettings.Favorites.RANK, item.rank)
-                .put(LauncherSettings.Favorites.SCREEN, item.screenId);
-
-        updateItemInDatabaseHelper(context, writer, item, "moveItemInDatabase");
-    }
-
-    /**
-     * Move items in the DB to a new <container, screen, cellX, cellY>. We assume that the
-     * cellX, cellY have already been updated on the ItemInfos.
-     */
-    public static void moveItemsInDatabase(Context context, final ArrayList<ItemInfo> items,
-            final long container, final int screen) {
-
-        ArrayList<ContentValues> contentValues = new ArrayList<ContentValues>();
-        int count = items.size();
-
-        for (int i = 0; i < count; i++) {
-            ItemInfo item = items.get(i);
-            item.container = container;
-
-            // We store hotseat items in canonical form which is this orientation invariant position
-            // in the hotseat
-            if (context instanceof Launcher && screen < 0 &&
-                    container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
-                item.screenId = Launcher.getLauncher(context).getHotseat().getOrderInHotseat(item.cellX,
-                        item.cellY);
-            } else {
-                item.screenId = screen;
-            }
-
-            final ContentValues values = new ContentValues();
-            values.put(LauncherSettings.Favorites.CONTAINER, item.container);
-            values.put(LauncherSettings.Favorites.CELLX, item.cellX);
-            values.put(LauncherSettings.Favorites.CELLY, item.cellY);
-            values.put(LauncherSettings.Favorites.RANK, item.rank);
-            values.put(LauncherSettings.Favorites.SCREEN, item.screenId);
-
-            contentValues.add(values);
-        }
-        updateItemsInDatabaseHelper(context, contentValues, items, "moveItemInDatabase");
-    }
-
-    /**
-     * Move and/or resize item in the DB to a new <container, screen, cellX, cellY, spanX, spanY>
-     */
-    static void modifyItemInDatabase(Context context, final ItemInfo item, final long container,
-            final long screenId, final int cellX, final int cellY, final int spanX, final int spanY) {
-        item.container = container;
-        item.cellX = cellX;
-        item.cellY = cellY;
-        item.spanX = spanX;
-        item.spanY = spanY;
-
-        // We store hotseat items in canonical form which is this orientation invariant position
-        // in the hotseat
-        if (context instanceof Launcher && screenId < 0 &&
-                container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
-            item.screenId = Launcher.getLauncher(context).getHotseat()
-                    .getOrderInHotseat(cellX, cellY);
-        } else {
-            item.screenId = screenId;
-        }
-
-        final ContentWriter writer = new ContentWriter(context)
-                .put(LauncherSettings.Favorites.CONTAINER, item.container)
-                .put(LauncherSettings.Favorites.CELLX, item.cellX)
-                .put(LauncherSettings.Favorites.CELLY, item.cellY)
-                .put(LauncherSettings.Favorites.RANK, item.rank)
-                .put(LauncherSettings.Favorites.SPANX, item.spanX)
-                .put(LauncherSettings.Favorites.SPANY, item.spanY)
-                .put(LauncherSettings.Favorites.SCREEN, item.screenId);
-
-        updateItemInDatabaseHelper(context, writer, item, "modifyItemInDatabase");
-    }
-
-    /**
-     * Update an item to the database in a specified container.
-     */
-    public static void updateItemInDatabase(Context context, final ItemInfo item) {
-        ContentWriter writer = new ContentWriter(context);
-        item.onAddToDatabase(writer);
-        updateItemInDatabaseHelper(context, writer, item, "updateItemInDatabase");
-    }
-
-    /**
-     * Add an item to the database in a specified container. Sets the container, screen, cellX and
-     * cellY fields of the item. Also assigns an ID to the item.
-     */
-    public static void addItemToDatabase(Context context, final ItemInfo item, final long container,
-            final long screenId, final int cellX, final int cellY) {
-        item.container = container;
-        item.cellX = cellX;
-        item.cellY = cellY;
-        // We store hotseat items in canonical form which is this orientation invariant position
-        // in the hotseat
-        if (context instanceof Launcher && screenId < 0 &&
-                container == LauncherSettings.Favorites.CONTAINER_HOTSEAT) {
-            item.screenId = Launcher.getLauncher(context).getHotseat()
-                    .getOrderInHotseat(cellX, cellY);
-        } else {
-            item.screenId = screenId;
-        }
-
-        final ContentWriter writer = new ContentWriter(context);
-        final ContentResolver cr = context.getContentResolver();
-        item.onAddToDatabase(writer);
-
-        item.id = LauncherSettings.Settings.call(cr, LauncherSettings.Settings.METHOD_NEW_ITEM_ID)
-                .getLong(LauncherSettings.Settings.EXTRA_VALUE);
-
-        writer.put(LauncherSettings.Favorites._ID, item.id);
-
-        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
-        final Context appContext = context.getApplicationContext();
-        Runnable r = new Runnable() {
-            public void run() {
-                cr.insert(LauncherSettings.Favorites.CONTENT_URI, writer.getValues(appContext));
-
-                synchronized (sBgDataModel) {
-                    checkItemInfoLocked(item.id, item, stackTrace);
-                    sBgDataModel.addItem(appContext, item, true);
-                }
-            }
-        };
-        runOnWorkerThread(r);
-    }
-
-    /**
-     * Removes the specified item from the database
-     */
-    public static void deleteItemFromDatabase(Context context, final ItemInfo item) {
-        ArrayList<ItemInfo> items = new ArrayList<>();
-        items.add(item);
-        deleteItemsFromDatabase(context, items);
-    }
-
-    /**
-     * Removes all the items from the database matching {@param matcher}.
-     */
-    public static void deleteItemsFromDatabase(Context context, ItemInfoMatcher matcher) {
-        deleteItemsFromDatabase(context, matcher.filterItemInfos(sBgDataModel.itemsIdMap));
-    }
-
-    /**
-     * Removes the specified items from the database
-     */
-    public static void deleteItemsFromDatabase(Context context,
-            final Iterable<? extends ItemInfo> items) {
-        final ContentResolver cr = context.getContentResolver();
-        final Context appContext = context.getApplicationContext();
-        Runnable r = new Runnable() {
-            public void run() {
-                for (ItemInfo item : items) {
-                    final Uri uri = LauncherSettings.Favorites.getContentUri(item.id);
-                    cr.delete(uri, null, null);
-
-                    sBgDataModel.removeItem(appContext, item);
-                }
-            }
-        };
-        runOnWorkerThread(r);
-    }
-
     /**
      * Update the order of the workspace screens in the database. The array list contains
      * a list of screen ids in the order that they should appear.
@@ -656,27 +371,6 @@
     }
 
     /**
-     * Remove the specified folder and all its contents from the database.
-     */
-    public static void deleteFolderAndContentsFromDatabase(Context context, final FolderInfo info) {
-        final ContentResolver cr = context.getContentResolver();
-        final Context appContext = context.getApplicationContext();
-
-        Runnable r = new Runnable() {
-            public void run() {
-                cr.delete(LauncherSettings.Favorites.CONTENT_URI,
-                        LauncherSettings.Favorites.CONTAINER + "=" + info.id, null);
-                sBgDataModel.removeItem(appContext, info.contents);
-                info.contents.clear();
-
-                cr.delete(LauncherSettings.Favorites.getContentUri(info.id), null, null);
-                sBgDataModel.removeItem(appContext, info);
-            }
-        };
-        runOnWorkerThread(r);
-    }
-
-    /**
      * Set this as the current Launcher activity object for the loader.
      */
     public void initialize(Callbacks callbacks) {
@@ -2193,6 +1887,11 @@
                 }
             });
         }
+
+        public ModelWriter getModelWriter() {
+            // Updates from model task, do not deal with icon position in hotseat.
+            return mModel.getWriter(false /* hasVerticalHotseat */);
+        }
     }
 
     public void updateAndBindShortcutInfo(final ShortcutInfo si, final ShortcutInfoCompat info) {
diff --git a/src/com/android/launcher3/LauncherViewPropertyAnimator.java b/src/com/android/launcher3/LauncherViewPropertyAnimator.java
deleted file mode 100644
index 4406a2c..0000000
--- a/src/com/android/launcher3/LauncherViewPropertyAnimator.java
+++ /dev/null
@@ -1,275 +0,0 @@
-/*
- * Copyright (C) 2012 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.launcher3;
-
-import android.animation.Animator;
-import android.animation.Animator.AnimatorListener;
-import android.animation.TimeInterpolator;
-import android.view.View;
-import android.view.ViewPropertyAnimator;
-
-import java.util.ArrayList;
-import java.util.EnumSet;
-
-public class LauncherViewPropertyAnimator extends Animator implements AnimatorListener {
-
-    enum Properties {
-            TRANSLATION_X,
-            TRANSLATION_Y,
-            SCALE_X,
-            SCALE_Y,
-            ROTATION_Y,
-            ALPHA,
-            START_DELAY,
-            DURATION,
-            INTERPOLATOR,
-            WITH_LAYER
-    }
-    EnumSet<Properties> mPropertiesToSet = EnumSet.noneOf(Properties.class);
-    ViewPropertyAnimator mViewPropertyAnimator;
-    View mTarget;
-
-    float mTranslationX;
-    float mTranslationY;
-    float mScaleX;
-    float mScaleY;
-    float mRotationY;
-    float mAlpha;
-    long mStartDelay;
-    long mDuration;
-    TimeInterpolator mInterpolator;
-    ArrayList<Animator.AnimatorListener> mListeners = new ArrayList<>();
-    boolean mRunning = false;
-    FirstFrameAnimatorHelper mFirstFrameHelper;
-
-    public LauncherViewPropertyAnimator(View target) {
-        mTarget = target;
-    }
-
-    @Override
-    public void addListener(Animator.AnimatorListener listener) {
-        mListeners.add(listener);
-    }
-
-    @Override
-    public void cancel() {
-        if (mViewPropertyAnimator != null) {
-            mViewPropertyAnimator.cancel();
-        }
-    }
-
-    @Override
-    public Animator clone() {
-        throw new RuntimeException("Not implemented");
-    }
-
-    @Override
-    public void end() {
-        throw new RuntimeException("Not implemented");
-    }
-
-    @Override
-    public long getDuration() {
-        return mDuration;
-    }
-
-    @Override
-    public ArrayList<Animator.AnimatorListener> getListeners() {
-        return mListeners;
-    }
-
-    @Override
-    public long getStartDelay() {
-        return mStartDelay;
-    }
-
-    @Override
-    public void onAnimationCancel(Animator animation) {
-        for (int i = 0; i < mListeners.size(); i++) {
-            Animator.AnimatorListener listener = mListeners.get(i);
-            listener.onAnimationCancel(this);
-        }
-        mRunning = false;
-    }
-
-    @Override
-    public void onAnimationEnd(Animator animation) {
-        for (int i = 0; i < mListeners.size(); i++) {
-            Animator.AnimatorListener listener = mListeners.get(i);
-            listener.onAnimationEnd(this);
-        }
-        mRunning = false;
-    }
-
-    @Override
-    public void onAnimationRepeat(Animator animation) {
-        for (int i = 0; i < mListeners.size(); i++) {
-            Animator.AnimatorListener listener = mListeners.get(i);
-            listener.onAnimationRepeat(this);
-        }
-    }
-
-    @Override
-    public void onAnimationStart(Animator animation) {
-        // This is the first time we get a handle to the internal ValueAnimator
-        // used by the ViewPropertyAnimator.
-        mFirstFrameHelper.onAnimationStart(animation);
-
-        for (int i = 0; i < mListeners.size(); i++) {
-            Animator.AnimatorListener listener = mListeners.get(i);
-            listener.onAnimationStart(this);
-        }
-        mRunning = true;
-    }
-
-    @Override
-    public boolean isRunning() {
-        return mRunning;
-    }
-
-    @Override
-    public boolean isStarted() {
-        return mViewPropertyAnimator != null;
-    }
-
-    @Override
-    public void removeAllListeners() {
-        mListeners.clear();
-    }
-
-    @Override
-    public void removeListener(Animator.AnimatorListener listener) {
-        mListeners.remove(listener);
-    }
-
-    @Override
-    public Animator setDuration(long duration) {
-        mPropertiesToSet.add(Properties.DURATION);
-        mDuration = duration;
-        return this;
-    }
-
-    @Override
-    public void setInterpolator(TimeInterpolator value) {
-        mPropertiesToSet.add(Properties.INTERPOLATOR);
-        mInterpolator = value;
-    }
-
-    @Override
-    public void setStartDelay(long startDelay) {
-        mPropertiesToSet.add(Properties.START_DELAY);
-        mStartDelay = startDelay;
-    }
-
-    @Override
-    public void setTarget(Object target) {
-        throw new RuntimeException("Not implemented");
-    }
-
-    @Override
-    public void setupEndValues() {
-
-    }
-
-    @Override
-    public void setupStartValues() {
-    }
-
-    @Override
-    public void start() {
-        mViewPropertyAnimator = mTarget.animate();
-
-        // FirstFrameAnimatorHelper hooks itself up to the updates on the animator,
-        // and then adjusts the play time to keep the first two frames jank-free
-        mFirstFrameHelper = new FirstFrameAnimatorHelper(mViewPropertyAnimator, mTarget);
-
-        if (mPropertiesToSet.contains(Properties.TRANSLATION_X)) {
-            mViewPropertyAnimator.translationX(mTranslationX);
-        }
-        if (mPropertiesToSet.contains(Properties.TRANSLATION_Y)) {
-            mViewPropertyAnimator.translationY(mTranslationY);
-        }
-        if (mPropertiesToSet.contains(Properties.SCALE_X)) {
-            mViewPropertyAnimator.scaleX(mScaleX);
-        }
-        if (mPropertiesToSet.contains(Properties.ROTATION_Y)) {
-            mViewPropertyAnimator.rotationY(mRotationY);
-        }
-        if (mPropertiesToSet.contains(Properties.SCALE_Y)) {
-            mViewPropertyAnimator.scaleY(mScaleY);
-        }
-        if (mPropertiesToSet.contains(Properties.ALPHA)) {
-            mViewPropertyAnimator.alpha(mAlpha);
-        }
-        if (mPropertiesToSet.contains(Properties.START_DELAY)) {
-            mViewPropertyAnimator.setStartDelay(mStartDelay);
-        }
-        if (mPropertiesToSet.contains(Properties.DURATION)) {
-            mViewPropertyAnimator.setDuration(mDuration);
-        }
-        if (mPropertiesToSet.contains(Properties.INTERPOLATOR)) {
-            mViewPropertyAnimator.setInterpolator(mInterpolator);
-        }
-        if (mPropertiesToSet.contains(Properties.WITH_LAYER)) {
-            mViewPropertyAnimator.withLayer();
-        }
-        mViewPropertyAnimator.setListener(this);
-        mViewPropertyAnimator.start();
-        LauncherAnimUtils.cancelOnDestroyActivity(this);
-    }
-
-    public LauncherViewPropertyAnimator translationX(float value) {
-        mPropertiesToSet.add(Properties.TRANSLATION_X);
-        mTranslationX = value;
-        return this;
-    }
-
-    public LauncherViewPropertyAnimator translationY(float value) {
-        mPropertiesToSet.add(Properties.TRANSLATION_Y);
-        mTranslationY = value;
-        return this;
-    }
-
-    public LauncherViewPropertyAnimator scaleX(float value) {
-        mPropertiesToSet.add(Properties.SCALE_X);
-        mScaleX = value;
-        return this;
-    }
-
-    public LauncherViewPropertyAnimator scaleY(float value) {
-        mPropertiesToSet.add(Properties.SCALE_Y);
-        mScaleY = value;
-        return this;
-    }
-
-    public LauncherViewPropertyAnimator rotationY(float value) {
-        mPropertiesToSet.add(Properties.ROTATION_Y);
-        mRotationY = value;
-        return this;
-    }
-
-    public LauncherViewPropertyAnimator alpha(float value) {
-        mPropertiesToSet.add(Properties.ALPHA);
-        mAlpha = value;
-        return this;
-    }
-
-    public LauncherViewPropertyAnimator withLayer() {
-        mPropertiesToSet.add(Properties.WITH_LAYER);
-        return this;
-    }
-}
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index 76e2073..fb6a611 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -47,6 +47,7 @@
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.view.animation.Interpolator;
 
+import com.android.launcher3.anim.PropertyListBuilder;
 import com.android.launcher3.pageindicators.PageIndicator;
 import com.android.launcher3.util.LauncherEdgeEffect;
 import com.android.launcher3.util.Thunk;
@@ -1998,11 +1999,12 @@
     // Animate the drag view back to the original position
     private void animateDragViewToOriginalPosition() {
         if (mDragView != null) {
-            Animator anim = new LauncherViewPropertyAnimator(mDragView)
-                    .translationX(0)
-                    .translationY(0)
-                    .scaleX(1)
-                    .scaleY(1)
+            Animator anim = LauncherAnimUtils.ofPropertyValuesHolder(mDragView,
+                    new PropertyListBuilder()
+                            .scale(1)
+                            .translationX(0)
+                            .translationY(0)
+                            .build())
                     .setDuration(REORDERING_DROP_REPOSITION_DURATION);
             anim.addListener(new AnimatorListenerAdapter() {
                 @Override
diff --git a/src/com/android/launcher3/PinchAnimationManager.java b/src/com/android/launcher3/PinchAnimationManager.java
index bae246e..f8196e5 100644
--- a/src/com/android/launcher3/PinchAnimationManager.java
+++ b/src/com/android/launcher3/PinchAnimationManager.java
@@ -24,6 +24,7 @@
 import android.view.View;
 import android.view.animation.LinearInterpolator;
 
+import com.android.launcher3.anim.AnimationLayerSet;
 import com.android.launcher3.userevent.nano.LauncherLogProto.Action;
 import com.android.launcher3.userevent.nano.LauncherLogProto.ContainerType;
 
@@ -211,7 +212,8 @@
     }
 
     private void animateShowHideView(int index, final View view, boolean show) {
-        Animator animator = new LauncherViewPropertyAnimator(view).alpha(show ? 1 : 0).withLayer();
+        Animator animator = ObjectAnimator.ofFloat(view, View.ALPHA, show ? 1 : 0);
+        animator.addListener(new AnimationLayerSet(view));
         if (show) {
             view.setVisibility(View.VISIBLE);
         } else {
diff --git a/src/com/android/launcher3/WidgetPreviewLoader.java b/src/com/android/launcher3/WidgetPreviewLoader.java
index 3512210..689cc9b 100644
--- a/src/com/android/launcher3/WidgetPreviewLoader.java
+++ b/src/com/android/launcher3/WidgetPreviewLoader.java
@@ -14,22 +14,24 @@
 import android.graphics.Bitmap.Config;
 import android.graphics.BitmapFactory;
 import android.graphics.Canvas;
-import android.graphics.ColorMatrix;
-import android.graphics.ColorMatrixColorFilter;
+import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuffXfermode;
+import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.drawable.Drawable;
 import android.os.AsyncTask;
 import android.os.Handler;
 import android.os.UserHandle;
+import android.support.v4.graphics.ColorUtils;
 import android.util.Log;
 import android.util.LongSparseArray;
 
 import com.android.launcher3.compat.AppWidgetManagerCompat;
 import com.android.launcher3.compat.ShortcutConfigActivityInfo;
 import com.android.launcher3.compat.UserManagerCompat;
+import com.android.launcher3.graphics.LauncherIcons;
 import com.android.launcher3.graphics.ShadowGenerator;
 import com.android.launcher3.model.WidgetItem;
 import com.android.launcher3.util.ComponentKey;
@@ -366,30 +368,13 @@
             drawable.setBounds(x, 0, x + previewWidth, previewHeight);
             drawable.draw(c);
         } else {
-            Resources res = mContext.getResources();
-            float shadowBlur = res.getDimension(R.dimen.widget_preview_shadow_blur);
-            float keyShadowDistance = res.getDimension(R.dimen.widget_preview_key_shadow_distance);
-            float corner = res.getDimension(R.dimen.widget_preview_corner_radius);
-
-            RectF boxRect = new RectF(shadowBlur, shadowBlur,
-                    previewWidth - shadowBlur, previewHeight - shadowBlur - keyShadowDistance);
-
             final Paint p = new Paint(Paint.ANTI_ALIAS_FLAG);
-            p.setColor(0xFFFFFFFF);
-
-            // Key shadow
-            p.setShadowLayer(shadowBlur, 0, keyShadowDistance,
-                    ShadowGenerator.KEY_SHADOW_ALPHA << 24);
-            c.drawRoundRect(boxRect, corner, corner, p);
-
-            // Ambient shadow
-            p.setShadowLayer(shadowBlur, 0, 0, ShadowGenerator.AMBIENT_SHADOW_ALPHA << 24);
-            c.drawRoundRect(boxRect, corner, corner, p);
+            RectF boxRect = drawBoxWithShadow(c, p, previewWidth, previewHeight);
 
             // Draw horizontal and vertical lines to represent individual columns.
-            p.clearShadowLayer();
             p.setStyle(Paint.Style.STROKE);
-            p.setStrokeWidth(res.getDimension(R.dimen.widget_preview_cell_divider_width));
+            p.setStrokeWidth(mContext.getResources()
+                    .getDimension(R.dimen.widget_preview_cell_divider_width));
             p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
 
             float t = boxRect.left;
@@ -426,47 +411,63 @@
         return preview;
     }
 
+    private RectF drawBoxWithShadow(Canvas c, Paint p, int width, int height) {
+        Resources res = mContext.getResources();
+        float shadowBlur = res.getDimension(R.dimen.widget_preview_shadow_blur);
+        float keyShadowDistance = res.getDimension(R.dimen.widget_preview_key_shadow_distance);
+        float corner = res.getDimension(R.dimen.widget_preview_corner_radius);
+
+        RectF bounds = new RectF(shadowBlur, shadowBlur,
+                width - shadowBlur, height - shadowBlur - keyShadowDistance);
+        p.setColor(Color.WHITE);
+
+        // Key shadow
+        p.setShadowLayer(shadowBlur, 0, keyShadowDistance,
+                ShadowGenerator.KEY_SHADOW_ALPHA << 24);
+        c.drawRoundRect(bounds, corner, corner, p);
+
+        // Ambient shadow
+        p.setShadowLayer(shadowBlur, 0, 0,
+                ColorUtils.setAlphaComponent(Color.BLACK, ShadowGenerator.AMBIENT_SHADOW_ALPHA));
+        c.drawRoundRect(bounds, corner, corner, p);
+
+        p.clearShadowLayer();
+        return bounds;
+    }
+
     private Bitmap generateShortcutPreview(BaseActivity launcher, ShortcutConfigActivityInfo info,
             int maxWidth, int maxHeight, Bitmap preview) {
+        int iconSize = launcher.getDeviceProfile().iconSizePx;
+        int padding = launcher.getResources()
+                .getDimensionPixelSize(R.dimen.widget_preview_shortcut_padding);
+
+        int size = iconSize + 2 * padding;
+        if (maxHeight < size || maxWidth < size) {
+            throw new RuntimeException("Max size is too small for preview");
+        }
         final Canvas c = new Canvas();
-        if (preview == null) {
-            preview = Bitmap.createBitmap(maxWidth, maxHeight, Config.ARGB_8888);
+        if (preview == null || preview.getWidth() < size || preview.getHeight() < size) {
+            preview = Bitmap.createBitmap(size, size, Config.ARGB_8888);
             c.setBitmap(preview);
-        } else if (preview.getWidth() != maxWidth || preview.getHeight() != maxHeight) {
-            throw new RuntimeException("Improperly sized bitmap passed as argument");
         } else {
+            if (preview.getWidth() > size || preview.getHeight() > size) {
+                preview.reconfigure(size, size, preview.getConfig());
+            }
+
             // Reusing bitmap. Clear it.
             c.setBitmap(preview);
             c.drawColor(0, PorterDuff.Mode.CLEAR);
         }
+        Paint p = new Paint(Paint.ANTI_ALIAS_FLAG | Paint.FILTER_BITMAP_FLAG);
+        RectF boxRect = drawBoxWithShadow(c, p, size, size);
 
-        Drawable icon = mutateOnMainThread(info.getFullResIcon(mIconCache));
-        icon.setFilterBitmap(true);
+        Bitmap icon = LauncherIcons.createScaledBitmapWithoutShadow(
+                mutateOnMainThread(info.getFullResIcon(mIconCache)), mContext);
+        Rect src = new Rect(0, 0, icon.getWidth(), icon.getHeight());
 
-        // Draw a desaturated/scaled version of the icon in the background as a watermark
-        ColorMatrix colorMatrix = new ColorMatrix();
-        colorMatrix.setSaturation(0);
-        icon.setColorFilter(new ColorMatrixColorFilter(colorMatrix));
-        icon.setAlpha((int) (255 * 0.06f));
-
-        Resources res = mContext.getResources();
-        int paddingTop = res.getDimensionPixelOffset(R.dimen.shortcut_preview_padding_top);
-        int paddingLeft = res.getDimensionPixelOffset(R.dimen.shortcut_preview_padding_left);
-        int paddingRight = res.getDimensionPixelOffset(R.dimen.shortcut_preview_padding_right);
-        int scaledIconWidth = (maxWidth - paddingLeft - paddingRight);
-        icon.setBounds(paddingLeft, paddingTop,
-                paddingLeft + scaledIconWidth, paddingTop + scaledIconWidth);
-        icon.draw(c);
-
-        // Draw the final icon at top left corner.
-        // TODO: use top right for RTL
-        int appIconSize = launcher.getDeviceProfile().iconSizePx;
-
-        icon.setAlpha(255);
-        icon.setColorFilter(null);
-        icon.setBounds(0, 0, appIconSize, appIconSize);
-        icon.draw(c);
-
+        boxRect.set(0, 0, iconSize, iconSize);
+        boxRect.offset(padding, padding);
+        c.drawBitmap(icon, src, boxRect, p);
         c.setBitmap(null);
         return preview;
     }
@@ -664,7 +665,6 @@
 
     private static final class WidgetCacheKey extends ComponentKey {
 
-        // TODO: remove dependency on size
         @Thunk final String size;
 
         public WidgetCacheKey(ComponentName componentName, UserHandle user, String size) {
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index 3aa8825..56aa69e 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -2654,8 +2654,8 @@
                         }
                     }
 
-                    LauncherModel.modifyItemInDatabase(mLauncher, info, container, screenId, lp.cellX,
-                            lp.cellY, item.spanX, item.spanY);
+                    mLauncher.getModelWriter().modifyItemInDatabase(info, container, screenId,
+                            lp.cellX, lp.cellY, item.spanX, item.spanY);
                 } else {
                     if (!returnToOriginalCellToPreventShuffling) {
                         onNoCellFound(dropTargetLayout);
@@ -3387,7 +3387,7 @@
             }
             // Add the item to DB before adding to screen ensures that the container and other
             // values of the info is properly updated.
-            LauncherModel.addOrMoveItemInDatabase(mLauncher, info, container, screenId,
+            mLauncher.getModelWriter().addOrMoveItemInDatabase(info, container, screenId,
                     mTargetCell[0], mTargetCell[1]);
 
             addInScreen(view, container, screenId, mTargetCell[0], mTargetCell[1],
@@ -4025,7 +4025,7 @@
         HashSet<String> packages = new HashSet<>(1);
         packages.add(packageName);
         ItemInfoMatcher matcher = ItemInfoMatcher.ofPackages(packages, user);
-        LauncherModel.deleteItemsFromDatabase(mLauncher, matcher);
+        mLauncher.getModelWriter().deleteItemsFromDatabase(matcher);
         removeItemsByMatcher(matcher);
     }
 
diff --git a/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java b/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
index 6a71bef..482a2c9 100644
--- a/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
+++ b/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
@@ -31,6 +31,7 @@
 import android.view.animation.DecelerateInterpolator;
 
 import com.android.launcher3.anim.AnimationLayerSet;
+import com.android.launcher3.anim.PropertyListBuilder;
 import com.android.launcher3.config.FeatureFlags;
 import com.android.launcher3.dragndrop.DragLayer;
 import com.android.launcher3.util.Thunk;
@@ -337,10 +338,9 @@
             if (animated) {
                 float oldBackgroundAlpha = cl.getBackgroundAlpha();
                 if (initialAlpha != finalAlpha) {
-                    LauncherViewPropertyAnimator alphaAnim =
-                            new LauncherViewPropertyAnimator(cl.getShortcutsAndWidgets());
-                    alphaAnim.alpha(finalAlpha)
-                            .setDuration(duration)
+                    Animator alphaAnim = ObjectAnimator.ofFloat(
+                            cl.getShortcutsAndWidgets(), View.ALPHA, finalAlpha);
+                    alphaAnim.setDuration(duration)
                             .setInterpolator(mZoomInInterpolator);
                     mStateAnimator.play(alphaAnim);
                 }
@@ -377,17 +377,16 @@
                 .animateAlphaAtIndex(finalQsbAlpha, Workspace.QSB_ALPHA_INDEX_STATE_CHANGE);
 
         if (animated) {
-            LauncherViewPropertyAnimator scale = new LauncherViewPropertyAnimator(mWorkspace);
-            scale.scaleX(mNewScale)
-                    .scaleY(mNewScale)
-                    .translationY(finalWorkspaceTranslationY)
-                    .setDuration(duration)
-                    .setInterpolator(mZoomInInterpolator);
+            Animator scale = LauncherAnimUtils.ofPropertyValuesHolder(mWorkspace,
+                    new PropertyListBuilder().scale(mNewScale)
+                            .translationY(finalWorkspaceTranslationY).build())
+                    .setDuration(duration);
+            scale.setInterpolator(mZoomInInterpolator);
             mStateAnimator.play(scale);
             Animator hotseatAlpha = mWorkspace.createHotseatAlphaAnimator(finalHotseatAlpha);
 
-            LauncherViewPropertyAnimator overviewPanelAlpha =
-                    new LauncherViewPropertyAnimator(overviewPanel).alpha(finalOverviewPanelAlpha);
+            Animator overviewPanelAlpha = ObjectAnimator.ofFloat(
+                    overviewPanel, View.ALPHA, finalOverviewPanelAlpha);
             overviewPanelAlpha.addListener(new AlphaUpdateListener(overviewPanel,
                     accessibilityEnabled));
 
diff --git a/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
index b77493b..a476650 100644
--- a/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
+++ b/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
@@ -168,7 +168,7 @@
                 public void run() {
                     if (item instanceof AppInfo) {
                         ShortcutInfo info = ((AppInfo) item).makeShortcut();
-                        LauncherModel.addItemToDatabase(mLauncher, info,
+                        mLauncher.getModelWriter().addItemToDatabase(info,
                                 LauncherSettings.Favorites.CONTAINER_DESKTOP,
                                 screenId, coordinates[0], coordinates[1]);
 
@@ -194,7 +194,7 @@
 
             final int[] coordinates = new int[2];
             final long screenId = findSpaceOnWorkspace(item, coordinates);
-            LauncherModel.moveItemInDatabase(mLauncher, info,
+            mLauncher.getModelWriter().moveItemInDatabase(info,
                     LauncherSettings.Favorites.CONTAINER_DESKTOP,
                     screenId, coordinates[0], coordinates[1]);
 
@@ -304,7 +304,7 @@
         ((LauncherAppWidgetHostView) host).updateAppWidgetSize(null,
                 sizeRange.left, sizeRange.top, sizeRange.right, sizeRange.bottom);
         host.requestLayout();
-        LauncherModel.updateItemInDatabase(mLauncher, info);
+        mLauncher.getModelWriter().updateItemInDatabase(info);
         announceConfirmation(mLauncher.getString(R.string.widget_resized, info.spanX, info.spanY));
     }
 
diff --git a/src/com/android/launcher3/accessibility/ShortcutMenuAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/ShortcutMenuAccessibilityDelegate.java
index f7ca703..b784fe7 100644
--- a/src/com/android/launcher3/accessibility/ShortcutMenuAccessibilityDelegate.java
+++ b/src/com/android/launcher3/accessibility/ShortcutMenuAccessibilityDelegate.java
@@ -59,7 +59,7 @@
             Runnable onComplete = new Runnable() {
                 @Override
                 public void run() {
-                    LauncherModel.addItemToDatabase(mLauncher, info,
+                    mLauncher.getModelWriter().addItemToDatabase(info,
                             LauncherSettings.Favorites.CONTAINER_DESKTOP,
                             screenId, coordinates[0], coordinates[1]);
                     ArrayList<ItemInfo> itemList = new ArrayList<>();
diff --git a/src/com/android/launcher3/anim/AnimationLayerSet.java b/src/com/android/launcher3/anim/AnimationLayerSet.java
index d2f5e78..14bcd17 100644
--- a/src/com/android/launcher3/anim/AnimationLayerSet.java
+++ b/src/com/android/launcher3/anim/AnimationLayerSet.java
@@ -29,7 +29,16 @@
  */
 public class AnimationLayerSet extends AnimatorListenerAdapter {
 
-    private final HashMap<View, Integer> mViewsToLayerTypeMap = new HashMap<>();
+    private final HashMap<View, Integer> mViewsToLayerTypeMap;
+
+    public AnimationLayerSet() {
+        mViewsToLayerTypeMap = new HashMap<>();
+    }
+
+    public AnimationLayerSet(View v) {
+        mViewsToLayerTypeMap = new HashMap<>(1);
+        addView(v);
+    }
 
     public void addView(View v) {
         mViewsToLayerTypeMap.put(v, v.getLayerType());
diff --git a/src/com/android/launcher3/anim/PropertyListBuilder.java b/src/com/android/launcher3/anim/PropertyListBuilder.java
new file mode 100644
index 0000000..33e7f66
--- /dev/null
+++ b/src/com/android/launcher3/anim/PropertyListBuilder.java
@@ -0,0 +1,50 @@
+package com.android.launcher3.anim;
+
+import android.animation.PropertyValuesHolder;
+import android.view.View;
+
+import java.util.ArrayList;
+
+/**
+ * Helper class to build a list of {@link PropertyValuesHolder} for view properties
+ */
+public class PropertyListBuilder {
+
+    private final ArrayList<PropertyValuesHolder> mProperties = new ArrayList<>();
+
+    public PropertyListBuilder translationX(float value) {
+        mProperties.add(PropertyValuesHolder.ofFloat(View.TRANSLATION_X, value));
+        return this;
+    }
+
+    public PropertyListBuilder translationY(float value) {
+        mProperties.add(PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, value));
+        return this;
+    }
+
+    public PropertyListBuilder scaleX(float value) {
+        mProperties.add(PropertyValuesHolder.ofFloat(View.SCALE_X, value));
+        return this;
+    }
+
+    public PropertyListBuilder scaleY(float value) {
+        mProperties.add(PropertyValuesHolder.ofFloat(View.SCALE_Y, value));
+        return this;
+    }
+
+    /**
+     * Helper method to set both scaleX and scaleY
+     */
+    public PropertyListBuilder scale(float value) {
+        return scaleX(value).scaleY(value);
+    }
+
+    public PropertyListBuilder alpha(float value) {
+        mProperties.add(PropertyValuesHolder.ofFloat(View.ALPHA, value));
+        return this;
+    }
+
+    public PropertyValuesHolder[] build() {
+        return mProperties.toArray(new PropertyValuesHolder[mProperties.size()]);
+    }
+}
diff --git a/src/com/android/launcher3/dynamicui/ColorExtractionService.java b/src/com/android/launcher3/dynamicui/ColorExtractionService.java
index 1a127dc..f94d442 100644
--- a/src/com/android/launcher3/dynamicui/ColorExtractionService.java
+++ b/src/com/android/launcher3/dynamicui/ColorExtractionService.java
@@ -98,7 +98,7 @@
                 if (bitmap != null) {
                     return Palette.from(bitmap).clearFilters().generate();
                 }
-            } catch (IOException e) {
+            } catch (IOException | NullPointerException e) {
                 Log.e(TAG, "Fetching partial bitmap failed, trying old method", e);
             }
         }
@@ -129,7 +129,7 @@
                 if (bitmap != null) {
                     return Palette.from(bitmap).clearFilters().generate();
                 }
-            } catch (IOException e) {
+            } catch (IOException | NullPointerException e) {
                 Log.e(TAG, "Fetching partial bitmap failed, trying old method", e);
             }
         }
diff --git a/src/com/android/launcher3/folder/Folder.java b/src/com/android/launcher3/folder/Folder.java
index eacea4a..3d28f22 100644
--- a/src/com/android/launcher3/folder/Folder.java
+++ b/src/com/android/launcher3/folder/Folder.java
@@ -355,7 +355,7 @@
         // gets saved.
         String newTitle = mFolderName.getText().toString();
         mInfo.setTitle(newTitle);
-        LauncherModel.updateItemInDatabase(mLauncher, mInfo);
+        mLauncher.getModelWriter().updateItemInDatabase(mInfo);
 
         Utilities.sendCustomAccessibilityEvent(
                 this, AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED,
@@ -445,7 +445,7 @@
         // TODO: Remove this, as with multi-page folders, there will never be any overflow
         for (ShortcutInfo item: overflow) {
             mInfo.remove(item, false);
-            LauncherModel.deleteItemFromDatabase(mLauncher, item);
+            mLauncher.getModelWriter().deleteItemFromDatabase(item);
         }
 
         DragLayer.LayoutParams lp = (DragLayer.LayoutParams) getLayoutParams();
@@ -647,7 +647,8 @@
                     mPageIndicator.playEntryAnimation();
 
                     if (updateAnimationFlag) {
-                        mInfo.setOption(FolderInfo.FLAG_MULTI_PAGE_ANIMATION, true, mLauncher);
+                        mInfo.setOption(FolderInfo.FLAG_MULTI_PAGE_ANIMATION, true,
+                                mLauncher.getModelWriter());
                     }
                 }
             });
@@ -973,7 +974,8 @@
         // been refreshed yet.
         if (getItemCount() <= mContent.itemsPerPage()) {
             // Show the animation, next time something is added to the folder.
-            mInfo.setOption(FolderInfo.FLAG_MULTI_PAGE_ANIMATION, false, mLauncher);
+            mInfo.setOption(FolderInfo.FLAG_MULTI_PAGE_ANIMATION, false,
+                    mLauncher.getModelWriter());
         }
 
         if (!isFlingToDelete) {
@@ -1022,7 +1024,7 @@
             items.add(info);
         }
 
-        LauncherModel.moveItemsInDatabase(mLauncher, items, mInfo.id, 0);
+        mLauncher.getModelWriter().moveItemsInDatabase(items, mInfo.id, 0);
     }
 
     public void notifyDrop() {
@@ -1189,8 +1191,8 @@
                                 mInfo.screenId);
                         ShortcutInfo finalItem = mInfo.contents.remove(0);
                         newIcon = mLauncher.createShortcut(cellLayout, finalItem);
-                        LauncherModel.addOrMoveItemInDatabase(mLauncher, finalItem, mInfo.container,
-                                mInfo.screenId, mInfo.cellX, mInfo.cellY);
+                        mLauncher.getModelWriter().addOrMoveItemInDatabase(finalItem,
+                                mInfo.container, mInfo.screenId, mInfo.cellX, mInfo.cellY);
                     }
 
                     // Remove the folder
@@ -1301,8 +1303,8 @@
             currentDragView = mContent.createAndAddViewForRank(si, mEmptyCellRank);
             // Actually move the item in the database if it was an external drag. Call this
             // before creating the view, so that ShortcutInfo is updated appropriately.
-            LauncherModel.addOrMoveItemInDatabase(
-                    mLauncher, si, mInfo.id, 0, si.cellX, si.cellY);
+            mLauncher.getModelWriter().addOrMoveItemInDatabase(
+                    si, mInfo.id, 0, si.cellX, si.cellY);
 
             // We only need to update the locations if it doesn't get handled in #onDropCompleted.
             if (d.dragSource != this) {
@@ -1342,7 +1344,7 @@
 
         if (mContent.getPageCount() > 1) {
             // The animation has already been shown while opening the folder.
-            mInfo.setOption(FolderInfo.FLAG_MULTI_PAGE_ANIMATION, true, mLauncher);
+            mInfo.setOption(FolderInfo.FLAG_MULTI_PAGE_ANIMATION, true, mLauncher.getModelWriter());
         }
 
         if (d.stateAnnouncer != null) {
@@ -1366,8 +1368,8 @@
     public void onAdd(ShortcutInfo item) {
         mContent.createAndAddViewForRank(item, mContent.allocateRankForNewItem());
         mItemsInvalidated = true;
-        LauncherModel.addOrMoveItemInDatabase(
-                mLauncher, item, mInfo.id, 0, item.cellX, item.cellY);
+        mLauncher.getModelWriter().addOrMoveItemInDatabase(
+                item, mInfo.id, 0, item.cellX, item.cellY);
     }
 
     public void onRemove(ShortcutInfo item) {
diff --git a/src/com/android/launcher3/folder/FolderPagedView.java b/src/com/android/launcher3/folder/FolderPagedView.java
index 4a2a735..9dfdfdc 100644
--- a/src/com/android/launcher3/folder/FolderPagedView.java
+++ b/src/com/android/launcher3/folder/FolderPagedView.java
@@ -336,7 +336,7 @@
                     info.cellY = newY;
                     info.rank = rank;
                     if (saveChanges) {
-                        LauncherModel.addOrMoveItemInDatabase(getContext(), info,
+                        mFolder.mLauncher.getModelWriter().addOrMoveItemInDatabase(info,
                                 mFolder.mInfo.id, 0, info.cellX, info.cellY);
                     }
                 }
diff --git a/src/com/android/launcher3/model/AddWorkspaceItemsTask.java b/src/com/android/launcher3/model/AddWorkspaceItemsTask.java
index c97b3b5..9696054 100644
--- a/src/com/android/launcher3/model/AddWorkspaceItemsTask.java
+++ b/src/com/android/launcher3/model/AddWorkspaceItemsTask.java
@@ -95,7 +95,9 @@
                 }
 
                 // Add the shortcut to the db
-                addItemToDatabase(context, itemInfo, screenId, cordinates);
+                getModelWriter().addItemToDatabase(itemInfo,
+                        LauncherSettings.Favorites.CONTAINER_DESKTOP, screenId,
+                        cordinates[0], cordinates[1]);
 
                 // Save the ShortcutInfo for binding in the workspace
                 addedItemsFinal.add(itemInfo);
@@ -129,11 +131,6 @@
         }
     }
 
-    protected void addItemToDatabase(Context context, ItemInfo item, long screenId, int[] pos) {
-        LauncherModel.addItemToDatabase(context, item,
-                LauncherSettings.Favorites.CONTAINER_DESKTOP, screenId, pos[0], pos[1]);
-    }
-
     protected void updateScreens(Context context, ArrayList<Long> workspaceScreens) {
         LauncherModel.updateWorkspaceScreenOrder(context, workspaceScreens);
     }
diff --git a/src/com/android/launcher3/model/GridSizeMigrationTask.java b/src/com/android/launcher3/model/GridSizeMigrationTask.java
index bbc7ae4..e50b912 100644
--- a/src/com/android/launcher3/model/GridSizeMigrationTask.java
+++ b/src/com/android/launcher3/model/GridSizeMigrationTask.java
@@ -27,6 +27,7 @@
 import com.android.launcher3.compat.AppWidgetManagerCompat;
 import com.android.launcher3.compat.PackageInstallerCompat;
 import com.android.launcher3.config.FeatureFlags;
+import com.android.launcher3.logging.FileLog;
 import com.android.launcher3.util.GridOccupancy;
 import com.android.launcher3.util.LongArrayMap;
 
@@ -889,6 +890,23 @@
                 .apply();
     }
 
+    public static void logDeviceProfileIfChanged(InvariantDeviceProfile idp, Context context) {
+        SharedPreferences prefs = Utilities.getPrefs(context);
+        String gridSizeString = getPointString(idp.numColumns, idp.numRows);
+
+        int oldHotseatCount = prefs.getInt(KEY_MIGRATION_SRC_HOTSEAT_COUNT, idp.numHotseatIcons);
+        String oldSize = prefs.getString(KEY_MIGRATION_SRC_WORKSPACE_SIZE, gridSizeString);
+        if (gridSizeString.equals(oldSize) && idp.numHotseatIcons == oldHotseatCount) {
+            // Skip if workspace and hotseat sizes have not changed.
+            return;
+        }
+
+        FileLog.e(TAG, "Grid size changed" + gridSizeString);
+        FileLog.e(TAG, "   oldSize: " + oldSize + "  , hotseat: " + oldHotseatCount);
+        FileLog.e(TAG, "   newSize: " + gridSizeString + "  , hotseat: " + idp.numHotseatIcons);
+        idp.dumpDisplayInfo(context);
+    }
+
     /**
      * Migrates the workspace and hotseat in case their sizes changed.
      * @return false if the migration failed.
@@ -900,7 +918,7 @@
         String gridSizeString = getPointString(idp.numColumns, idp.numRows);
 
         if (gridSizeString.equals(prefs.getString(KEY_MIGRATION_SRC_WORKSPACE_SIZE, "")) &&
-                idp.numHotseatIcons != prefs.getInt(KEY_MIGRATION_SRC_HOTSEAT_COUNT, idp.numHotseatIcons)) {
+                idp.numHotseatIcons == prefs.getInt(KEY_MIGRATION_SRC_HOTSEAT_COUNT, idp.numHotseatIcons)) {
             // Skip if workspace and hotseat sizes have not changed.
             return true;
         }
diff --git a/src/com/android/launcher3/model/ModelWriter.java b/src/com/android/launcher3/model/ModelWriter.java
new file mode 100644
index 0000000..4931dca
--- /dev/null
+++ b/src/com/android/launcher3/model/ModelWriter.java
@@ -0,0 +1,374 @@
+/*
+ * 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.launcher3.model;
+
+import android.content.ContentProviderOperation;
+import android.content.ContentResolver;
+import android.content.ContentValues;
+import android.content.Context;
+import android.net.Uri;
+import android.util.Log;
+
+import com.android.launcher3.FolderInfo;
+import com.android.launcher3.ItemInfo;
+import com.android.launcher3.LauncherAppState;
+import com.android.launcher3.LauncherModel;
+import com.android.launcher3.LauncherProvider;
+import com.android.launcher3.LauncherSettings;
+import com.android.launcher3.LauncherSettings.Favorites;
+import com.android.launcher3.LauncherSettings.Settings;
+import com.android.launcher3.ShortcutInfo;
+import com.android.launcher3.util.ContentWriter;
+import com.android.launcher3.util.ItemInfoMatcher;
+import com.android.launcher3.util.LooperExecuter;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.concurrent.Executor;
+
+/**
+ * Class for handling model updates.
+ */
+public class ModelWriter {
+
+    private static final String TAG = "ModelWriter";
+
+    private final Context mContext;
+    private final BgDataModel mBgDataModel;
+    private final Executor mWorkerExecutor;
+    private final boolean mHasVerticalHotseat;
+
+    public ModelWriter(Context context, BgDataModel dataModel, boolean hasVerticalHotseat) {
+        mContext = context;
+        mBgDataModel = dataModel;
+        mWorkerExecutor = new LooperExecuter(LauncherModel.getWorkerLooper());
+        mHasVerticalHotseat = hasVerticalHotseat;
+    }
+
+    private void updateItemInfoProps(
+            ItemInfo item, long container, long screenId, int cellX, int cellY) {
+        item.container = container;
+        item.cellX = cellX;
+        item.cellY = cellY;
+        // We store hotseat items in canonical form which is this orientation invariant position
+        // in the hotseat
+        if (container == Favorites.CONTAINER_HOTSEAT) {
+            item.screenId = mHasVerticalHotseat
+                    ? LauncherAppState.getIDP(mContext).numHotseatIcons - cellY - 1 : cellX;
+        } else {
+            item.screenId = screenId;
+        }
+    }
+
+    /**
+     * Adds an item to the DB if it was not created previously, or move it to a new
+     * <container, screen, cellX, cellY>
+     */
+    public void addOrMoveItemInDatabase(ItemInfo item,
+            long container, long screenId, int cellX, int cellY) {
+        if (item.container == ItemInfo.NO_ID) {
+            // From all apps
+            addItemToDatabase(item, container, screenId, cellX, cellY);
+        } else {
+            // From somewhere else
+            moveItemInDatabase(item, container, screenId, cellX, cellY);
+        }
+    }
+
+    private void checkItemInfoLocked(long itemId, ItemInfo item, StackTraceElement[] stackTrace) {
+        ItemInfo modelItem = mBgDataModel.itemsIdMap.get(itemId);
+        if (modelItem != null && item != modelItem) {
+            // check all the data is consistent
+            if (modelItem instanceof ShortcutInfo && item instanceof ShortcutInfo) {
+                ShortcutInfo modelShortcut = (ShortcutInfo) modelItem;
+                ShortcutInfo shortcut = (ShortcutInfo) item;
+                if (modelShortcut.title.toString().equals(shortcut.title.toString()) &&
+                        modelShortcut.intent.filterEquals(shortcut.intent) &&
+                        modelShortcut.id == shortcut.id &&
+                        modelShortcut.itemType == shortcut.itemType &&
+                        modelShortcut.container == shortcut.container &&
+                        modelShortcut.screenId == shortcut.screenId &&
+                        modelShortcut.cellX == shortcut.cellX &&
+                        modelShortcut.cellY == shortcut.cellY &&
+                        modelShortcut.spanX == shortcut.spanX &&
+                        modelShortcut.spanY == shortcut.spanY) {
+                    // For all intents and purposes, this is the same object
+                    return;
+                }
+            }
+
+            // the modelItem needs to match up perfectly with item if our model is
+            // to be consistent with the database-- for now, just require
+            // modelItem == item or the equality check above
+            String msg = "item: " + ((item != null) ? item.toString() : "null") +
+                    "modelItem: " +
+                    ((modelItem != null) ? modelItem.toString() : "null") +
+                    "Error: ItemInfo passed to checkItemInfo doesn't match original";
+            RuntimeException e = new RuntimeException(msg);
+            if (stackTrace != null) {
+                e.setStackTrace(stackTrace);
+            }
+            throw e;
+        }
+    }
+
+    /**
+     * Move an item in the DB to a new <container, screen, cellX, cellY>
+     */
+    public void moveItemInDatabase(final ItemInfo item,
+            long container, long screenId, int cellX, int cellY) {
+        updateItemInfoProps(item, container, screenId, cellX, cellY);
+
+        final ContentWriter writer = new ContentWriter(mContext)
+                .put(Favorites.CONTAINER, item.container)
+                .put(Favorites.CELLX, item.cellX)
+                .put(Favorites.CELLY, item.cellY)
+                .put(Favorites.RANK, item.rank)
+                .put(Favorites.SCREEN, item.screenId);
+
+        mWorkerExecutor.execute(new UpdateItemRunnable(item, writer));
+    }
+
+    /**
+     * Move items in the DB to a new <container, screen, cellX, cellY>. We assume that the
+     * cellX, cellY have already been updated on the ItemInfos.
+     */
+    public void moveItemsInDatabase(final ArrayList<ItemInfo> items, long container, int screen) {
+        ArrayList<ContentValues> contentValues = new ArrayList<>();
+        int count = items.size();
+
+        for (int i = 0; i < count; i++) {
+            ItemInfo item = items.get(i);
+            updateItemInfoProps(item, container, screen, item.cellX, item.cellY);
+
+            final ContentValues values = new ContentValues();
+            values.put(Favorites.CONTAINER, item.container);
+            values.put(Favorites.CELLX, item.cellX);
+            values.put(Favorites.CELLY, item.cellY);
+            values.put(Favorites.RANK, item.rank);
+            values.put(Favorites.SCREEN, item.screenId);
+
+            contentValues.add(values);
+        }
+        mWorkerExecutor.execute(new UpdateItemsRunnable(items, contentValues));
+    }
+
+    /**
+     * Move and/or resize item in the DB to a new <container, screen, cellX, cellY, spanX, spanY>
+     */
+    public void modifyItemInDatabase(final ItemInfo item,
+            long container, long screenId, int cellX, int cellY, int spanX, int spanY) {
+        updateItemInfoProps(item, container, screenId, cellX, cellY);
+        item.spanX = spanX;
+        item.spanY = spanY;
+
+        final ContentWriter writer = new ContentWriter(mContext)
+                .put(Favorites.CONTAINER, item.container)
+                .put(Favorites.CELLX, item.cellX)
+                .put(Favorites.CELLY, item.cellY)
+                .put(Favorites.RANK, item.rank)
+                .put(Favorites.SPANX, item.spanX)
+                .put(Favorites.SPANY, item.spanY)
+                .put(Favorites.SCREEN, item.screenId);
+
+        mWorkerExecutor.execute(new UpdateItemRunnable(item, writer));
+    }
+
+    /**
+     * Update an item to the database in a specified container.
+     */
+    public void updateItemInDatabase(ItemInfo item) {
+        ContentWriter writer = new ContentWriter(mContext);
+        item.onAddToDatabase(writer);
+        mWorkerExecutor.execute(new UpdateItemRunnable(item, writer));
+    }
+
+    /**
+     * Add an item to the database in a specified container. Sets the container, screen, cellX and
+     * cellY fields of the item. Also assigns an ID to the item.
+     */
+    public void addItemToDatabase(final ItemInfo item,
+            long container, long screenId, int cellX, int cellY) {
+        updateItemInfoProps(item, container, screenId, cellX, cellY);
+
+        final ContentWriter writer = new ContentWriter(mContext);
+        final ContentResolver cr = mContext.getContentResolver();
+        item.onAddToDatabase(writer);
+
+        item.id = Settings.call(cr, Settings.METHOD_NEW_ITEM_ID).getLong(Settings.EXTRA_VALUE);
+        writer.put(Favorites._ID, item.id);
+
+        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
+        mWorkerExecutor.execute(new Runnable() {
+            public void run() {
+                cr.insert(Favorites.CONTENT_URI, writer.getValues(mContext));
+
+                synchronized (mBgDataModel) {
+                    checkItemInfoLocked(item.id, item, stackTrace);
+                    mBgDataModel.addItem(mContext, item, true);
+                }
+            }
+        });
+    }
+
+    /**
+     * Removes the specified item from the database
+     */
+    public void deleteItemFromDatabase(ItemInfo item) {
+        deleteItemsFromDatabase(Arrays.asList(item));
+    }
+
+    /**
+     * Removes all the items from the database matching {@param matcher}.
+     */
+    public void deleteItemsFromDatabase(ItemInfoMatcher matcher) {
+        deleteItemsFromDatabase(matcher.filterItemInfos(mBgDataModel.itemsIdMap));
+    }
+
+    /**
+     * Removes the specified items from the database
+     */
+    public void deleteItemsFromDatabase(final Iterable<? extends ItemInfo> items) {
+        mWorkerExecutor.execute(new Runnable() {
+            public void run() {
+                for (ItemInfo item : items) {
+                    final Uri uri = Favorites.getContentUri(item.id);
+                    mContext.getContentResolver().delete(uri, null, null);
+
+                    mBgDataModel.removeItem(mContext, item);
+                }
+            }
+        });
+    }
+
+    /**
+     * Remove the specified folder and all its contents from the database.
+     */
+    public void deleteFolderAndContentsFromDatabase(final FolderInfo info) {
+        mWorkerExecutor.execute(new Runnable() {
+            public void run() {
+                ContentResolver cr = mContext.getContentResolver();
+                cr.delete(LauncherSettings.Favorites.CONTENT_URI,
+                        LauncherSettings.Favorites.CONTAINER + "=" + info.id, null);
+                mBgDataModel.removeItem(mContext, info.contents);
+                info.contents.clear();
+
+                cr.delete(LauncherSettings.Favorites.getContentUri(info.id), null, null);
+                mBgDataModel.removeItem(mContext, info);
+            }
+        });
+    }
+
+    private class UpdateItemRunnable extends UpdateItemBaseRunnable {
+        private final ItemInfo mItem;
+        private final ContentWriter mWriter;
+        private final long mItemId;
+
+        UpdateItemRunnable(ItemInfo item, ContentWriter writer) {
+            mItem = item;
+            mWriter = writer;
+            mItemId = item.id;
+        }
+
+        @Override
+        public void run() {
+            Uri uri = Favorites.getContentUri(mItemId);
+            mContext.getContentResolver().update(uri, mWriter.getValues(mContext), null, null);
+            updateItemArrays(mItem, mItemId);
+        }
+    }
+
+    private class UpdateItemsRunnable extends UpdateItemBaseRunnable {
+        private final ArrayList<ContentValues> mValues;
+        private final ArrayList<ItemInfo> mItems;
+
+        UpdateItemsRunnable(ArrayList<ItemInfo> items, ArrayList<ContentValues> values) {
+            mValues = values;
+            mItems = items;
+        }
+
+        @Override
+        public void run() {
+            ArrayList<ContentProviderOperation> ops = new ArrayList<>();
+            int count = mItems.size();
+            for (int i = 0; i < count; i++) {
+                ItemInfo item = mItems.get(i);
+                final long itemId = item.id;
+                final Uri uri = Favorites.getContentUri(itemId);
+                ContentValues values = mValues.get(i);
+
+                ops.add(ContentProviderOperation.newUpdate(uri).withValues(values).build());
+                updateItemArrays(item, itemId);
+            }
+            try {
+                mContext.getContentResolver().applyBatch(LauncherProvider.AUTHORITY, ops);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    private abstract class UpdateItemBaseRunnable implements Runnable {
+        private final StackTraceElement[] mStackTrace;
+
+        UpdateItemBaseRunnable() {
+            mStackTrace = new Throwable().getStackTrace();
+        }
+
+        protected void updateItemArrays(ItemInfo item, long itemId) {
+            // Lock on mBgLock *after* the db operation
+            synchronized (mBgDataModel) {
+                checkItemInfoLocked(itemId, item, mStackTrace);
+
+                if (item.container != Favorites.CONTAINER_DESKTOP &&
+                        item.container != Favorites.CONTAINER_HOTSEAT) {
+                    // Item is in a folder, make sure this folder exists
+                    if (!mBgDataModel.folders.containsKey(item.container)) {
+                        // An items container is being set to a that of an item which is not in
+                        // the list of Folders.
+                        String msg = "item: " + item + " container being set to: " +
+                                item.container + ", not in the list of folders";
+                        Log.e(TAG, msg);
+                    }
+                }
+
+                // Items are added/removed from the corresponding FolderInfo elsewhere, such
+                // as in Workspace.onDrop. Here, we just add/remove them from the list of items
+                // that are on the desktop, as appropriate
+                ItemInfo modelItem = mBgDataModel.itemsIdMap.get(itemId);
+                if (modelItem != null &&
+                        (modelItem.container == Favorites.CONTAINER_DESKTOP ||
+                                modelItem.container == Favorites.CONTAINER_HOTSEAT)) {
+                    switch (modelItem.itemType) {
+                        case Favorites.ITEM_TYPE_APPLICATION:
+                        case Favorites.ITEM_TYPE_SHORTCUT:
+                        case Favorites.ITEM_TYPE_DEEP_SHORTCUT:
+                        case Favorites.ITEM_TYPE_FOLDER:
+                            if (!mBgDataModel.workspaceItems.contains(modelItem)) {
+                                mBgDataModel.workspaceItems.add(modelItem);
+                            }
+                            break;
+                        default:
+                            break;
+                    }
+                } else {
+                    mBgDataModel.workspaceItems.remove(modelItem);
+                }
+            }
+        }
+    }
+}
diff --git a/src/com/android/launcher3/model/PackageUpdatedTask.java b/src/com/android/launcher3/model/PackageUpdatedTask.java
index 211b979..ee7186a 100644
--- a/src/com/android/launcher3/model/PackageUpdatedTask.java
+++ b/src/com/android/launcher3/model/PackageUpdatedTask.java
@@ -270,7 +270,7 @@
                             updatedShortcuts.add(si);
                         }
                         if (infoUpdated) {
-                            LauncherModel.updateItemInDatabase(context, si);
+                            getModelWriter().updateItemInDatabase(si);
                         }
                     } else if (info instanceof LauncherAppWidgetInfo && mOp == OP_ADD) {
                         LauncherAppWidgetInfo widgetInfo = (LauncherAppWidgetInfo) info;
@@ -287,7 +287,7 @@
                             widgetInfo.restoreStatus |= LauncherAppWidgetInfo.FLAG_UI_NOT_READY;
 
                             widgets.add(widgetInfo);
-                            LauncherModel.updateItemInDatabase(context, widgetInfo);
+                            getModelWriter().updateItemInDatabase(widgetInfo);
                         }
                     }
                 }
@@ -295,7 +295,7 @@
 
             bindUpdatedShortcuts(updatedShortcuts, removedShortcuts, mUser);
             if (!removedShortcuts.isEmpty()) {
-                LauncherModel.deleteItemsFromDatabase(context, removedShortcuts);
+                getModelWriter().deleteItemsFromDatabase(removedShortcuts);
             }
 
             if (!widgets.isEmpty()) {
@@ -332,10 +332,10 @@
         }
 
         if (!removedPackages.isEmpty() || !removedComponents.isEmpty()) {
-            LauncherModel.deleteItemsFromDatabase(
-                    context, ItemInfoMatcher.ofPackages(removedPackages, mUser));
-            LauncherModel.deleteItemsFromDatabase(
-                    context, ItemInfoMatcher.ofComponents(removedComponents, mUser));
+            getModelWriter().deleteItemsFromDatabase(
+                    ItemInfoMatcher.ofPackages(removedPackages, mUser));
+            getModelWriter().deleteItemsFromDatabase(
+                    ItemInfoMatcher.ofComponents(removedComponents, mUser));
 
             // Remove any queued items from the install queue
             InstallShortcutReceiver.removeFromInstallQueue(context, removedPackages, mUser);
diff --git a/src/com/android/launcher3/model/ShortcutsChangedTask.java b/src/com/android/launcher3/model/ShortcutsChangedTask.java
index ba7112f..d8a429c 100644
--- a/src/com/android/launcher3/model/ShortcutsChangedTask.java
+++ b/src/com/android/launcher3/model/ShortcutsChangedTask.java
@@ -104,7 +104,7 @@
 
         bindUpdatedShortcuts(updatedShortcutInfos, removedShortcutInfos, mUser);
         if (!removedShortcutInfos.isEmpty()) {
-            LauncherModel.deleteItemsFromDatabase(context, removedShortcutInfos);
+            getModelWriter().deleteItemsFromDatabase(removedShortcutInfos);
         }
 
         if (mUpdateIdMap) {
diff --git a/src/com/android/launcher3/model/UserLockStateChangedTask.java b/src/com/android/launcher3/model/UserLockStateChangedTask.java
index 25f2f9d..363f1ee 100644
--- a/src/com/android/launcher3/model/UserLockStateChangedTask.java
+++ b/src/com/android/launcher3/model/UserLockStateChangedTask.java
@@ -95,7 +95,7 @@
         }
         bindUpdatedShortcuts(updatedShortcutInfos, deletedShortcutInfos, mUser);
         if (!deletedShortcutInfos.isEmpty()) {
-            LauncherModel.deleteItemsFromDatabase(context, deletedShortcutInfos);
+            getModelWriter().deleteItemsFromDatabase(deletedShortcutInfos);
         }
 
         // Remove shortcut id map for that user
diff --git a/src/com/android/launcher3/notification/NotificationFooterLayout.java b/src/com/android/launcher3/notification/NotificationFooterLayout.java
index 58789f6..57ec5d1 100644
--- a/src/com/android/launcher3/notification/NotificationFooterLayout.java
+++ b/src/com/android/launcher3/notification/NotificationFooterLayout.java
@@ -19,6 +19,7 @@
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
+import android.animation.ObjectAnimator;
 import android.content.Context;
 import android.content.res.ColorStateList;
 import android.graphics.Rect;
@@ -30,8 +31,8 @@
 
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherAnimUtils;
-import com.android.launcher3.LauncherViewPropertyAnimator;
 import com.android.launcher3.R;
+import com.android.launcher3.anim.PropertyListBuilder;
 import com.android.launcher3.graphics.IconPalette;
 import com.android.launcher3.popup.PopupContainerWithArrow;
 
@@ -154,10 +155,9 @@
         Rect fromBounds = sTempRect;
         firstNotification.getGlobalVisibleRect(fromBounds);
         float scale = (float) toBounds.height() / fromBounds.height();
-        Animator moveAndScaleIcon = new LauncherViewPropertyAnimator(firstNotification)
-                .translationY(toBounds.top - fromBounds.top
-                        + (fromBounds.height() * scale - fromBounds.height()) / 2)
-                .scaleX(scale).scaleY(scale);
+        Animator moveAndScaleIcon = LauncherAnimUtils.ofPropertyValuesHolder(firstNotification,
+                new PropertyListBuilder().scale(scale).translationY(toBounds.top - fromBounds.top
+                        + (fromBounds.height() * scale - fromBounds.height()) / 2).build());
         moveAndScaleIcon.addListener(new AnimatorListenerAdapter() {
             @Override
             public void onAnimationEnd(Animator animation) {
@@ -172,7 +172,7 @@
                 - (mOverflowNotifications.isEmpty() ? 0 : 1);
         for (int i = 1; i < numIcons; i++) {
             final View child = mIconRow.getChildAt(i);
-            Animator shiftChild = new LauncherViewPropertyAnimator(child).translationX(-gapWidth);
+            Animator shiftChild = ObjectAnimator.ofFloat(child, TRANSLATION_X, -gapWidth);
             shiftChild.addListener(new AnimatorListenerAdapter() {
                 @Override
                 public void onAnimationEnd(Animator animation) {
diff --git a/src/com/android/launcher3/notification/NotificationItemView.java b/src/com/android/launcher3/notification/NotificationItemView.java
index 639447d..c9b3940 100644
--- a/src/com/android/launcher3/notification/NotificationItemView.java
+++ b/src/com/android/launcher3/notification/NotificationItemView.java
@@ -83,12 +83,20 @@
 
     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
+        if (mMainView.getNotificationInfo() == null) {
+            // The notification hasn't been populated yet.
+            return false;
+        }
         getParent().requestDisallowInterceptTouchEvent(true);
         return mSwipeHelper.onInterceptTouchEvent(ev);
     }
 
     @Override
     public boolean onTouchEvent(MotionEvent ev) {
+        if (mMainView.getNotificationInfo() == null) {
+            // The notification hasn't been populated yet.
+            return false;
+        }
         return mSwipeHelper.onTouchEvent(ev) || super.onTouchEvent(ev);
     }
 
diff --git a/src/com/android/launcher3/notification/NotificationListener.java b/src/com/android/launcher3/notification/NotificationListener.java
index 206bb31..5c16176 100644
--- a/src/com/android/launcher3/notification/NotificationListener.java
+++ b/src/com/android/launcher3/notification/NotificationListener.java
@@ -80,9 +80,9 @@
             switch (message.what) {
                 case MSG_NOTIFICATION_POSTED:
                     if (sNotificationsChangedListener != null) {
-                        Pair<PackageUserKey, String> pair
-                                = (Pair<PackageUserKey, String>) message.obj;
-                        sNotificationsChangedListener.onNotificationPosted(pair.first, pair.second);
+                        NotificationPostedMsg msg = (NotificationPostedMsg) message.obj;
+                        sNotificationsChangedListener.onNotificationPosted(msg.packageUserKey,
+                                msg.notificationKey, msg.shouldBeFilteredOut);
                     }
                     break;
                 case MSG_NOTIFICATION_REMOVED:
@@ -149,23 +149,32 @@
     @Override
     public void onNotificationPosted(final StatusBarNotification sbn) {
         super.onNotificationPosted(sbn);
-        if (!shouldBeFilteredOut(sbn.getNotification())) {
-            Pair<PackageUserKey, String> packageUserKeyAndNotificationKey
-                    = new Pair<>(PackageUserKey.fromNotification(sbn), sbn.getKey());
-            mWorkerHandler.obtainMessage(MSG_NOTIFICATION_POSTED, packageUserKeyAndNotificationKey)
-                    .sendToTarget();
+        mWorkerHandler.obtainMessage(MSG_NOTIFICATION_POSTED, new NotificationPostedMsg(sbn))
+                .sendToTarget();
+    }
+
+    /**
+     * An object containing data to send to MSG_NOTIFICATION_POSTED targets.
+     */
+    private class NotificationPostedMsg {
+        PackageUserKey packageUserKey;
+        String notificationKey;
+        boolean shouldBeFilteredOut;
+
+        NotificationPostedMsg(StatusBarNotification sbn) {
+            packageUserKey = PackageUserKey.fromNotification(sbn);
+            notificationKey = sbn.getKey();
+            shouldBeFilteredOut = shouldBeFilteredOut(sbn.getNotification());
         }
     }
 
     @Override
     public void onNotificationRemoved(final StatusBarNotification sbn) {
         super.onNotificationRemoved(sbn);
-        if (!shouldBeFilteredOut(sbn.getNotification())) {
-            Pair<PackageUserKey, String> packageUserKeyAndNotificationKey
-                    = new Pair<>(PackageUserKey.fromNotification(sbn), sbn.getKey());
-            mWorkerHandler.obtainMessage(MSG_NOTIFICATION_REMOVED, packageUserKeyAndNotificationKey)
-                    .sendToTarget();
-        }
+        Pair<PackageUserKey, String> packageUserKeyAndNotificationKey
+                = new Pair<>(PackageUserKey.fromNotification(sbn), sbn.getKey());
+        mWorkerHandler.obtainMessage(MSG_NOTIFICATION_REMOVED, packageUserKeyAndNotificationKey)
+                .sendToTarget();
     }
 
     /** This makes a potentially expensive binder call and should be run on a background thread. */
@@ -206,7 +215,8 @@
     }
 
     public interface NotificationsChangedListener {
-        void onNotificationPosted(PackageUserKey postedPackageUserKey, String notificationKey);
+        void onNotificationPosted(PackageUserKey postedPackageUserKey, String notificationKey,
+                boolean shouldBeFilteredOut);
         void onNotificationRemoved(PackageUserKey removedPackageUserKey, String notificationKey);
         void onNotificationFullRefresh(List<StatusBarNotification> activeNotifications);
     }
diff --git a/src/com/android/launcher3/notification/NotificationMainView.java b/src/com/android/launcher3/notification/NotificationMainView.java
index 6677c2f..b342525 100644
--- a/src/com/android/launcher3/notification/NotificationMainView.java
+++ b/src/com/android/launcher3/notification/NotificationMainView.java
@@ -18,8 +18,11 @@
 
 import android.animation.Animator;
 import android.animation.AnimatorSet;
+import android.animation.ArgbEvaluator;
+import android.animation.ObjectAnimator;
 import android.animation.ValueAnimator;
 import android.content.Context;
+import android.graphics.drawable.ColorDrawable;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.View;
@@ -29,7 +32,6 @@
 import com.android.launcher3.ItemInfo;
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherAnimUtils;
-import com.android.launcher3.LauncherViewPropertyAnimator;
 import com.android.launcher3.R;
 import com.android.launcher3.graphics.IconPalette;
 import com.android.launcher3.userevent.nano.LauncherLogProto;
@@ -39,10 +41,13 @@
  */
 public class NotificationMainView extends LinearLayout implements SwipeHelper.Callback {
 
+    private final ArgbEvaluator mArgbEvaluator = new ArgbEvaluator();
+
     private NotificationInfo mNotificationInfo;
     private TextView mTitleView;
     private TextView mTextView;
     private IconPalette mIconPalette;
+    private ColorDrawable mColorBackground;
 
     public NotificationMainView(Context context) {
         this(context, null, 0);
@@ -65,7 +70,8 @@
     }
 
     public void applyColors(IconPalette iconPalette) {
-        setBackgroundColor(iconPalette.backgroundColor);
+        mColorBackground = new ColorDrawable(iconPalette.backgroundColor);
+        setBackground(mColorBackground);
         mIconPalette = iconPalette;
     }
 
@@ -81,7 +87,7 @@
         if (animate) {
             mTitleView.setAlpha(0);
             mTextView.setAlpha(0);
-            setBackgroundColor(mIconPalette.secondaryColor);
+            mColorBackground.setColor(mIconPalette.secondaryColor);
         }
         mNotificationInfo = mainNotification;
         mTitleView.setText(mNotificationInfo.title);
@@ -95,16 +101,10 @@
         setTag(new ItemInfo());
         if (animate) {
             AnimatorSet animation = LauncherAnimUtils.createAnimatorSet();
-            Animator textFade = new LauncherViewPropertyAnimator(mTextView).alpha(1);
-            Animator titleFade = new LauncherViewPropertyAnimator(mTitleView).alpha(1);
-            ValueAnimator colorChange = ValueAnimator.ofArgb(mIconPalette.secondaryColor,
-                    mIconPalette.backgroundColor);
-            colorChange.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
-                @Override
-                public void onAnimationUpdate(ValueAnimator valueAnimator) {
-                    setBackgroundColor((Integer) valueAnimator.getAnimatedValue());
-                }
-            });
+            Animator textFade = ObjectAnimator.ofFloat(mTextView, View.ALPHA, 1);
+            Animator titleFade = ObjectAnimator.ofFloat(mTitleView, View.ALPHA, 1);
+            ValueAnimator colorChange = ObjectAnimator.ofObject(mColorBackground, "color",
+                    mArgbEvaluator, mIconPalette.secondaryColor, mIconPalette.backgroundColor);
             animation.playTogether(textFade, titleFade, colorChange);
             animation.setDuration(150);
             animation.start();
diff --git a/src/com/android/launcher3/popup/PopupContainerWithArrow.java b/src/com/android/launcher3/popup/PopupContainerWithArrow.java
index 7fda8b5..d34727c 100644
--- a/src/com/android/launcher3/popup/PopupContainerWithArrow.java
+++ b/src/com/android/launcher3/popup/PopupContainerWithArrow.java
@@ -19,6 +19,7 @@
 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
+import android.animation.ObjectAnimator;
 import android.animation.TimeInterpolator;
 import android.animation.ValueAnimator;
 import android.annotation.SuppressLint;
@@ -53,12 +54,12 @@
 import com.android.launcher3.LauncherAnimUtils;
 import com.android.launcher3.LauncherModel;
 import com.android.launcher3.LauncherSettings;
-import com.android.launcher3.LauncherViewPropertyAnimator;
 import com.android.launcher3.LogAccelerateInterpolator;
 import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.accessibility.LauncherAccessibilityDelegate;
 import com.android.launcher3.accessibility.ShortcutMenuAccessibilityDelegate;
+import com.android.launcher3.anim.PropertyListBuilder;
 import com.android.launcher3.badge.BadgeInfo;
 import com.android.launcher3.dragndrop.DragController;
 import com.android.launcher3.dragndrop.DragLayer;
@@ -298,7 +299,7 @@
             anim.setInterpolator(interpolator);
             shortcutAnims.play(anim);
 
-            Animator fadeAnim = new LauncherViewPropertyAnimator(popupItemView).alpha(1);
+            Animator fadeAnim = ObjectAnimator.ofFloat(popupItemView, View.ALPHA, 1);
             fadeAnim.setInterpolator(fadeInterpolator);
             // We want the shortcut to be fully opaque before the arrow starts animating.
             fadeAnim.setDuration(arrowScaleDelay);
@@ -318,9 +319,8 @@
         // Animate the arrow
         mArrow.setScaleX(0);
         mArrow.setScaleY(0);
-        Animator arrowScale = new LauncherViewPropertyAnimator(mArrow).scaleX(1).scaleY(1);
+        Animator arrowScale = createArrowScaleAnim(1).setDuration(arrowScaleDuration);
         arrowScale.setStartDelay(arrowScaleDelay);
-        arrowScale.setDuration(arrowScaleDuration);
         shortcutAnims.play(arrowScale);
 
         mOpenCloseAnimator = shortcutAnims;
@@ -603,7 +603,7 @@
                 removeNotification.play(removeMargin);
             }
             removeNotification.play(reduceHeight);
-            Animator fade = new LauncherViewPropertyAnimator(notificationView).alpha(0)
+            Animator fade = ObjectAnimator.ofFloat(notificationView, ALPHA, 0)
                     .setDuration(duration);
             fade.addListener(new AnimatorListenerAdapter() {
                 @Override
@@ -620,11 +620,9 @@
             removeNotification.play(fade);
             final long arrowScaleDuration = getResources().getInteger(
                     R.integer.config_deepShortcutArrowOpenDuration);
-            Animator hideArrow = new LauncherViewPropertyAnimator(mArrow)
-                    .scaleX(0).scaleY(0).setDuration(arrowScaleDuration);
+            Animator hideArrow = createArrowScaleAnim(0).setDuration(arrowScaleDuration);
             hideArrow.setStartDelay(0);
-            Animator showArrow = new LauncherViewPropertyAnimator(mArrow)
-                    .scaleX(1).scaleY(1).setDuration(arrowScaleDuration);
+            Animator showArrow = createArrowScaleAnim(1).setDuration(arrowScaleDuration);
             showArrow.setStartDelay((long) (duration - arrowScaleDuration * 1.5));
             removeNotification.playSequentially(hideArrow, showArrow);
             removeNotification.start();
@@ -633,6 +631,10 @@
         notificationView.trimNotifications(badgeInfo.getNotificationKeys());
     }
 
+    private ObjectAnimator createArrowScaleAnim(float scale) {
+        return LauncherAnimUtils.ofPropertyValuesHolder(
+                mArrow, new PropertyListBuilder().scale(scale).build());
+    }
     /**
      * Animates the translationY of this container if it is open above the icon.
      * If it is below the icon, the container already shifts up when the height
@@ -640,8 +642,8 @@
      */
     public @Nullable Animator animateTranslationYBy(int translationY, int duration) {
         if (mIsAboveIcon) {
-            return new LauncherViewPropertyAnimator(this)
-                    .translationY(getTranslationY() + translationY).setDuration(duration);
+            return ObjectAnimator.ofFloat(this, TRANSLATION_Y, getTranslationY() + translationY)
+                    .setDuration(duration);
         }
         return null;
     }
@@ -744,7 +746,7 @@
                         : numOpenShortcuts - i - 1;
                 anim.setStartDelay(stagger * animationIndex);
 
-                Animator fadeAnim = new LauncherViewPropertyAnimator(view).alpha(0);
+                Animator fadeAnim = ObjectAnimator.ofFloat(view, View.ALPHA, 0);
                 // Don't start fading until the arrow is gone.
                 fadeAnim.setStartDelay(stagger * animationIndex + arrowScaleDuration);
                 fadeAnim.setDuration(duration - arrowScaleDuration);
@@ -761,12 +763,13 @@
                 view.setPivotY(iconCenter.y);
 
                 float scale = ((float) mLauncher.getDeviceProfile().iconSizePx) / view.getHeight();
-                LauncherViewPropertyAnimator anim2 = new LauncherViewPropertyAnimator(view)
-                        .scaleX(scale)
-                        .scaleY(scale)
-                        .translationX(mIconShift.x)
-                        .translationY(mIconShift.y);
-                anim2.setDuration(DragView.VIEW_ZOOM_DURATION);
+                Animator anim2 = LauncherAnimUtils.ofPropertyValuesHolder(view,
+                        new PropertyListBuilder()
+                                .scale(scale)
+                                .translationX(mIconShift.x)
+                                .translationY(mIconShift.y)
+                                .build())
+                        .setDuration(DragView.VIEW_ZOOM_DURATION);
                 shortcutAnims.play(anim2);
             }
             anim.addListener(new AnimatorListenerAdapter() {
@@ -777,8 +780,7 @@
             });
             shortcutAnims.play(anim);
         }
-        Animator arrowAnim = new LauncherViewPropertyAnimator(mArrow)
-                .scaleX(0).scaleY(0).setDuration(arrowScaleDuration);
+        Animator arrowAnim = createArrowScaleAnim(0).setDuration(arrowScaleDuration);
         arrowAnim.setStartDelay(0);
         shortcutAnims.play(arrowAnim);
 
diff --git a/src/com/android/launcher3/popup/PopupDataProvider.java b/src/com/android/launcher3/popup/PopupDataProvider.java
index c754fda..e314b64 100644
--- a/src/com/android/launcher3/popup/PopupDataProvider.java
+++ b/src/com/android/launcher3/popup/PopupDataProvider.java
@@ -58,19 +58,26 @@
     }
 
     @Override
-    public void onNotificationPosted(PackageUserKey postedPackageUserKey, String notificationKey) {
+    public void onNotificationPosted(PackageUserKey postedPackageUserKey, String notificationKey,
+            boolean shouldBeFilteredOut) {
         BadgeInfo badgeInfo = mPackageUserToBadgeInfos.get(postedPackageUserKey);
-        boolean notificationWasAdded; // As opposed to updated.
+        boolean notificationWasAddedOrRemoved; // As opposed to updated.
         if (badgeInfo == null) {
-            BadgeInfo newBadgeInfo = new BadgeInfo(postedPackageUserKey);
-            newBadgeInfo.addNotificationKeyIfNotExists(notificationKey);
-            mPackageUserToBadgeInfos.put(postedPackageUserKey, newBadgeInfo);
-            notificationWasAdded = true;
+            if (!shouldBeFilteredOut) {
+                BadgeInfo newBadgeInfo = new BadgeInfo(postedPackageUserKey);
+                newBadgeInfo.addNotificationKeyIfNotExists(notificationKey);
+                mPackageUserToBadgeInfos.put(postedPackageUserKey, newBadgeInfo);
+                notificationWasAddedOrRemoved = true;
+            } else {
+                notificationWasAddedOrRemoved = false;
+            }
         } else {
-            notificationWasAdded = badgeInfo.addNotificationKeyIfNotExists(notificationKey);
+            notificationWasAddedOrRemoved = shouldBeFilteredOut
+                    ? badgeInfo.removeNotificationKey(notificationKey)
+                    : badgeInfo.addNotificationKeyIfNotExists(notificationKey);
         }
         updateLauncherIconBadges(Utilities.singletonHashSet(postedPackageUserKey),
-                notificationWasAdded);
+                notificationWasAddedOrRemoved);
     }
 
     @Override
diff --git a/src/com/android/launcher3/util/ManagedProfileHeuristic.java b/src/com/android/launcher3/util/ManagedProfileHeuristic.java
index af61554..577d19f 100644
--- a/src/com/android/launcher3/util/ManagedProfileHeuristic.java
+++ b/src/com/android/launcher3/util/ManagedProfileHeuristic.java
@@ -203,7 +203,7 @@
             long workFolderId, int startingRank, ArrayList<ShortcutInfo> workFolderApps) {
         for (ItemInfo info : workFolderApps) {
             info.rank = startingRank++;
-            LauncherModel.addItemToDatabase(mContext, info, workFolderId, 0, 0, 0);
+            mModel.getWriter(false).addItemToDatabase(info, workFolderId, 0, 0, 0);
         }
     }
 
diff --git a/src/com/android/launcher3/widget/PendingItemDragHelper.java b/src/com/android/launcher3/widget/PendingItemDragHelper.java
index c723f9e..6f4c286 100644
--- a/src/com/android/launcher3/widget/PendingItemDragHelper.java
+++ b/src/com/android/launcher3/widget/PendingItemDragHelper.java
@@ -29,6 +29,7 @@
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.PendingAddItemInfo;
+import com.android.launcher3.R;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.dragndrop.DragOptions;
 import com.android.launcher3.graphics.DragPreviewProvider;
@@ -112,6 +113,11 @@
             DeviceProfile dp = launcher.getDeviceProfile();
             int iconSize = dp.iconSizePx;
 
+            int padding = launcher.getResources()
+                    .getDimensionPixelSize(R.dimen.widget_preview_shortcut_padding);
+            previewBounds.left += padding;
+            previewBounds.top += padding;
+
             dragRegion = new Rect();
             dragRegion.left = (size[0] - iconSize) / 2;
             dragRegion.right = dragRegion.left + iconSize;
diff --git a/src/com/android/launcher3/widget/WidgetImageView.java b/src/com/android/launcher3/widget/WidgetImageView.java
index 1211c08..df2bcff 100644
--- a/src/com/android/launcher3/widget/WidgetImageView.java
+++ b/src/com/android/launcher3/widget/WidgetImageView.java
@@ -89,16 +89,25 @@
     }
 
     private void updateDstRectF() {
-        if (mBitmap.getWidth() > getWidth()) {
-            float scale = ((float) getWidth()) / mBitmap.getWidth();
-            mDstRectF.set(0, 0, getWidth(), scale * mBitmap.getHeight());
+        float myWidth = getWidth();
+        float myHeight = getHeight();
+        float bitmapWidth = mBitmap.getWidth();
+
+        final float scale = bitmapWidth > myWidth ? myWidth / bitmapWidth : 1;
+        float scaledWidth = bitmapWidth * scale;
+        float scaledHeight = mBitmap.getHeight() * scale;
+
+        mDstRectF.left = (myWidth - scaledWidth) / 2;
+        mDstRectF.right = (myWidth + scaledWidth) / 2;
+
+        if (scaledHeight > myHeight) {
+            mDstRectF.top = 0;
+            mDstRectF.bottom = scaledHeight;
         } else {
-            mDstRectF.set(
-                    (getWidth() - mBitmap.getWidth()) * 0.5f,
-                    0,
-                    (getWidth() + mBitmap.getWidth()) * 0.5f,
-                    mBitmap.getHeight());
+            mDstRectF.top = (myHeight - scaledHeight) / 2;
+            mDstRectF.bottom = (myHeight + scaledHeight) / 2;
         }
+
         if (mBadge != null) {
             Rect bounds = mBadge.getBounds();
             int left = Utilities.boundToRange(
diff --git a/tests/AndroidManifest-common.xml b/tests/AndroidManifest-common.xml
index 763481a..24882aa 100644
--- a/tests/AndroidManifest-common.xml
+++ b/tests/AndroidManifest-common.xml
@@ -18,6 +18,8 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.launcher3.tests">
 
+    <uses-sdk android:targetSdkVersion="25" android:minSdkVersion="21"/>
+
     <application android:debuggable="true">
         <uses-library android:name="android.test.runner" />
 
diff --git a/tests/AndroidManifest.xml b/tests/AndroidManifest.xml
index afe8952..43030ae 100644
--- a/tests/AndroidManifest.xml
+++ b/tests/AndroidManifest.xml
@@ -18,6 +18,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     package="com.android.launcher3.tests">
 
+    <uses-sdk android:targetSdkVersion="25" android:minSdkVersion="21"/>
     <uses-sdk tools:overrideLibrary="android.support.test.uiautomator.v18"/>
 
     <application android:debuggable="true">
diff --git a/tests/src/com/android/launcher3/model/AddWorkspaceItemsTaskTest.java b/tests/src/com/android/launcher3/model/AddWorkspaceItemsTaskTest.java
index 2071389..d0ba907 100644
--- a/tests/src/com/android/launcher3/model/AddWorkspaceItemsTaskTest.java
+++ b/tests/src/com/android/launcher3/model/AddWorkspaceItemsTaskTest.java
@@ -53,14 +53,6 @@
         return new AddWorkspaceItemsTask(Provider.of(Arrays.asList(items))) {
 
             @Override
-            protected void addItemToDatabase(Context context, ItemInfo item,
-                    long screenId, int[] pos) {
-                item.screenId = screenId;
-                item.cellX = pos[0];
-                item.cellY = pos[1];
-            }
-
-            @Override
             protected void updateScreens(Context context, ArrayList<Long> workspaceScreens) { }
         };
     }
diff --git a/tests/src/com/android/launcher3/model/BaseModelUpdateTaskTestCase.java b/tests/src/com/android/launcher3/model/BaseModelUpdateTaskTestCase.java
index 9b7fc6e..b9944db 100644
--- a/tests/src/com/android/launcher3/model/BaseModelUpdateTaskTestCase.java
+++ b/tests/src/com/android/launcher3/model/BaseModelUpdateTaskTestCase.java
@@ -37,6 +37,7 @@
 import java.util.HashMap;
 import java.util.List;
 
+import static org.mockito.Matchers.anyBoolean;
 import static org.mockito.Mockito.atLeast;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
@@ -54,6 +55,8 @@
 
     public InvariantDeviceProfile idp;
     public LauncherAppState appState;
+    public LauncherModel model;
+    public ModelWriter modelWriter;
     public MyIconCache iconCache;
 
     public BgDataModel bgDataModel;
@@ -70,6 +73,11 @@
 
         callbacks = mock(Callbacks.class);
         appState = mock(LauncherAppState.class);
+        model = mock(LauncherModel.class);
+        modelWriter = mock(ModelWriter.class);
+        when(appState.getModel()).thenReturn(model);
+        when(model.getWriter(anyBoolean())).thenReturn(modelWriter);
+
         myUser = Process.myUserHandle();
 
         bgDataModel = new BgDataModel();