PagedView: Transition Effects

Change-Id: Ib134705952877165c334181548d577b3dceece68

10 files changed, 699 insertions, 211 deletions

diff --git a/res/layout/overview_panel.xml b/res/layout/overview_panel.xml
index ada2b2483..fad5ebe18 100644
--- a/res/layout/overview_panel.xml
+++ b/res/layout/overview_panel.xml
@@ -17,19 +17,44 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
-    <TextView
-        android:id="@+id/default_screen_button"
+
+    <LinearLayout
+        xmlns:android="http://schemas.android.com/apk/res/android"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
+        android:orientation="horizontal"
         android:layout_gravity="center_horizontal|top"
-        android:paddingTop="@dimen/overview_panel_top_padding"
-        android:text="@string/default_screen_button_text"
-        android:drawablePadding="4dp"
-        android:drawableTop="@drawable/default_screen_button"
-        android:gravity="center_horizontal"
-        android:fontFamily="sans-serif-condensed"
-        android:textAllCaps="true"
-        android:textSize="12sp" />
+        android:paddingTop="@dimen/overview_panel_top_padding">
+
+        <TextView
+            android:id="@+id/default_screen_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
+            android:text="@string/default_screen_button_text"
+            android:drawablePadding="4dp"
+            android:drawableTop="@drawable/default_screen_button"
+            android:gravity="center_horizontal"
+            android:fontFamily="sans-serif-condensed"
+            android:textAllCaps="true"
+            android:textSize="12sp" />
+
+        <TextView
+            android:id="@+id/transition_effect_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
+            android:text="@string/transition_effect_button_text"
+            android:drawablePadding="4dp"
+            android:drawableTop="@drawable/wallpaper_button"
+            android:gravity="center_horizontal"
+            android:fontFamily="sans-serif-condensed"
+            android:textAllCaps="true"
+            android:textSize="12sp" />
+
+    </LinearLayout>
 
     <LinearLayout
         xmlns:android="http://schemas.android.com/apk/res/android"
@@ -43,6 +68,8 @@
             android:id="@+id/wallpaper_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
             android:text="@string/wallpaper_button_text"
             android:drawablePadding="4dp"
             android:drawableTop="@drawable/wallpaper_button"
@@ -54,6 +81,8 @@
             android:id="@+id/sort_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
             android:text="@string/sort_button_text"
             android:drawablePadding="4dp"
             android:drawableTop="@drawable/wallpaper_button"
@@ -61,13 +90,12 @@
             android:fontFamily="sans-serif-condensed"
             android:textAllCaps="true"
             android:textSize="12sp" />
-        <Space
-            android:layout_width="@dimen/overview_panel_buttonSpacing"
-            android:layout_height="wrap_content"/>
         <TextView
             android:id="@+id/widget_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
             android:text="@string/widget_button_text"
             android:drawablePadding="4dp"
             android:gravity="center_horizontal"
@@ -79,6 +107,8 @@
             android:id="@+id/filter_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
             android:text="@string/filter_button_text"
             android:drawablePadding="4dp"
             android:gravity="center_horizontal"
@@ -86,13 +116,12 @@
             android:fontFamily="sans-serif-condensed"
             android:textAllCaps="true"
             android:textSize="12sp"/>
-        <Space
-            android:layout_width="@dimen/overview_panel_buttonSpacing"
-            android:layout_height="wrap_content"/>
         <TextView
             android:id="@+id/settings_button"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
+            android:paddingLeft="@dimen/overview_panel_button_spacing"
+            android:paddingRight="@dimen/overview_panel_button_spacing"
             android:text="@string/settings_button_text"
             android:drawablePadding="4dp"
             android:gravity="center_horizontal"
diff --git a/res/values/cm_arrays.xml b/res/values/cm_arrays.xml
index 580e89317..5d614ab2d 100644
--- a/res/values/cm_arrays.xml
+++ b/res/values/cm_arrays.xml
@@ -10,4 +10,37 @@
         <item>sans-serif-light</item>
         <item>sans-serif-condensed</item>
     </string-array>
+
+    <string-array name="transition_effect_entries">
+        <item>None</item>
+        <item>Zoom In</item>
+        <item>Zoom Out</item>
+        <item>Rotate Up</item>
+        <item>Rotate Down</item>
+        <item>Cube In</item>
+        <item>Cube Out</item>
+        <item>Stack</item>
+        <item>Accordion</item>
+        <item>Flip</item>
+        <item>Cylinder In</item>
+        <item>Cylinder Out</item>
+        <item>Carousel</item>
+        <item>Overview</item>
+    </string-array>
+    <string-array name="transition_effect_values">
+        <item>none</item>
+        <item>zoom-in</item>
+        <item>zoom-out</item>
+        <item>rotate-up</item>
+        <item>rotate-down</item>
+        <item>cube-in</item>
+        <item>cube-out</item>
+        <item>stack</item>
+        <item>accordion</item>
+        <item>flip</item>
+        <item>cylinder-in</item>
+        <item>cylinder-out</item>
+        <item>carousel</item>
+        <item>overview</item>
+    </string-array>
 </resources>
\ No newline at end of file
diff --git a/res/values/cm_strings.xml b/res/values/cm_strings.xml
index 2dc3fa4bc..50b8bad73 100644
--- a/res/values/cm_strings.xml
+++ b/res/values/cm_strings.xml
@@ -12,6 +12,8 @@
     <string name="filter_button_text">Filter</string>
     <!-- Text for default screen button -->
     <string name="default_screen_button_text">Default Screen</string>
+    <!-- Text for transition effect button -->
+    <string name="transition_effect_button_text">Scroll Effect</string>
 
     <string name="sort_mode_title">Title</string>
     <string name="sort_mode_launch_count">Launch Count</string>
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index 8176c8192..3b692a1d1 100644
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -43,7 +43,7 @@
     <dimen name="workspace_spring_loaded_page_spacing">15dp</dimen>
     <dimen name="overview_panel_top_padding">20dp</dimen>
     <dimen name="overview_panel_bottom_padding">50dp</dimen>
-    <dimen name="overview_panel_buttonSpacing">60dp</dimen>
+    <dimen name="overview_panel_button_spacing">30dp</dimen>
     <dimen name="overview_mode_page_offset">130dp</dimen>
 
 <!-- QSB -->
diff --git a/res/values/preferences_defaults.xml b/res/values/preferences_defaults.xml
index 9fa44b27e..ebb1650f4 100644
--- a/res/values/preferences_defaults.xml
+++ b/res/values/preferences_defaults.xml
@@ -1,8 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <bool name="preferences_interface_homescreen_search_default">true</bool>
+    <string name="preferences_interface_homescreen_scrolling_transition_effect">none</string>
     <bool name="preferences_interface_homescreen_scrolling_wallpaper_scroll_default">true</bool>
     <bool name="preferences_interface_homescreen_scrolling_page_outlines_default">@bool/config_workspaceDefaultShowOutlines</bool>
+    <string name="preferences_interface_drawer_scrolling_transition_effect">stack</string>
     <bool name="preferences_interface_general_icons_large_default">@bool/config_largeIcons</bool>
     <string name="preferences_interface_general_icons_text_font_family_default">sans-serif-condensed</string>
     <integer name="preferences_interface_general_icons_text_font_style_default">0</integer>
diff --git a/src/com/android/launcher3/AppsCustomizePagedView.java b/src/com/android/launcher3/AppsCustomizePagedView.java
index 34625dfd7..44f50b200 100644
--- a/src/com/android/launcher3/AppsCustomizePagedView.java
+++ b/src/com/android/launcher3/AppsCustomizePagedView.java
@@ -56,6 +56,7 @@ import android.widget.ImageView;
 import android.widget.Toast;
 
 import com.android.launcher3.DropTarget.DragObject;
+import com.android.launcher3.settings.SettingsProvider;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -213,28 +214,15 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
     // Animation values
     private float mNewScale;
     private float[] mOldBackgroundAlphas;
-    private float[] mOldTranslationXs;
-    private float[] mOldTranslationYs;
-    private float[] mOldScaleXs;
-    private float[] mOldScaleYs;
     private float[] mOldAlphas;
     private float[] mNewBackgroundAlphas;
-    private float[] mNewTranslationXs;
-    private float[] mNewTranslationYs;
-    private float[] mNewScaleXs;
-    private float[] mNewScaleYs;
     private float[] mNewAlphas;
 
     // Relating to the scroll and overscroll effects
-    Workspace.ZInterpolator mZInterpolator = new Workspace.ZInterpolator(0.5f);
-    private static float CAMERA_DISTANCE = 6500;
-    private static float TRANSITION_SCALE_FACTOR = 0.74f;
-    private static float TRANSITION_PIVOT = 0.65f;
     private static float TRANSITION_MAX_ROTATION = 22;
     private static final float ALPHA_CUTOFF_THRESHOLD = 0.01f;
-    private static final boolean PERFORM_OVERSCROLL_ROTATION = true;
-    private AccelerateInterpolator mAlphaInterpolator = new AccelerateInterpolator(0.9f);
-    private DecelerateInterpolator mLeftScreenAlphaInterpolator = new DecelerateInterpolator(4);
+    private boolean mOverscrollTransformsSet;
+    private float mLastOverscrollPivotX;
 
     public static boolean DISABLE_ALL_APPS = false;
 
@@ -311,6 +299,10 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
         // (top + bottom)
         mFadeInAdjacentScreens = false;
 
+        TransitionEffect.setFromString(this, SettingsProvider.getString(context,
+                SettingsProvider.SETTINGS_UI_DRAWER_SCROLLING_TRANSITION_EFFECT,
+                R.string.preferences_interface_drawer_scrolling_transition_effect));
+
         // Unless otherwise specified this view is important for accessibility.
         if (getImportantForAccessibility() == View.IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
             setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
@@ -324,6 +316,7 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
 
         Context context = getContext();
         Resources r = context.getResources();
+        mCameraDistance = (int) CAMERA_DISTANCE;//r.getInteger(R.integer.config_cameraDistance);
         setDragSlopeThreshold(r.getInteger(R.integer.config_appsCustomizeDragSlopeThreshold)/100f);
         mOverviewModeShrinkFactor =
                 r.getInteger(R.integer.config_workspaceOverviewShrinkPercentage) / 100.0f;
@@ -1057,6 +1050,15 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
     }
 
     @Override
+    public void setChildAlpha(View child, float alpha) {
+        if (child instanceof CellLayout) {
+            ((CellLayout) child).getShortcutsAndWidgets().setAlpha(alpha);
+        } else {
+            child.setAlpha(alpha);
+        }
+    }
+
+    @Override
     public void onChildViewAdded(View parent, View child) {
         // For overview mode
         if (child instanceof CellLayout) {
@@ -1068,6 +1070,12 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
         super.onChildViewAdded(parent, child);
     }
 
+    protected boolean shouldDrawChild(View child) {
+        return super.shouldDrawChild(child) && (mIsSwitchingState ||
+                !(child instanceof CellLayout) ||
+                ((CellLayout) child).getShortcutsAndWidgets().getAlpha() > 0);
+    }
+
     public void syncAppsPageItems(int page, boolean immediate) {
         // ensure that we have the right number of items on the pages
         final boolean isRtl = isLayoutRtl();
@@ -1433,92 +1441,51 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
     @Override
     protected void screenScrolled(int screenCenter) {
         final boolean isRtl = isLayoutRtl();
-        super.screenScrolled(screenCenter);
 
+        mUseTransitionEffect = !isInOverviewMode() && !mIsSwitchingState;
+
+        super.screenScrolled(screenCenter);
         enableHwLayersOnVisiblePages();
 
-        if (isInOverviewMode()) {
-            return;
-        }
+        boolean isInOverscroll = mOverScrollX < 0 || mOverScrollX > mMaxScrollX;
 
-        for (int i = 0; i < getChildCount(); i++) {
-            View v = getPageAt(i);
-            if (v != null) {
-                float scrollProgress = getScrollProgress(screenCenter, v, i);
+        if (isInOverscroll) {
+            int index = 0;
+            float pivotX = 0f;
+            final float leftBiasedPivot = 0.35f;
+            final float rightBiasedPivot = 0.65f;
+            final int lowerIndex = 0;
+            final int upperIndex = getChildCount() - 1;
 
-                float interpolatedProgress;
-                float translationX;
-                float maxScrollProgress = Math.max(0, scrollProgress);
-                float minScrollProgress = Math.min(0, scrollProgress);
+            final boolean isLeftPage = mOverScrollX < 0;
+            index = (!isRtl && isLeftPage) || (isRtl && !isLeftPage) ? lowerIndex : upperIndex;
+            pivotX = isLeftPage ? rightBiasedPivot : leftBiasedPivot;
 
-                if (isRtl) {
-                    translationX = maxScrollProgress * v.getMeasuredWidth();
-                    interpolatedProgress = mZInterpolator.getInterpolation(Math.abs(maxScrollProgress));
-                } else {
-                    translationX = minScrollProgress * v.getMeasuredWidth();
-                    interpolatedProgress = mZInterpolator.getInterpolation(Math.abs(minScrollProgress));
-                }
-                float scale = (1 - interpolatedProgress) +
-                        interpolatedProgress * TRANSITION_SCALE_FACTOR;
-
-                float alpha;
-                if (isRtl && (scrollProgress > 0)) {
-                    alpha = mAlphaInterpolator.getInterpolation(1 - Math.abs(maxScrollProgress));
-                } else if (!isRtl && (scrollProgress < 0)) {
-                    alpha = mAlphaInterpolator.getInterpolation(1 - Math.abs(scrollProgress));
-                } else {
-                    //  On large screens we need to fade the page as it nears its leftmost position
-                    alpha = mLeftScreenAlphaInterpolator.getInterpolation(1 - scrollProgress);
-                }
-
-                v.setCameraDistance(mDensity * CAMERA_DISTANCE);
-                int pageWidth = v.getMeasuredWidth();
-                int pageHeight = v.getMeasuredHeight();
-
-                if (PERFORM_OVERSCROLL_ROTATION) {
-                    float xPivot = isRtl ? 1f - TRANSITION_PIVOT : TRANSITION_PIVOT;
-                    boolean isOverscrollingFirstPage = isRtl ? scrollProgress > 0 : scrollProgress < 0;
-                    boolean isOverscrollingLastPage = isRtl ? scrollProgress < 0 : scrollProgress > 0;
-
-                    if (i == 0 && isOverscrollingFirstPage) {
-                        // Overscroll to the left
-                        v.setPivotX(xPivot * pageWidth);
-                        v.setRotationY(-TRANSITION_MAX_ROTATION * scrollProgress);
-                        scale = 1.0f;
-                        alpha = 1.0f;
-                        // On the first page, we don't want the page to have any lateral motion
-                        translationX = 0;
-                    } else if (i == getChildCount() - 1 && isOverscrollingLastPage) {
-                        // Overscroll to the right
-                        v.setPivotX((1 - xPivot) * pageWidth);
-                        v.setRotationY(-TRANSITION_MAX_ROTATION * scrollProgress);
-                        scale = 1.0f;
-                        alpha = 1.0f;
-                        // On the last page, we don't want the page to have any lateral motion.
-                        translationX = 0;
-                    } else {
-                        v.setPivotY(pageHeight / 2.0f);
-                        v.setPivotX(pageWidth / 2.0f);
-                        v.setRotationY(0f);
-                    }
-                }
+            View v = getPageAt(index);
 
-                v.setTranslationX(translationX);
-                v.setScaleX(scale);
-                v.setScaleY(scale);
-                if (v instanceof CellLayout) {
-                    ((CellLayout) v).getShortcutsAndWidgets().setAlpha(alpha);
-                } else {
-                    v.setAlpha(alpha);
-                }
+            if (!mOverscrollTransformsSet || Float.compare(mLastOverscrollPivotX, pivotX) != 0) {
+                mOverscrollTransformsSet = true;
+                mLastOverscrollPivotX = pivotX;
+                v.setCameraDistance(mDensity * mCameraDistance);
+                v.setPivotX(v.getMeasuredWidth() * pivotX);
+            }
 
-                // If the view has 0 alpha, we set it to be invisible so as to prevent
-                // it from accepting touches
-                if (alpha == 0) {
-                    v.setVisibility(INVISIBLE);
-                } else if (v.getVisibility() != VISIBLE) {
-                    v.setVisibility(VISIBLE);
-                }
+            float scrollProgress = getScrollProgress(screenCenter, v, index);
+            float rotation = -TRANSITION_MAX_ROTATION * scrollProgress;
+            v.setRotationY(rotation);
+        } else {
+            if (mOverscrollTransformsSet) {
+                mOverscrollTransformsSet = false;
+                View v0 = getPageAt(0);
+                View v1 = getPageAt(getChildCount() - 1);
+                v0.setRotationY(0);
+                v1.setRotationY(0);
+                v0.setCameraDistance(mDensity * mCameraDistance);
+                v1.setCameraDistance(mDensity * mCameraDistance);
+                v0.setPivotX(v0.getMeasuredWidth() / 2);
+                v1.setPivotX(v1.getMeasuredWidth() / 2);
+                v0.setPivotY(v0.getMeasuredHeight() / 2);
+                v1.setPivotY(v1.getMeasuredHeight() / 2);
             }
         }
     }
@@ -1631,16 +1598,8 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
         final int childCount = getChildCount();
         if (mOldBackgroundAlphas != null) return;
         mOldBackgroundAlphas = new float[childCount];
-        mOldTranslationXs = new float[childCount];
-        mOldTranslationYs = new float[childCount];
-        mOldScaleXs = new float[childCount];
-        mOldScaleYs = new float[childCount];
         mOldAlphas = new float[childCount];
         mNewBackgroundAlphas = new float[childCount];
-        mNewTranslationXs = new float[childCount];
-        mNewTranslationYs = new float[childCount];
-        mNewScaleXs = new float[childCount];
-        mNewScaleYs = new float[childCount];
         mNewAlphas = new float[childCount];
     }
 
@@ -1680,15 +1639,17 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
 
         for (int i = 0; i < getChildCount(); i++) {
             final CellLayout cl = (CellLayout) getChildAt(i);
-            float translationX = 0f;
-            float translationY = 0f;
-            float scaleX = 1f;
-            float scaleY = 1f;
             float finalAlpha = 1f;
 
             if (stateIsOverview) {
                 cl.setVisibility(VISIBLE);
                 cl.setTranslationX(0f);
+                cl.setTranslationY(0f);
+                cl.setPivotX(cl.getMeasuredWidth() * 0.5f);
+                cl.setPivotY(cl.getMeasuredHeight() * 0.5f);
+                cl.setRotation(0f);
+                cl.setRotationY(0f);
+                cl.setRotationX(0f);
                 cl.setScaleX(1f);
                 cl.setScaleY(1f);
                 cl.setShortcutAndWidgetAlpha(1f);
@@ -1698,22 +1659,9 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
             mNewAlphas[i] = finalAlpha;
             if (animated) {
                 mOldBackgroundAlphas[i] = cl.getBackgroundAlpha();
-                mOldTranslationXs[i] = cl.getTranslationX();
-                mOldTranslationYs[i] = cl.getTranslationY();
-                mOldScaleXs[i] = cl.getScaleX();
-                mNewScaleXs[i] = cl.getScaleY();
-
                 mNewBackgroundAlphas[i] = finalBackgroundAlpha;
-                mNewTranslationXs[i] = translationX;
-                mNewTranslationYs[i] = translationY;
-                mNewScaleXs[i] = scaleX;
-                mNewScaleYs[i] = scaleY;
             } else {
                 cl.setBackgroundAlpha(finalBackgroundAlpha);
-                cl.setTranslationX(translationX);
-                cl.setTranslationY(translationY);
-                cl.setScaleX(scaleX);
-                cl.setScaleY(scaleY);
                 cl.setShortcutAndWidgetAlpha(finalAlpha);
             }
         }
@@ -1762,23 +1710,10 @@ public class AppsCustomizePagedView extends PagedViewWithDraggableItems implemen
                 final CellLayout cl = (CellLayout) getChildAt(i);
                 if (mOldAlphas[i] == 0 && mNewAlphas[i] == 0) {
                     cl.setBackgroundAlpha(mNewBackgroundAlphas[i]);
-                    cl.setTranslationX(mNewTranslationXs[i]);
-                    cl.setTranslationY(mNewTranslationYs[i]);
-                    cl.setScaleX(mNewScaleXs[i]);
-                    cl.setScaleY(mNewScaleYs[i]);
                     cl.getShortcutsAndWidgets().setAlpha(mNewAlphas[i]);
                 } else {
-                    LauncherViewPropertyAnimator a = new LauncherViewPropertyAnimator(cl);
-                    a.translationX(mNewTranslationXs[i])
-                            .translationY(mNewTranslationYs[i])
-                            .scaleX(mNewScaleXs[i])
-                            .scaleY(mNewScaleYs[i])
-                            .setDuration(duration)
-                            .setInterpolator(mZoomInInterpolator);
-                    anim.play(a);
-                    a = new LauncherViewPropertyAnimator(cl.getShortcutsAndWidgets());
-                    a.translationX(mNewTranslationXs[i])
-                            .alpha(mNewAlphas[i])
+                    LauncherViewPropertyAnimator a = new LauncherViewPropertyAnimator(cl.getShortcutsAndWidgets());
+                    a.alpha(mNewAlphas[i])
                             .setDuration(duration)
                             .setInterpolator(mZoomInInterpolator);
                     anim.play(a);
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index bfd5271df..d0df9c371 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -29,6 +29,8 @@ import android.animation.ValueAnimator.AnimatorUpdateListener;
 import android.app.Activity;
 import android.app.ActivityManager;
 import android.app.ActivityOptions;
+import android.app.AlertDialog;
+import android.app.Dialog;
 import android.app.SearchManager;
 import android.appwidget.AppWidgetHostView;
 import android.appwidget.AppWidgetManager;
@@ -39,6 +41,7 @@ import android.content.ComponentCallbacks2;
 import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.SharedPreferences;
@@ -111,7 +114,6 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.lang.reflect.Array;
 import java.text.DateFormat;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -271,6 +273,8 @@ public class Launcher extends Activity
 
     private Bundle mSavedInstanceState;
 
+    private Dialog mTransitionEffectDialog;
+
     private LauncherModel mModel;
     private IconCache mIconCache;
     private boolean mUserPresent = true;
@@ -1029,6 +1033,88 @@ public class Launcher extends Activity
         popupMenu.show();
     }
 
+    public void onClickTransitionEffectButton(View v) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(R.string.transition_effect_button_text);
+
+        if (isAllAppsVisible()) {
+            mAppsCustomizeContent.exitOverviewMode(true);
+        } else {
+            mWorkspace.exitOverviewMode(true);
+        }
+
+        final PagedView pagedView = isAllAppsVisible() ? mAppsCustomizeContent : mWorkspace;
+        final PagedView.TransitionEffect oldEffect = pagedView.getTransitionEffect();
+        final String oldEffectName = oldEffect != null ? oldEffect.getName() :
+                PagedView.TransitionEffect.TRANSITION_EFFECT_NONE;
+
+        final String[] entries = getResources().getStringArray(R.array.transition_effect_entries);
+        final String[] values = getResources().getStringArray(R.array.transition_effect_values);
+
+        int selected = -1;
+        for (int i = values.length - 1; i >= 0; i--) {
+            if (values[i].equals(oldEffectName)) {
+                selected = i;
+                break;
+            }
+        }
+
+        builder.setSingleChoiceItems(entries, selected, new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        String effect = values[which];
+                        PagedView.TransitionEffect.setFromString(pagedView, effect);
+
+                        final int currentPage = pagedView.getNextPage();
+                        final int nextPage = currentPage + (currentPage != pagedView.getPageCount() - 1 ? 1 : -1);
+
+
+                        pagedView.snapToPageImmediately(currentPage);
+                        pagedView.snapToPage(nextPage, new Runnable() {
+                            @Override
+                            public void run() {
+                                pagedView.snapToPage(currentPage);
+                            }
+                        });
+                    }
+                })
+                .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
+                    public void onClick(DialogInterface dialog, int id) {
+                        PagedView.TransitionEffect effect = pagedView.getTransitionEffect();
+                        String name = effect != null ? effect.getName() : PagedView.TransitionEffect.TRANSITION_EFFECT_NONE;
+
+                        SettingsProvider.get(Launcher.this).edit()
+                                .putString(!isAllAppsVisible() ?
+                                        SettingsProvider.SETTINGS_UI_HOMESCREEN_SCROLLING_TRANSITION_EFFECT :
+                                        SettingsProvider.SETTINGS_UI_DRAWER_SCROLLING_TRANSITION_EFFECT, name)
+                                .commit();
+
+                        dialog.dismiss();
+                    }
+                })
+                .setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
+                    public void onClick(DialogInterface dialog, int id) {
+                        dialog.cancel();
+                    }
+                })
+                .setOnCancelListener(new DialogInterface.OnCancelListener() {
+                    @Override
+                    public void onCancel(DialogInterface dialog) {
+                        pagedView.setTransitionEffect(oldEffect);
+                    }
+                })
+                .setOnDismissListener(new DialogInterface.OnDismissListener() {
+                    @Override
+                    public void onDismiss(DialogInterface dialog) {
+                        mTransitionEffectDialog = null;
+                    }
+                });
+        mTransitionEffectDialog = builder.create();
+        mTransitionEffectDialog.show();
+        mTransitionEffectDialog.setCanceledOnTouchOutside(true);
+        mTransitionEffectDialog.getWindow().getDecorView().setAlpha(0.6f);
+    }
+
     public interface QSBScroller {
         public void setScrollY(int scrollY);
     }
@@ -1239,11 +1325,20 @@ public class Launcher extends Activity
         });
         defaultScreenButton.setOnTouchListener(getHapticFeedbackTouchListener());
 
+        View transitionEffectButton = findViewById(R.id.transition_effect_button);
+        transitionEffectButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View arg0) {
+                onClickTransitionEffectButton(arg0);
+            }
+        });
+        transitionEffectButton.setOnTouchListener(getHapticFeedbackTouchListener());
+
         View sortButton = findViewById(R.id.sort_button);
         sortButton.setOnClickListener(new OnClickListener() {
             @Override
-            public void onClick(View v) {
-                onClickSortModeButton(v);
+            public void onClick(View arg0) {
+                onClickSortModeButton(arg0);
             }
         });
         sortButton.setOnTouchListener(getHapticFeedbackTouchListener());
@@ -1732,6 +1827,10 @@ public class Launcher extends Activity
             // also will cancel mWaitingForResult.
             closeSystemDialogs();
 
+            if (mTransitionEffectDialog != null) {
+                mTransitionEffectDialog.cancel();
+            }
+
             final boolean alreadyOnHome = mHasFocus && ((intent.getFlags() &
                     Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT)
                     != Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT);
@@ -2761,12 +2860,16 @@ public class Launcher extends Activity
 
     public void updateOverviewPanel() {
         View defaultScreenButton = mOverviewPanel.findViewById(R.id.default_screen_button);
+        View transitionEffectButton = mOverviewPanel.findViewById(R.id.transition_effect_button);
         View widgetButton = mOverviewPanel.findViewById(R.id.widget_button);
         View wallpaperButton = mOverviewPanel.findViewById(R.id.wallpaper_button);
         View sortButton = mOverviewPanel.findViewById(R.id.sort_button);
         View filterButton = mOverviewPanel.findViewById(R.id.filter_button);
 
-        defaultScreenButton.setVisibility(!isAllAppsVisible() ? View.VISIBLE : View.GONE);
+        PagedView pagedView = !isAllAppsVisible() ? mWorkspace : mAppsCustomizeContent;
+
+        defaultScreenButton.setVisibility((!isAllAppsVisible() && pagedView.getPageCount() > 1) ? View.VISIBLE : View.GONE);
+        transitionEffectButton.setVisibility(pagedView.getPageCount() > 1 ? View.VISIBLE : View.GONE);
         widgetButton.setVisibility(!isAllAppsVisible() ? View.VISIBLE : View.GONE);
         wallpaperButton.setVisibility(!isAllAppsVisible() ? View.VISIBLE : View.GONE);
         sortButton.setVisibility(isAllAppsVisible() ? View.VISIBLE : View.GONE);
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index e982985f1..b70175ee8 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -47,12 +47,10 @@ import android.view.ViewParent;
 import android.view.accessibility.AccessibilityEvent;
 import android.view.accessibility.AccessibilityManager;
 import android.view.accessibility.AccessibilityNodeInfo;
-import android.view.animation.AnimationUtils;
-import android.view.animation.DecelerateInterpolator;
-import android.view.animation.Interpolator;
-import android.view.animation.LinearInterpolator;
+import android.view.animation.*;
 import android.widget.Scroller;
 
+import java.lang.reflect.Array;
 import java.util.ArrayList;
 
 interface Page {
@@ -270,6 +268,17 @@ public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarc
 
     protected int mFirstChildLeft;
 
+    private Runnable mDelayedSnapToPageRunnable;
+
+    // Relating to the scroll and overscroll effects
+    protected static float CAMERA_DISTANCE = 6500;
+    protected static final float TRANSITION_SCALE_FACTOR = 0.74f;
+    protected static final float TRANSITION_SCREEN_ROTATION = 12.5f;
+    protected int mCameraDistance;
+    private boolean mScrollTransformsSet;
+    protected TransitionEffect mTransitionEffect;
+    protected boolean mUseTransitionEffect = true;
+
     public interface PageSwitchListener {
         void onPageSwitch(View newPage, int newPageIndex);
     }
@@ -597,6 +606,10 @@ public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarc
 
     // a method that subclasses can override to add behavior
     protected void onPageEndMoving() {
+        if (mDelayedSnapToPageRunnable != null) {
+            mDelayedSnapToPageRunnable.run();
+            mDelayedSnapToPageRunnable = null;
+        }
     }
 
     /**
@@ -997,20 +1010,68 @@ public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarc
         }
     }
 
+    public TransitionEffect getTransitionEffect() {
+        return mTransitionEffect;
+    }
+
+    public void setTransitionEffect(TransitionEffect effect) {
+        mTransitionEffect = effect;
+
+        // Reset scroll transforms
+        if (mScrollTransformsSet) {
+            for (int i = 0; i < getChildCount(); i++) {
+                View v = getPageAt(i);
+                if (v != null) {
+                    v.setPivotX(v.getMeasuredWidth() * 0.5f);
+                    v.setPivotY(v.getMeasuredHeight() * 0.5f);
+                    v.setRotation(0);
+                    v.setRotationX(0);
+                    v.setRotationY(0);
+                    v.setScaleX(1f);
+                    v.setScaleY(1f);
+                    v.setTranslationX(0f);
+                    v.setTranslationY(0f);
+                    v.setVisibility(VISIBLE);
+                    setChildAlpha(v, 1f);
+                }
+            }
+
+            mScrollTransformsSet = false;
+        }
+    }
+
     protected void screenScrolled(int screenCenter) {
         boolean isInOverscroll = mOverScrollX < 0 || mOverScrollX > mMaxScrollX;
-
-        if (mFadeInAdjacentScreens && !isInOverscroll) {
+        // Apply transition effect and adjacent screen fade if enabled
+        if (mFadeInAdjacentScreens || (mTransitionEffect != null && mUseTransitionEffect) || mScrollTransformsSet) {
             for (int i = 0; i < getChildCount(); i++) {
-                View child = getChildAt(i);
-                if (child != null) {
-                    float scrollProgress = getScrollProgress(screenCenter, child, i);
-                    float alpha = 1 - Math.abs(scrollProgress);
-                    child.setAlpha(alpha);
+                View v = getPageAt(i);
+                if (v != null) {
+                    float scrollProgress = getScrollProgress(screenCenter, v, i);
+                    // Fade first to allow transition effects to override alpha
+                    if (mFadeInAdjacentScreens && !isInOverscroll) {
+                        float alpha = 1 - Math.abs(scrollProgress);
+                        setChildAlpha(v, alpha);
+                    }
+                    if (mTransitionEffect != null && mUseTransitionEffect && !isInOverscroll) {
+                        mTransitionEffect.screenScrolled(v, i, scrollProgress);
+                    } else if (mScrollTransformsSet) {
+                        v.setPivotX(v.getMeasuredWidth() * 0.5f);
+                        v.setPivotY(v.getMeasuredHeight() * 0.5f);
+                        v.setRotation(0);
+                        v.setRotationX(0);
+                        v.setRotationY(0);
+                        v.setScaleX(1f);
+                        v.setScaleY(1f);
+                        v.setTranslationX(0f);
+                        v.setTranslationY(0f);
+                        v.setVisibility(VISIBLE);
+                        setChildAlpha(v, 1f);
+                    }
                 }
             }
-            invalidate();
         }
+        mScrollTransformsSet = mTransitionEffect != null && mUseTransitionEffect && !isInOverscroll;
     }
 
     protected void enablePagedViewAnimations() {
@@ -1021,6 +1082,42 @@ public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarc
         mAllowPagedViewAnimations = false;
     }
 
+    /*
+ * This interpolator emulates the rate at which the perceived scale of an object changes
+ * as its distance from a camera increases. When this interpolator is applied to a scale
+ * animation on a view, it evokes the sense that the object is shrinking due to moving away
+ * from the camera.
+ */
+    static class ZInterpolator implements TimeInterpolator {
+        private float focalLength;
+
+        public ZInterpolator(float foc) {
+            focalLength = foc;
+        }
+
+        public float getInterpolation(float input) {
+            return (1.0f - focalLength / (focalLength + input)) /
+                    (1.0f - focalLength / (focalLength + 1.0f));
+        }
+    }
+
+    /*
+     * The exact reverse of ZInterpolator.
+     */
+    static class InverseZInterpolator implements TimeInterpolator {
+        private ZInterpolator zInterpolator;
+        public InverseZInterpolator(float foc) {
+            zInterpolator = new ZInterpolator(foc);
+        }
+        public float getInterpolation(float input) {
+            return 1 - zInterpolator.getInterpolation(1 - input);
+        }
+    }
+
+    protected void setChildAlpha(View child, float alpha) {
+        child.setAlpha(alpha);
+    }
+
     @Override
     public void onChildViewAdded(View parent, View child) {
         // Update the page indicator, we don't update the page indicator as we
@@ -2153,6 +2250,14 @@ public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarc
         snapToPage(whichPage, delta, duration);
     }
 
+    protected void snapToPage(int whichPage, Runnable r) {
+        if (mDelayedSnapToPageRunnable != null) {
+            mDelayedSnapToPageRunnable.run();
+        }
+        mDelayedSnapToPageRunnable = r;
+        snapToPage(whichPage, SLOW_PAGE_SNAP_ANIMATION_DURATION);
+    }
+
     protected void snapToPage(int whichPage) {
         snapToPage(whichPage, PAGE_SNAP_ANIMATION_DURATION);
     }
@@ -2815,4 +2920,294 @@ public abstract class PagedView extends ViewGroup implements ViewGroup.OnHierarc
     public boolean onHoverEvent(android.view.MotionEvent event) {
         return true;
     }
+
+    protected static abstract class TransitionEffect {
+        public static final String TRANSITION_EFFECT_NONE = "none";
+        public static final String TRANSITION_EFFECT_ZOOM_IN = "zoom-in";
+        public static final String TRANSITION_EFFECT_ZOOM_OUT = "zoom-out";
+        public static final String TRANSITION_EFFECT_ROTATE_UP = "rotate-up";
+        public static final String TRANSITION_EFFECT_ROTATE_DOWN = "rotate-down";
+        public static final String TRANSITION_EFFECT_CUBE_IN = "cube-in";
+        public static final String TRANSITION_EFFECT_CUBE_OUT = "cube-out";
+        public static final String TRANSITION_EFFECT_STACK = "stack";
+        public static final String TRANSITION_EFFECT_ACCORDION = "accordion";
+        public static final String TRANSITION_EFFECT_FLIP = "flip";
+        public static final String TRANSITION_EFFECT_CYLINDER_IN = "cylinder-in";
+        public static final String TRANSITION_EFFECT_CYLINDER_OUT = "cylinder-out";
+        public static final String TRANSITION_EFFECT_CAROUSEL = "carousel";
+        public static final String TRANSITION_EFFECT_OVERVIEW = "overview";
+
+        protected final PagedView mPagedView;
+        private final String mName;
+
+        public TransitionEffect(PagedView pagedView, String name) {
+            mPagedView = pagedView;
+            mName = name;
+        }
+
+        public abstract void screenScrolled(View v, int i, float scrollProgress);
+
+        public final String getName() {
+            return mName;
+        }
+
+        public static void setFromString(PagedView pagedView, String effect) {
+            if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_NONE)) {
+                pagedView.setTransitionEffect(null);
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_ZOOM_IN)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Zoom(pagedView, true));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_ZOOM_OUT)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Zoom(pagedView, false));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_CUBE_IN)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Cube(pagedView, true));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_CUBE_OUT)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Cube(pagedView, false));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_ROTATE_UP)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Rotate(pagedView, true));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_ROTATE_DOWN)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Rotate(pagedView, false));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_STACK)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Stack(pagedView));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_ACCORDION)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Accordion(pagedView));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_FLIP)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Flip(pagedView));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_CYLINDER_IN)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Cylinder(pagedView, true));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_CYLINDER_OUT)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Cylinder(pagedView, false));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_CAROUSEL)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Carousel(pagedView));
+            } else if (effect.equals(PagedView.TransitionEffect.TRANSITION_EFFECT_OVERVIEW)) {
+                pagedView.setTransitionEffect(new PagedView.TransitionEffect.Overview(pagedView));
+            }
+        }
+
+        public static class Zoom extends TransitionEffect {
+            private boolean mIn;
+
+            public Zoom(PagedView pagedView, boolean in) {
+                super(pagedView, in ? TRANSITION_EFFECT_ZOOM_IN : TRANSITION_EFFECT_ZOOM_OUT);
+                mIn = in;
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float scale = 1.0f + (mIn ? -0.2f : 0.1f) * Math.abs(scrollProgress);
+
+                // Extra translation to account for the increase in size
+                if (!mIn) {
+                    float translationX = v.getMeasuredWidth() * 0.1f * -scrollProgress;
+                    v.setTranslationX(translationX);
+                }
+
+                v.setScaleX(scale);
+                v.setScaleY(scale);
+            }
+        }
+
+        public static class Rotate extends TransitionEffect {
+            private boolean mUp;
+
+            public Rotate(PagedView pagedView, boolean up) {
+                super(pagedView, up ? TRANSITION_EFFECT_ROTATE_UP : TRANSITION_EFFECT_ROTATE_DOWN);
+                mUp = up;
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float rotation =
+                        (mUp ? TRANSITION_SCREEN_ROTATION : -TRANSITION_SCREEN_ROTATION) * scrollProgress;
+
+                float translationX = v.getMeasuredWidth() * scrollProgress;
+
+                float rotatePoint =
+                        (v.getMeasuredWidth() * 0.5f) /
+                                (float) Math.tan(Math.toRadians((double) (TRANSITION_SCREEN_ROTATION * 0.5f)));
+
+                v.setPivotX(v.getMeasuredWidth() * 0.5f);
+                if (mUp) {
+                    v.setPivotY(-rotatePoint);
+                } else {
+                    v.setPivotY(v.getMeasuredHeight() + rotatePoint);
+                }
+                v.setRotation(rotation);
+                v.setTranslationX(translationX);
+            }
+        }
+
+        public static class Cube extends TransitionEffect {
+            private boolean mIn;
+
+            public Cube(PagedView pagedView, boolean in) {
+                super(pagedView, in ? TRANSITION_EFFECT_CUBE_IN : TRANSITION_EFFECT_CUBE_OUT);
+                mIn = in;
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float rotation = (mIn ? 90.0f : -90.0f) * scrollProgress;
+
+                if (mIn) {
+                    v.setCameraDistance(mPagedView.mDensity * PagedView.CAMERA_DISTANCE);
+                }
+
+                v.setPivotX(scrollProgress < 0 ? 0 : v.getMeasuredWidth());
+                v.setPivotY(v.getMeasuredHeight() * 0.5f);
+                v.setRotationY(rotation);
+            }
+        }
+
+        public static class Stack extends TransitionEffect {
+            private ZInterpolator mZInterpolator = new ZInterpolator(0.5f);
+            private DecelerateInterpolator mLeftScreenAlphaInterpolator = new DecelerateInterpolator(4);
+            protected AccelerateInterpolator mAlphaInterpolator = new AccelerateInterpolator(0.9f);
+
+            public Stack(PagedView pagedView) {
+                super(pagedView, TRANSITION_EFFECT_STACK);
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                final boolean isRtl = mPagedView.isLayoutRtl();
+                float interpolatedProgress;
+                float translationX;
+                float maxScrollProgress = Math.max(0, scrollProgress);
+                float minScrollProgress = Math.min(0, scrollProgress);
+
+                if (mPagedView.isLayoutRtl()) {
+                    translationX = maxScrollProgress * v.getMeasuredWidth();
+                    interpolatedProgress = mZInterpolator.getInterpolation(Math.abs(maxScrollProgress));
+                } else {
+                    translationX = minScrollProgress * v.getMeasuredWidth();
+                    interpolatedProgress = mZInterpolator.getInterpolation(Math.abs(minScrollProgress));
+                }
+                float scale = (1 - interpolatedProgress) +
+                        interpolatedProgress * TRANSITION_SCALE_FACTOR;
+
+                float alpha;
+                if (isRtl && (scrollProgress > 0)) {
+                    alpha = mAlphaInterpolator.getInterpolation(1 - Math.abs(maxScrollProgress));
+                } else if (!isRtl && (scrollProgress < 0)) {
+                    alpha = mAlphaInterpolator.getInterpolation(1 - Math.abs(scrollProgress));
+                } else {
+                    //  On large screens we need to fade the page as it nears its leftmost position
+                    alpha = mLeftScreenAlphaInterpolator.getInterpolation(1 - scrollProgress);
+                }
+
+                v.setTranslationX(translationX);
+                v.setScaleX(scale);
+                v.setScaleY(scale);
+                if (v instanceof CellLayout) {
+                    ((CellLayout) v).getShortcutsAndWidgets().setAlpha(alpha);
+                } else {
+                    v.setAlpha(alpha);
+                }
+
+                // If the view has 0 alpha, we set it to be invisible so as to prevent
+                // it from accepting touches
+                if (alpha == 0) {
+                    v.setVisibility(INVISIBLE);
+                } else if (v.getVisibility() != VISIBLE) {
+                    v.setVisibility(VISIBLE);
+                }
+            }
+        }
+
+        public static class Accordion extends TransitionEffect {
+            public Accordion(PagedView pagedView) {
+                super(pagedView, TRANSITION_EFFECT_ACCORDION);
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float scale = 1.0f - Math.abs(scrollProgress);
+
+                v.setScaleX(scale);
+                v.setPivotX(scrollProgress < 0 ? 0 : v.getMeasuredWidth());
+                v.setPivotY(v.getMeasuredHeight() / 2f);
+            }
+        }
+
+        public static class Flip extends TransitionEffect {
+            public Flip(PagedView pagedView) {
+                super(pagedView, TRANSITION_EFFECT_FLIP);
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float rotation = -180.0f * Math.max(-1f, Math.min(1f, scrollProgress));
+
+                v.setCameraDistance(mPagedView.mDensity * PagedView.CAMERA_DISTANCE);
+                v.setPivotX(v.getMeasuredWidth() * 0.5f);
+                v.setPivotY(v.getMeasuredHeight() * 0.5f);
+                v.setRotationY(rotation);
+
+                if (scrollProgress >= -0.5f && scrollProgress <= 0.5f) {
+                    v.setTranslationX(v.getMeasuredWidth() * scrollProgress);
+                    if (v.getVisibility() != VISIBLE) {
+                        v.setVisibility(VISIBLE);
+                    }
+                } else {
+                    v.setTranslationX(0f);
+                    v.setVisibility(INVISIBLE);
+                }
+            }
+        }
+
+        public static class Cylinder extends TransitionEffect {
+            private boolean mIn;
+
+            public Cylinder(PagedView pagedView, boolean in) {
+                super(pagedView, in ? TRANSITION_EFFECT_CYLINDER_IN : TRANSITION_EFFECT_CYLINDER_OUT);
+                mIn = in;
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float rotation = (mIn ? TRANSITION_SCREEN_ROTATION : -TRANSITION_SCREEN_ROTATION) * scrollProgress;
+
+                v.setPivotX((scrollProgress + 1) * v.getMeasuredWidth() * 0.5f);
+                v.setPivotY(v.getMeasuredHeight() * 0.5f);
+                v.setRotationY(rotation);
+            }
+        }
+
+        public static class Carousel extends TransitionEffect {
+            public Carousel(PagedView pagedView) {
+                super(pagedView, TRANSITION_EFFECT_CAROUSEL);
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float rotation = 90.0f * scrollProgress;
+
+                v.setCameraDistance(mPagedView.mDensity * PagedView.CAMERA_DISTANCE);
+                v.setTranslationX(v.getMeasuredWidth() * scrollProgress);
+                v.setPivotX(!mPagedView.isLayoutRtl() ? 0f : v.getMeasuredWidth());
+                v.setPivotY(v.getMeasuredHeight() / 2);
+                v.setRotationY(-rotation);
+            }
+        }
+
+        public static class Overview extends TransitionEffect {
+            private AccelerateDecelerateInterpolator mScaleInterpolator = new AccelerateDecelerateInterpolator();
+
+            public Overview(PagedView pagedView) {
+                super(pagedView, TRANSITION_EFFECT_OVERVIEW);
+            }
+
+            @Override
+            public void screenScrolled(View v, int i, float scrollProgress) {
+                float scale = 1.0f - 0.1f *
+                        mScaleInterpolator.getInterpolation(Math.min(0.3f, Math.abs(scrollProgress)) / 0.3f);
+
+                v.setPivotX(scrollProgress < 0 ? 0 : v.getMeasuredWidth());
+                v.setPivotY(v.getMeasuredHeight() * 0.5f);
+                v.setScaleX(scale);
+                v.setScaleY(scale);
+                mPagedView.setChildAlpha(v, scale);
+            }
+        }
+    }
 }
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index f2a06e86c..ebe2e9af0 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -211,7 +211,7 @@ public class Workspace extends SmoothPagedView
     WallpaperOffsetInterpolator mWallpaperOffset;
     private boolean mScrollWallpaper;
     private Runnable mDelayedResizeRunnable;
-    private Runnable mDelayedSnapToPageRunnable;
+
     private Point mDisplaySize = new Point();
     private int mCameraDistance;
 
@@ -316,6 +316,9 @@ public class Workspace extends SmoothPagedView
         mScrollWallpaper = SettingsProvider.getBoolean(context,
                 SettingsProvider.SETTINGS_UI_HOMESCREEN_SCROLLING_WALLPAPER_SCROLL,
                 R.bool.preferences_interface_homescreen_scrolling_wallpaper_scroll_default);
+        TransitionEffect.setFromString(this, SettingsProvider.getString(context,
+                SettingsProvider.SETTINGS_UI_HOMESCREEN_SCROLLING_TRANSITION_EFFECT,
+                R.string.preferences_interface_homescreen_scrolling_transition_effect));
 
         mLauncher = (Launcher) context;
         final Resources res = getResources();
@@ -476,6 +479,11 @@ public class Workspace extends SmoothPagedView
     }
 
     @Override
+    public void setChildAlpha(View child, float alpha) {
+        ((CellLayout) child).setShortcutAndWidgetAlpha(alpha);
+    }
+
+    @Override
     public void onChildViewAdded(View parent, View child) {
         if (!(child instanceof CellLayout)) {
             throw new IllegalArgumentException("A Workspace can only have CellLayout children.");
@@ -1101,10 +1109,6 @@ public class Workspace extends SmoothPagedView
             mDelayedResizeRunnable = null;
         }
 
-        if (mDelayedSnapToPageRunnable != null) {
-            mDelayedSnapToPageRunnable.run();
-            mDelayedSnapToPageRunnable = null;
-        }
         if (mStripScreensOnPageStopMoving) {
             stripEmptyScreens();
             mStripScreensOnPageStopMoving = false;
@@ -1147,14 +1151,6 @@ public class Workspace extends SmoothPagedView
                 sp, mLauncher.getWindowManager(), mWallpaperManager);
     }
 
-    protected void snapToPage(int whichPage, Runnable r) {
-        if (mDelayedSnapToPageRunnable != null) {
-            mDelayedSnapToPageRunnable.run();
-        }
-        mDelayedSnapToPageRunnable = r;
-        snapToPage(whichPage, SLOW_PAGE_SNAP_ANIMATION_DURATION);
-    }
-
     protected void snapToScreenId(long screenId, Runnable r) {
         snapToPage(getPageIndexForScreenId(screenId), r);
     }
@@ -1527,6 +1523,15 @@ public class Workspace extends SmoothPagedView
     @Override
     protected void screenScrolled(int screenCenter) {
         final boolean isRtl = isLayoutRtl();
+
+        boolean isOnLastPageBeforeCustomContent = false;
+        if (hasCustomContent()) {
+            int customContentWidth = mWorkspaceScreens.get(CUSTOM_CONTENT_SCREEN_ID).getMeasuredWidth();
+            isOnLastPageBeforeCustomContent = (mOverScrollX < customContentWidth && (!hasCustomContent() || isLayoutRtl())) ||
+                    (mOverScrollX > mMaxScrollX - customContentWidth && (!hasCustomContent() || !isLayoutRtl()));
+        }
+        mUseTransitionEffect = !isOnLastPageBeforeCustomContent && mState == State.NORMAL && !mIsSwitchingState;
+
         super.screenScrolled(screenCenter);
 
         updatePageAlphaValues(screenCenter);
@@ -1783,38 +1788,6 @@ public class Workspace extends SmoothPagedView
     }
 
     /*
-     * This interpolator emulates the rate at which the perceived scale of an object changes
-     * as its distance from a camera increases. When this interpolator is applied to a scale
-     * animation on a view, it evokes the sense that the object is shrinking due to moving away
-     * from the camera.
-     */
-    static class ZInterpolator implements TimeInterpolator {
-        private float focalLength;
-
-        public ZInterpolator(float foc) {
-            focalLength = foc;
-        }
-
-        public float getInterpolation(float input) {
-            return (1.0f - focalLength / (focalLength + input)) /
-                (1.0f - focalLength / (focalLength + 1.0f));
-        }
-    }
-
-    /*
-     * The exact reverse of ZInterpolator.
-     */
-    static class InverseZInterpolator implements TimeInterpolator {
-        private ZInterpolator zInterpolator;
-        public InverseZInterpolator(float foc) {
-            zInterpolator = new ZInterpolator(foc);
-        }
-        public float getInterpolation(float input) {
-            return 1 - zInterpolator.getInterpolation(1 - input);
-        }
-    }
-
-    /*
      * ZInterpolator compounded with an ease-out.
      */
     static class ZoomOutInterpolator implements TimeInterpolator {
@@ -2100,6 +2073,20 @@ public class Workspace extends SmoothPagedView
             float initialAlpha = cl.getShortcutsAndWidgets().getAlpha();
             float finalAlpha = stateIsSmall ? 0f : 1f;
 
+            if (stateIsOverview) {
+                cl.setVisibility(VISIBLE);
+                cl.setTranslationX(0f);
+                cl.setTranslationY(0f);
+                cl.setPivotX(cl.getMeasuredWidth() * 0.5f);
+                cl.setPivotY(cl.getMeasuredHeight() * 0.5f);
+                cl.setRotation(0f);
+                cl.setRotationY(0f);
+                cl.setRotationX(0f);
+                cl.setScaleX(1f);
+                cl.setScaleY(1f);
+                cl.setShortcutAndWidgetAlpha(1f);
+            }
+
             // If we are animating to/from the small state, then hide the side pages and fade the
             // current page in
             if (!mIsSwitchingState) {
diff --git a/src/com/android/launcher3/settings/SettingsProvider.java b/src/com/android/launcher3/settings/SettingsProvider.java
index 9c0a283ac..fb4c75056 100644
--- a/src/com/android/launcher3/settings/SettingsProvider.java
+++ b/src/com/android/launcher3/settings/SettingsProvider.java
@@ -26,8 +26,10 @@ public final class SettingsProvider {
 
     public static final String SETTINGS_UI_HOMESCREEN_DEFAULT_SCREEN_ID = "ui_homescreen_default_screen_id";
     public static final String SETTINGS_UI_HOMESCREEN_SEARCH = "ui_homescreen_search";
+    public static final String SETTINGS_UI_HOMESCREEN_SCROLLING_TRANSITION_EFFECT = "ui_homescreen_scrolling_transition_effect";
     public static final String SETTINGS_UI_HOMESCREEN_SCROLLING_WALLPAPER_SCROLL = "ui_homescreen_scrolling_wallpaper_scroll";
     public static final String SETTINGS_UI_HOMESCREEN_SCROLLING_PAGE_OUTLINES = "ui_homescreen_scrolling_page_outlines";
+    public static final String SETTINGS_UI_DRAWER_SCROLLING_TRANSITION_EFFECT = "ui_drawer_scrolling_transition_effect";
     public static final String SETTINGS_UI_GENERAL_ICONS_LARGE = "ui_general_icons_large";
     public static final String SETTINGS_UI_GENERAL_ICONS_TEXT_FONT_FAMILY = "ui_general_icons_text_font";
     public static final String SETTINGS_UI_GENERAL_ICONS_TEXT_FONT_STYLE = "ui_general_icons_text_font_style";