diff --git a/AndroidManifest-common.xml b/AndroidManifest-common.xml
index c24850d..fe8d65e 100644
--- a/AndroidManifest-common.xml
+++ b/AndroidManifest-common.xml
@@ -20,7 +20,6 @@
 <manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.launcher3">
-    <uses-sdk android:targetSdkVersion="23" android:minSdkVersion="21"/>
 
     <!--
     The manifest defines the common entries that should be present in any derivative of Launcher3.
diff --git a/build.gradle b/build.gradle
index 0030b8b..4ae6600 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,14 +1,16 @@
 buildscript {
     repositories {
         mavenCentral()
-        jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
-        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.0'
+        classpath 'com.android.tools.build:gradle:3.2.0-alpha12'
+        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.3'
     }
 }
 
+final String SUPPORT_LIBS_VERSION = '28.0.0-SNAPSHOT'
+
 apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
@@ -23,6 +25,7 @@
         versionName "1.0"
 
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        vectorDrawables.useSupportLibrary = true
     }
     buildTypes {
         debug {
@@ -30,18 +33,28 @@
         }
     }
 
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+
+    flavorDimensions "default"
+
     productFlavors {
         aosp {
+            dimension "default"
             applicationId 'com.android.launcher3'
             testApplicationId 'com.android.launcher3.tests'
         }
 
         l3go {
+            dimension "default"
             applicationId 'com.android.launcher3'
             testApplicationId 'com.android.launcher3.tests'
         }
 
         quickstep {
+            dimension "default"
             applicationId 'com.android.launcher3'
             testApplicationId 'com.android.launcher3.tests'
         }
@@ -98,27 +111,28 @@
 }
 
 repositories {
+    maven { url "../../../prebuilts/fullsdk-darwin/extras/android/m2repository" }
+    maven { url "../../../prebuilts/fullsdk-linux/extras/android/m2repository" }
     mavenCentral()
-    jcenter()
+    google()
 }
 
-final String SUPPORT_LIBS_VERSION = '28.0.0-SNAPSHOT'
 dependencies {
-    compile "com.android.support:support-v4:${SUPPORT_LIBS_VERSION}"
-    compile "com.android.support:support-dynamic-animation:${SUPPORT_LIBS_VERSION}"
-    compile "com.android.support:recyclerview-v7:${SUPPORT_LIBS_VERSION}"
-    compile 'com.google.protobuf.nano:protobuf-javanano:3.0.0-alpha-7'
+    implementation "com.android.support:support-v4:${SUPPORT_LIBS_VERSION}"
+    implementation "com.android.support:support-dynamic-animation:${SUPPORT_LIBS_VERSION}"
+    implementation "com.android.support:recyclerview-v7:${SUPPORT_LIBS_VERSION}"
+    implementation 'com.google.protobuf.nano:protobuf-javanano:3.0.0-alpha-7'
 
-    quickstepCompile fileTree(dir: "quickstep/libs", include: 'sysui_shared.jar')
+    quickstepImplementation fileTree(dir: "quickstep/libs", include: 'sysui_shared.jar')
 
-    testCompile 'junit:junit:4.12'
-    androidTestCompile "org.mockito:mockito-core:1.9.5"
-    androidTestCompile 'com.google.dexmaker:dexmaker:1.2'
-    androidTestCompile 'com.google.dexmaker:dexmaker-mockito:1.2'
-    androidTestCompile 'com.android.support.test:runner:1.0.0'
-    androidTestCompile 'com.android.support.test:rules:1.0.0'
-    androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.2'
-    androidTestCompile "com.android.support:support-annotations:${SUPPORT_LIBS_VERSION}"
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation "org.mockito:mockito-core:1.9.5"
+    androidTestImplementation 'com.google.dexmaker:dexmaker:1.2'
+    androidTestImplementation 'com.google.dexmaker:dexmaker-mockito:1.2'
+    androidTestImplementation 'com.android.support.test:runner:1.0.0'
+    androidTestImplementation 'com.android.support.test:rules:1.0.0'
+    androidTestImplementation 'com.android.support.test.uiautomator:uiautomator-v18:2.1.2'
+    androidTestImplementation "com.android.support:support-annotations:${SUPPORT_LIBS_VERSION}"
 }
 
 protobuf {
diff --git a/quickstep/AndroidManifest.xml b/quickstep/AndroidManifest.xml
index f62d1d6..bab2cd7 100644
--- a/quickstep/AndroidManifest.xml
+++ b/quickstep/AndroidManifest.xml
@@ -21,8 +21,6 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.android.launcher3" >
 
-    <uses-sdk android:targetSdkVersion="23" android:minSdkVersion="21"/>
-
     <uses-permission android:name="android.permission.CONTROL_REMOTE_APP_TRANSITION_ANIMATIONS" />
     <application
         android:backupAgent="com.android.launcher3.LauncherBackupAgent"
diff --git a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
index a4d3a50..fb4aa02 100644
--- a/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
+++ b/quickstep/src/com/android/quickstep/fallback/FallbackRecentsView.java
@@ -35,7 +35,6 @@
     public FallbackRecentsView(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
         setOverviewStateEnabled(true);
-        updateEmptyMessage();
     }
 
     @Override
diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index a7b018a..1004aa3 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -213,6 +213,7 @@
         mEmptyMessagePadding = getResources()
                 .getDimensionPixelSize(R.dimen.recents_empty_message_text_padding);
         setWillNotDraw(false);
+        updateEmptyMessage();
     }
 
     @Override
@@ -310,6 +311,56 @@
         }
     }
 
+    private float calculateClearAllButtonAlpha() {
+        if (mClearAllButton.getVisibility() != View.VISIBLE) return 0;
+
+        // Current visible coordinate of the right border of the rightmost task.
+        final int carouselCurrentRight = getChildAt(getChildCount() - 1).getRight() - getScrollX();
+
+        // As the right border (let's call it E aka carouselCurrentRight) of the carousel moves
+        // over Clear all button, the button changes trasparency.
+        // leftOfAlphaChange < rightOfAlphaChange; these are the points of the 100% and 0% alpha
+        // correspondingly. Alpha changes linearly between 100% and 0% as E moves through this
+        // range. It doesn't change outside of the range.
+
+        // Once E hits the left border of the Clear-All button, the whole button is uncovered,
+        // and it should have alpha 100%.
+        final float leftOfAlphaChange = mClearAllButton.getX();
+
+        // The rightmost possible right coordinate of the carousel.
+        final int carouselMotionLimit = getScrollForPage(getChildCount() - 1) + getWidth()
+                - getPaddingRight() - mInsets.right;
+
+        // The carousel might not be able to ever cover a part of the Clear-all button. Then
+        // always show the button as 100%. Technically, this check also prevents dividing by zero
+        // or a negative number when calculating the transparency ratio below.
+        if (carouselMotionLimit <= leftOfAlphaChange) return 1;
+
+        // If the carousel is able to cover the button completely, we make the button completely
+        // transparent when E hits the right border of the button.
+        // Or, the carousel may not be able to move that far to the right so it completely covers
+        // the button. Then we set the rightmost possible position of the carousel as the point
+        // where the button reaches 0 alpha.
+        final float rightOfAlphaChange = Math.min(
+                mClearAllButton.getX() + mClearAllButton.getWidth(), carouselMotionLimit);
+
+        return Utilities.boundToRange(
+                (rightOfAlphaChange - carouselCurrentRight) /
+                        (rightOfAlphaChange - leftOfAlphaChange), 0, 1);
+    }
+
+    private void updateClearAllButtonAlpha() {
+        if (mClearAllButton != null) {
+            mClearAllButton.setAlpha(calculateClearAllButtonAlpha() * mContentAlpha);
+        }
+    }
+
+    @Override
+    protected void onScrollChanged(int l, int t, int oldl, int oldt) {
+        super.onScrollChanged(l, t, oldl, oldt);
+        updateClearAllButtonAlpha();
+    }
+
     @Override
     public boolean onTouchEvent(MotionEvent ev) {
         if (DEBUG_SHOW_CLEAR_ALL_BUTTON && ev.getAction() == MotionEvent.ACTION_DOWN
@@ -864,6 +915,7 @@
         int alphaInt = Math.round(alpha * 255);
         mEmptyMessagePaint.setAlpha(alphaInt);
         mEmptyIcon.setAlpha(alphaInt);
+        updateClearAllButtonAlpha();
     }
 
     public void setAdjacentScale(float adjacentScale) {
@@ -948,6 +1000,7 @@
             mEmptyTextLayout = null;
             mLastMeasureSize.set(getWidth(), getHeight());
         }
+        updateClearAllButtonVisibility();
 
         if (!mShowEmptyMessage) return;
 
@@ -1140,8 +1193,10 @@
     }
 
     private void updateClearAllButtonVisibility() {
+        if (mClearAllButton == null) return;
         mClearAllButton.setVisibility(
                 !DEBUG_SHOW_CLEAR_ALL_BUTTON || mShowEmptyMessage ? GONE : VISIBLE);
+        updateClearAllButtonAlpha();
     }
 
     public void setClearAllButton(View clearAllButton) {
diff --git a/src/com/android/launcher3/views/SpringRelativeLayout.java b/src/com/android/launcher3/views/SpringRelativeLayout.java
index 090b3e6..a508191 100644
--- a/src/com/android/launcher3/views/SpringRelativeLayout.java
+++ b/src/com/android/launcher3/views/SpringRelativeLayout.java
@@ -24,7 +24,6 @@
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.RecyclerView.EdgeEffectFactory;
 import android.util.AttributeSet;
-import android.util.Log;
 import android.util.SparseBooleanArray;
 import android.view.View;
 import android.widget.EdgeEffect;
@@ -58,6 +57,7 @@
     private final SpringAnimation mSpring;
 
     private float mDampedScrollShift = 0;
+    private SpringEdgeEffect mActiveEdge;
 
     public SpringRelativeLayout(Context context) {
         this(context, null);
@@ -90,6 +90,13 @@
         return super.drawChild(canvas, child, drawingTime);
     }
 
+    private void setActiveEdge(SpringEdgeEffect edge) {
+        if (mActiveEdge != edge && mActiveEdge != null) {
+            mActiveEdge.mDistance = 0;
+        }
+        mActiveEdge = edge;
+    }
+
     private void setDampedScrollShift(float shift) {
         if (shift != mDampedScrollShift) {
             mDampedScrollShift = shift;
@@ -144,6 +151,7 @@
 
         @Override
         public void onPull(float deltaDistance, float displacement) {
+            setActiveEdge(this);
             mDistance += deltaDistance * (mVelocityMultiplier / 3f);
             setDampedScrollShift(mDistance * getHeight());
         }
diff --git a/tests/AndroidManifest-common.xml b/tests/AndroidManifest-common.xml
index a54268a..af8b15c 100644
--- a/tests/AndroidManifest-common.xml
+++ b/tests/AndroidManifest-common.xml
@@ -18,8 +18,6 @@
     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" />