diff --git a/packages/DocumentsUI/res/layout/drawer_layout.xml b/packages/DocumentsUI/res/layout/drawer_layout.xml
index b65c5a066bf6f..f7824c1ebd1eb 100644
--- a/packages/DocumentsUI/res/layout/drawer_layout.xml
+++ b/packages/DocumentsUI/res/layout/drawer_layout.xml
@@ -52,7 +52,20 @@
 
             </com.android.documentsui.DocumentsToolbar>
 
-            <include layout="@layout/directory_cluster"/>
+            <FrameLayout
+                android:layout_width="match_parent"
+                android:layout_height="match_parent">
+
+                <include layout="@layout/directory_cluster"/>
+
+                <!-- Drawer edge is a dummy view used to capture hovering event
+                     on view edge to open the drawer. (b/28345294) -->
+                <View
+                    android:id="@+id/drawer_edge"
+                    android:background="@android:color/transparent"
+                    android:layout_width="@dimen/drawer_edge_width"
+                    android:layout_height="match_parent"/>
+            </FrameLayout>
 
         </LinearLayout>
 
diff --git a/packages/DocumentsUI/res/values/dimens.xml b/packages/DocumentsUI/res/values/dimens.xml
index e682994749b9d..cad26e250e5a4 100644
--- a/packages/DocumentsUI/res/values/dimens.xml
+++ b/packages/DocumentsUI/res/values/dimens.xml
@@ -39,6 +39,8 @@
     <dimen name="grid_item_elevation">2dp</dimen>
     <dimen name="max_drawer_width">280dp</dimen>
 
+    <dimen name="drawer_edge_width">12dp</dimen>
+
     <dimen name="drag_shadow_width">160dp</dimen>
     <dimen name="drag_shadow_height">48dp</dimen>
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java b/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java
index d1285c83cc89d..3597a7495b0b4 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/BaseActivity.java
@@ -256,6 +256,8 @@ public abstract class BaseActivity extends Activity
         } else {
             new PickRootTask(this, root).executeOnExecutor(getExecutorForCurrentDirectory());
         }
+
+        mNavigator.revealRootsDrawer(false);
     }
 
     @Override
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java b/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
index 7a7d3a1d0a98a..2ca13dcf7b4d4 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
@@ -316,12 +316,6 @@ public class DocumentsActivity extends BaseActivity {
                 .executeOnExecutor(getExecutorForCurrentDirectory());
     }
 
-    @Override
-    void onRootPicked(RootInfo root) {
-        super.onRootPicked(root);
-        mNavigator.revealRootsDrawer(false);
-    }
-
     @Override
     public void onDocumentPicked(DocumentInfo doc, Model model) {
         final FragmentManager fm = getFragmentManager();
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java b/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java
index 14e6b69bfc192..97d459bf18622 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DrawerController.java
@@ -20,7 +20,7 @@ import static com.android.documentsui.Shared.DEBUG;
 
 import android.annotation.IntDef;
 import android.app.Activity;
-import android.content.Context;
+import android.support.annotation.ColorRes;
 import android.support.v4.app.ActionBarDrawerToggle;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v4.widget.DrawerLayout.DrawerListener;
@@ -120,7 +120,8 @@ abstract class DrawerController implements DrawerListener {
     /**
      * Runtime controller that manages a real drawer.
      */
-    private static final class RuntimeDrawerController extends DrawerController {
+    private static final class RuntimeDrawerController extends DrawerController
+            implements ItemDragListener.DragHost {
         private final ActionBarDrawerToggle mToggle;
         private DrawerLayout mLayout;
         private View mDrawer;
@@ -138,6 +139,30 @@ abstract class DrawerController implements DrawerListener {
             mToggle = toggle;
 
             mLayout.setDrawerListener(this);
+
+            View edge = layout.findViewById(R.id.drawer_edge);
+            edge.setOnDragListener(new ItemDragListener<>(this));
+        }
+
+        @Override
+        public void runOnUiThread(Runnable runnable) {
+            mDrawer.post(runnable);
+        }
+
+        @Override
+        public void setDropTargetHighlight(View v, boolean highlight) {
+            assert (v.getId() == R.id.drawer_edge);
+
+            @ColorRes int id = highlight ? R.color.item_doc_background_selected :
+                android.R.color.transparent;
+            v.setBackgroundColor(id);
+        }
+
+        @Override
+        public void onViewHovered(View v) {
+            assert (v.getId() == R.id.drawer_edge);
+
+            setOpen(true);
         }
 
         @Override
diff --git a/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java b/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java
index b2142a2c26570..282cc70cd22a1 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/FilesActivity.java
@@ -263,12 +263,6 @@ public class FilesActivity extends BaseActivity {
         }
     }
 
-    @Override
-    void onRootPicked(RootInfo root) {
-        super.onRootPicked(root);
-        mDrawer.setOpen(false);
-    }
-
     @Override
     public void onDocumentsPicked(List<DocumentInfo> docs) {
         throw new UnsupportedOperationException();
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java b/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java
index 8f0113c1a6371..ad2ee07c85a98 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java
@@ -186,25 +186,6 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
         startActivity(intent);
     }
 
-    private void openItem(int position) {
-        Item item = mAdapter.getItem(position);
-        if (item instanceof RootItem) {
-            BaseActivity activity = BaseActivity.get(this);
-            RootInfo newRoot = ((RootItem) item).root;
-            Metrics.logRootVisited(getActivity(), newRoot);
-            activity.onRootPicked(newRoot);
-        } else if (item instanceof AppItem) {
-            DocumentsActivity activity = DocumentsActivity.get(this);
-            ResolveInfo info = ((AppItem) item).info;
-            Metrics.logAppVisited(getActivity(), info);
-            activity.onAppPicked(info);
-        } else if (item instanceof SpacerItem) {
-            if (DEBUG) Log.d(TAG, "Ignoring click/hover on spacer item.");
-        } else {
-            throw new IllegalStateException("Unknown root: " + item);
-        }
-    }
-
     @Override
     public void runOnUiThread(Runnable runnable) {
         getActivity().runOnUiThread(runnable);
@@ -217,8 +198,9 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
      */
     @Override
     public void onViewHovered(View view) {
-        int position = (Integer) view.getTag(R.id.item_position_tag);
-        openItem(position);
+        final int position = (Integer) view.getTag(R.id.item_position_tag);
+        final Item item = mAdapter.getItem(position);
+        item.open(this);
     }
 
     @Override
@@ -232,7 +214,8 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
     private OnItemClickListener mItemListener = new OnItemClickListener() {
         @Override
         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
-            openItem(position);
+            final Item item = mAdapter.getItem(position);
+            item.open(RootsFragment.this);
         }
     };
 
@@ -269,6 +252,8 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
         abstract void bindView(View convertView);
 
         abstract boolean isDropTarget();
+
+        abstract void open(RootsFragment fragment);
     }
 
     private static class RootItem extends Item {
@@ -304,6 +289,13 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
         boolean isDropTarget() {
             return root.supportsCreate() && !root.isLibrary();
         }
+
+        @Override
+        public void open(RootsFragment fragment) {
+            BaseActivity activity = BaseActivity.get(fragment);
+            Metrics.logRootVisited(fragment.getActivity(), root);
+            activity.onRootPicked(root);
+        }
     }
 
     private static class SpacerItem extends Item {
@@ -320,6 +312,11 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
         boolean isDropTarget() {
             return false;
         }
+
+        @Override
+        public void open(RootsFragment fragment) {
+            if (DEBUG) Log.d(TAG, "Ignoring click/hover on spacer item.");
+        }
     }
 
     private static class AppItem extends Item {
@@ -349,6 +346,13 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
             // We won't support drag n' drop in DocumentsActivity, and apps only show up there.
             return false;
         }
+
+        @Override
+        public void open(RootsFragment fragment) {
+            DocumentsActivity activity = DocumentsActivity.get(fragment);
+            Metrics.logAppVisited(fragment.getActivity(), info);
+            activity.onAppPicked(info);
+        }
     }
 
     private static class RootsAdapter extends ArrayAdapter<Item> {
diff --git a/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java b/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java
index eec12c89048d4..b401e0a7ba63f 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/dirlist/DirectoryFragment.java
@@ -1274,12 +1274,18 @@ public class DirectoryFragment extends Fragment
      */
     @Override
     public void onViewHovered(View view) {
+        BaseActivity activity = (BaseActivity) getActivity();
         if (getModelId(view) != null) {
-            ((BaseActivity) getActivity()).springOpenDirectory(getDestination(view));
+           activity.springOpenDirectory(getDestination(view));
         }
+
+        activity.setRootsDrawerOpen(false);
     }
 
     public boolean handleDropEvent(View v, DragEvent event) {
+        BaseActivity activity = (BaseActivity) getActivity();
+        activity.setRootsDrawerOpen(false);
+
         ClipData clipData = event.getClipData();
         assert (clipData != null);