Refactor FragmentTuner to ActivityConfig.

* Move model listener that opens drawer to ActionHandler.
* Move showChooserForDoc() to ActionHandler.
* Statically initialize ActionHandler.
* Isolate OnDragListener to FilesActivity only.

Bug: 28315278
Change-Id: I760c8411922fca827fd08c115bd2590ab671c380

20 files changed, 360 insertions, 362 deletions

diff --git a/src/com/android/documentsui/AbstractActionHandler.java b/src/com/android/documentsui/AbstractActionHandler.java
index 6b341b8da..6a6d71cd6 100644
--- a/src/com/android/documentsui/AbstractActionHandler.java
+++ b/src/com/android/documentsui/AbstractActionHandler.java
@@ -138,6 +138,11 @@ public abstract class AbstractActionHandler<T extends Activity & CommonAddons>
     }
 
     @Override
+    public void showChooserForDoc(DocumentInfo doc) {
+        throw new UnsupportedOperationException("Show chooser for doc not supported!");
+    }
+
+    @Override
     public void deleteDocuments(Model model, Selection selection, ConfirmationCallback callback) {
         throw new UnsupportedOperationException("Delete not supported!");
     }
@@ -171,5 +176,6 @@ public abstract class AbstractActionHandler<T extends Activity & CommonAddons>
         void openContainerDocument(DocumentInfo doc);
         RootInfo getCurrentRoot();
         DocumentInfo getCurrentDirectory();
+        void setRootsDrawerOpen(boolean open);
     }
 }
diff --git a/src/com/android/documentsui/ActionHandler.java b/src/com/android/documentsui/ActionHandler.java
index 0c33f6c0b..00aaee0a1 100644
--- a/src/com/android/documentsui/ActionHandler.java
+++ b/src/com/android/documentsui/ActionHandler.java
@@ -23,6 +23,7 @@ import android.net.Uri;
 
 import com.android.documentsui.base.BooleanConsumer;
 import com.android.documentsui.base.ConfirmationCallback;
+import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
 import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.dirlist.DocumentDetails;
@@ -35,7 +36,6 @@ public interface ActionHandler {
 
     /**
      * Drops documents on a root.
-     * @param check The check to make sure RootsFragment is not detached from activity.
      */
     boolean dropOn(ClipData data, RootInfo root);
 
@@ -64,6 +64,8 @@ public interface ActionHandler {
 
     boolean openDocument(DocumentDetails doc);
 
+    void showChooserForDoc(DocumentInfo doc);
+
     void deleteDocuments(Model model, Selection selection, ConfirmationCallback callback);
 
     /**
diff --git a/src/com/android/documentsui/dirlist/FragmentTuner.java b/src/com/android/documentsui/ActivityConfig.java
index 2451bd2fd..5b70fd5a3 100644
--- a/src/com/android/documentsui/dirlist/FragmentTuner.java
+++ b/src/com/android/documentsui/ActivityConfig.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 The Android Open Source Project
+ * Copyright (C) 2016 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.
@@ -14,24 +14,25 @@
  * limitations under the License.
  */
 
-package com.android.documentsui.dirlist;
+package com.android.documentsui;
 
-import com.android.documentsui.base.DocumentInfo;
+import com.android.documentsui.base.DocumentStack;
+import com.android.documentsui.base.State;
 
 /**
  * Providers support for specializing the DirectoryFragment to the "host" Activity.
  * Feel free to expand the role of this class to handle other specializations.
  */
-public abstract class FragmentTuner {
+public abstract class ActivityConfig {
 
     // Subtly different from isDocumentEnabled. The reason may be illuminated as follows.
     // A folder is enabled such that it may be double clicked, even in settings
     // when the folder itself cannot be selected. This may also be true of container types.
-    public boolean canSelectType(String docMimeType, int docFlags) {
+    public boolean canSelectType(String docMimeType, int docFlags, State state) {
         return true;
     }
 
-    public boolean isDocumentEnabled(String docMimeType, int docFlags) {
+    public boolean isDocumentEnabled(String docMimeType, int docFlags, State state) {
         return true;
     }
 
@@ -39,20 +40,14 @@ public abstract class FragmentTuner {
      * When managed mode is enabled, active downloads will be visible in the UI.
      * Presumably this should only be true when in the downloads directory.
      */
-    protected boolean managedModeEnabled() {
+    public boolean managedModeEnabled(DocumentStack stack) {
         return false;
     }
 
     /**
      * Whether drag n' drop is allowed in this context
      */
-    protected boolean dragAndDropEnabled() {
+    public boolean dragAndDropEnabled() {
         return false;
     }
-
-    // TODO: Move to action handler.
-    @Deprecated
-    protected void showChooserForDoc(DocumentInfo doc) {
-        throw new UnsupportedOperationException("Show chooser not supported!");
-    }
 }
diff --git a/src/com/android/documentsui/BaseActivity.java b/src/com/android/documentsui/BaseActivity.java
index 5d1c40c93..e24794a6d 100644
--- a/src/com/android/documentsui/BaseActivity.java
+++ b/src/com/android/documentsui/BaseActivity.java
@@ -64,7 +64,6 @@ import com.android.documentsui.base.State;
 import com.android.documentsui.base.State.ViewMode;
 import com.android.documentsui.dirlist.AnimationView;
 import com.android.documentsui.dirlist.DirectoryFragment;
-import com.android.documentsui.dirlist.FragmentTuner;
 import com.android.documentsui.dirlist.Model;
 import com.android.documentsui.dirlist.MultiSelectManager;
 import com.android.documentsui.dirlist.MultiSelectManager.Selection;
@@ -120,7 +119,7 @@ public abstract class BaseActivity
      * Provides Activity a means of injection into and specialization of
      * DirectoryFragment.
      */
-    public abstract FragmentTuner getFragmentTuner(Model model, boolean mSearchMode);
+    public abstract ActivityConfig getActivityConfig();
 
     /**
      * Provides Activity a means of injection into and specialization of
@@ -144,10 +143,10 @@ public abstract class BaseActivity
      * Provides Activity a means of injection into and specialization of
      * fragment actions.
      *
-     * Args can be nullable when called from a context lacking them, such as RootsFragment.
+     * Args can be null when called from a context lacking fragment, such as RootsFragment.
      */
     public abstract ActionHandler getActionHandler(
-            @Nullable Model model, @Nullable MultiSelectManager selectionMgr);
+            @Nullable Model model, @Nullable MultiSelectManager selectionMgr, boolean searchMode);
 
     public BaseActivity(@LayoutRes int layoutId, String tag) {
         mLayoutId = layoutId;
@@ -168,8 +167,8 @@ public abstract class BaseActivity
 
         setContentView(mLayoutId);
 
-        mDrawer = DrawerController.create(this);
         mState = getState(icicle);
+        mDrawer = DrawerController.create(this, getActivityConfig());
         Metrics.logActivityLaunch(this, mState, intent);
 
         // we're really interested in retainining state in our very complex
@@ -216,7 +215,6 @@ public abstract class BaseActivity
         mSearchManager = new SearchViewManager(searchListener, icicle);
         mSortController = SortController.create(this, mState.derivedMode, mState.sortModel);
 
-
         // Base classes must update result in their onCreate.
         setResult(Activity.RESULT_CANCELED);
     }
@@ -284,6 +282,7 @@ public abstract class BaseActivity
         return state;
     }
 
+    @Override
     public void setRootsDrawerOpen(boolean open) {
         mNavigator.revealRootsDrawer(open);
     }
diff --git a/src/com/android/documentsui/DrawerController.java b/src/com/android/documentsui/DrawerController.java
index 2b181f2d1..d5b8f4ff6 100644
--- a/src/com/android/documentsui/DrawerController.java
+++ b/src/com/android/documentsui/DrawerController.java
@@ -20,7 +20,6 @@ import static com.android.documentsui.base.Shared.DEBUG;
 
 import android.annotation.IntDef;
 import android.app.Activity;
-import android.support.annotation.ColorRes;
 import android.support.v4.app.ActionBarDrawerToggle;
 import android.support.v4.widget.DrawerLayout;
 import android.support.v4.widget.DrawerLayout.DrawerListener;
@@ -76,7 +75,7 @@ public abstract class DrawerController implements DrawerListener {
     /**
      * Returns a controller suitable for {@code Layout}.
      */
-    static DrawerController create(Activity activity) {
+    public static DrawerController create(Activity activity, ActivityConfig activityConfig) {
 
         DrawerLayout layout = (DrawerLayout) activity.findViewById(R.id.drawer_layout);
 
@@ -96,7 +95,7 @@ public abstract class DrawerController implements DrawerListener {
                 R.string.drawer_open,
                 R.string.drawer_close);
 
-        return new RuntimeDrawerController(layout, drawer, toggle, toolbar);
+        return new RuntimeDrawerController(layout, drawer, toggle, toolbar, activityConfig);
     }
 
     /**
@@ -131,8 +130,11 @@ public abstract class DrawerController implements DrawerListener {
         private @Trigger int mTrigger = OPENED_OTHER;
 
         public RuntimeDrawerController(
-                DrawerLayout layout, View drawer, ActionBarDrawerToggle toggle,
-                Toolbar drawerToolbar) {
+                DrawerLayout layout,
+                View drawer,
+                ActionBarDrawerToggle toggle,
+                Toolbar drawerToolbar,
+                ActivityConfig activityConfig) {
             mToolbar = drawerToolbar;
             assert(layout != null);
 
@@ -142,8 +144,10 @@ public abstract class DrawerController implements DrawerListener {
 
             mLayout.setDrawerListener(this);
 
-            View edge = layout.findViewById(R.id.drawer_edge);
-            edge.setOnDragListener(new ItemDragListener<>(this));
+            if (activityConfig.dragAndDropEnabled()) {
+                View edge = layout.findViewById(R.id.drawer_edge);
+                edge.setOnDragListener(new ItemDragListener<>(this));
+            }
         }
 
         @Override
diff --git a/src/com/android/documentsui/dirlist/BandController.java b/src/com/android/documentsui/dirlist/BandController.java
index c938d9391..429b326f1 100644
--- a/src/com/android/documentsui/dirlist/BandController.java
+++ b/src/com/android/documentsui/dirlist/BandController.java
@@ -642,7 +642,7 @@ public class BandController extends OnScrollListener {
          */
         private boolean canSelect(String id) {
             // TODO: Simplify the logic, so the check whether we can select is done in one place.
-            // Consider injecting FragmentTuner, or move the checks from MultiSelectManager to
+            // Consider injecting ActivityConfig, or move the checks from MultiSelectManager to
             // Selection.
             for (GridModel.OnSelectionChangedListener listener : mOnSelectionChangedListeners) {
                 if (!listener.onBeforeItemStateChange(id, true)) {
diff --git a/src/com/android/documentsui/dirlist/DirectoryFragment.java b/src/com/android/documentsui/dirlist/DirectoryFragment.java
index a5c2564d6..00c25058a 100644
--- a/src/com/android/documentsui/dirlist/DirectoryFragment.java
+++ b/src/com/android/documentsui/dirlist/DirectoryFragment.java
@@ -61,6 +61,7 @@ import android.widget.ImageView;
 import android.widget.TextView;
 
 import com.android.documentsui.ActionHandler;
+import com.android.documentsui.ActivityConfig;
 import com.android.documentsui.BaseActivity;
 import com.android.documentsui.BaseActivity.RetainedState;
 import com.android.documentsui.DirectoryLoader;
@@ -142,7 +143,7 @@ public class DirectoryFragment extends Fragment
     private final EventListener<Model.Update> mModelUpdateListener = new ModelUpdateListener();
 
     // This dependency is informally "injected" from the owning Activity in our onCreate method.
-    private FragmentTuner mTuner;
+    private ActivityConfig mActivityConfig;
 
     // This dependency is informally "injected" from the owning Activity in our onCreate method.
     private FocusManager mFocusManager;
@@ -161,7 +162,7 @@ public class DirectoryFragment extends Fragment
     private SelectionMetadata mSelectionMetadata;
     private UserInputHandler<InputEvent> mInputHandler;
     private @Nullable BandController mBandController;
-    private DragHoverListener mDragHoverListener;
+    private @Nullable DragHoverListener mDragHoverListener;
     private IconHelper mIconHelper;
     private SwipeRefreshLayout mRefreshLayout;
     private View mEmptyView;
@@ -173,7 +174,6 @@ public class DirectoryFragment extends Fragment
     private GridLayoutManager mLayout;
     private int mColumnCount = 1;  // This will get updated when layout changes.
 
-    private LayoutInflater mInflater;
     private MessageBar mMessageBar;
     private View mProgressBar;
 
@@ -193,7 +193,7 @@ public class DirectoryFragment extends Fragment
     @Override
     public View onCreateView(
             LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        mInflater = inflater;
+
         final View view = inflater.inflate(R.layout.fragment_directory, container, false);
 
         mMessageBar = MessageBar.create(getChildFragmentManager());
@@ -215,9 +215,12 @@ public class DirectoryFragment extends Fragment
         mRecView.setItemAnimator(new DirectoryItemAnimator(getActivity()));
         mFileList = view.findViewById(R.id.file_list);
 
-        mDragHoverListener = DragHoverListener.create(new DirectoryDragListener(this), mRecView);
+        mActivityConfig = getBaseActivity().getActivityConfig();
+        mDragHoverListener = mActivityConfig.dragAndDropEnabled()
+                ? DragHoverListener.create(new DirectoryDragListener(this), mRecView)
+                : null;
 
-        // Make the recycler and the empty views responsive to drop events.
+        // Make the recycler and the empty views responsive to drop events when allowed.
         mRecView.setOnDragListener(mDragHoverListener);
         mEmptyView.setOnDragListener(mDragHoverListener);
 
@@ -301,9 +304,8 @@ public class DirectoryFragment extends Fragment
         GestureSelector gestureSel = GestureSelector.create(mSelectionMgr, mRecView);
 
         final BaseActivity activity = getBaseActivity();
-        mTuner = activity.getFragmentTuner(mModel, mConfig.mSearchMode);
         mFocusManager = activity.getFocusManager(mRecView, mModel);
-        mActions = activity.getActionHandler(mModel, mSelectionMgr);
+        mActions = activity.getActionHandler(mModel, mSelectionMgr, mConfig.mSearchMode);
         mMenuManager = activity.getMenuManager();
         mDialogs = activity.getDialogController();
 
@@ -311,7 +313,7 @@ public class DirectoryFragment extends Fragment
             mBandController = new BandController(mRecView, mAdapter, mSelectionMgr);
         }
 
-        DragStartListener mDragStartListener = mTuner.dragAndDropEnabled()
+        DragStartListener mDragStartListener = mActivityConfig.dragAndDropEnabled()
                 ? DragStartListener.create(
                         mIconHelper,
                         getContext(),
@@ -669,7 +671,7 @@ public class DirectoryFragment extends Fragment
         assert(selected.size() == 1);
         DocumentInfo doc =
                 DocumentInfo.fromDirectoryCursor(mModel.getItem(selected.iterator().next()));
-        mTuner.showChooserForDoc(doc);
+        mActions.showChooserForDoc(doc);
     }
 
     // TODO: Once selection manager is activity owned, move this logic into
@@ -843,7 +845,7 @@ public class DirectoryFragment extends Fragment
 
     @Override
     public boolean isDocumentEnabled(String docMimeType, int docFlags) {
-        return mTuner.isDocumentEnabled(docMimeType, docFlags);
+        return mActivityConfig.isDocumentEnabled(docMimeType, docFlags, getDisplayState());
     }
 
     private void showEmptyDirectory() {
@@ -1196,7 +1198,7 @@ public class DirectoryFragment extends Fragment
 
             final String docMimeType = getCursorString(cursor, Document.COLUMN_MIME_TYPE);
             final int docFlags = getCursorInt(cursor, Document.COLUMN_FLAGS);
-            return mTuner.canSelectType(docMimeType, docFlags);
+            return mActivityConfig.canSelectType(docMimeType, docFlags, getDisplayState());
         } else {
             // Right now all selected items can be deselected.
             return true;
@@ -1303,7 +1305,7 @@ public class DirectoryFragment extends Fragment
                         mConfig.mRoot.authority, mConfig.mRoot.rootId, mConfig.mQuery)
                         : DocumentsContract.buildChildDocumentsUri(
                                 mConfig.mDocument.authority, mConfig.mDocument.documentId);
-                if (mTuner.managedModeEnabled()) {
+                if (mActivityConfig.managedModeEnabled(state.stack)) {
                     contentsUri = DocumentsContract.setManageMode(contentsUri);
                 }
                 if (DEBUG) Log.d(TAG, "Creating new directory loader for: "
diff --git a/src/com/android/documentsui/files/ActionHandler.java b/src/com/android/documentsui/files/ActionHandler.java
index 121409774..6a1f3adeb 100644
--- a/src/com/android/documentsui/files/ActionHandler.java
+++ b/src/com/android/documentsui/files/ActionHandler.java
@@ -34,16 +34,18 @@ import com.android.documentsui.base.ConfirmationCallback;
 import com.android.documentsui.base.ConfirmationCallback.Result;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
+import com.android.documentsui.base.EventListener;
 import com.android.documentsui.base.Lookup;
 import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.base.State;
 import com.android.documentsui.clipping.ClipStore;
 import com.android.documentsui.clipping.DocumentClipper;
 import com.android.documentsui.clipping.UrisSupplier;
+import com.android.documentsui.ActivityConfig;
 import com.android.documentsui.dirlist.AnimationView;
 import com.android.documentsui.dirlist.DocumentDetails;
-import com.android.documentsui.dirlist.FragmentTuner;
 import com.android.documentsui.dirlist.Model;
+import com.android.documentsui.dirlist.Model.Update;
 import com.android.documentsui.dirlist.MultiSelectManager;
 import com.android.documentsui.dirlist.MultiSelectManager.Selection;
 import com.android.documentsui.files.ActionHandler.Addons;
@@ -68,7 +70,7 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
     private static final String TAG = "ManagerActionHandler";
 
     private final DialogController mDialogs;
-    private final FragmentTuner mTuner;
+    private final ActivityConfig mTuner;
     private final DocumentClipper mClipper;
     private final ClipStore mClipStore;
 
@@ -81,7 +83,7 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
             DocumentsAccess docs,
             Lookup<String, Executor> executors,
             DialogController dialogs,
-            FragmentTuner tuner,
+            ActivityConfig tuner,
             DocumentClipper clipper,
             ClipStore clipStore) {
 
@@ -92,7 +94,7 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
         mClipper = clipper;
         mClipStore = clipStore;
 
-        mConfig = new Config();
+        mConfig = new Config(this::onModelLoaded);
     }
 
     @Override
@@ -146,7 +148,7 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
             return false;
         }
 
-        if (mTuner.isDocumentEnabled(doc.mimeType, doc.flags)) {
+        if (mTuner.isDocumentEnabled(doc.mimeType, doc.flags, mState)) {
             onDocumentPicked(doc);
             mConfig.selectionMgr.clearSelection();
             return true;
@@ -292,6 +294,7 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
         return false;
     }
 
+    @Override
     public void showChooserForDoc(DocumentInfo doc) {
         assert(!doc.isContainer());
 
@@ -449,8 +452,22 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
         return intent;
     }
 
-    ActionHandler<T> reset(Model model, MultiSelectManager selectionMgr) {
-        mConfig.reset(model, selectionMgr);
+    private void onModelLoaded(Model.Update update) {
+        // When launched into empty root, open drawer.
+        if (mConfig.model.isEmpty()
+                && !mState.hasInitialLocationChanged()
+                && !mConfig.searchMode
+                && !mConfig.modelLoadObserved) {
+            // Opens the drawer *if* an openable drawer is present
+            // else this is a no-op.
+            mActivity.setRootsDrawerOpen(true);
+        }
+
+        mConfig.modelLoadObserved = true;
+    }
+
+    ActionHandler<T> reset(Model model, MultiSelectManager selectionMgr, boolean searchMode) {
+        mConfig.reset(model, selectionMgr, searchMode);
         return this;
     }
 
@@ -458,12 +475,28 @@ public class ActionHandler<T extends Activity & Addons> extends AbstractActionHa
 
         @Nullable Model model;
         @Nullable MultiSelectManager selectionMgr;
+        boolean searchMode;
 
-        public void reset(Model model, MultiSelectManager selectionMgr) {
+        private final EventListener<Update> mModelUpdateListener;
+
+        // We use this to keep track of whether a model has been previously loaded or not so we can
+        // open the drawer on empty directories on first launch
+        private boolean modelLoadObserved;
+
+        public Config(EventListener<Update> modelUpdateListener) {
+            mModelUpdateListener = modelUpdateListener;
+        }
+
+        public void reset(Model model, MultiSelectManager selectionMgr, boolean searchMode) {
             assert(model != null);
 
             this.model = model;
             this.selectionMgr = selectionMgr;
+            this.modelLoadObserved = false;
+            this.searchMode = searchMode;
+
+            model.addUpdateListener(mModelUpdateListener);
+            modelLoadObserved = false;
         }
     }
 
diff --git a/src/com/android/documentsui/files/Config.java b/src/com/android/documentsui/files/Config.java
new file mode 100644
index 000000000..69da89e99
--- /dev/null
+++ b/src/com/android/documentsui/files/Config.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2016 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.documentsui.files;
+
+import com.android.documentsui.base.DocumentStack;
+import com.android.documentsui.ActivityConfig;
+
+/**
+ * Provides support for Files activity specific specializations.
+ */
+public final class Config extends ActivityConfig {
+
+    @Override
+    public boolean managedModeEnabled(DocumentStack stack) {
+        // When in downloads top level directory, we also show active downloads.
+        // And while we don't allow folders in Downloads, we do allow Zip files in
+        // downloads that themselves can be opened and viewed like directories.
+        // This method helps us understand when to kick in on those special behaviors.
+        return stack.root != null
+                && stack.root.isDownloads()
+                && stack.size() == 1;
+    }
+
+    @Override
+    public boolean dragAndDropEnabled() {
+        return true;
+    }
+}
diff --git a/src/com/android/documentsui/files/FilesActivity.java b/src/com/android/documentsui/files/FilesActivity.java
index f3dfd7751..4feb5f1f2 100644
--- a/src/com/android/documentsui/files/FilesActivity.java
+++ b/src/com/android/documentsui/files/FilesActivity.java
@@ -47,9 +47,9 @@ import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.base.Shared;
 import com.android.documentsui.base.State;
 import com.android.documentsui.clipping.DocumentClipper;
+import com.android.documentsui.ActivityConfig;
 import com.android.documentsui.dirlist.AnimationView.AnimationType;
 import com.android.documentsui.dirlist.DirectoryFragment;
-import com.android.documentsui.dirlist.FragmentTuner;
 import com.android.documentsui.dirlist.Model;
 import com.android.documentsui.dirlist.MultiSelectManager;
 import com.android.documentsui.services.FileOperationService;
@@ -67,7 +67,7 @@ public class FilesActivity extends BaseActivity implements ActionHandler.Addons
 
     public static final String TAG = "FilesActivity";
 
-    private Tuner mTuner;
+    private final Config mConfig = new Config();
     private MenuManager mMenuManager;
     private FocusManager mFocusManager;
     private ActionHandler<FilesActivity> mActions;
@@ -93,7 +93,6 @@ public class FilesActivity extends BaseActivity implements ActionHandler.Addons
                     }
                 });
 
-        mTuner = new Tuner(this, mState);
         // Make sure this is done after the RecyclerView and the Model are set up.
         mFocusManager = new FocusManager(getColor(R.color.accent_dark));
         mDialogs = DialogController.create(this);
@@ -104,7 +103,7 @@ public class FilesActivity extends BaseActivity implements ActionHandler.Addons
                 DocumentsAccess.create(this),
                 ProviderExecutor::forAuthority,
                 mDialogs,
-                mTuner,
+                mConfig,
                 mClipper,
                 DocumentsApplication.getClipStore(this));
 
@@ -341,8 +340,8 @@ public class FilesActivity extends BaseActivity implements ActionHandler.Addons
     }
 
     @Override
-    public FragmentTuner getFragmentTuner(Model model, boolean mSearchMode) {
-        return mTuner.reset(model, mSearchMode);
+    public ActivityConfig getActivityConfig() {
+        return mConfig;
     }
 
     @Override
@@ -357,7 +356,7 @@ public class FilesActivity extends BaseActivity implements ActionHandler.Addons
 
     @Override
     public ActionHandler<FilesActivity> getActionHandler(
-            Model model, MultiSelectManager selectionMgr) {
+            Model model, MultiSelectManager selectionMgr, boolean searchMode) {
 
         // provide our friend, RootsFragment, early access to this special feature!
         if (model == null || selectionMgr == null) {
@@ -365,7 +364,7 @@ public class FilesActivity extends BaseActivity implements ActionHandler.Addons
             assert(selectionMgr == null);
             return mActions;
         }
-        return mActions.reset(model, selectionMgr);
+        return mActions.reset(model, selectionMgr, searchMode);
     }
 
     @Override
diff --git a/src/com/android/documentsui/files/Tuner.java b/src/com/android/documentsui/files/Tuner.java
deleted file mode 100644
index d8bb224a7..000000000
--- a/src/com/android/documentsui/files/Tuner.java
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright (C) 2016 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.documentsui.files;
-
-import com.android.documentsui.base.DocumentInfo;
-import com.android.documentsui.base.EventListener;
-import com.android.documentsui.base.State;
-import com.android.documentsui.dirlist.FragmentTuner;
-import com.android.documentsui.dirlist.Model;
-import com.android.documentsui.dirlist.Model.Update;
-
-import javax.annotation.Nullable;
-
-/**
- * Provides support for Files activity specific specializations of DirectoryFragment.
- */
-public final class Tuner extends FragmentTuner {
-
-    private final FilesActivity mActivity;
-    private final State mState;
-
-    private Config mConfig = new Config(this::onModelLoaded);
-
-    public Tuner(FilesActivity activity, State state) {
-
-        assert(activity != null);
-        assert(state != null);
-
-        mActivity = activity;
-        mState = state;
-    }
-
-    private void onModelLoaded(Model.Update update) {
-        mConfig.modelLoadObserved = true;
-
-        // When launched into empty root, open drawer.
-        if (mConfig.model.isEmpty()
-                && !mState.hasInitialLocationChanged()
-                && !mConfig.searchMode
-                && !mConfig.modelLoadObserved) {
-            // Opens the drawer *if* an openable drawer is present
-            // else this is a no-op.
-            mActivity.setRootsDrawerOpen(true);
-        }
-    }
-
-    @Override
-    public boolean managedModeEnabled() {
-        // When in downloads top level directory, we also show active downloads.
-        // And while we don't allow folders in Downloads, we do allow Zip files in
-        // downloads that themselves can be opened and viewed like directories.
-        // This method helps us understand when to kick in on those special behaviors.
-        return mState.stack.root != null
-                && mState.stack.root.isDownloads()
-                && mState.stack.size() == 1;
-    }
-
-    @Override
-    public boolean dragAndDropEnabled() {
-        return true;
-    }
-
-    // TODO: Move to action handler.
-    @Override
-    public void showChooserForDoc(DocumentInfo doc) {
-        mActivity.showChooserForDoc(doc);
-    }
-
-    Tuner reset(Model model, boolean searchMode) {
-        mConfig.reset(model, searchMode);
-        return this;
-    }
-
-    private static final class Config {
-
-        @Nullable Model model;
-        boolean searchMode;
-
-        private final EventListener<Update> mModelUpdateListener;
-
-        public Config(EventListener<Update> modelUpdateListener) {
-            mModelUpdateListener = modelUpdateListener;
-        }
-
-        // We use this to keep track of whether a model has been previously loaded or not so we can
-        // open the drawer on empty directories on first launch
-        private boolean modelLoadObserved;
-
-        public void reset(Model model, boolean searchMode) {
-            this.searchMode = searchMode;
-            assert(model != null);
-
-            this.model = model;
-
-            model.addUpdateListener(mModelUpdateListener);
-            modelLoadObserved = false;
-        }
-    }
-}
diff --git a/src/com/android/documentsui/picker/ActionHandler.java b/src/com/android/documentsui/picker/ActionHandler.java
index d5f7bbea8..11173633f 100644
--- a/src/com/android/documentsui/picker/ActionHandler.java
+++ b/src/com/android/documentsui/picker/ActionHandler.java
@@ -17,6 +17,8 @@
 package com.android.documentsui.picker;
 
 import static com.android.documentsui.base.Shared.DEBUG;
+import static com.android.documentsui.base.State.ACTION_GET_CONTENT;
+import static com.android.documentsui.base.State.ACTION_PICK_COPY_DESTINATION;
 
 import android.app.Activity;
 import android.content.Intent;
@@ -30,13 +32,16 @@ import com.android.documentsui.DocumentsAccess;
 import com.android.documentsui.Metrics;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
+import com.android.documentsui.base.EventListener;
 import com.android.documentsui.base.Lookup;
+import com.android.documentsui.base.MimePredicate;
 import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.base.Shared;
 import com.android.documentsui.base.State;
+import com.android.documentsui.ActivityConfig;
 import com.android.documentsui.dirlist.DocumentDetails;
-import com.android.documentsui.dirlist.FragmentTuner;
 import com.android.documentsui.dirlist.Model;
+import com.android.documentsui.dirlist.Model.Update;
 import com.android.documentsui.dirlist.MultiSelectManager;
 import com.android.documentsui.picker.ActionHandler.Addons;
 import com.android.documentsui.roots.RootsAccess;
@@ -52,7 +57,7 @@ class ActionHandler<T extends Activity & Addons> extends AbstractActionHandler<T
 
     private static final String TAG = "PickerActionHandler";
 
-    private final FragmentTuner mTuner;
+    private final ActivityConfig mActivityConfig;
     private final Config mConfig;
 
     ActionHandler(
@@ -61,12 +66,12 @@ class ActionHandler<T extends Activity & Addons> extends AbstractActionHandler<T
             RootsAccess roots,
             DocumentsAccess docs,
             Lookup<String, Executor> executors,
-            FragmentTuner tuner) {
+            ActivityConfig activityConfig) {
 
         super(activity, state, roots, docs, executors);
 
-        mTuner = tuner;
-        mConfig = new Config();
+        mActivityConfig = activityConfig;
+        mConfig = new Config(this::onModelLoaded);
     }
 
     @Override
@@ -135,7 +140,7 @@ class ActionHandler<T extends Activity & Addons> extends AbstractActionHandler<T
             return false;
         }
 
-        if (mTuner.isDocumentEnabled(doc.mimeType, doc.flags)) {
+        if (mActivityConfig.isDocumentEnabled(doc.mimeType, doc.flags, mState)) {
             mActivity.onDocumentPicked(doc);
             mConfig.selectionMgr.clearSelection();
             return true;
@@ -143,8 +148,35 @@ class ActionHandler<T extends Activity & Addons> extends AbstractActionHandler<T
         return false;
     }
 
-    ActionHandler<T> reset(Model model, MultiSelectManager selectionMgr) {
-        mConfig.reset(model, selectionMgr);
+    private void onModelLoaded(Model.Update update) {
+        boolean showDrawer = false;
+
+        if (MimePredicate.mimeMatches(MimePredicate.VISUAL_MIMES, mState.acceptMimes)) {
+            showDrawer = false;
+        }
+        if (mState.external && mState.action == ACTION_GET_CONTENT) {
+            showDrawer = true;
+        }
+        if (mState.action == ACTION_PICK_COPY_DESTINATION) {
+            showDrawer = true;
+        }
+
+        // When launched into empty root, open drawer.
+        if (mConfig.model.isEmpty()) {
+            showDrawer = true;
+        }
+
+        if (showDrawer && !mState.hasInitialLocationChanged() && !mConfig.searchMode
+                && !mConfig.modelLoadObserved) {
+            // This noops on layouts without drawer, so no need to guard.
+            mActivity.setRootsDrawerOpen(true);
+        }
+
+        mConfig.modelLoadObserved = true;
+    }
+
+    ActionHandler<T> reset(Model model, MultiSelectManager selectionMgr, boolean searchMode) {
+        mConfig.reset(model, selectionMgr, searchMode);
         return this;
     }
 
@@ -152,12 +184,26 @@ class ActionHandler<T extends Activity & Addons> extends AbstractActionHandler<T
 
         @Nullable Model model;
         @Nullable MultiSelectManager selectionMgr;
+        boolean searchMode;
+
+        // We use this to keep track of whether a model has been previously loaded or not so we can
+        // open the drawer on empty directories on first launch
+        private boolean modelLoadObserved;
 
-        public void reset(Model model, MultiSelectManager selectionMgr) {
+        private final EventListener<Update> mModelUpdateListener;
+
+        public Config(EventListener<Update> modelUpdateListener) {
+            mModelUpdateListener = modelUpdateListener;
+        }
+
+        public void reset(Model model, MultiSelectManager selectionMgr, boolean searchMode) {
             assert(model != null);
 
             this.model = model;
             this.selectionMgr = selectionMgr;
+            this.searchMode = searchMode;
+
+            model.addUpdateListener(mModelUpdateListener);
         }
     }
 
diff --git a/src/com/android/documentsui/picker/Config.java b/src/com/android/documentsui/picker/Config.java
new file mode 100644
index 000000000..2d83ba1cd
--- /dev/null
+++ b/src/com/android/documentsui/picker/Config.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2016 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.documentsui.picker;
+
+import static com.android.documentsui.base.State.ACTION_CREATE;
+import static com.android.documentsui.base.State.ACTION_GET_CONTENT;
+import static com.android.documentsui.base.State.ACTION_OPEN;
+import static com.android.documentsui.base.State.ACTION_OPEN_TREE;
+import static com.android.documentsui.base.State.ACTION_PICK_COPY_DESTINATION;
+
+import android.provider.DocumentsContract.Document;
+
+import com.android.documentsui.base.MimePredicate;
+import com.android.documentsui.base.State;
+import com.android.documentsui.ActivityConfig;
+
+/**
+ * Provides support for Platform specific specializations of DirectoryFragment.
+ */
+final class Config extends ActivityConfig {
+
+    @Override
+    public boolean canSelectType(String docMimeType, int docFlags, State state) {
+        if (!isDocumentEnabled(docMimeType, docFlags, state)) {
+            return false;
+        }
+
+        if (MimePredicate.isDirectoryType(docMimeType)) {
+            return false;
+        }
+
+        if (state.action == ACTION_OPEN_TREE || state.action == ACTION_PICK_COPY_DESTINATION) {
+            // In this case nothing *ever* is selectable...the expected user behavior is
+            // they navigate *into* a folder, then click a confirmation button indicating
+            // that the current directory is the directory they are picking.
+            return false;
+        }
+
+        return true;
+    }
+
+    @Override
+    public boolean isDocumentEnabled(String mimeType, int docFlags, State state) {
+        // Directories are always enabled.
+        if (MimePredicate.isDirectoryType(mimeType)) {
+            return true;
+        }
+
+        switch (state.action) {
+            case ACTION_CREATE:
+                // Read-only files are disabled when creating.
+                if ((docFlags & Document.FLAG_SUPPORTS_WRITE) == 0) {
+                    return false;
+                }
+            case ACTION_OPEN:
+            case ACTION_GET_CONTENT:
+                final boolean isVirtual = (docFlags & Document.FLAG_VIRTUAL_DOCUMENT) != 0;
+                if (isVirtual && state.openableOnly) {
+                    return false;
+                }
+        }
+
+        return MimePredicate.mimeMatches(state.acceptMimes, mimeType);
+    }
+}
diff --git a/src/com/android/documentsui/picker/PickActivity.java b/src/com/android/documentsui/picker/PickActivity.java
index 962d3a9bd..da8b97bf9 100644
--- a/src/com/android/documentsui/picker/PickActivity.java
+++ b/src/com/android/documentsui/picker/PickActivity.java
@@ -55,8 +55,8 @@ import com.android.documentsui.base.PairedTask;
 import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.base.Shared;
 import com.android.documentsui.base.State;
+import com.android.documentsui.ActivityConfig;
 import com.android.documentsui.dirlist.DirectoryFragment;
-import com.android.documentsui.dirlist.FragmentTuner;
 import com.android.documentsui.dirlist.Model;
 import com.android.documentsui.dirlist.MultiSelectManager;
 import com.android.documentsui.picker.LastAccessedProvider.Columns;
@@ -72,7 +72,7 @@ public class PickActivity extends BaseActivity implements ActionHandler.Addons {
 
     private static final int CODE_FORWARD = 42;
     private static final String TAG = "PickActivity";
-    private Tuner mTuner;
+    private final Config mConfig = new Config();
     private FocusManager mFocusManager;
     private MenuManager mMenuManager;
     private ActionHandler<PickActivity> mActionHandler;
@@ -85,7 +85,6 @@ public class PickActivity extends BaseActivity implements ActionHandler.Addons {
     public void onCreate(Bundle icicle) {
         super.onCreate(icicle);
 
-        mTuner = new Tuner(this, mState);
         mFocusManager = new FocusManager(getColor(R.color.accent_dark));
         mMenuManager = new MenuManager(mSearchManager, mState, new DirectoryDetails(this));
         mActionHandler = new ActionHandler<>(
@@ -94,7 +93,7 @@ public class PickActivity extends BaseActivity implements ActionHandler.Addons {
                 DocumentsApplication.getRootsCache(this),
                 DocumentsAccess.create(this),
                 ProviderExecutor::forAuthority,
-                mTuner);
+                mConfig);
 
         Intent intent = getIntent();
 
@@ -395,8 +394,8 @@ public class PickActivity extends BaseActivity implements ActionHandler.Addons {
     }
 
     @Override
-    public FragmentTuner getFragmentTuner(Model model, boolean mSearchMode) {
-        return mTuner.reset(model, mSearchMode);
+    public ActivityConfig getActivityConfig() {
+        return mConfig;
     }
 
     @Override
@@ -411,7 +410,7 @@ public class PickActivity extends BaseActivity implements ActionHandler.Addons {
 
     @Override
     public ActionHandler<PickActivity> getActionHandler(
-            Model model, MultiSelectManager selectionMgr) {
+            Model model, MultiSelectManager selectionMgr, boolean searchMode) {
 
         // provide our friend, RootsFragment, early access to this special feature!
         if (model == null || selectionMgr == null) {
@@ -419,7 +418,7 @@ public class PickActivity extends BaseActivity implements ActionHandler.Addons {
             assert(selectionMgr == null);
             return mActionHandler;
         }
-        return mActionHandler.reset(model, selectionMgr);
+        return mActionHandler.reset(model, selectionMgr, searchMode);
     }
 
     /* (non-Javadoc)
diff --git a/src/com/android/documentsui/picker/Tuner.java b/src/com/android/documentsui/picker/Tuner.java
deleted file mode 100644
index cccb01f0f..000000000
--- a/src/com/android/documentsui/picker/Tuner.java
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
- * Copyright (C) 2016 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.documentsui.picker;
-
-import static com.android.documentsui.base.State.ACTION_CREATE;
-import static com.android.documentsui.base.State.ACTION_GET_CONTENT;
-import static com.android.documentsui.base.State.ACTION_OPEN;
-import static com.android.documentsui.base.State.ACTION_OPEN_TREE;
-import static com.android.documentsui.base.State.ACTION_PICK_COPY_DESTINATION;
-
-import android.provider.DocumentsContract.Document;
-
-import com.android.documentsui.base.EventListener;
-import com.android.documentsui.base.MimePredicate;
-import com.android.documentsui.base.State;
-import com.android.documentsui.dirlist.FragmentTuner;
-import com.android.documentsui.dirlist.Model;
-import com.android.documentsui.dirlist.Model.Update;
-
-import javax.annotation.Nullable;
-
-/**
- * Provides support for Platform specific specializations of DirectoryFragment.
- */
-final class Tuner extends FragmentTuner {
-
-    private static final String TAG = "PickTuner";
-
-
-    private final PickActivity mActivity;
-    private final State mState;
-
-    private final Config mConfig = new Config(this::onModelLoaded);
-
-    public Tuner(PickActivity activity, State state) {
-
-        assert(activity != null);
-        assert(state != null);
-
-        mActivity = activity;
-        mState = state;
-    }
-
-    @Override
-    public boolean canSelectType(String docMimeType, int docFlags) {
-        if (!isDocumentEnabled(docMimeType, docFlags)) {
-            return false;
-        }
-
-        if (MimePredicate.isDirectoryType(docMimeType)) {
-            return false;
-        }
-
-        if (mState.action == ACTION_OPEN_TREE
-                || mState.action == ACTION_PICK_COPY_DESTINATION) {
-            // In this case nothing *ever* is selectable...the expected user behavior is
-            // they navigate *into* a folder, then click a confirmation button indicating
-            // that the current directory is the directory they are picking.
-            return false;
-        }
-
-        return true;
-    }
-
-    @Override
-    public boolean isDocumentEnabled(String mimeType, int docFlags) {
-        // Directories are always enabled.
-        if (MimePredicate.isDirectoryType(mimeType)) {
-            return true;
-        }
-
-        switch (mState.action) {
-            case ACTION_CREATE:
-                // Read-only files are disabled when creating.
-                if ((docFlags & Document.FLAG_SUPPORTS_WRITE) == 0) {
-                    return false;
-                }
-            case ACTION_OPEN:
-            case ACTION_GET_CONTENT:
-                final boolean isVirtual = (docFlags & Document.FLAG_VIRTUAL_DOCUMENT) != 0;
-                if (isVirtual && mState.openableOnly) {
-                    return false;
-                }
-        }
-
-        return MimePredicate.mimeMatches(mState.acceptMimes, mimeType);
-    }
-
-    private void onModelLoaded(Model.Update update) {
-        mConfig.modelLoadObserved = true;
-        boolean showDrawer = false;
-
-        if (MimePredicate.mimeMatches(MimePredicate.VISUAL_MIMES, mState.acceptMimes)) {
-            showDrawer = false;
-        }
-        if (mState.external && mState.action == ACTION_GET_CONTENT) {
-            showDrawer = true;
-        }
-        if (mState.action == ACTION_PICK_COPY_DESTINATION) {
-            showDrawer = true;
-        }
-
-        // When launched into empty root, open drawer.
-        if (mConfig.model.isEmpty()) {
-            showDrawer = true;
-        }
-
-        if (showDrawer && !mState.hasInitialLocationChanged() && !mConfig.searchMode
-                && !mConfig.modelLoadObserved) {
-            // This noops on layouts without drawer, so no need to guard.
-            mActivity.setRootsDrawerOpen(true);
-        }
-    }
-
-    Tuner reset(Model model, boolean searchMode) {
-        mConfig.reset(model, searchMode);
-        return this;
-    }
-
-    private static final class Config {
-
-        @Nullable Model model;
-        boolean searchMode;
-
-        private final EventListener<Update> mModelUpdateListener;
-
-        public Config(EventListener<Update> modelUpdateListener) {
-            mModelUpdateListener = modelUpdateListener;
-        }
-
-        // We use this to keep track of whether a model has been previously loaded or not so we can
-        // open the drawer on empty directories on first launch
-        private boolean modelLoadObserved;
-
-        public void reset(Model model, boolean searchMode) {
-            assert(model != null);
-
-            this.searchMode = searchMode;
-            this.model = model;
-
-            model.addUpdateListener(mModelUpdateListener);
-            modelLoadObserved = false;
-        }
-    }
-}
diff --git a/src/com/android/documentsui/sidebar/RootsFragment.java b/src/com/android/documentsui/sidebar/RootsFragment.java
index a250a8d68..2a4dca3f3 100644
--- a/src/com/android/documentsui/sidebar/RootsFragment.java
+++ b/src/com/android/documentsui/sidebar/RootsFragment.java
@@ -59,6 +59,7 @@ import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.base.Shared;
 import com.android.documentsui.base.State;
 import com.android.documentsui.roots.GetRootDocumentTask;
+import com.android.documentsui.ActivityConfig;
 import com.android.documentsui.roots.RootsCache;
 import com.android.documentsui.roots.RootsLoader;
 
@@ -78,18 +79,6 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
     private static final String EXTRA_INCLUDE_APPS = "includeApps";
     private static final int CONTEXT_MENU_ITEM_TIMEOUT = 500;
 
-    private final OnDragListener mDragListener = new ItemDragListener<RootsFragment>(this) {
-        @Override
-        public boolean handleDropEventChecked(View v, DragEvent event) {
-            final int position = (Integer) v.getTag(R.id.item_position_tag);
-            final Item item = mAdapter.getItem(position);
-
-            assert(item.isDropTarget());
-
-            return item.dropOn(event.getClipData());
-        }
-    };
-
     private final OnItemClickListener mItemListener = new OnItemClickListener() {
         @Override
         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
@@ -111,8 +100,14 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
     private ListView mList;
     private RootsAdapter mAdapter;
     private LoaderCallbacks<Collection<RootInfo>> mCallbacks;
+    private @Nullable OnDragListener mDragListener;
+
+    // This dependency is informally "injected" from the owning Activity in our onCreate method.
     private ActionHandler mActionHandler;
 
+    // This dependency is informally "injected" from the owning Activity in our onCreate method.
+    private ActivityConfig mActivityConfig;
+
     public static RootsFragment show(FragmentManager fm, Intent includeApps) {
         final Bundle args = new Bundle();
         args.putParcelable(EXTRA_INCLUDE_APPS, includeApps);
@@ -201,7 +196,23 @@ public class RootsFragment extends Fragment implements ItemDragListener.DragHost
         final RootsCache roots = DocumentsApplication.getRootsCache(activity);
         final State state = activity.getDisplayState();
 
-        mActionHandler = activity.getActionHandler(null, null);
+        mActionHandler = activity.getActionHandler(null, null, false);
+        mActivityConfig = activity.getActivityConfig();
+
+        if (mActivityConfig.dragAndDropEnabled()) {
+            mDragListener = new ItemDragListener<RootsFragment>(this) {
+                @Override
+                public boolean handleDropEventChecked(View v, DragEvent event) {
+                    final int position = (Integer) v.getTag(R.id.item_position_tag);
+                    final Item item = mAdapter.getItem(position);
+
+                    assert (item.isDropTarget());
+
+                    return item.dropOn(event.getClipData());
+                }
+            };
+        }
+
 
         mCallbacks = new LoaderCallbacks<Collection<RootInfo>>() {
             @Override
diff --git a/tests/common/com/android/documentsui/TestActivity.java b/tests/common/com/android/documentsui/TestActivity.java
index 7d73589f5..a2a7b55d5 100644
--- a/tests/common/com/android/documentsui/TestActivity.java
+++ b/tests/common/com/android/documentsui/TestActivity.java
@@ -50,6 +50,7 @@ public abstract class TestActivity extends AbstractBase {
     public TestEventListener<RootInfo> rootPicked;
     public TestEventListener<DocumentInfo> openContainer;
     public TestEventListener<Integer> refreshCurrentRootAndDirectory;
+    public TestEventListener<Boolean> setRootsDrawerOpen;
 
     public static TestActivity create() {
         TestActivity activity = Mockito.mock(TestActivity.class, Mockito.CALLS_REAL_METHODS);
@@ -67,6 +68,7 @@ public abstract class TestActivity extends AbstractBase {
        rootPicked = new TestEventListener<>();
        openContainer = new TestEventListener<>();
        refreshCurrentRootAndDirectory =  new TestEventListener<>();
+       setRootsDrawerOpen = new TestEventListener<>();
    }
 
     @Override
@@ -132,6 +134,11 @@ public abstract class TestActivity extends AbstractBase {
     public final RootInfo getCurrentRoot() {
         return currentRoot;
     }
+
+    @Override
+    public final void setRootsDrawerOpen(boolean open) {
+        setRootsDrawerOpen.accept(open);
+    }
 }
 
 // Trick Mockito into finding our Addons methods correctly. W/o this
diff --git a/tests/common/com/android/documentsui/dirlist/TestModel.java b/tests/common/com/android/documentsui/dirlist/TestModel.java
index abe4d5f53..82849a34f 100644
--- a/tests/common/com/android/documentsui/dirlist/TestModel.java
+++ b/tests/common/com/android/documentsui/dirlist/TestModel.java
@@ -22,10 +22,13 @@ import android.provider.DocumentsContract.Document;
 
 import com.android.documentsui.DirectoryResult;
 import com.android.documentsui.base.DocumentInfo;
+import com.android.documentsui.base.EventListener;
 import com.android.documentsui.roots.RootCursorWrapper;
 
 import libcore.net.MimeUtils;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Random;
 
 public class TestModel extends Model {
@@ -43,6 +46,7 @@ public class TestModel extends Model {
     private int mLastId = 0;
     private Random mRand = new Random();
     private MatrixCursor mCursor;
+    private List<EventListener<Update>> mUpdateListeners = new ArrayList<>();
 
     public TestModel(String authority) {
         super();
diff --git a/tests/unit/com/android/documentsui/files/ActionHandlerTest.java b/tests/unit/com/android/documentsui/files/ActionHandlerTest.java
index 457c2ba08..496fb5109 100644
--- a/tests/unit/com/android/documentsui/files/ActionHandlerTest.java
+++ b/tests/unit/com/android/documentsui/files/ActionHandlerTest.java
@@ -74,7 +74,17 @@ public class ActionHandlerTest {
         mSelection = new Selection();
         mSelection.add("1");
 
-        mHandler.reset(mEnv.model, null);
+        mHandler.reset(mEnv.model, null, false);
+    }
+
+    @Test
+    public void testOpenDrawerOnLaunchingEmptyRoot() {
+        mEnv.model.reset();
+        // state should not say we've changed our location
+
+        mEnv.model.update();
+
+        mActivity.setRootsDrawerOpen.assertLastArgument(true);
     }
 
     @Test
diff --git a/tests/unit/com/android/documentsui/picker/ActionHandlerTest.java b/tests/unit/com/android/documentsui/picker/ActionHandlerTest.java
index c7afff1ea..8a11b084e 100644
--- a/tests/unit/com/android/documentsui/picker/ActionHandlerTest.java
+++ b/tests/unit/com/android/documentsui/picker/ActionHandlerTest.java
@@ -16,6 +16,9 @@
 
 package com.android.documentsui.picker;
 
+import static com.android.documentsui.base.State.ACTION_GET_CONTENT;
+import static com.android.documentsui.base.State.ACTION_PICK_COPY_DESTINATION;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
@@ -67,7 +70,36 @@ public class ActionHandlerTest {
         mSelection = new Selection();
         mSelection.add("1");
 
-        mHandler.reset(mEnv.model, null);
+        mHandler.reset(mEnv.model, null, false);
+    }
+
+    @Test
+    public void testOpenDrawerOnLaunchingEmptyRoot() {
+        mEnv.model.reset();
+        // state should not say we've changed our location
+
+        mEnv.model.update();
+
+        mActivity.setRootsDrawerOpen.assertLastArgument(true);
+    }
+
+    @Test
+    public void testOpenDrawerOnGettingContent() {
+        mEnv.state.external = true;
+        mEnv.state.action = ACTION_GET_CONTENT;
+
+        mEnv.model.update();
+
+        mActivity.setRootsDrawerOpen.assertLastArgument(true);
+    }
+
+    @Test
+    public void testOpenDrawerOnPickingCopyDestination() {
+        mEnv.state.action = ACTION_PICK_COPY_DESTINATION;
+
+        mEnv.model.update();
+
+        mActivity.setRootsDrawerOpen.assertLastArgument(true);
     }
 
     @Test