Merge "Make drag and drop also work when the widget tray is still in scroll mode." into ub-launcher3-burnaby
diff --git a/res/values/config.xml b/res/values/config.xml
index 21e1d69..6ef8635 100644
--- a/res/values/config.xml
+++ b/res/values/config.xml
@@ -100,4 +100,6 @@
     <item type="id" name="action_add_to_workspace" />
     <item type="id" name="action_move" />
     <item type="id" name="action_move_to_workspace" />
+    <item type="id" name="action_move_screen_backwards" />
+    <item type="id" name="action_move_screen_forwards" />
 </resources>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 57f23ae..1681fc6 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -243,4 +243,13 @@
 
     <!-- Accessibility action to move an item from folder to workspace. [CHAR_LIMIT=30] [DO NOT TRANSLATE] -->
     <string name="action_move_to_workspace">Move to home screen</string>
+
+    <!-- Accessibility action to move an homescreen to the left. [CHAR_LIMIT=30] [DO NOT TRANSLATE] -->
+    <string name="action_move_screen_left">Move screen to left</string>
+
+    <!-- Accessibility action to move an homescreen to the right. [CHAR_LIMIT=30] [DO NOT TRANSLATE] -->
+    <string name="action_move_screen_right">Move screen to right</string>
+
+    <!-- Accessibility confirmation when a screen was moved [DO NOT TRANSLATE] -->
+    <string name="screen_moved">Screen moved</string>
 </resources>
diff --git a/src/com/android/launcher3/AllAppsList.java b/src/com/android/launcher3/AllAppsList.java
index dd646bb..3b25dca 100644
--- a/src/com/android/launcher3/AllAppsList.java
+++ b/src/com/android/launcher3/AllAppsList.java
@@ -24,6 +24,7 @@
 import com.android.launcher3.compat.UserHandleCompat;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 
 
@@ -117,6 +118,16 @@
         }
     }
 
+    public void updateIconsAndLabels(HashSet<String> packages, UserHandleCompat user,
+            ArrayList<AppInfo> outUpdates) {
+        for (AppInfo info : data) {
+            if (info.user.equals(user) && packages.contains(info.componentName.getPackageName())) {
+                mIconCache.updateTitleAndIcon(info);
+                outUpdates.add(info);
+            }
+        }
+    }
+
     /**
      * Add and remove icons for this package which has been updated.
      */
diff --git a/src/com/android/launcher3/AppsContainerView.java b/src/com/android/launcher3/AppsContainerView.java
index f7adaf8..c3cf629 100644
--- a/src/com/android/launcher3/AppsContainerView.java
+++ b/src/com/android/launcher3/AppsContainerView.java
@@ -232,8 +232,15 @@
 
             mFixedBounds.set(fixedBounds);
         }
-        updateBackgrounds();
-        updatePaddings();
+        // Post the updates since they can trigger a relayout, and this call can be triggered from
+        // a layout pass itself.
+        post(new Runnable() {
+            @Override
+            public void run() {
+                updateBackgrounds();
+                updatePaddings();
+            }
+        });
     }
 
     @Override
diff --git a/src/com/android/launcher3/IconCache.java b/src/com/android/launcher3/IconCache.java
index fd45714..6c2aa39 100644
--- a/src/com/android/launcher3/IconCache.java
+++ b/src/com/android/launcher3/IconCache.java
@@ -407,6 +407,20 @@
     }
 
     /**
+     * Updates {@param application} only if a valid entry is found.
+     */
+    public synchronized void updateTitleAndIcon(AppInfo application) {
+        CacheEntry entry = cacheLocked(application.componentName, null, application.user,
+                false, application.usingLowResIcon);
+        if (entry.icon != null && !isDefaultIcon(entry.icon, application.user)) {
+            application.title = entry.title;
+            application.iconBitmap = entry.icon;
+            application.contentDescription = entry.contentDescription;
+            application.usingLowResIcon = entry.isLowResIcon;
+        }
+    }
+
+    /**
      * Returns a high res icon for the given intent and user
      */
     public synchronized Bitmap getIcon(Intent intent, UserHandleCompat user) {
@@ -655,7 +669,7 @@
     }
 
     private static final class IconDB extends SQLiteOpenHelper {
-        private final static int DB_VERSION = 3;
+        private final static int DB_VERSION = 4;
 
         private final static String TABLE_NAME = "icons";
         private final static String COLUMN_ROWID = "rowid";
diff --git a/src/com/android/launcher3/LauncherModel.java b/src/com/android/launcher3/LauncherModel.java
index 95ff6a4..ddbae3a 100644
--- a/src/com/android/launcher3/LauncherModel.java
+++ b/src/com/android/launcher3/LauncherModel.java
@@ -107,6 +107,7 @@
     @Thunk DeferredHandler mHandler = new DeferredHandler();
     @Thunk LoaderTask mLoaderTask;
     @Thunk boolean mIsLoaderTaskRunning;
+    @Thunk boolean mHasLoaderCompletedOnce;
 
     private static final String MIGRATE_AUTHORITY = "com.android.launcher2.settings";
 
@@ -128,6 +129,12 @@
     // a normal load, we also clear this set of Runnables.
     static final ArrayList<Runnable> mDeferredBindRunnables = new ArrayList<Runnable>();
 
+    /**
+     * Set of runnables to be called on the background thread after the workspace binding
+     * is complete.
+     */
+    static final ArrayList<Runnable> mBindCompleteRunnables = new ArrayList<Runnable>();
+
     @Thunk WeakReference<Callbacks> mCallbacks;
 
     // < only access in worker thread >
@@ -263,6 +270,19 @@
         }
     }
 
+    /**
+     * Runs the specified runnable after the loader is complete
+     */
+    private void runAfterBindCompletes(Runnable r) {
+        if (isLoadingWorkspace() || !mHasLoaderCompletedOnce) {
+            synchronized (mBindCompleteRunnables) {
+                mBindCompleteRunnables.add(r);
+            }
+        } else {
+            runOnWorkerThread(r);
+        }
+    }
+
     boolean canMigrateFromOldLauncherDb(Launcher launcher) {
         return mOldContentProviderExists && !launcher.isLauncherPreinstalled() ;
     }
@@ -424,7 +444,7 @@
      * Find a position on the screen for the given size or adds a new screen.
      * @return screenId and the coordinates for the item.
      */
-    @Thunk static Pair<Long, int[]> findSpaceForItem(
+    @Thunk Pair<Long, int[]> findSpaceForItem(
             Context context,
             ArrayList<Long> workspaceScreens,
             ArrayList<Long> addedWorkspaceScreensFinal,
@@ -432,7 +452,7 @@
         LongSparseArray<ArrayList<ItemInfo>> screenItems = new LongSparseArray<>();
 
         // Use sBgItemsIdMap as all the items are already loaded.
-        // TODO: Throw exception is above condition is not met.
+        assertWorkspaceLoaded();
         synchronized (sBgLock) {
             for (ItemInfo info : sBgItemsIdMap) {
                 if (info.container == LauncherSettings.Favorites.CONTAINER_DESKTOP) {
@@ -875,12 +895,18 @@
         updateItemInDatabaseHelper(context, values, item, "updateItemInDatabase");
     }
 
+    private void assertWorkspaceLoaded() {
+        if (LauncherAppState.isDogfoodBuild() && (isLoadingWorkspace() || !mHasLoaderCompletedOnce)) {
+            throw new RuntimeException("Trying to add shortcut while loader is running");
+        }
+    }
+
     /**
      * Returns true if the shortcuts already exists on the workspace. This must be called after
      * the workspace has been loaded. We identify a shortcut by its intent.
-     * TODO: Throw exception is above condition is not met.
      */
-    @Thunk static boolean shortcutExists(Context context, Intent intent, UserHandleCompat user) {
+    @Thunk boolean shortcutExists(Context context, Intent intent, UserHandleCompat user) {
+        assertWorkspaceLoaded();
         final String intentWithPkg, intentWithoutPkg;
         final String packageName;
         if (intent.getComponent() != null) {
@@ -1390,6 +1416,16 @@
                 mHandler.post(r);
             }
         }
+
+        // Run all the bind complete runnables after workspace is bound.
+        if (!mBindCompleteRunnables.isEmpty()) {
+            synchronized (mBindCompleteRunnables) {
+                for (final Runnable r : mBindCompleteRunnables) {
+                    runOnWorkerThread(r);
+                }
+                mBindCompleteRunnables.clear();
+            }
+        }
     }
 
     public void stopLoader() {
@@ -1615,6 +1651,7 @@
                     mLoaderTask = null;
                 }
                 mIsLoaderTaskRunning = false;
+                mHasLoaderCompletedOnce = true;
             }
         }
 
@@ -2730,6 +2767,7 @@
             }
             if (!mAllAppsLoaded) {
                 loadAllApps();
+                updateAllAppsIconsCache();
                 synchronized (LoaderTask.this) {
                     if (mStopped) {
                         return;
@@ -2784,9 +2822,6 @@
                 return;
             }
 
-            final Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
-            mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
-
             final List<UserHandleCompat> profiles = mUserManager.getUserProfiles();
 
             // Clear the list of apps
@@ -2794,7 +2829,7 @@
             for (UserHandleCompat user : profiles) {
                 // Query for the set of apps
                 final long qiaTime = DEBUG_LOADERS ? SystemClock.uptimeMillis() : 0;
-                List<LauncherActivityInfoCompat> apps = mLauncherApps.getActivityList(null, user);
+                final List<LauncherActivityInfoCompat> apps = mLauncherApps.getActivityList(null, user);
                 if (DEBUG_LOADERS) {
                     Log.d(TAG, "getActivityList took "
                             + (SystemClock.uptimeMillis()-qiaTime) + "ms for user " + user);
@@ -2806,42 +2841,6 @@
                     return;
                 }
 
-                // Update icon cache
-                HashSet<String> updatedPackages = mIconCache.updateDBIcons(user, apps);
-
-                // If any package icon has changed (app was updated while launcher was dead),
-                // update the corresponding shortcuts.
-                if (!updatedPackages.isEmpty()) {
-                    final ArrayList<ShortcutInfo> updates = new ArrayList<ShortcutInfo>();
-                    synchronized (sBgLock) {
-                        for (ItemInfo info : sBgItemsIdMap) {
-                            if (info instanceof ShortcutInfo && user.equals(info.user)
-                                    && info.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
-                                ShortcutInfo si = (ShortcutInfo) info;
-                                ComponentName cn = si.getTargetComponent();
-                                if (cn != null && updatedPackages.contains(cn.getPackageName())) {
-                                    si.updateIcon(mIconCache);
-                                    updates.add(si);
-                                }
-                            }
-                        }
-                    }
-
-                    if (!updates.isEmpty()) {
-                        final UserHandleCompat userFinal = user;
-                        mHandler.post(new Runnable() {
-
-                            public void run() {
-                                Callbacks cb = getCallback();
-                                if (cb != null) {
-                                    cb.bindShortcutsChanged(
-                                            updates, new ArrayList<ShortcutInfo>(), userFinal);
-                                }
-                            }
-                        });
-                    }
-                }
-
                 // Create the ApplicationInfos
                 for (int i = 0; i < apps.size(); i++) {
                     LauncherActivityInfoCompat app = apps.get(i);
@@ -2849,11 +2848,15 @@
                     mBgAllAppsList.add(new AppInfo(mContext, app, user, mIconCache));
                 }
 
-                if (!user.equals(UserHandleCompat.myUserHandle())) {
-                    ManagedProfileHeuristic heuristic = ManagedProfileHeuristic.get(mContext, user);
-                    if (heuristic != null) {
-                        heuristic.processUserApps(apps);
-                    }
+                final ManagedProfileHeuristic heuristic = ManagedProfileHeuristic.get(mContext, user);
+                if (heuristic != null) {
+                    runAfterBindCompletes(new Runnable() {
+
+                        @Override
+                        public void run() {
+                            heuristic.processUserApps(apps);
+                        }
+                    });
                 }
             }
             // Huh? Shouldn't this be inside the Runnable below?
@@ -2888,6 +2891,68 @@
             }
         }
 
+        private void updateAllAppsIconsCache() {
+            final ArrayList<AppInfo> updatedApps = new ArrayList<>();
+
+            for (UserHandleCompat user : mUserManager.getUserProfiles()) {
+                // Query for the set of apps
+                final List<LauncherActivityInfoCompat> apps = mLauncherApps.getActivityList(null, user);
+                // Fail if we don't have any apps
+                // TODO: Fix this. Only fail for the current user.
+                if (apps == null || apps.isEmpty()) {
+                    return;
+                }
+
+                // Update icon cache
+                HashSet<String> updatedPackages = mIconCache.updateDBIcons(user, apps);
+
+                // If any package icon has changed (app was updated while launcher was dead),
+                // update the corresponding shortcuts.
+                if (!updatedPackages.isEmpty()) {
+                    final ArrayList<ShortcutInfo> updatedShortcuts = new ArrayList<>();
+                    synchronized (sBgLock) {
+                        for (ItemInfo info : sBgItemsIdMap) {
+                            if (info instanceof ShortcutInfo && user.equals(info.user)
+                                    && info.itemType == LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
+                                ShortcutInfo si = (ShortcutInfo) info;
+                                ComponentName cn = si.getTargetComponent();
+                                if (cn != null && updatedPackages.contains(cn.getPackageName())) {
+                                    si.updateIcon(mIconCache);
+                                    updatedShortcuts.add(si);
+                                }
+                            }
+                        }
+                        mBgAllAppsList.updateIconsAndLabels(updatedPackages, user, updatedApps);
+                    }
+
+                    if (!updatedShortcuts.isEmpty()) {
+                        final UserHandleCompat userFinal = user;
+                        mHandler.post(new Runnable() {
+
+                            public void run() {
+                                Callbacks cb = getCallback();
+                                if (cb != null) {
+                                    cb.bindShortcutsChanged(updatedShortcuts,
+                                            new ArrayList<ShortcutInfo>(), userFinal);
+                                }
+                            }
+                        });
+                    }
+                }
+            }
+            if (!updatedApps.isEmpty()) {
+                mHandler.post(new Runnable() {
+
+                    public void run() {
+                        Callbacks cb = getCallback();
+                        if (cb != null) {
+                            cb.bindAppsUpdated(updatedApps);
+                        }
+                    }
+                });
+            }
+        }
+
         public void dumpState() {
             synchronized (sBgLock) {
                 Log.d(TAG, "mLoaderTask.mContext=" + mContext);
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index a4593ec..0739bab 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -559,7 +559,7 @@
     /**
      * Sets the current page.
      */
-    void setCurrentPage(int currentPage) {
+    public void setCurrentPage(int currentPage) {
         if (!mScroller.isFinished()) {
             abortScrollerAnimation(true);
         }
@@ -2535,7 +2535,7 @@
         }
     }
 
-    protected void onStartReordering() {
+    public void onStartReordering() {
         // Set the touch state to reordering (allows snapping to pages, dragging a child, etc.)
         mTouchState = TOUCH_STATE_REORDERING;
         mIsReordering = true;
@@ -2555,7 +2555,7 @@
         }
     }
 
-    protected void onEndReordering() {
+    public void onEndReordering() {
         mIsReordering = false;
     }
 
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index e7a41e0..f2fa59b 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -63,6 +63,7 @@
 import com.android.launcher3.LauncherAccessibilityDelegate.AccessibilityDragSource;
 import com.android.launcher3.LauncherSettings.Favorites;
 import com.android.launcher3.UninstallDropTarget.UninstallSource;
+import com.android.launcher3.accessibility.OverviewScreenAccessibilityDelegate;
 import com.android.launcher3.compat.UserHandleCompat;
 import com.android.launcher3.util.LongArrayMap;
 import com.android.launcher3.util.Thunk;
@@ -277,6 +278,8 @@
     // Handles workspace state transitions
     private WorkspaceStateTransitionAnimation mStateTransitionAnimation;
 
+    private AccessibilityDelegate mPagesAccessibilityDelegate;
+
     private final Runnable mBindPages = new Runnable() {
         @Override
         public void run() {
@@ -2000,14 +2003,14 @@
         range[1] = Math.max(0,  end);
     }
 
-    protected void onStartReordering() {
+    public void onStartReordering() {
         super.onStartReordering();
         showOutlines();
         // Reordering handles its own animations, disable the automatic ones.
         disableLayoutTransitions();
     }
 
-    protected void onEndReordering() {
+    public void onEndReordering() {
         super.onEndReordering();
 
         if (mLauncher.isWorkspaceLoading()) {
@@ -2068,11 +2071,45 @@
         return mState;
     }
 
-    private void updateAccessibilityFlags() {
-        int accessible = mState == State.NORMAL ?
-                IMPORTANT_FOR_ACCESSIBILITY_NO :
-                IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS;
-        setImportantForAccessibility(accessible);
+    public void updateAccessibilityFlags() {
+        if (Utilities.isLmpOrAbove()) {
+            int total = getPageCount();
+            for (int i = numCustomPages(); i < total; i++) {
+                updateAccessibilityFlags((CellLayout) getPageAt(i), i);
+            }
+            if (mState == State.NORMAL) {
+                setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_NO);
+            } else {
+                setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);
+            }
+        } else {
+            int accessible = mState == State.NORMAL ?
+                    IMPORTANT_FOR_ACCESSIBILITY_NO :
+                        IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS;
+            setImportantForAccessibility(accessible);
+        }
+    }
+
+    private void updateAccessibilityFlags(CellLayout page, int pageNo) {
+        if (mState == State.OVERVIEW) {
+            page.setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_YES);
+            page.getShortcutsAndWidgets().setImportantForAccessibility(
+                    IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
+            page.setContentDescription(getPageDescription(pageNo));
+
+            if (mPagesAccessibilityDelegate == null) {
+                mPagesAccessibilityDelegate = new OverviewScreenAccessibilityDelegate(this);
+            }
+            page.setAccessibilityDelegate(mPagesAccessibilityDelegate);
+        } else {
+            int accessible = mState == State.NORMAL ?
+                    IMPORTANT_FOR_ACCESSIBILITY_NO :
+                        IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS;
+            page.setImportantForAccessibility(IMPORTANT_FOR_ACCESSIBILITY_NO);
+            page.getShortcutsAndWidgets().setImportantForAccessibility(accessible);
+            page.setContentDescription(null);
+            page.setAccessibilityDelegate(null);
+        }
     }
 
     @Override
@@ -4460,11 +4497,15 @@
     }
 
     protected String getCurrentPageDescription() {
-        int page = (mNextPage != INVALID_PAGE) ? mNextPage : mCurrentPage;
-        int delta = numCustomPages();
         if (hasCustomContent() && getNextPage() == 0) {
             return mCustomContentDescription;
         }
+        int page = (mNextPage != INVALID_PAGE) ? mNextPage : mCurrentPage;
+        return getPageDescription(page);
+    }
+
+    private String getPageDescription(int page) {
+        int delta = numCustomPages();
         return String.format(getContext().getString(R.string.workspace_scroll_format),
                 page + 1 - delta, getChildCount() - delta);
     }
diff --git a/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java b/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
index a0cedeb..61a64e3 100644
--- a/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
+++ b/src/com/android/launcher3/WorkspaceStateTransitionAnimation.java
@@ -24,8 +24,11 @@
 import android.content.Context;
 import android.content.res.Resources;
 import android.view.View;
+import android.view.ViewGroup;
 import android.view.accessibility.AccessibilityManager;
+import android.view.accessibility.AccessibilityNodeInfo;
 import android.view.animation.DecelerateInterpolator;
+
 import com.android.launcher3.util.Thunk;
 
 import java.util.HashMap;
@@ -190,7 +193,7 @@
                               final HashMap<View, Integer> layerViews) {
         AccessibilityManager am = (AccessibilityManager)
                 mLauncher.getSystemService(Context.ACCESSIBILITY_SERVICE);
-        boolean accessibilityEnabled = am.isEnabled();
+        final boolean accessibilityEnabled = am.isEnabled();
 
         // Reinitialize animation arrays for the current workspace state
         reinitializeAnimationArrays();
@@ -301,7 +304,7 @@
         }
 
         final View searchBar = mLauncher.getOrCreateQsbBar();
-        final View overviewPanel = mLauncher.getOverviewPanel();
+        final ViewGroup overviewPanel = mLauncher.getOverviewPanel();
         final View hotseat = mLauncher.getHotseat();
         final View pageIndicator = mWorkspace.getPageIndicator();
         if (animated) {
@@ -424,6 +427,11 @@
                 @Override
                 public void onAnimationEnd(Animator animation) {
                     mStateAnimator = null;
+
+                    if (accessibilityEnabled && overviewPanel.getVisibility() == View.VISIBLE) {
+                        overviewPanel.getChildAt(0).performAccessibilityAction(
+                                AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null);
+                    }
                 }
             });
         } else {
@@ -443,6 +451,11 @@
             mWorkspace.setScaleX(mNewScale);
             mWorkspace.setScaleY(mNewScale);
             mWorkspace.setTranslationY(finalWorkspaceTranslationY);
+
+            if (accessibilityEnabled && overviewPanel.getVisibility() == View.VISIBLE) {
+                overviewPanel.getChildAt(0).performAccessibilityAction(
+                        AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null);
+            }
         }
 
         if (stateIsNormal) {
diff --git a/src/com/android/launcher3/accessibility/OverviewScreenAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/OverviewScreenAccessibilityDelegate.java
new file mode 100644
index 0000000..d3f5230
--- /dev/null
+++ b/src/com/android/launcher3/accessibility/OverviewScreenAccessibilityDelegate.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3.accessibility;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.util.SparseArray;
+import android.view.View;
+import android.view.View.AccessibilityDelegate;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction;
+
+import com.android.launcher3.R;
+import com.android.launcher3.Workspace;
+
+public class OverviewScreenAccessibilityDelegate extends AccessibilityDelegate {
+
+    private static final int MOVE_BACKWARD = R.id.action_move_screen_backwards;
+    private static final int MOVE_FORWARD = R.id.action_move_screen_forwards;
+
+    private final SparseArray<AccessibilityAction> mActions = new SparseArray<>();
+    private final Workspace mWorkspace;
+
+    public OverviewScreenAccessibilityDelegate(Workspace workspace) {
+        mWorkspace = workspace;
+
+        Context context = mWorkspace.getContext();
+        boolean isRtl = mWorkspace.isLayoutRtl();
+        mActions.put(MOVE_BACKWARD, new AccessibilityAction(MOVE_BACKWARD,
+                context.getText(isRtl ? R.string.action_move_screen_right :
+                    R.string.action_move_screen_left)));
+        mActions.put(MOVE_FORWARD, new AccessibilityAction(MOVE_FORWARD,
+                context.getText(isRtl ? R.string.action_move_screen_left :
+                    R.string.action_move_screen_right)));
+    }
+
+    @Override
+    public boolean performAccessibilityAction(View host, int action, Bundle args) {
+        if (host != null) {
+            if (action == AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS ) {
+                int index = mWorkspace.indexOfChild(host);
+                mWorkspace.setCurrentPage(index);
+            } else if (action == MOVE_FORWARD) {
+                movePage(mWorkspace.indexOfChild(host) + 1, host);
+                return true;
+            } else if (action == MOVE_BACKWARD) {
+                movePage(mWorkspace.indexOfChild(host) - 1, host);
+                return true;
+            }
+        }
+
+        return super.performAccessibilityAction(host, action, args);
+    }
+
+    private void movePage(int finalIndex, View view) {
+        mWorkspace.onStartReordering();
+        mWorkspace.removeView(view);
+        mWorkspace.addView(view, finalIndex);
+        mWorkspace.onEndReordering();
+        mWorkspace.announceForAccessibility(mWorkspace.getContext().getText(R.string.screen_moved));
+
+        mWorkspace.updateAccessibilityFlags();
+        view.performAccessibilityAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null);
+    }
+
+    @Override
+    public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
+        super.onInitializeAccessibilityNodeInfo(host, info);
+
+        int index = mWorkspace.indexOfChild(host);
+        if (index < mWorkspace.getChildCount() - 1) {
+            info.addAction(mActions.get(MOVE_FORWARD));
+        }
+        if (index > mWorkspace.numCustomPages()) {
+            info.addAction(mActions.get(MOVE_BACKWARD));
+        }
+    }
+}