resolved conflicts for merge of 13ef17a3 to mnc-dr-dev

b/22609402
Change-Id: I140cf972d57e14737a6f91c0b4a8ec6c7ff1af2b

5 files changed, 887 insertions, 0 deletions

diff --git a/src/com/android/launcher3/accessibility/DragAndDropAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/DragAndDropAccessibilityDelegate.java
new file mode 100644
index 000000000..78accf720
--- /dev/null
+++ b/src/com/android/launcher3/accessibility/DragAndDropAccessibilityDelegate.java
@@ -0,0 +1,136 @@
+/*
+ * 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.graphics.Rect;
+import android.os.Bundle;
+import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
+import android.support.v4.widget.ExploreByTouchHelper;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.accessibility.AccessibilityEvent;
+
+import com.android.launcher3.CellLayout;
+import com.android.launcher3.LauncherAppState;
+import com.android.launcher3.R;
+
+import java.util.List;
+
+/**
+ * Helper class to make drag-and-drop in a {@link CellLayout} accessible.
+ */
+public abstract class DragAndDropAccessibilityDelegate extends ExploreByTouchHelper
+        implements OnClickListener {
+    protected static final int INVALID_POSITION = -1;
+
+    private static final int[] sTempArray = new int[2];
+
+    protected final CellLayout mView;
+    protected final Context mContext;
+    protected final LauncherAccessibilityDelegate mDelegate;
+
+    private final Rect mTempRect = new Rect();
+
+    public DragAndDropAccessibilityDelegate(CellLayout forView) {
+        super(forView);
+        mView = forView;
+        mContext = mView.getContext();
+        mDelegate = LauncherAppState.getInstance().getAccessibilityDelegate();
+    }
+
+    @Override
+    protected int getVirtualViewAt(float x, float y) {
+        if (x < 0 || y < 0 || x > mView.getMeasuredWidth() || y > mView.getMeasuredHeight()) {
+            return INVALID_ID;
+        }
+        mView.pointToCellExact((int) x, (int) y, sTempArray);
+
+        // Map cell to id
+        int id = sTempArray[0] + sTempArray[1] * mView.getCountX();
+        return intersectsValidDropTarget(id);
+    }
+
+    /**
+     * @return the view id of the top left corner of a valid drop region or
+     * {@link #INVALID_POSITION} if there is no such valid region.
+     */
+    protected abstract int intersectsValidDropTarget(int id);
+
+    @Override
+    protected void getVisibleVirtualViews(List<Integer> virtualViews) {
+        // We create a virtual view for each cell of the grid
+        // The cell ids correspond to cells in reading order.
+        int nCells = mView.getCountX() * mView.getCountY();
+
+        for (int i = 0; i < nCells; i++) {
+            if (intersectsValidDropTarget(i) == i) {
+                virtualViews.add(i);
+            }
+        }
+    }
+
+    @Override
+    protected boolean onPerformActionForVirtualView(int viewId, int action, Bundle args) {
+        if (action == AccessibilityNodeInfoCompat.ACTION_CLICK && viewId != INVALID_ID) {
+            String confirmation = getConfirmationForIconDrop(viewId);
+            mDelegate.handleAccessibleDrop(mView, getItemBounds(viewId), confirmation);
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public void onClick(View v) {
+        onPerformActionForVirtualView(getFocusedVirtualView(),
+                AccessibilityNodeInfoCompat.ACTION_CLICK, null);
+    }
+
+    @Override
+    protected void onPopulateEventForVirtualView(int id, AccessibilityEvent event) {
+        if (id == INVALID_ID) {
+            throw new IllegalArgumentException("Invalid virtual view id");
+        }
+        event.setContentDescription(mContext.getString(R.string.action_move_here));
+    }
+
+    @Override
+    protected void onPopulateNodeForVirtualView(int id, AccessibilityNodeInfoCompat node) {
+        if (id == INVALID_ID) {
+            throw new IllegalArgumentException("Invalid virtual view id");
+        }
+
+        node.setContentDescription(getLocationDescriptionForIconDrop(id));
+        node.setBoundsInParent(getItemBounds(id));
+
+        node.addAction(AccessibilityNodeInfoCompat.ACTION_CLICK);
+        node.setClickable(true);
+        node.setFocusable(true);
+    }
+
+    protected abstract String getLocationDescriptionForIconDrop(int id);
+
+    protected abstract String getConfirmationForIconDrop(int id);
+
+    private Rect getItemBounds(int id) {
+        int cellX = id % mView.getCountX();
+        int cellY = id / mView.getCountX();
+        LauncherAccessibilityDelegate.DragInfo dragInfo = mDelegate.getDragInfo();
+        mView.cellToRect(cellX, cellY, dragInfo.info.spanX, dragInfo.info.spanY, mTempRect);
+        return mTempRect;
+    }
+}
\ No newline at end of file
diff --git a/src/com/android/launcher3/accessibility/FolderAccessibilityHelper.java b/src/com/android/launcher3/accessibility/FolderAccessibilityHelper.java
new file mode 100644
index 000000000..ff9989036
--- /dev/null
+++ b/src/com/android/launcher3/accessibility/FolderAccessibilityHelper.java
@@ -0,0 +1,56 @@
+/*
+ * 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 com.android.launcher3.CellLayout;
+import com.android.launcher3.FolderPagedView;
+import com.android.launcher3.R;
+
+/**
+ * Implementation of {@link DragAndDropAccessibilityDelegate} to support DnD in a folder.
+ */
+public class FolderAccessibilityHelper extends DragAndDropAccessibilityDelegate {
+
+    /**
+     * 0-index position for the first cell in {@link #mView} in {@link #mParent}.
+     */
+    private final int mStartPosition;
+
+    private final FolderPagedView mParent;
+
+    public FolderAccessibilityHelper(CellLayout layout) {
+        super(layout);
+        mParent = (FolderPagedView) layout.getParent();
+
+        int index = mParent.indexOfChild(layout);
+        mStartPosition = index * layout.getCountX() * layout.getCountY();
+    }
+    @Override
+    protected int intersectsValidDropTarget(int id) {
+        return Math.min(id, mParent.getAllocatedContentSize() - mStartPosition - 1);
+    }
+
+    @Override
+    protected String getLocationDescriptionForIconDrop(int id) {
+        return mContext.getString(R.string.move_to_position, id + mStartPosition + 1);
+    }
+
+    @Override
+    protected String getConfirmationForIconDrop(int id) {
+        return mContext.getString(R.string.item_moved);
+    }
+}
diff --git a/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
new file mode 100644
index 000000000..fe7b25edd
--- /dev/null
+++ b/src/com/android/launcher3/accessibility/LauncherAccessibilityDelegate.java
@@ -0,0 +1,434 @@
+package com.android.launcher3.accessibility;
+
+import android.annotation.TargetApi;
+import android.app.AlertDialog;
+import android.appwidget.AppWidgetProviderInfo;
+import android.content.DialogInterface;
+import android.graphics.Rect;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.Handler;
+import android.text.TextUtils;
+import android.util.Log;
+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.AppInfo;
+import com.android.launcher3.AppWidgetResizeFrame;
+import com.android.launcher3.CellLayout;
+import com.android.launcher3.DeleteDropTarget;
+import com.android.launcher3.DragController.DragListener;
+import com.android.launcher3.DragSource;
+import com.android.launcher3.Folder;
+import com.android.launcher3.FolderInfo;
+import com.android.launcher3.InfoDropTarget;
+import com.android.launcher3.ItemInfo;
+import com.android.launcher3.Launcher;
+import com.android.launcher3.LauncherAppWidgetHostView;
+import com.android.launcher3.LauncherAppWidgetInfo;
+import com.android.launcher3.LauncherModel;
+import com.android.launcher3.LauncherSettings;
+import com.android.launcher3.PendingAddItemInfo;
+import com.android.launcher3.R;
+import com.android.launcher3.ShortcutInfo;
+import com.android.launcher3.UninstallDropTarget;
+import com.android.launcher3.Workspace;
+import com.android.launcher3.util.Thunk;
+
+import java.util.ArrayList;
+
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+public class LauncherAccessibilityDelegate extends AccessibilityDelegate implements DragListener {
+
+    private static final String TAG = "LauncherAccessibilityDelegate";
+
+    private static final int REMOVE = R.id.action_remove;
+    private static final int INFO = R.id.action_info;
+    private static final int UNINSTALL = R.id.action_uninstall;
+    private static final int ADD_TO_WORKSPACE = R.id.action_add_to_workspace;
+    private static final int MOVE = R.id.action_move;
+    private static final int MOVE_TO_WORKSPACE = R.id.action_move_to_workspace;
+    private static final int RESIZE = R.id.action_resize;
+
+    public enum DragType {
+        ICON,
+        FOLDER,
+        WIDGET
+    }
+
+    public static class DragInfo {
+        public DragType dragType;
+        public ItemInfo info;
+        public View item;
+    }
+
+    private final SparseArray<AccessibilityAction> mActions = new SparseArray<>();
+    @Thunk final Launcher mLauncher;
+
+    private DragInfo mDragInfo = null;
+    private AccessibilityDragSource mDragSource = null;
+
+    public LauncherAccessibilityDelegate(Launcher launcher) {
+        mLauncher = launcher;
+
+        mActions.put(REMOVE, new AccessibilityAction(REMOVE,
+                launcher.getText(R.string.delete_target_label)));
+        mActions.put(INFO, new AccessibilityAction(INFO,
+                launcher.getText(R.string.info_target_label)));
+        mActions.put(UNINSTALL, new AccessibilityAction(UNINSTALL,
+                launcher.getText(R.string.delete_target_uninstall_label)));
+        mActions.put(ADD_TO_WORKSPACE, new AccessibilityAction(ADD_TO_WORKSPACE,
+                launcher.getText(R.string.action_add_to_workspace)));
+        mActions.put(MOVE, new AccessibilityAction(MOVE,
+                launcher.getText(R.string.action_move)));
+        mActions.put(MOVE_TO_WORKSPACE, new AccessibilityAction(MOVE_TO_WORKSPACE,
+                launcher.getText(R.string.action_move_to_workspace)));
+        mActions.put(RESIZE, new AccessibilityAction(RESIZE,
+                        launcher.getText(R.string.action_resize)));
+    }
+
+    @Override
+    public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfo info) {
+        super.onInitializeAccessibilityNodeInfo(host, info);
+        if (!(host.getTag() instanceof ItemInfo)) return;
+        ItemInfo item = (ItemInfo) host.getTag();
+
+        if (DeleteDropTarget.supportsDrop(item)) {
+            info.addAction(mActions.get(REMOVE));
+        }
+        if (UninstallDropTarget.supportsDrop(host.getContext(), item)) {
+            info.addAction(mActions.get(UNINSTALL));
+        }
+        if (InfoDropTarget.supportsDrop(host.getContext(), item)) {
+            info.addAction(mActions.get(INFO));
+        }
+
+        if ((item instanceof ShortcutInfo)
+                || (item instanceof LauncherAppWidgetInfo)
+                || (item instanceof FolderInfo)) {
+            info.addAction(mActions.get(MOVE));
+
+            if (item.container >= 0) {
+                info.addAction(mActions.get(MOVE_TO_WORKSPACE));
+            } else if (item instanceof LauncherAppWidgetInfo) {
+                if (!getSupportedResizeActions(host, (LauncherAppWidgetInfo) item).isEmpty()) {
+                    info.addAction(mActions.get(RESIZE));
+                }
+            }
+        } if ((item instanceof AppInfo) || (item instanceof PendingAddItemInfo)) {
+            info.addAction(mActions.get(ADD_TO_WORKSPACE));
+        }
+    }
+
+    @Override
+    public boolean performAccessibilityAction(View host, int action, Bundle args) {
+        if ((host.getTag() instanceof ItemInfo)
+                && performAction(host, (ItemInfo) host.getTag(), action)) {
+            return true;
+        }
+        return super.performAccessibilityAction(host, action, args);
+    }
+
+    public boolean performAction(final View host, final ItemInfo item, int action) {
+        if (action == REMOVE) {
+            if (DeleteDropTarget.removeWorkspaceOrFolderItem(mLauncher, item, host)) {
+                announceConfirmation(R.string.item_removed);
+                return true;
+            }
+            return false;
+        } else if (action == INFO) {
+            InfoDropTarget.startDetailsActivityForInfo(item, mLauncher);
+            return true;
+        } else if (action == UNINSTALL) {
+            return UninstallDropTarget.startUninstallActivity(mLauncher, item);
+        } else if (action == MOVE) {
+            beginAccessibleDrag(host, item);
+        } else if (action == ADD_TO_WORKSPACE) {
+            final int[] coordinates = new int[2];
+            final long screenId = findSpaceOnWorkspace(item, coordinates);
+            mLauncher.showWorkspace(true, new Runnable() {
+
+                @Override
+                public void run() {
+                    if (item instanceof AppInfo) {
+                        ShortcutInfo info = ((AppInfo) item).makeShortcut();
+                        LauncherModel.addItemToDatabase(mLauncher, info,
+                                LauncherSettings.Favorites.CONTAINER_DESKTOP,
+                                screenId, coordinates[0], coordinates[1]);
+
+                        ArrayList<ItemInfo> itemList = new ArrayList<>();
+                        itemList.add(info);
+                        mLauncher.bindItems(itemList, 0, itemList.size(), true);
+                    } else if (item instanceof PendingAddItemInfo) {
+                        PendingAddItemInfo info = (PendingAddItemInfo) item;
+                        Workspace workspace = mLauncher.getWorkspace();
+                        workspace.snapToPage(workspace.getPageIndexForScreenId(screenId));
+                        mLauncher.addPendingItem(info, LauncherSettings.Favorites.CONTAINER_DESKTOP,
+                                screenId, coordinates, info.spanX, info.spanY);
+                    }
+                    announceConfirmation(R.string.item_added_to_workspace);
+                }
+            });
+            return true;
+        } else if (action == MOVE_TO_WORKSPACE) {
+            Folder folder = mLauncher.getWorkspace().getOpenFolder();
+            mLauncher.closeFolder(folder);
+            ShortcutInfo info = (ShortcutInfo) item;
+            folder.getInfo().remove(info);
+
+            final int[] coordinates = new int[2];
+            final long screenId = findSpaceOnWorkspace(item, coordinates);
+            LauncherModel.moveItemInDatabase(mLauncher, info,
+                    LauncherSettings.Favorites.CONTAINER_DESKTOP,
+                    screenId, coordinates[0], coordinates[1]);
+
+            // Bind the item in next frame so that if a new workspace page was created,
+            // it will get laid out.
+            new Handler().post(new Runnable() {
+
+                @Override
+                public void run() {
+                    ArrayList<ItemInfo> itemList = new ArrayList<>();
+                    itemList.add(item);
+                    mLauncher.bindItems(itemList, 0, itemList.size(), true);
+                    announceConfirmation(R.string.item_moved);
+                }
+            });
+        } else if (action == RESIZE) {
+            final LauncherAppWidgetInfo info = (LauncherAppWidgetInfo) item;
+            final ArrayList<Integer> actions = getSupportedResizeActions(host, info);
+            CharSequence[] labels = new CharSequence[actions.size()];
+            for (int i = 0; i < actions.size(); i++) {
+                labels[i] = mLauncher.getText(actions.get(i));
+            }
+
+            new AlertDialog.Builder(mLauncher)
+                .setTitle(R.string.action_resize)
+                .setItems(labels, new DialogInterface.OnClickListener() {
+
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        performResizeAction(actions.get(which), host, info);
+                        dialog.dismiss();
+                    }
+                })
+                .show();
+        }
+        return false;
+    }
+
+    private ArrayList<Integer> getSupportedResizeActions(View host, LauncherAppWidgetInfo info) {
+        ArrayList<Integer> actions = new ArrayList<>();
+
+        AppWidgetProviderInfo providerInfo = ((LauncherAppWidgetHostView) host).getAppWidgetInfo();
+        if (providerInfo == null) {
+            return actions;
+        }
+
+        CellLayout layout = (CellLayout) host.getParent().getParent();
+        if ((providerInfo.resizeMode & AppWidgetProviderInfo.RESIZE_HORIZONTAL) != 0) {
+            if (layout.isRegionVacant(info.cellX + info.spanX, info.cellY, 1, info.spanY) ||
+                    layout.isRegionVacant(info.cellX - 1, info.cellY, 1, info.spanY)) {
+                actions.add(R.string.action_increase_width);
+            }
+
+            if (info.spanX > info.minSpanX && info.spanX > 1) {
+                actions.add(R.string.action_decrease_width);
+            }
+        }
+
+        if ((providerInfo.resizeMode & AppWidgetProviderInfo.RESIZE_VERTICAL) != 0) {
+            if (layout.isRegionVacant(info.cellX, info.cellY + info.spanY, info.spanX, 1) ||
+                    layout.isRegionVacant(info.cellX, info.cellY - 1, info.spanX, 1)) {
+                actions.add(R.string.action_increase_height);
+            }
+
+            if (info.spanY > info.minSpanY && info.spanY > 1) {
+                actions.add(R.string.action_decrease_height);
+            }
+        }
+        return actions;
+    }
+
+    @Thunk void performResizeAction(int action, View host, LauncherAppWidgetInfo info) {
+        CellLayout.LayoutParams lp = (CellLayout.LayoutParams) host.getLayoutParams();
+        CellLayout layout = (CellLayout) host.getParent().getParent();
+        layout.markCellsAsUnoccupiedForView(host);
+
+        if (action == R.string.action_increase_width) {
+            if (((host.getLayoutDirection() == View.LAYOUT_DIRECTION_RTL)
+                    && layout.isRegionVacant(info.cellX - 1, info.cellY, 1, info.spanY))
+                    || !layout.isRegionVacant(info.cellX + info.spanX, info.cellY, 1, info.spanY)) {
+                lp.cellX --;
+                info.cellX --;
+            }
+            lp.cellHSpan ++;
+            info.spanX ++;
+        } else if (action == R.string.action_decrease_width) {
+            lp.cellHSpan --;
+            info.spanX --;
+        } else if (action == R.string.action_increase_height) {
+            if (!layout.isRegionVacant(info.cellX, info.cellY + info.spanY, info.spanX, 1)) {
+                lp.cellY --;
+                info.cellY --;
+            }
+            lp.cellVSpan ++;
+            info.spanY ++;
+        } else if (action == R.string.action_decrease_height) {
+            lp.cellVSpan --;
+            info.spanY --;
+        }
+
+        layout.markCellsAsOccupiedForView(host);
+        Rect sizeRange = new Rect();
+        AppWidgetResizeFrame.getWidgetSizeRanges(mLauncher, info.spanX, info.spanY, sizeRange);
+        ((LauncherAppWidgetHostView) host).updateAppWidgetSize(null,
+                sizeRange.left, sizeRange.top, sizeRange.right, sizeRange.bottom);
+        host.requestLayout();
+        LauncherModel.updateItemInDatabase(mLauncher, info);
+        announceConfirmation(mLauncher.getString(R.string.widget_resized, info.spanX, info.spanY));
+    }
+
+    @Thunk void announceConfirmation(int resId) {
+        announceConfirmation(mLauncher.getResources().getString(resId));
+    }
+
+    @Thunk void announceConfirmation(String confirmation) {
+        mLauncher.getDragLayer().announceForAccessibility(confirmation);
+
+    }
+
+    public boolean isInAccessibleDrag() {
+        return mDragInfo != null;
+    }
+
+    public DragInfo getDragInfo() {
+        return mDragInfo;
+    }
+
+    /**
+     * @param clickedTarget the actual view that was clicked
+     * @param dropLocation relative to {@param clickedTarget}. If provided, its center is used
+     * as the actual drop location otherwise the views center is used.
+     */
+    public void handleAccessibleDrop(View clickedTarget, Rect dropLocation,
+            String confirmation) {
+        if (!isInAccessibleDrag()) return;
+
+        int[] loc = new int[2];
+        if (dropLocation == null) {
+            loc[0] = clickedTarget.getWidth() / 2;
+            loc[1] = clickedTarget.getHeight() / 2;
+        } else {
+            loc[0] = dropLocation.centerX();
+            loc[1] = dropLocation.centerY();
+        }
+
+        mLauncher.getDragLayer().getDescendantCoordRelativeToSelf(clickedTarget, loc);
+        mLauncher.getDragController().completeAccessibleDrag(loc);
+
+        if (!TextUtils.isEmpty(confirmation)) {
+            announceConfirmation(confirmation);
+        }
+    }
+
+    public void beginAccessibleDrag(View item, ItemInfo info) {
+        mDragInfo = new DragInfo();
+        mDragInfo.info = info;
+        mDragInfo.item = item;
+        mDragInfo.dragType = DragType.ICON;
+        if (info instanceof FolderInfo) {
+            mDragInfo.dragType = DragType.FOLDER;
+        } else if (info instanceof LauncherAppWidgetInfo) {
+            mDragInfo.dragType = DragType.WIDGET;
+        }
+
+        CellLayout.CellInfo cellInfo = new CellLayout.CellInfo(item, info);
+
+        Rect pos = new Rect();
+        mLauncher.getDragLayer().getDescendantRectRelativeToSelf(item, pos);
+        mLauncher.getDragController().prepareAccessibleDrag(pos.centerX(), pos.centerY());
+
+        Workspace workspace = mLauncher.getWorkspace();
+
+        Folder folder = workspace.getOpenFolder();
+        if (folder != null) {
+            if (folder.getItemsInReadingOrder().contains(item)) {
+                mDragSource = folder;
+            } else {
+                mLauncher.closeFolder();
+            }
+        }
+        if (mDragSource == null) {
+            mDragSource = workspace;
+        }
+        mDragSource.enableAccessibleDrag(true);
+        mDragSource.startDrag(cellInfo, true);
+
+        if (mLauncher.getDragController().isDragging()) {
+            mLauncher.getDragController().addDragListener(this);
+        }
+    }
+
+
+    @Override
+    public void onDragStart(DragSource source, Object info, int dragAction) {
+        // No-op
+    }
+
+    @Override
+    public void onDragEnd() {
+        mLauncher.getDragController().removeDragListener(this);
+        mDragInfo = null;
+        if (mDragSource != null) {
+            mDragSource.enableAccessibleDrag(false);
+            mDragSource = null;
+        }
+    }
+
+    public static interface AccessibilityDragSource {
+        void startDrag(CellLayout.CellInfo cellInfo, boolean accessible);
+
+        void enableAccessibleDrag(boolean enable);
+    }
+
+    /**
+     * Find empty space on the workspace and returns the screenId.
+     */
+    private long findSpaceOnWorkspace(ItemInfo info, int[] outCoordinates) {
+        Workspace workspace = mLauncher.getWorkspace();
+        ArrayList<Long> workspaceScreens = workspace.getScreenOrder();
+        long screenId;
+
+        // First check if there is space on the current screen.
+        int screenIndex = workspace.getCurrentPage();
+        screenId = workspaceScreens.get(screenIndex);
+        CellLayout layout = (CellLayout) workspace.getPageAt(screenIndex);
+
+        boolean found = layout.findCellForSpan(outCoordinates, info.spanX, info.spanY);
+        screenIndex = workspace.hasCustomContent() ? 1 : 0;
+        while (!found && screenIndex < workspaceScreens.size()) {
+            screenId = workspaceScreens.get(screenIndex);
+            layout = (CellLayout) workspace.getPageAt(screenIndex);
+            found = layout.findCellForSpan(outCoordinates, info.spanX, info.spanY);
+            screenIndex++;
+        }
+
+        if (found) {
+            return screenId;
+        }
+
+        workspace.addExtraEmptyScreen();
+        screenId = workspace.commitExtraEmptyScreen();
+        layout = workspace.getScreenWithId(screenId);
+        found = layout.findCellForSpan(outCoordinates, info.spanX, info.spanY);
+
+        if (!found) {
+            Log.wtf(TAG, "Not enough space on an empty screen");
+        }
+        return screenId;
+    }
+}
diff --git a/src/com/android/launcher3/accessibility/OverviewScreenAccessibilityDelegate.java b/src/com/android/launcher3/accessibility/OverviewScreenAccessibilityDelegate.java
new file mode 100644
index 000000000..c5b52de72
--- /dev/null
+++ b/src/com/android/launcher3/accessibility/OverviewScreenAccessibilityDelegate.java
@@ -0,0 +1,95 @@
+/*
+ * 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.annotation.TargetApi;
+import android.content.Context;
+import android.os.Build;
+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.Utilities;
+import com.android.launcher3.Workspace;
+
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+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 = Utilities.isRtl(context.getResources());
+        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));
+        }
+    }
+}
diff --git a/src/com/android/launcher3/accessibility/WorkspaceAccessibilityHelper.java b/src/com/android/launcher3/accessibility/WorkspaceAccessibilityHelper.java
new file mode 100644
index 000000000..80ddc13b7
--- /dev/null
+++ b/src/com/android/launcher3/accessibility/WorkspaceAccessibilityHelper.java
@@ -0,0 +1,166 @@
+/*
+ * 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.text.TextUtils;
+import android.view.View;
+
+import com.android.launcher3.AppInfo;
+import com.android.launcher3.CellLayout;
+import com.android.launcher3.FolderInfo;
+import com.android.launcher3.ItemInfo;
+import com.android.launcher3.accessibility.LauncherAccessibilityDelegate.DragType;
+import com.android.launcher3.R;
+import com.android.launcher3.ShortcutInfo;
+
+/**
+ * Implementation of {@link DragAndDropAccessibilityDelegate} to support DnD on workspace.
+ */
+public class WorkspaceAccessibilityHelper extends DragAndDropAccessibilityDelegate {
+
+    public WorkspaceAccessibilityHelper(CellLayout layout) {
+        super(layout);
+    }
+
+    /**
+     * Find the virtual view id corresponding to the top left corner of any drop region by which
+     * the passed id is contained. For an icon, this is simply
+     */
+    @Override
+    protected int intersectsValidDropTarget(int id) {
+        int mCountX = mView.getCountX();
+        int mCountY = mView.getCountY();
+
+        int x = id % mCountX;
+        int y = id / mCountX;
+        LauncherAccessibilityDelegate.DragInfo dragInfo = mDelegate.getDragInfo();
+
+        if (dragInfo.dragType == DragType.WIDGET && mView.isHotseat()) {
+            return INVALID_POSITION;
+        }
+
+        if (dragInfo.dragType == DragType.WIDGET) {
+            // For a widget, every cell must be vacant. In addition, we will return any valid
+            // drop target by which the passed id is contained.
+            boolean fits = false;
+
+            // These represent the amount that we can back off if we hit a problem. They
+            // get consumed as we move up and to the right, trying new regions.
+            int spanX = dragInfo.info.spanX;
+            int spanY = dragInfo.info.spanY;
+
+            for (int m = 0; m < spanX; m++) {
+                for (int n = 0; n < spanY; n++) {
+
+                    fits = true;
+                    int x0 = x - m;
+                    int y0 = y - n;
+
+                    if (x0 < 0 || y0 < 0) continue;
+
+                    for (int i = x0; i < x0 + spanX; i++) {
+                        if (!fits) break;
+                        for (int j = y0; j < y0 + spanY; j++) {
+                            if (i >= mCountX || j >= mCountY || mView.isOccupied(i, j)) {
+                                fits = false;
+                                break;
+                            }
+                        }
+                    }
+                    if (fits) {
+                        return x0 + mCountX * y0;
+                    }
+                }
+            }
+            return INVALID_POSITION;
+        } else {
+            // For an icon, we simply check the view directly below
+            View child = mView.getChildAt(x, y);
+            if (child == null || child == dragInfo.item) {
+                // Empty cell. Good for an icon or folder.
+                return id;
+            } else if (dragInfo.dragType != DragType.FOLDER) {
+                // For icons, we can consider cells that have another icon or a folder.
+                ItemInfo info = (ItemInfo) child.getTag();
+                if (info instanceof AppInfo || info instanceof FolderInfo ||
+                        info instanceof ShortcutInfo) {
+                    return id;
+                }
+            }
+            return INVALID_POSITION;
+        }
+    }
+
+    @Override
+    protected String getConfirmationForIconDrop(int id) {
+        int x = id % mView.getCountX();
+        int y = id / mView.getCountX();
+        LauncherAccessibilityDelegate.DragInfo dragInfo = mDelegate.getDragInfo();
+
+        View child = mView.getChildAt(x, y);
+        if (child == null || child == dragInfo.item) {
+            return mContext.getString(R.string.item_moved);
+        } else {
+            ItemInfo info = (ItemInfo) child.getTag();
+            if (info instanceof AppInfo || info instanceof ShortcutInfo) {
+                return mContext.getString(R.string.folder_created);
+
+            } else if (info instanceof FolderInfo) {
+                return mContext.getString(R.string.added_to_folder);
+            }
+        }
+        return "";
+    }
+
+    @Override
+    protected String getLocationDescriptionForIconDrop(int id) {
+        int x = id % mView.getCountX();
+        int y = id / mView.getCountX();
+        LauncherAccessibilityDelegate.DragInfo dragInfo = mDelegate.getDragInfo();
+
+        View child = mView.getChildAt(x, y);
+        if (child == null || child == dragInfo.item) {
+            if (mView.isHotseat()) {
+                return mContext.getString(R.string.move_to_hotseat_position, id + 1);
+            } else {
+                return mContext.getString(R.string.move_to_empty_cell, y + 1, x + 1);
+            }
+        } else {
+            ItemInfo info = (ItemInfo) child.getTag();
+            if (info instanceof ShortcutInfo) {
+                return mContext.getString(R.string.create_folder_with, info.title);
+            } else if (info instanceof FolderInfo) {
+                if (TextUtils.isEmpty(info.title)) {
+                    // Find the first item in the folder.
+                    FolderInfo folder = (FolderInfo) info;
+                    ShortcutInfo firstItem = null;
+                    for (ShortcutInfo shortcut : folder.contents) {
+                        if (firstItem == null || firstItem.rank > shortcut.rank) {
+                            firstItem = shortcut;
+                        }
+                    }
+
+                    if (firstItem != null) {
+                        return mContext.getString(R.string.add_to_folder_with_app, firstItem.title);
+                    }
+                }
+                return mContext.getString(R.string.add_to_folder, info.title);
+            }
+        }
+        return "";
+    }
+}