Enabling accessibility drag and drop in folder

> Moving DragAndDropAccessibilityDelegate to a separate class
> Using getFocusedVirtualView() instead of using DownX and downY
> Updating various accessibility strings

Bug: 19776741

Change-Id: I85c2551d4d6172c30702e68f41b114bb999655b6

src/com/android/launcher3/accessibility/WorkspaceAccessibilityHelper.java

@@ -0,0 +1,167 @@
+/*
+ * 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.LauncherAccessibilityDelegate;
+import com.android.launcher3.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.toString().trim())) {
+                    // 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 "";
+    }
+}