| /* |
| * 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; |
| |
| import static com.android.documentsui.base.Shared.DEBUG; |
| |
| import android.util.Log; |
| |
| import com.android.documentsui.base.DocumentInfo; |
| |
| import java.util.List; |
| |
| /** |
| * A helper class for drag and drop operations |
| */ |
| public final class DragAndDropHelper { |
| |
| private static final String TAG = "DragAndDropHelper"; |
| |
| private DragAndDropHelper() {} |
| |
| /** |
| * Helper method to see whether an item can be dropped/copied into a particular destination. |
| * Don't copy from the cwd into a provided list of prohibited directories. (ie. into cwd, into a |
| * selected directory). Note: this currently doesn't work for multi-window drag, because |
| * localState isn't carried over from one process to another. |
| */ |
| public static boolean canCopyTo(Object dragLocalState, DocumentInfo dst) { |
| if (dragLocalState == null || !(dragLocalState instanceof List<?>)) { |
| if (DEBUG) Log.d(TAG, "Invalid local state object. Will allow copy."); |
| return true; |
| } |
| List<?> src = (List<?>) dragLocalState; |
| if (src.contains(dst)) { |
| if (DEBUG) Log.d(TAG, "Drop target same as source. Ignoring."); |
| return false; |
| } |
| return true; |
| } |
| } |