Ben Lin | d020212 | 2016-11-10 18:00:12 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.android.documentsui; |
| 18 | |
| 19 | import static com.android.documentsui.base.Shared.DEBUG; |
| 20 | |
| 21 | import android.util.Log; |
| 22 | |
| 23 | import com.android.documentsui.base.DocumentInfo; |
| 24 | |
| 25 | import java.util.List; |
| 26 | |
| 27 | /** |
| 28 | * A helper class for drag and drop operations |
| 29 | */ |
| 30 | public final class DragAndDropHelper { |
| 31 | |
| 32 | private static final String TAG = "DragAndDropHelper"; |
| 33 | |
| 34 | private DragAndDropHelper() {} |
| 35 | |
| 36 | /** |
| 37 | * Helper method to see whether an item can be dropped/copied into a particular destination. |
| 38 | * Don't copy from the cwd into a provided list of prohibited directories. (ie. into cwd, into a |
| 39 | * selected directory). Note: this currently doesn't work for multi-window drag, because |
| 40 | * localState isn't carried over from one process to another. |
| 41 | */ |
| 42 | public static boolean canCopyTo(Object dragLocalState, DocumentInfo dst) { |
| 43 | if (dragLocalState == null || !(dragLocalState instanceof List<?>)) { |
| 44 | if (DEBUG) Log.d(TAG, "Invalid local state object. Will allow copy."); |
| 45 | return true; |
| 46 | } |
| 47 | List<?> src = (List<?>) dragLocalState; |
| 48 | if (src.contains(dst)) { |
| 49 | if (DEBUG) Log.d(TAG, "Drop target same as source. Ignoring."); |
| 50 | return false; |
| 51 | } |
| 52 | return true; |
| 53 | } |
| 54 | } |