1 2 Android DragAndDropAcrossApps-new Sample 3 =================================== 4 5 This sample contains two separate Android applications: DragSource and 6 DropTarget. DragSource contains images and text that can be dropped into the DropTarget 7 app. Images are shared between the two apps through a URI for which the receiving app 8 must request permission first, before it can be used. 9 10 It also demonstrates the use of the DragStartHelper from the v13 support library to easily 11 handle drag and drop events. 12 13 Introduction 14 ------------ 15 16 Android N introduces support for drag and drop between applications, 17 augmenting the existing APIs that have enabled this within a single 18 window before. 19 20 To start a drag operation you need to call `View.startDragAndDrop`. 21 Which gesture or action triggers this is up to you as an app developer. 22 The API guide recommends doing this from 23 `View.OnLongClickListener.onLongClick` and this seems to be the de-facto 24 standard, but you are free to use other gestures (single tap, tap and drag 25 etc). 26 However, if you go for a unconventional drag start gesture, note that 27 the framework implementation assumes that the pointer (touch or mouse) 28 is down while the drag is starting, and the most recent touch/click 29 position is used as the original position of the drag shadow. 30 31 See also `android.support.v13.view.DragStartHelper` which uses different 32 gestures for touch and mouse (click and drag works better for mouse 33 than a long click). 34 35 By default a drag and drop operation is constrained by the window 36 containing the view that started the drag. 37 To enable cross-window and cross-app drag and drop add 38 `View.DRAG_FLAG_GLOBAL` to the flags passed to the `View.startDragAndDrop` 39 call. 40 41 If a Uri requiring permission grants is being sent, then the 42 `android.view.View.DRAG_FLAG_GLOBAL_URI_READ` and/or the 43 `android.view.View.DRAG_FLAG_GLOBAL_URI_WRITE` flags must be used also. 44 To access content URIs requiring permissions on the receiving side, the target 45 app needs to request the `android.view.DropPermissions` from the activity via 46 `android.app.Activity.requestDropPermissions`. This permission will stay either 47 until the activity is alive, or until the `release()` method is called on the 48 `android.view.DropPermissions` object. 49 50 Pre-requisites 51 -------------- 52 53 - Android SDK 25 54 - Android Build Tools v25.0.3 55 - Android Support Repository 56 57 Screenshots 58 ------------- 59 60 <img src="screenshots/phone.png" height="400" alt="Screenshot"/> <img src="screenshots/tablet.png" height="400" alt="Screenshot"/> 61 62 Getting Started 63 --------------- 64 65 This sample uses the Gradle build system. To build this project, use the 66 "gradlew build" command or use "Import Project" in Android Studio. 67 68 Support 69 ------- 70 71 - Google+ Community: https://plus.google.com/communities/105153134372062985968 72 - Stack Overflow: http://stackoverflow.com/questions/tagged/android 73 74 If you've found an error in this sample, please file an issue: 75 https://github.com/googlesamples/android-DragAndDropAcrossApps-new 76 77 Patches are encouraged, and may be submitted by forking this project and 78 submitting a pull request through GitHub. Please see CONTRIBUTING.md for more details. 79 80 License 81 ------- 82 83 Copyright 2017 The Android Open Source Project, Inc. 84 85 Licensed to the Apache Software Foundation (ASF) under one or more contributor 86 license agreements. See the NOTICE file distributed with this work for 87 additional information regarding copyright ownership. The ASF licenses this 88 file to you under the Apache License, Version 2.0 (the "License"); you may not 89 use this file except in compliance with the License. You may obtain a copy of 90 the License at 91 92 http://www.apache.org/licenses/LICENSE-2.0 93 94 Unless required by applicable law or agreed to in writing, software 95 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 96 WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 97 License for the specific language governing permissions and limitations under 98 the License. 99
