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
17package android.support.v13.view;
18
19import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;
20
21import android.app.Activity;
22import android.os.Build;
23import android.support.annotation.RequiresApi;
24import android.support.annotation.RestrictTo;
25import android.view.DragAndDropPermissions;
26import android.view.DragEvent;
27
28/**
29 * Helper for accessing features in {@link android.view.DragAndDropPermissions}
30 * introduced after API level 13 in a backwards compatible fashion.
31 */
32public final class DragAndDropPermissionsCompat {
33
34    interface DragAndDropPermissionsCompatImpl {
35        Object request(Activity activity, DragEvent dragEvent);
36        void release(Object dragAndDropPermissions);
37    }
38
39    static class BaseDragAndDropPermissionsCompatImpl implements DragAndDropPermissionsCompatImpl {
40        @Override
41        public Object request(Activity activity, DragEvent dragEvent) {
42            return null;
43        }
44
45        @Override
46        public void release(Object dragAndDropPermissions) {
47            // no-op
48        }
49    }
50
51    @RequiresApi(24)
52    static class Api24DragAndDropPermissionsCompatImpl
53            extends BaseDragAndDropPermissionsCompatImpl {
54        @Override
55        public Object request(Activity activity, DragEvent dragEvent) {
56            return activity.requestDragAndDropPermissions(dragEvent);
57        }
58
59        @Override
60        public void release(Object dragAndDropPermissions) {
61            ((DragAndDropPermissions) dragAndDropPermissions).release();
62        }
63    }
64
65    private static DragAndDropPermissionsCompatImpl IMPL;
66    static {
67        if (Build.VERSION.SDK_INT >= 24) {
68            IMPL = new Api24DragAndDropPermissionsCompatImpl();
69        } else {
70            IMPL = new BaseDragAndDropPermissionsCompatImpl();
71        }
72    }
73
74    private Object mDragAndDropPermissions;
75
76    private DragAndDropPermissionsCompat(Object dragAndDropPermissions) {
77        mDragAndDropPermissions = dragAndDropPermissions;
78    }
79
80    /** @hide */
81    @RestrictTo(LIBRARY_GROUP)
82    public static DragAndDropPermissionsCompat request(Activity activity, DragEvent dragEvent) {
83        Object dragAndDropPermissions = IMPL.request(activity, dragEvent);
84        if (dragAndDropPermissions != null) {
85            return new DragAndDropPermissionsCompat(dragAndDropPermissions);
86        }
87        return null;
88    }
89
90    /*
91     * Revoke the permission grant explicitly.
92     */
93    public void release() {
94        IMPL.release(mDragAndDropPermissions);
95    }
96}
97