1/*
2 * Copyright (C) 2011 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.app;
18
19import android.app.Fragment;
20import android.content.Context;
21import android.content.pm.PackageManager;
22import android.os.Build;
23import android.os.Handler;
24import android.os.Looper;
25import android.support.annotation.NonNull;
26
27import java.util.Arrays;
28
29/**
30 * Helper for accessing features in {@link Fragment} introduced after
31 * API level 13 in a backwards compatible fashion.
32 */
33public class FragmentCompat {
34    interface FragmentCompatImpl {
35        void setMenuVisibility(Fragment f, boolean visible);
36        void setUserVisibleHint(Fragment f, boolean deferStart);
37        void requestPermissions(Fragment fragment, String[] permissions, int requestCode);
38        boolean shouldShowRequestPermissionRationale(Fragment fragment, String permission);
39    }
40
41    static class BaseFragmentCompatImpl implements FragmentCompatImpl {
42        public void setMenuVisibility(Fragment f, boolean visible) {
43        }
44        public void setUserVisibleHint(Fragment f, boolean deferStart) {
45        }
46        public void requestPermissions(final Fragment fragment, final String[] permissions,
47                final int requestCode) {
48            Handler handler = new Handler(Looper.getMainLooper());
49            handler.post(new Runnable() {
50                @Override
51                public void run() {
52                    final int[] grantResults = new int[permissions.length];
53
54                    Context context = fragment.getActivity();
55                    if (context != null) {
56                        PackageManager packageManager = context.getPackageManager();
57                        String packageName = context.getPackageName();
58
59                        final int permissionCount = permissions.length;
60                        for (int i = 0; i < permissionCount; i++) {
61                            grantResults[i] = packageManager.checkPermission(
62                                    permissions[i], packageName);
63                        }
64                    } else {
65                        Arrays.fill(grantResults, PackageManager.PERMISSION_DENIED);
66                    }
67
68                    ((OnRequestPermissionsResultCallback) fragment).onRequestPermissionsResult(
69                            requestCode, permissions, grantResults);
70                }
71            });
72        }
73        public boolean shouldShowRequestPermissionRationale(Fragment fragment, String permission) {
74            return false;
75        }
76    }
77
78    static class ICSFragmentCompatImpl extends BaseFragmentCompatImpl {
79        @Override
80        public void setMenuVisibility(Fragment f, boolean visible) {
81            FragmentCompatICS.setMenuVisibility(f, visible);
82        }
83    }
84
85    static class ICSMR1FragmentCompatImpl extends ICSFragmentCompatImpl {
86        @Override
87        public void setUserVisibleHint(Fragment f, boolean deferStart) {
88            FragmentCompatICSMR1.setUserVisibleHint(f, deferStart);
89        }
90    }
91
92    static class MncFragmentCompatImpl extends ICSMR1FragmentCompatImpl {
93        @Override
94        public void requestPermissions(Fragment fragment, String[] permissions, int requestCode) {
95            FragmentCompat23.requestPermissions(fragment, permissions, requestCode);
96        }
97
98        @Override
99        public boolean shouldShowRequestPermissionRationale(Fragment fragment, String permission) {
100            return FragmentCompat23.shouldShowRequestPermissionRationale(fragment, permission);
101        }
102    }
103
104    static final FragmentCompatImpl IMPL;
105    static {
106        if (Build.VERSION.SDK_INT >= 23) {
107            IMPL = new MncFragmentCompatImpl();
108        } else if (android.os.Build.VERSION.SDK_INT >= 15) {
109            IMPL = new ICSMR1FragmentCompatImpl();
110        } else if (android.os.Build.VERSION.SDK_INT >= 14) {
111            IMPL = new ICSFragmentCompatImpl();
112        } else {
113            IMPL = new BaseFragmentCompatImpl();
114        }
115    }
116
117    /**
118     * This interface is the contract for receiving the results for permission requests.
119     */
120    public interface OnRequestPermissionsResultCallback {
121
122        /**
123         * Callback for the result from requesting permissions. This method
124         * is invoked for every call on {@link #requestPermissions(android.app.Fragment,
125         * String[], int)}
126         *
127         * @param requestCode The request code passed in {@link #requestPermissions(
128         *     android.app.Fragment, String[], int)}
129         * @param permissions The requested permissions. Never null.
130         * @param grantResults The grant results for the corresponding permissions
131         *     which is either {@link android.content.pm.PackageManager#PERMISSION_GRANTED}
132         *     or {@link android.content.pm.PackageManager#PERMISSION_DENIED}. Never null.
133         *
134         * @see #requestPermissions(android.app.Fragment, String[], int)
135         */
136        public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
137                @NonNull int[] grantResults);
138    }
139
140    /**
141     * Call {@link Fragment#setMenuVisibility(boolean) Fragment.setMenuVisibility(boolean)}
142     * if running on an appropriate version of the platform.
143     */
144    public static void setMenuVisibility(Fragment f, boolean visible) {
145        IMPL.setMenuVisibility(f, visible);
146    }
147
148    /**
149     * Call {@link Fragment#setUserVisibleHint(boolean) setUserVisibleHint(boolean)}
150     * if running on an appropriate version of the platform.
151     */
152    public static void setUserVisibleHint(Fragment f, boolean deferStart) {
153        IMPL.setUserVisibleHint(f, deferStart);
154    }
155
156    /**
157     * Requests permissions to be granted to this application. These permissions
158     * must be requested in your manifest, they should not be granted to your app,
159     * and they should have protection level {@link android.content.pm.PermissionInfo
160     * #PROTECTION_DANGEROUS dangerous}, regardless whether they are declared by
161     * the platform or a third-party app.
162     * <p>
163     * Normal permissions {@link android.content.pm.PermissionInfo#PROTECTION_NORMAL}
164     * are granted at install time if requested in the manifest. Signature permissions
165     * {@link android.content.pm.PermissionInfo#PROTECTION_SIGNATURE} are granted at
166     * install time if requested in the manifest and the signature of your app matches
167     * the signature of the app declaring the permissions.
168     * </p>
169     * <p>
170     * If your app does not have the requested permissions the user will be presented
171     * with UI for accepting them. After the user has accepted or rejected the
172     * requested permissions you will receive a callback reporting whether the
173     * permissions were granted or not. Your fragment has to implement {@link
174     * OnRequestPermissionsResultCallback}
175     * and the results of permission requests will be delivered to its
176     * {@link OnRequestPermissionsResultCallback#onRequestPermissionsResult(
177     * int, String[], int[])}.
178     * </p>
179     * <p>
180     * Note that requesting a permission does not guarantee it will be granted and
181     * your app should be able to run without having this permission.
182     * </p>
183     * <p>
184     * This method may start an activity allowing the user to choose which permissions
185     * to grant and which to reject. Hence, you should be prepared that your activity
186     * may be paused and resumed. Further, granting some permissions may require
187     * a restart of you application. In such a case, the system will recreate the
188     * activity stack before delivering the result to your onRequestPermissionsResult(
189     * int, String[], int[]).
190     * </p>
191     * <p>
192     * When checking whether you have a permission you should use {@link
193     * android.support.v4.content.ContextCompat#checkSelfPermission(
194     * android.content.Context, String)}.
195     * </p>
196     *
197     * @param fragment The target fragment.
198     * @param permissions The requested permissions.
199     * @param requestCode Application specific request code to match with a result
200     *    reported to {@link OnRequestPermissionsResultCallback#onRequestPermissionsResult(
201     *    int, String[], int[])}.
202     *
203     * @see android.support.v4.content.ContextCompat#checkSelfPermission(
204     *     android.content.Context, String)
205     * @see #shouldShowRequestPermissionRationale(android.app.Fragment, String)
206     */
207    public static void requestPermissions(@NonNull Fragment fragment,
208            @NonNull String[] permissions, int requestCode) {
209        IMPL.requestPermissions(fragment, permissions, requestCode);
210    }
211
212    /**
213     * Gets whether you should show UI with rationale for requesting a permission.
214     * You should do this only if you do not have the permission and the context in
215     * which the permission is requested does not clearly communicate to the user
216     * what would be the benefit from granting this permission.
217     * <p>
218     * For example, if you write a camera app, requesting the camera permission
219     * would be expected by the user and no rationale for why it is requested is
220     * needed. If however, the app needs location for tagging photos then a non-tech
221     * savvy user may wonder how location is related to taking photos. In this case
222     * you may choose to show UI with rationale of requesting this permission.
223     * </p>
224     *
225     * @param fragment The target fragment.
226     * @param permission A permission your app wants to request.
227     * @return Whether you can show permission rationale UI.
228     *
229     * @see android.support.v4.content.ContextCompat#checkSelfPermission(
230     *     android.content.Context, String)
231     * @see #requestPermissions(android.app.Fragment, String[], int)
232     */
233    public static boolean shouldShowRequestPermissionRationale(@NonNull Fragment fragment,
234            @NonNull String permission) {
235        return IMPL.shouldShowRequestPermissionRationale(fragment, permission);
236    }
237}
238