Java tutorial
/* * Copyright Google Inc. All Rights Reserved. * * 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 cn.motalks.mtdc.utils; import android.annotation.TargetApi; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.net.Uri; import android.os.Build; import android.provider.Settings; import android.support.design.widget.Snackbar; import android.support.v4.app.ActivityCompat; import android.support.v4.app.Fragment; import android.support.v4.content.ContextCompat; import android.util.Log; import android.view.View; import java.util.ArrayList; import java.util.List; /** * Utility to request and check System permissions for apps targeting Android M (API >= 23). * The permissions helper class is on the basis of EasyPermissions(@link https://github.com/googlesamples/easypermissions). * * Author: douyoumi (https://github.com/xinshoucb/EasyPermissionsEx/) * Date: 2016-09-13 * Email: xinshou.cb@gmail.com */ public class EasyPermissionsEx { private static final String TAG = "EasyPermissionsEx"; public interface PermissionCallbacks extends ActivityCompat.OnRequestPermissionsResultCallback { void onPermissionsGranted(int requestCode, List<String> perms); void onPermissionsDenied(int requestCode, List<String> perms); } /** * Check if the calling context has a set of permissions. * * @param context the calling context. * @param perms one ore more permissions, such as {@code android.Manifest.permission.CAMERA}. * @return true if all permissions are already granted, false if at least one permission * is not yet granted. */ public static boolean hasPermissions(Context context, String... perms) { // Always return true for SDK < M, let the system deal with the permissions if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) { Log.w(TAG, "hasPermissions: API version < M, returning true by default"); return true; } for (String perm : perms) { boolean hasPerm = (ActivityCompat.checkSelfPermission(context, perm) == PackageManager.PERMISSION_GRANTED); if (!hasPerm) { return false; } } return true; } /** * Request a set of permissions, showing rationale if the system requests it. * * @param object Activity or Fragment requesting permissions. Should implement * {@link ActivityCompat.OnRequestPermissionsResultCallback} * or {@link android.support.v13.app.FragmentCompat.OnRequestPermissionsResultCallback} * @param rationale a message explaining why the application needs this set of permissions, will * be displayed if the user rejects the request the first time. * @param requestCode request code to track this request, must be < 256. * @param perms a set of permissions to be requested. */ public static void requestPermissions(Object object, String rationale, int requestCode, String... perms) { requestPermissions(object, rationale, android.R.string.ok, requestCode, perms); } /** * Request a set of permissions, showing rationale if the system requests it. * * @param object Activity or Fragment requesting permissions. Should implement * {@link ActivityCompat.OnRequestPermissionsResultCallback} * or {@link android.support.v13.app.FragmentCompat.OnRequestPermissionsResultCallback} * @param rationale a message explaining why the application needs this set of permissions, will * be displayed if the user rejects the request the first time. * @param snackbarActionResId custom text for snackbar action button * @param requestCode request code to track this request, must be < 256. * @param perms a set of permissions to be requested. */ public static void requestPermissions(final Object object, String rationale, int snackbarActionResId, final int requestCode, final String... perms) { checkCallingObjectSuitability(object); boolean shouldShowRationale = false; for (String perm : perms) { shouldShowRationale = shouldShowRationale || shouldShowRequestPermissionRationale(object, perm); } if (shouldShowRationale) { Activity activity = getActivity(object); if (null == activity) { return; } Snackbar.make(activity.findViewById(android.R.id.content), rationale, Snackbar.LENGTH_LONG) .setAction(snackbarActionResId, new View.OnClickListener() { @Override public void onClick(View v) { executePermissionsRequest(object, perms, requestCode); } }).show(); } else { executePermissionsRequest(object, perms, requestCode); } } /** * Check if at least one permission in the list of denied permissions has been permanently * denied (user clicked "Never ask again"). * @param object Activity or Fragment requesting permissions. * @param deniedPermissions list of denied permissions, usually from * {@link PermissionCallbacks#onPermissionsDenied(int, List)} * @return {@code true} if at least one permission in the list was permanently denied. */ public static boolean somePermissionPermanentlyDenied(Object object, final String... deniedPermissions) { for (String deniedPermission : deniedPermissions) { if (permissionPermanentlyDenied(object, deniedPermission)) { return true; } } return false; } /** * Check if a permission has been permanently denied (user clicked "Never ask again"). * @param object Activity or Fragment requesting permissions. * @param deniedPermission denied permission. * @return {@code true} if the permissions has been permanently denied. */ public static boolean permissionPermanentlyDenied(Object object, String deniedPermission) { return !shouldShowRequestPermissionRationale(object, deniedPermission); } /** * Handle the result of a permission request, should be called from the calling Activity's * {@link ActivityCompat.OnRequestPermissionsResultCallback#onRequestPermissionsResult(int, String[], int[])} * method. * <p> * If any permissions were granted or denied, the {@code object} will receive the appropriate * callbacks through {@link PermissionCallbacks} * * @param requestCode requestCode argument to permission result callback. * @param permissions permissions argument to permission result callback. * @param grantResults grantResults argument to permission result callback. * @param receivers an array of objects that implement {@link PermissionCallbacks}. */ public static void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults, Object... receivers) { // Make a collection of granted and denied permissions from the request. ArrayList<String> granted = new ArrayList<>(); ArrayList<String> denied = new ArrayList<>(); for (int i = 0; i < permissions.length; i++) { String perm = permissions[i]; if (grantResults[i] == PackageManager.PERMISSION_GRANTED) { granted.add(perm); } else { denied.add(perm); } } // iterate through all receivers for (Object object : receivers) { // Report granted permissions, if any. if (!granted.isEmpty()) { if (object instanceof PermissionCallbacks) { ((PermissionCallbacks) object).onPermissionsGranted(requestCode, granted); } } // Report denied permissions, if any. if (!denied.isEmpty()) { if (object instanceof PermissionCallbacks) { ((PermissionCallbacks) object).onPermissionsDenied(requestCode, denied); } } } } /** * * prompt the user to go to the app's settings screen and enable permissions. If the * user clicks snackbar's action, they are sent to the settings screen. The result is returned * to the Activity via {@link Activity#onActivityResult(int, int, Intent)}. * * @param object Activity or Fragment requesting permissions. * @param rationale a message explaining why the application needs this set of permissions, will * be displayed on the snackbar. * @param snackbarAction text disPlayed on the snackbar's action * @param requestCode If >= 0, this code will be returned in onActivityResult() when the activity exits. */ public static void goSettings2Permissions(final Object object, String rationale, String snackbarAction, final int requestCode) { checkCallingObjectSuitability(object); final Activity activity = getActivity(object); if (null == activity) { return; } Snackbar.make(activity.findViewById(android.R.id.content), rationale, Snackbar.LENGTH_LONG) .setAction(snackbarAction, new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS); Uri uri = Uri.fromParts("package", activity.getPackageName(), null); intent.setData(uri); startForResult(object, intent, requestCode); } }).show(); } @TargetApi(23) private static boolean shouldShowRequestPermissionRationale(Object object, String perm) { if (object instanceof Activity) { return ActivityCompat.shouldShowRequestPermissionRationale((Activity) object, perm); } else if (object instanceof Fragment) { return ((Fragment) object).shouldShowRequestPermissionRationale(perm); } else if (object instanceof android.app.Fragment) { return ((android.app.Fragment) object).shouldShowRequestPermissionRationale(perm); } else { return false; } } @TargetApi(23) private static void executePermissionsRequest(Object object, String[] perms, int requestCode) { checkCallingObjectSuitability(object); if (object instanceof Activity) { ActivityCompat.requestPermissions((Activity) object, perms, requestCode); } else if (object instanceof Fragment) { ((Fragment) object).requestPermissions(perms, requestCode); } else if (object instanceof android.app.Fragment) { ((android.app.Fragment) object).requestPermissions(perms, requestCode); } } @TargetApi(11) private static Activity getActivity(Object object) { if (object instanceof Activity) { return ((Activity) object); } else if (object instanceof Fragment) { return ((Fragment) object).getActivity(); } else if (object instanceof android.app.Fragment) { return ((android.app.Fragment) object).getActivity(); } else { return null; } } @TargetApi(11) private static void startForResult(Object object, Intent intent, int requestCode) { if (object instanceof Activity) { ((Activity) object).startActivityForResult(intent, requestCode); } else if (object instanceof Fragment) { ((Fragment) object).startActivityForResult(intent, requestCode); } else if (object instanceof android.app.Fragment) { ((android.app.Fragment) object).startActivityForResult(intent, requestCode); } } private static void checkCallingObjectSuitability(Object object) { // Make sure Object is an Activity or Fragment boolean isActivity = object instanceof Activity; boolean isSupportFragment = object instanceof Fragment; boolean isAppFragment = object instanceof android.app.Fragment; boolean isMinSdkM = Build.VERSION.SDK_INT >= Build.VERSION_CODES.M; if (!(isSupportFragment || isActivity || (isAppFragment && isMinSdkM))) { if (isAppFragment) { throw new IllegalArgumentException( "Target SDK needs to be greater than 23 if caller is android.app.Fragment"); } else { throw new IllegalArgumentException("Caller must be an Activity or a Fragment."); } } } }