Java tutorial
/* * Copyright Google Inc. All Rights Reserved. * Modifications Copyright(C) 2016 Fred Grott(GrottWorkShop) * * 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 com.github.shareme.blackandroids.greenandroid.easpermissions; import android.annotation.TargetApi; import android.app.Activity; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.content.pm.PackageManager; import android.os.Build; import android.support.annotation.StringRes; import android.support.v4.app.ActivityCompat; import android.support.v4.app.Fragment; import android.support.v4.content.ContextCompat; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import timber.log.Timber; /** * Created by fgrott on 9/23/2016. */ public class EasyPermissions { private static final String TAG = "EasyPermissions"; 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) { Timber.w(TAG, "hasPermissions: API version < M, returning true by default"); return true; } for (String perm : perms) { boolean hasPerm = (ContextCompat.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 * {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(final Object object, String rationale, final int requestCode, final String... perms) { requestPermissions(object, rationale, android.R.string.ok, android.R.string.cancel, 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 * {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 positiveButton custom text for positive button * @param negativeButton custom text for negative 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, @StringRes int positiveButton, @StringRes int negativeButton, 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; } AlertDialog dialog = new AlertDialog.Builder(activity).setMessage(rationale) .setPositiveButton(positiveButton, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { executePermissionsRequest(object, perms, requestCode); } }).setNegativeButton(negativeButton, new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // act as if the permissions were denied if (object instanceof PermissionCallbacks) { ((PermissionCallbacks) object).onPermissionsDenied(requestCode, Arrays.asList(perms)); } } }).create(); dialog.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, List<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} and methods annotated with * {@link AfterPermissionGranted} will be run if appropriate. * * @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 have a method annotated with {@link AfterPermissionGranted} * or 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); } } // If 100% successful, call annotated methods if (!granted.isEmpty() && denied.isEmpty()) { runAnnotatedMethods(object, requestCode); } } } @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; } } private static void runAnnotatedMethods(Object object, int requestCode) { Class clazz = object.getClass(); if (isUsingAndroidAnnotations(object)) { clazz = clazz.getSuperclass(); } for (Method method : clazz.getDeclaredMethods()) { if (method.isAnnotationPresent(AfterPermissionGranted.class)) { // Check for annotated methods with matching request code. AfterPermissionGranted ann = method.getAnnotation(AfterPermissionGranted.class); if (ann.value() == requestCode) { // Method must be void so that we can invoke it if (method.getParameterTypes().length > 0) { throw new RuntimeException("Cannot execute non-void method " + method.getName()); } try { // Make method accessible if private if (!method.isAccessible()) { method.setAccessible(true); } method.invoke(object); } catch (IllegalAccessException e) { Timber.e(TAG, "runDefaultMethod:IllegalAccessException", e); } catch (InvocationTargetException e) { Timber.e(TAG, "runDefaultMethod:InvocationTargetException", e); } } } } } 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."); } } } private static boolean isUsingAndroidAnnotations(Object object) { if (!object.getClass().getSimpleName().endsWith("_")) { return false; } try { Class clazz = Class.forName("org.androidannotations.api.view.HasViews"); return clazz.isInstance(object); } catch (ClassNotFoundException e) { return false; } } }