Java tutorial
/* * Copyright (c) 2016 Google Inc. * * 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.google.samples.apps.iosched.util; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.net.Uri; import android.provider.Settings; import android.support.annotation.NonNull; import android.support.design.widget.Snackbar; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.view.View; import com.google.samples.apps.iosched.BuildConfig; import com.google.samples.apps.iosched.R; import static com.google.samples.apps.iosched.util.LogUtils.LOGI; import static com.google.samples.apps.iosched.util.LogUtils.makeLogTag; /** * Set of runtime permission utility methods. */ public class PermissionsUtils { private static final String TAG = makeLogTag(PermissionsUtils.class); /** * Determine if any permission is in the denied state. */ public static boolean anyPermissionDenied(Context context, String[] permissions) { for (String permission : permissions) { if (ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_DENIED) { return true; } } return false; } /** * Displays a persistent {@link Snackbar} acknowledging the permission dismissal. If one of the * permissions is detected in the "Don't ask again" state then the OK button forwards to the * AppInfo screen, otherwise, the OK button invokes a permissions request. * <p/> * This method determines the Do-Not-Ask-Again-State by: 1.) Only being called from {@code * onRequestPermissionResult} when at least one permission was not granted. 2.) Checking that a * permission is currently in the permission-denied and no-rationale-needed states. 3.) The * combination of 1 and 2 indicates that at least one permission is in the Do-Not-Ask state and * the only resolution to that is for the user to visit the App Info -> Permissions screen. */ @NonNull public static Snackbar displayConditionalPermissionDenialSnackbar(@NonNull final Activity activity, final int messageResId, @NonNull String[] permissions, int requestCode) { return displayConditionalPermissionDenialSnackbar(activity, messageResId, permissions, requestCode, true); } /** * Displays a {@link Snackbar} acknowledging the permission dismissal. If one of the permissions * is detected in the "Don't ask again" state then the OK button forwards to the AppInfo screen, * otherwise, the OK button invokes a permissions request. * <p/> * This method determines the Do-Not-Ask-Again-State by: 1.) Only being called from {@code * onRequestPermissionResult} when at least one permission was not granted. 2.) Checking that a * permission is currently in the permission-denied and no-rationale-needed states. 3.) The * combination of 1 and 2 indicates that at least one permission is in the Do-Not-Ask state and * the only resolution to that is for the user to visit the App Info -> Permissions screen. */ @NonNull public static Snackbar displayConditionalPermissionDenialSnackbar(@NonNull final Activity activity, final int messageResId, @NonNull String[] permissions, int requestCode, boolean isPersistent) { boolean permissionInDoNotAskAgainState = false; for (final String permission : permissions) { if (ActivityCompat.checkSelfPermission(activity, permission) == PackageManager.PERMISSION_DENIED && !ActivityCompat.shouldShowRequestPermissionRationale(activity, permission)) { permissionInDoNotAskAgainState = true; break; } } if (permissionInDoNotAskAgainState) { // User has to manually enable permissions on the AppInfo screen. return displayPermissionDeniedAppInfoResolutionSnackbar(activity, messageResId, isPersistent); } else { // User clicks OK to re-start the permissions requests. return displayPermissionRationaleSnackbar(activity, messageResId, permissions, requestCode, isPersistent); } } private static Snackbar displayPermissionDeniedAppInfoResolutionSnackbar(@NonNull final Activity activity, final int messageResId, final boolean isPersistent) { View view = UIUtils.getRootView(activity); final int length = isPersistent ? Snackbar.LENGTH_INDEFINITE : Snackbar.LENGTH_LONG; Snackbar snackbar = Snackbar.make(view, messageResId, length).setAction(R.string.ok, new View.OnClickListener() { @Override public void onClick(final View v) { LOGI(TAG, "Invoking App Info screen"); final Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS); Uri uri = Uri.fromParts("package", BuildConfig.APPLICATION_ID, null); intent.setData(uri); activity.startActivity(intent); } }); snackbar.show(); return snackbar; } /** * A persistent Snackbar is displayed that gives a {@code permission} rationale and forwards to * the App Info screen to allow the user to resolve the error. */ @NonNull public static Snackbar displayPermissionDeniedAppInfoResolutionSnackbar(@NonNull final Activity activity, final int messageResId) { return displayPermissionDeniedAppInfoResolutionSnackbar(activity, messageResId, true); } /** * A Snackbar is displayed that gives a {@code permission} rationale and an action that only * dismisses the Snackbar. */ @NonNull public static Snackbar displayPermissionDeniedSnackbar(@NonNull final Activity activity, final int messageResId) { View view = UIUtils.getRootView(activity); final Snackbar snackbar = Snackbar.make(view, messageResId, Snackbar.LENGTH_INDEFINITE); snackbar.setAction(R.string.ok, new View.OnClickListener() { @Override public void onClick(final View v) { snackbar.dismiss(); } }).show(); return snackbar; } /** * A persistent Snackbar is displayed that prompts for {@code permissions} again when OK is * clicked. */ @NonNull public static Snackbar displayPermissionRationaleSnackbar(@NonNull final Activity activity, final int messageResId, @NonNull final String[] permissions, final int requestCode) { return displayPermissionRationaleSnackbar(activity, messageResId, permissions, requestCode, true); } /** * A Snackbar is displayed that prompts for {@code permissions} again when OK is clicked. */ @NonNull public static Snackbar displayPermissionRationaleSnackbar(@NonNull final Activity activity, final int messageResId, @NonNull final String[] permissions, final int requestCode, boolean isPersistent) { View view = UIUtils.getRootView(activity); final int length = isPersistent ? Snackbar.LENGTH_INDEFINITE : Snackbar.LENGTH_LONG; Snackbar snackbar = Snackbar.make(view, messageResId, length).setAction(R.string.ok, new View.OnClickListener() { @Override public void onClick(final View v) { ActivityCompat.requestPermissions(activity, permissions, requestCode); } }); snackbar.show(); return snackbar; } /** * Determines if all {@code permissions} have already been granted. */ public static boolean permissionsAlreadyGranted(@NonNull Context context, @NonNull String[] permissions) { for (String permission : permissions) { if (ContextCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) { return false; } } return true; } /** * Determines if {@code permission} rationale should be displayed for any {@code permission}. */ public static boolean shouldShowAnyPermissionRationale(@NonNull Activity activity, String[] permissions) { for (String permission : permissions) { if (ActivityCompat.shouldShowRequestPermissionRationale(activity, permission)) { return true; } } return false; } }