Java tutorial
/* * Copyright (C) 2015 The Android Open Source Project * * 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.android.contacts.activities; import android.app.Activity; import android.content.Context; import android.content.Intent; import android.content.pm.PackageManager; import android.os.Bundle; import android.os.Trace; import android.support.v4.app.ActivityCompat; import com.android.contacts.model.AccountTypeManager; import com.android.contacts.util.PermissionsUtil; import java.util.ArrayList; import java.util.Arrays; /** * Activity that asks the user for all {@link #getPermissions} if any are missing. * * NOTE: As a result of b/22095159, this can behave oddly in the case where the final permission * you are requesting causes an application restart. */ public abstract class RequestPermissionsActivityBase extends Activity implements ActivityCompat.OnRequestPermissionsResultCallback { public static final String PREVIOUS_ACTIVITY_INTENT = "previous_intent"; /** Whether the permissions activity was already started. */ protected static final String EXTRA_STARTED_PERMISSIONS_ACTIVITY = "started_permissions_activity"; protected static final String EXTRA_IS_CALLER_SELF = "is_caller_self"; private static final int PERMISSIONS_REQUEST_ALL_PERMISSIONS = 1; /** * @return list of permissions that are needed in order for {@link #PREVIOUS_ACTIVITY_INTENT} * to operate. You only need to return a single permission per permission group you care about. */ protected abstract String[] getPermissions(); protected Intent mPreviousActivityIntent; /** If true then start the target activity "for result" after permissions are granted. */ protected boolean mIsCallerSelf; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mPreviousActivityIntent = (Intent) getIntent().getExtras().get(PREVIOUS_ACTIVITY_INTENT); mIsCallerSelf = getIntent().getBooleanExtra(EXTRA_IS_CALLER_SELF, false); // Only start a requestPermissions() flow when first starting this activity the first time. // The process is likely to be restarted during the permission flow (necessary to enable // permissions) so this is important to track. if (savedInstanceState == null) { requestPermissions(); } } /** * If any permissions the Contacts app needs are missing, open an Activity * to prompt the user for these permissions. Moreover, finish the current activity. * * This is designed to be called inside {@link android.app.Activity#onCreate} */ protected static boolean startPermissionActivity(Activity activity, String[] requiredPermissions, Class<?> newActivityClass) { return startPermissionActivity(activity, requiredPermissions, /* isCallerSelf */ false, newActivityClass); } protected static boolean startPermissionActivity(Activity activity, String[] requiredPermissions, boolean isCallerSelf, Class<?> newActivityClass) { if (!hasPermissions(activity, requiredPermissions)) { final Intent intent = new Intent(activity, newActivityClass); activity.getIntent().putExtra(EXTRA_STARTED_PERMISSIONS_ACTIVITY, true); intent.putExtra(PREVIOUS_ACTIVITY_INTENT, activity.getIntent()); intent.putExtra(EXTRA_IS_CALLER_SELF, isCallerSelf); activity.startActivity(intent); activity.finish(); return true; } // Account type initialization must be delayed until the Contacts permission group // has been granted (since GET_ACCOUNTS) falls under that groups. Previously it // was initialized in ContactApplication which would cause problems as // AccountManager.getAccounts would return an empty array. See b/22690336 AccountTypeManager.getInstance(activity); return false; } protected boolean isAllGranted(String permissions[], int[] grantResult) { for (int i = 0; i < permissions.length; i++) { if (grantResult[i] != PackageManager.PERMISSION_GRANTED && isPermissionRequired(permissions[i])) { return false; } } return true; } private boolean isPermissionRequired(String p) { return Arrays.asList(getPermissions()).contains(p); } private void requestPermissions() { Trace.beginSection("requestPermissions"); try { // Construct a list of missing permissions final ArrayList<String> unsatisfiedPermissions = new ArrayList<>(); for (String permission : getPermissions()) { if (!PermissionsUtil.hasPermission(this, permission)) { unsatisfiedPermissions.add(permission); } } if (unsatisfiedPermissions.size() == 0) { throw new RuntimeException( "Request permission activity was called even" + " though all permissions are satisfied."); } ActivityCompat.requestPermissions(this, unsatisfiedPermissions.toArray(new String[unsatisfiedPermissions.size()]), PERMISSIONS_REQUEST_ALL_PERMISSIONS); } finally { Trace.endSection(); } } protected static boolean hasPermissions(Context context, String[] permissions) { Trace.beginSection("hasPermission"); try { for (String permission : permissions) { if (!PermissionsUtil.hasPermission(context, permission)) { return false; } } return true; } finally { Trace.endSection(); } } }