global: get rid of nonnull gradle hack

Hacking things up via gradle is not right, and package-info.java poses
problems with two modules, so instead we just apply it manually to every
class.

Remember to add this to new classes!

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

.gitignore

@@ -15,4 +15,3 @@ build/
 *.iml
 *.jks
 keystore.properties
-package-info.java

nonnull.gradle

@@ -1,86 +0,0 @@
-/*
- * Copyright © 2017-2019 WireGuard LLC. All Rights Reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-
-task generateNonNullJavaFiles(dependsOn: "assembleDebug", type: Copy) {
-    group = "Copying"
-    description = "Generate package-info.java classes"
-
-    def basePackage = "com" + File.separatorChar + "wireguard"
-    def mainSrcPhrase = "src" + File.separatorChar + "main" + File.separatorChar +
-            "java" + File.separatorChar
-    def mainTestSrcPhrase = "src" + File.separatorChar + "test" + File.separatorChar +
-            "java" + File.separatorChar
-    def mainAndroidTestSrcPhrase = "src" + File.separatorChar + "androidTest" + File.separatorChar +
-            "java" + File.separatorChar
-
-    def sourceDir = file( "${projectDir}" + File.separatorChar + "src" + File.separatorChar +
-            "main" + File.separatorChar + "java" + File.separatorChar +
-            basePackage )
-    def testSourceDir = file( "${projectDir}" + File.separatorChar + "src" + File.separatorChar +
-            "test" + File.separatorChar + "java" + File.separatorChar +
-            basePackage)
-    def androidTestSourceDir = file( "${projectDir}" + File.separatorChar + "src" + File
-            .separatorChar +
-            "androidTest" + File.separatorChar + "java" + File.separatorChar +
-            basePackage )
-
-    generateInfoFiles(sourceDir, mainSrcPhrase)
-    sourceDir.eachDirRecurse { dir ->
-        generateInfoFiles(dir, mainSrcPhrase)
-    }
-    if (file(testSourceDir).exists()) {
-        generateInfoFiles(testSourceDir, mainTestSrcPhrase)
-        testSourceDir.eachDirRecurse { dir ->
-            generateInfoFiles(dir, mainTestSrcPhrase)
-        }
-    }
-    if (file(androidTestSourceDir).exists()) {
-        generateInfoFiles(androidTestSourceDir, mainAndroidTestSrcPhrase)
-        androidTestSourceDir.eachDirRecurse { dir ->
-            generateInfoFiles(dir, mainAndroidTestSrcPhrase)
-        }
-    }
-    println "[SUCCESS] NonNull generator: package-info.java files checked"
-}
-
-private void generateInfoFiles(File dir, String mainSrcPhrase) {
-    def infoFileContentHeader = getFileContentHeader()
-    def infoFileContentFooter = getFileContentFooter()
-    def infoFilePath = dir.getAbsolutePath() + File.separatorChar + "package-info.java"
-
-    //file(infoFilePath).delete(); //do not use in production code
-    if (!file(infoFilePath).exists()) {
-        def infoFileContentPackage = getFileContentPackage(dir.getAbsolutePath(), mainSrcPhrase)
-        new File(infoFilePath).write(infoFileContentHeader +
-                infoFileContentPackage + infoFileContentFooter)
-        println "[dir] " + infoFilePath + "  created"
-    }
-}
-
-static def getFileContentPackage(String path, String mainSrcPhrase) {
-    def mainSrcPhraseIndex = path.indexOf(mainSrcPhrase)
-    def output = path.substring(mainSrcPhraseIndex)
-
-    // Win hotfix
-    if (System.properties['os.name'].toLowerCase().contains('windows')) {
-        output = output.replace("\\", "/")
-        mainSrcPhrase = mainSrcPhrase.replace("\\", "/")
-    }
-
-    return "package " + output.replaceAll(mainSrcPhrase, "").replaceAll(
-                "/", ".") + ";\n"
-}
-
-static def getFileContentHeader() {
-    return  "/**\n" +
-            " * Make all method parameters @NonNull by default.\n" +
-            " */\n" +
-            "@NonNullForAll\n"
-}
-
-static def getFileContentFooter() {
-    return  "\n" +
-            "import com.wireguard.util.NonNullForAll;\n"
-}

tunnel/build.gradle

@@ -1,5 +1,4 @@
 apply plugin: 'com.android.library'
-apply from: rootProject.file('nonnull.gradle')
 
 android {
     buildToolsVersion '29.0.3'

tunnel/src/main/java/com/wireguard/android/backend/Backend.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.backend;
 
+import com.wireguard.util.NonNullForAll;
+
 import com.wireguard.config.Config;
 
 import java.util.Collection;
@@ -16,6 +18,7 @@ import androidx.annotation.Nullable;
  * Interface for implementations of the WireGuard secure network tunnel.
  */
 
+@NonNullForAll
 public interface Backend {
     /**
      * Enumerate names of currently-running tunnels.

tunnel/src/main/java/com/wireguard/android/backend/BackendException.java

@@ -5,6 +5,9 @@
 
 package com.wireguard.android.backend;
 
+import com.wireguard.util.NonNullForAll;
+
+@NonNullForAll
 public final class BackendException extends Exception {
     public enum Reason {
         UNKNOWN_KERNEL_MODULE_NAME,

tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.backend;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.content.Intent;
 import android.os.Build;
@@ -30,6 +32,7 @@ import java.util.concurrent.TimeoutException;
 
 import java9.util.concurrent.CompletableFuture;
 
+@NonNullForAll
 public final class GoBackend implements Backend {
     private static final String TAG = "WireGuard/" + GoBackend.class.getSimpleName();
     private static CompletableFuture<VpnService> vpnService = new CompletableFuture<>();

tunnel/src/main/java/com/wireguard/android/backend/Statistics.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.backend;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.os.SystemClock;
 import android.util.Pair;
 
@@ -13,6 +15,7 @@ import com.wireguard.crypto.Key;
 import java.util.HashMap;
 import java.util.Map;
 
+@NonNullForAll
 public class Statistics {
     private long lastTouched = SystemClock.elapsedRealtime();
     private final Map<Key, Pair<Long, Long>> peerBytes = new HashMap<>();

tunnel/src/main/java/com/wireguard/android/backend/Tunnel.java

@@ -5,12 +5,15 @@
 
 package com.wireguard.android.backend;
 
+import com.wireguard.util.NonNullForAll;
+
 import java.util.regex.Pattern;
 
 /**
  * Represents a WireGuard tunnel.
  */
 
+@NonNullForAll
 public interface Tunnel {
     enum State {
         DOWN,

tunnel/src/main/java/com/wireguard/android/backend/WgQuickBackend.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.backend;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import android.content.Context;
@@ -39,6 +41,7 @@ import java9.util.stream.Stream;
  * WireGuard backend that uses {@code wg-quick} to implement tunnel configuration.
  */
 
+@NonNullForAll
 public final class WgQuickBackend implements Backend {
     private static final String TAG = "WireGuard/" + WgQuickBackend.class.getSimpleName();
 

tunnel/src/main/java/com/wireguard/android/util/ModuleLoader.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.system.OsConstants;
 import android.util.Base64;
@@ -36,6 +38,7 @@ import java.util.Map;
 
 import androidx.annotation.Nullable;
 
+@NonNullForAll
 public class ModuleLoader {
     private static final String MODULE_PUBLIC_KEY_BASE64 = "RWRmHuT9PSqtwfsLtEx+QS06BJtLgFYteL9WCNjH7yuyu5Y1DieSN7If";
     private static final String MODULE_LIST_URL = "https://download.wireguard.com/android-module/modules.txt.sig";

tunnel/src/main/java/com/wireguard/android/util/RootShell.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import androidx.annotation.Nullable;
 import android.util.Log;
@@ -24,6 +26,7 @@ import java.util.UUID;
  * Helper class for running commands as root.
  */
 
+@NonNullForAll
 public class RootShell {
     private static final String SU = "su";
     private static final String TAG = "WireGuard/" + RootShell.class.getSimpleName();

tunnel/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.os.Build;
 import android.util.Log;
@@ -19,6 +21,7 @@ import java.util.HashSet;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
+@NonNullForAll
 public final class SharedLibraryLoader {
     private static final String TAG = "WireGuard/" + SharedLibraryLoader.class.getSimpleName();
 

tunnel/src/main/java/com/wireguard/android/util/ToolsInstaller.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import androidx.annotation.Nullable;
 import android.system.OsConstants;
@@ -22,6 +24,7 @@ import java.util.List;
  * Helper to install WireGuard tools to the system partition.
  */
 
+@NonNullForAll
 public final class ToolsInstaller {
     public static final int ERROR = 0x0;
     public static final int MAGISK = 0x4;

tunnel/src/main/java/com/wireguard/config/Attribute.java

@@ -5,12 +5,15 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import java.util.Iterator;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import java9.util.Optional;
 
+@NonNullForAll
 public final class Attribute {
     private static final Pattern LINE_PATTERN = Pattern.compile("(\\w+)\\s*=\\s*([^\\s#][^#]*)");
     private static final Pattern LIST_SEPARATOR = Pattern.compile("\\s*,\\s*");

tunnel/src/main/java/com/wireguard/config/BadConfigException.java

@@ -5,10 +5,13 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import com.wireguard.crypto.KeyFormatException;
 
+@NonNullForAll
 public class BadConfigException extends Exception {
     private final Location location;
     private final Reason reason;

tunnel/src/main/java/com/wireguard/config/Config.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import com.wireguard.config.BadConfigException.Location;
@@ -29,6 +31,7 @@ import java.util.Set;
  * <p>
  * Instances of this class are immutable.
  */
+@NonNullForAll
 public final class Config {
     private final Interface interfaze;
     private final List<Peer> peers;

tunnel/src/main/java/com/wireguard/config/InetAddresses.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import java.lang.reflect.Method;
 import java.net.Inet4Address;
 import java.net.Inet6Address;
@@ -17,6 +19,7 @@ import androidx.annotation.Nullable;
 /**
  * Utility methods for creating instances of {@link InetAddress}.
  */
+@NonNullForAll
 public final class InetAddresses {
     @Nullable private static final Method PARSER_METHOD;
     private static final Pattern WONT_TOUCH_RESOLVER = Pattern.compile("^(((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)(\\.(25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]?\\d)){3}))|:)))(%.+)?)|((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))$");

tunnel/src/main/java/com/wireguard/config/InetEndpoint.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import org.threeten.bp.Duration;
@@ -25,6 +27,7 @@ import java9.util.Optional;
  * <p>
  * Instances of this class are externally immutable.
  */
+@NonNullForAll
 public final class InetEndpoint {
     private static final Pattern BARE_IPV6 = Pattern.compile("^[^\\[\\]]*:[^\\[\\]]*");
     private static final Pattern FORBIDDEN_CHARACTERS = Pattern.compile("[/?#]");

tunnel/src/main/java/com/wireguard/config/InetNetwork.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import java.net.Inet4Address;
 import java.net.InetAddress;
 
@@ -13,6 +15,7 @@ import java.net.InetAddress;
  * <p>
  * Instances of this class are immutable.
  */
+@NonNullForAll
 public final class InetNetwork {
     private final InetAddress address;
     private final int mask;

tunnel/src/main/java/com/wireguard/config/Interface.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import com.wireguard.config.BadConfigException.Location;
@@ -35,6 +37,7 @@ import java9.util.stream.StreamSupport;
  * <p>
  * Instances of this class are immutable.
  */
+@NonNullForAll
 public final class Interface {
     private static final int MAX_UDP_PORT = 65535;
     private static final int MIN_UDP_PORT = 0;

tunnel/src/main/java/com/wireguard/config/ParseException.java

@@ -5,10 +5,13 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 /**
  */
+@NonNullForAll
 public class ParseException extends Exception {
     private final Class<?> parsingClass;
     private final CharSequence text;

tunnel/src/main/java/com/wireguard/config/Peer.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.config;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import com.wireguard.config.BadConfigException.Location;
@@ -28,6 +30,7 @@ import java9.util.Optional;
  * <p>
  * Instances of this class are immutable.
  */
+@NonNullForAll
 public final class Peer {
     private final Set<InetNetwork> allowedIps;
     private final Optional<InetEndpoint> endpoint;

tunnel/src/main/java/com/wireguard/crypto/Curve25519.java

@@ -6,6 +6,8 @@
 
 package com.wireguard.crypto;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import java.util.Arrays;
@@ -25,6 +27,7 @@ import java.util.Arrays;
  * References: http://cr.yp.to/ecdh.html, RFC 7748
  */
 @SuppressWarnings({"MagicNumber", "NonConstantFieldWithUpperCaseName", "SuspiciousNameCombination"})
+@NonNullForAll
 public final class Curve25519 {
     // Numbers modulo 2^255 - 19 are broken up into ten 26-bit words.
     private static final int NUM_LIMBS_255BIT = 10;

tunnel/src/main/java/com/wireguard/crypto/Key.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.crypto;
 
+import com.wireguard.util.NonNullForAll;
+
 import com.wireguard.crypto.KeyFormatException.Type;
 
 import java.security.MessageDigest;
@@ -18,6 +20,7 @@ import java.util.Arrays;
  * Instances of this class are immutable.
  */
 @SuppressWarnings("MagicNumber")
+@NonNullForAll
 public final class Key {
     private final byte[] key;
 

tunnel/src/main/java/com/wireguard/crypto/KeyFormatException.java

@@ -5,11 +5,14 @@
 
 package com.wireguard.crypto;
 
+import com.wireguard.util.NonNullForAll;
+
 /**
  * An exception thrown when attempting to parse an invalid key (too short, too long, or byte
  * data inappropriate for the format). The format being parsed can be accessed with the
  * {@link #getFormat} method.
  */
+@NonNullForAll
 public final class KeyFormatException extends Exception {
     private final Key.Format format;
     private final Type type;

tunnel/src/main/java/com/wireguard/crypto/KeyPair.java

@@ -5,11 +5,14 @@
 
 package com.wireguard.crypto;
 
+import com.wireguard.util.NonNullForAll;
+
 /**
  * Represents a Curve25519 key pair as used by WireGuard.
  * <p>
  * Instances of this class are immutable.
  */
+@NonNullForAll
 public class KeyPair {
     private final Key privateKey;
     private final Key publicKey;

tunnel/src/main/java/com/wireguard/util/NonNullForAll.java

@@ -22,5 +22,6 @@ import javax.annotation.meta.TypeQualifierDefault;
 @Nonnull
 @TypeQualifierDefault({ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
 @Retention(RetentionPolicy.RUNTIME)
+
 public @interface NonNullForAll {
 }

ui/build.gradle

@@ -1,6 +1,5 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
-apply from: rootProject.file('nonnull.gradle')
 
 // Create a variable called keystorePropertiesFile, and initialize it to your
 // keystore.properties file, in the rootProject folder.

ui/src/main/java/com/wireguard/android/Application.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
@@ -35,6 +37,7 @@ import java.util.Locale;
 
 import java9.util.concurrent.CompletableFuture;
 
+@NonNullForAll
 public class Application extends android.app.Application implements SharedPreferences.OnSharedPreferenceChangeListener {
     private static final String TAG = "WireGuard/" + Application.class.getSimpleName();
     public static final String USER_AGENT = String.format(Locale.ENGLISH, "WireGuard/%s (Android %d; %s; %s; %s %s; %s)", BuildConfig.VERSION_NAME, Build.VERSION.SDK_INT, Build.SUPPORTED_ABIS.length > 0 ? Build.SUPPORTED_ABIS[0] : "unknown ABI", Build.BOARD, Build.MANUFACTURER, Build.MODEL, Build.FINGERPRINT);

ui/src/main/java/com/wireguard/android/BootShutdownReceiver.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
@@ -14,6 +16,7 @@ import com.wireguard.android.backend.WgQuickBackend;
 import com.wireguard.android.model.TunnelManager;
 import com.wireguard.android.util.ExceptionLoggers;
 
+@NonNullForAll
 public class BootShutdownReceiver extends BroadcastReceiver {
     private static final String TAG = "WireGuard/" + BootShutdownReceiver.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/QuickTileService.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Intent;
 import androidx.databinding.Observable;
 import androidx.databinding.Observable.OnPropertyChangedCallback;
@@ -34,6 +36,7 @@ import java.util.Objects;
  */
 
 @RequiresApi(Build.VERSION_CODES.N)
+@NonNullForAll
 public class QuickTileService extends TileService {
     private static final String TAG = "WireGuard/" + QuickTileService.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/activity/BaseActivity.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.activity;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.CallbackRegistry;
 import androidx.databinding.CallbackRegistry.NotifierCallback;
 import android.os.Bundle;
@@ -19,6 +21,7 @@ import java.util.Objects;
  * Base class for activities that need to remember the currently-selected tunnel.
  */
 
+@NonNullForAll
 public abstract class BaseActivity extends ThemeChangeAwareActivity {
     private static final String KEY_SELECTED_TUNNEL = "selected_tunnel";
 

ui/src/main/java/com/wireguard/android/activity/MainActivity.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.activity;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.os.Bundle;
@@ -31,6 +33,7 @@ import java.util.List;
  * editing the configuration and interface state of WireGuard tunnels.
  */
 
+@NonNullForAll
 public class MainActivity extends BaseActivity
         implements FragmentManager.OnBackStackChangedListener {
     @Nullable private ActionBar actionBar;

ui/src/main/java/com/wireguard/android/activity/SettingsActivity.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.activity;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.pm.PackageManager;
 import android.os.Build;
 import android.os.Bundle;
@@ -30,6 +32,7 @@ import java.util.List;
  * Interface for changing application-global persistent settings.
  */
 
+@NonNullForAll
 public class SettingsActivity extends ThemeChangeAwareActivity {
     private final SparseArray<PermissionRequestCallback> permissionRequestCallbacks = new SparseArray<>();
     private int permissionRequestCounter;

ui/src/main/java/com/wireguard/android/activity/ThemeChangeAwareActivity.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.activity;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.SharedPreferences;
 import android.content.res.Resources;
 import android.os.Build;
@@ -18,6 +20,7 @@ import com.wireguard.android.Application;
 
 import java.lang.reflect.Field;
 
+@NonNullForAll
 public abstract class ThemeChangeAwareActivity extends AppCompatActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
     private static final String TAG = "WireGuard/" + ThemeChangeAwareActivity.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/activity/TunnelCreatorActivity.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.activity;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.os.Bundle;
 import androidx.annotation.Nullable;
 
@@ -15,6 +17,7 @@ import com.wireguard.android.model.ObservableTunnel;
  * Standalone activity for creating tunnels.
  */
 
+@NonNullForAll
 public class TunnelCreatorActivity extends BaseActivity {
     @Override
     @SuppressWarnings("UnnecessaryFullyQualifiedName")

ui/src/main/java/com/wireguard/android/activity/TunnelToggleActivity.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.activity;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.appcompat.app.AppCompatActivity;
@@ -24,6 +26,7 @@ import com.wireguard.android.backend.Tunnel.State;
 import com.wireguard.android.util.ErrorMessages;
 
 @RequiresApi(Build.VERSION_CODES.N)
+@NonNullForAll
 public class TunnelToggleActivity extends AppCompatActivity {
     private static final String TAG = "WireGuard/" + TunnelToggleActivity.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/configStore/ConfigStore.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.configStore;
 
+import com.wireguard.util.NonNullForAll;
+
 import com.wireguard.config.Config;
 
 import java.util.Set;
@@ -13,6 +15,7 @@ import java.util.Set;
  * Interface for persistent storage providers for WireGuard configurations.
  */
 
+@NonNullForAll
 public interface ConfigStore {
     /**
      * Create a persistent tunnel, which must have a unique name within the persistent storage

ui/src/main/java/com/wireguard/android/configStore/FileConfigStore.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.configStore;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.util.Log;
 
@@ -27,6 +29,7 @@ import java9.util.stream.Stream;
  * Configuration store that uses a {@code wg-quick}-style file for each configured tunnel.
  */
 
+@NonNullForAll
 public final class FileConfigStore implements ConfigStore {
     private static final String TAG = "WireGuard/" + FileConfigStore.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/databinding/BindingAdapters.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.databinding;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.BindingAdapter;
 import androidx.databinding.DataBindingUtil;
 import androidx.databinding.ObservableList;
@@ -35,6 +37,7 @@ import java9.util.Optional;
  */
 
 @SuppressWarnings("unused")
+@NonNullForAll
 public final class BindingAdapters {
     private BindingAdapters() {
         // Prevent instantiation.

ui/src/main/java/com/wireguard/android/databinding/ItemChangeListener.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.databinding;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.DataBindingUtil;
 import androidx.databinding.ObservableList;
 import androidx.databinding.ViewDataBinding;
@@ -22,6 +24,7 @@ import java.util.Objects;
  * Helper class for binding an ObservableList to the children of a ViewGroup.
  */
 
+@NonNullForAll
 class ItemChangeListener<T> {
     private final OnListChangedCallback<T> callback = new OnListChangedCallback<>(this);
     private final ViewGroup container;

ui/src/main/java/com/wireguard/android/databinding/ObservableKeyedRecyclerViewAdapter.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.databinding;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import androidx.databinding.DataBindingUtil;
 import androidx.databinding.ObservableList;
@@ -25,6 +27,7 @@ import java.lang.ref.WeakReference;
  * A generic {@code RecyclerView.Adapter} backed by a {@code ObservableKeyedList}.
  */
 
+@NonNullForAll
 public class ObservableKeyedRecyclerViewAdapter<K, E extends Keyed<? extends K>> extends Adapter<ObservableKeyedRecyclerViewAdapter.ViewHolder> {
 
     private final OnListChangedCallback<E> callback = new OnListChangedCallback<>(this);

ui/src/main/java/com/wireguard/android/fragment/AppListDialogFragment.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.fragment;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.app.Activity;
 import android.app.Dialog;
 import android.content.DialogInterface;
@@ -34,6 +36,7 @@ import java9.util.Comparators;
 import java9.util.stream.Collectors;
 import java9.util.stream.StreamSupport;
 
+@NonNullForAll
 public class AppListDialogFragment extends DialogFragment {
 
     private static final String KEY_EXCLUDED_APPS = "excludedApps";

ui/src/main/java/com/wireguard/android/fragment/BaseFragment.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.fragment;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.content.Intent;
 import androidx.databinding.DataBindingUtil;
@@ -32,6 +34,7 @@ import com.wireguard.android.util.ErrorMessages;
  * attached to a {@code BaseActivity}.
  */
 
+@NonNullForAll
 public abstract class BaseFragment extends Fragment implements OnSelectedTunnelChangedListener {
     private static final int REQUEST_CODE_VPN_PERMISSION = 23491;
     private static final String TAG = "WireGuard/" + BaseFragment.class.getSimpleName();

ui/src/main/java/com/wireguard/android/fragment/ConfigNamingDialogFragment.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.fragment;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.app.Activity;
 import android.app.Dialog;
 import android.content.Context;
@@ -26,6 +28,7 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Objects;
 
+@NonNullForAll
 public class ConfigNamingDialogFragment extends DialogFragment {
     private static final String KEY_CONFIG_TEXT = "config_text";
 

ui/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.fragment;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.os.Bundle;
 import androidx.annotation.Nullable;
 import androidx.databinding.DataBindingUtil;
@@ -30,6 +32,7 @@ import java.util.TimerTask;
  * Fragment that shows details about a specific tunnel.
  */
 
+@NonNullForAll
 public class TunnelDetailFragment extends BaseFragment {
     @Nullable private TunnelDetailFragmentBinding binding;
     @Nullable private Timer timer;

ui/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.fragment;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.app.Activity;
 import android.content.Context;
 import androidx.databinding.ObservableList;
@@ -41,6 +43,7 @@ import java.util.Objects;
  * Fragment for editing a WireGuard configuration.
  */
 
+@NonNullForAll
 public class TunnelEditorFragment extends BaseFragment implements AppExclusionListener {
     private static final String KEY_LOCAL_CONFIG = "local_config";
     private static final String KEY_ORIGINAL_NAME = "original_name";

ui/src/main/java/com/wireguard/android/fragment/TunnelListFragment.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.fragment;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.content.ContentResolver;
@@ -64,6 +66,7 @@ import java9.util.stream.StreamSupport;
  * Fragment containing a list of known WireGuard tunnels. It allows creating and deleting tunnels.
  */
 
+@NonNullForAll
 public class TunnelListFragment extends BaseFragment {
     public static final int REQUEST_IMPORT = 1;
     private static final int REQUEST_TARGET_FRAGMENT = 2;

ui/src/main/java/com/wireguard/android/model/ApplicationData.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.model;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.BaseObservable;
 import androidx.databinding.Bindable;
 import android.graphics.drawable.Drawable;
@@ -12,6 +14,7 @@ import android.graphics.drawable.Drawable;
 import com.wireguard.android.BR;
 import com.wireguard.util.Keyed;
 
+@NonNullForAll
 public class ApplicationData extends BaseObservable implements Keyed<String> {
     private final Drawable icon;
     private final String name;

ui/src/main/java/com/wireguard/android/model/ObservableTunnel.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.model;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.BaseObservable;
 import androidx.databinding.Bindable;
 import androidx.annotation.Nullable;
@@ -23,6 +25,7 @@ import java9.util.concurrent.CompletionStage;
  * Encapsulates the volatile and nonvolatile state of a WireGuard tunnel.
  */
 
+@NonNullForAll
 public class ObservableTunnel extends BaseObservable implements Keyed<String>, Tunnel {
     private final TunnelManager manager;
     @Nullable private Config config;

ui/src/main/java/com/wireguard/android/model/TunnelManager.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.model;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
@@ -39,6 +41,7 @@ import java9.util.stream.StreamSupport;
  * Maintains and mediates changes to the set of available WireGuard tunnels,
  */
 
+@NonNullForAll
 public final class TunnelManager extends BaseObservable {
     private static final Comparator<String> COMPARATOR = Comparators.<String>thenComparing(
             String.CASE_INSENSITIVE_ORDER, Comparators.naturalOrder());

ui/src/main/java/com/wireguard/android/preference/LogExporterPreference.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.preference;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.Manifest;
 import android.content.Context;
 import android.content.pm.PackageManager;
@@ -29,6 +31,7 @@ import java.io.InputStreamReader;
  * Preference implementing a button that asynchronously exports logs.
  */
 
+@NonNullForAll
 public class LogExporterPreference extends Preference {
     private static final String TAG = "WireGuard/" + LogExporterPreference.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/preference/ModuleDownloaderPreference.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.preference;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.content.Intent;
 import android.system.OsConstants;
@@ -18,6 +20,7 @@ import com.wireguard.android.util.ErrorMessages;
 import androidx.annotation.Nullable;
 import androidx.preference.Preference;
 
+@NonNullForAll
 public class ModuleDownloaderPreference extends Preference {
     private State state = State.INITIAL;
 

ui/src/main/java/com/wireguard/android/preference/ToolsInstallerPreference.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.preference;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import androidx.annotation.Nullable;
 import androidx.preference.Preference;
@@ -19,6 +21,7 @@ import com.wireguard.android.util.ToolsInstaller;
  * result as the preference summary.
  */
 
+@NonNullForAll
 public class ToolsInstallerPreference extends Preference {
     private State state = State.INITIAL;
 

ui/src/main/java/com/wireguard/android/preference/VersionPreference.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.preference;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.content.Intent;
@@ -22,6 +24,7 @@ import com.wireguard.android.backend.WgQuickBackend;
 
 import java.util.Locale;
 
+@NonNullForAll
 public class VersionPreference extends Preference {
     @Nullable private String versionSummary;
 

ui/src/main/java/com/wireguard/android/preference/ZipExporterPreference.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.preference;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.Manifest;
 import android.content.Context;
 import android.content.pm.PackageManager;
@@ -35,6 +37,7 @@ import java9.util.concurrent.CompletableFuture;
  * Preference implementing a button that asynchronously exports config zips.
  */
 
+@NonNullForAll
 public class ZipExporterPreference extends Preference {
     private static final String TAG = "WireGuard/" + ZipExporterPreference.class.getSimpleName();
 

ui/src/main/java/com/wireguard/android/util/AsyncWorker.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.os.Handler;
 
 import java.util.concurrent.Executor;
@@ -16,6 +18,7 @@ import java9.util.concurrent.CompletionStage;
  * Helper class for running asynchronous tasks and ensuring they are completed on the main thread.
  */
 
+@NonNullForAll
 public class AsyncWorker {
     private final Executor executor;
     private final Handler handler;

ui/src/main/java/com/wireguard/android/util/ClipboardUtils.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.Context;
@@ -16,6 +18,7 @@ import android.widget.TextView;
  * Standalone utilities for interacting with the system clipboard.
  */
 
+@NonNullForAll
 public final class ClipboardUtils {
     private ClipboardUtils() {
         // Prevent instantiation

ui/src/main/java/com/wireguard/android/util/DownloadsFileSaver.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
@@ -22,6 +24,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 
+@NonNullForAll
 public class DownloadsFileSaver {
 
     public static class DownloadsFile {

ui/src/main/java/com/wireguard/android/util/ErrorMessages.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.res.Resources;
 import android.os.RemoteException;
 
@@ -29,6 +31,7 @@ import java.util.Map;
 
 import java9.util.Maps;
 
+@NonNullForAll
 public final class ErrorMessages {
     private static final Map<BadConfigException.Reason, Integer> BCE_REASON_MAP = new EnumMap<>(Maps.of(
             BadConfigException.Reason.INVALID_KEY, R.string.bad_config_reason_invalid_key,

ui/src/main/java/com/wireguard/android/util/ExceptionLoggers.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 import android.util.Log;
 

ui/src/main/java/com/wireguard/android/util/FragmentUtils.java

@@ -4,12 +4,15 @@
  */
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import androidx.preference.Preference;
 import android.view.ContextThemeWrapper;
 
 import com.wireguard.android.activity.SettingsActivity;
 
+@NonNullForAll
 public final class FragmentUtils {
     private FragmentUtils() {
         // Prevent instantiation

ui/src/main/java/com/wireguard/android/util/ObservableKeyedArrayList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.ObservableArrayList;
 import androidx.annotation.Nullable;
 
@@ -21,6 +23,7 @@ import java.util.Objects;
  * operations, require O(n) time.
  */
 
+@NonNullForAll
 public class ObservableKeyedArrayList<K, E extends Keyed<? extends K>>
         extends ObservableArrayList<E> implements ObservableKeyedList<K, E> {
     @Override

ui/src/main/java/com/wireguard/android/util/ObservableKeyedList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.ObservableList;
 
 import com.wireguard.util.Keyed;
@@ -14,6 +16,7 @@ import com.wireguard.util.KeyedList;
  * A list that is both keyed and observable.
  */
 
+@NonNullForAll
 public interface ObservableKeyedList<K, E extends Keyed<? extends K>>
         extends KeyedList<K, E>, ObservableList<E> {
 }

ui/src/main/java/com/wireguard/android/util/ObservableSortedKeyedArrayList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import com.wireguard.util.Keyed;
@@ -26,6 +28,7 @@ import java.util.Spliterator;
  * key still require O(n) time.
  */
 
+@NonNullForAll
 public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
         extends ObservableKeyedArrayList<K, E> implements ObservableSortedKeyedList<K, E> {
     @Nullable private final Comparator<? super K> comparator;

ui/src/main/java/com/wireguard/android/util/ObservableSortedKeyedList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import com.wireguard.util.Keyed;
 import com.wireguard.util.SortedKeyedList;
 
@@ -12,6 +14,7 @@ import com.wireguard.util.SortedKeyedList;
  * A list that is both sorted/keyed and observable.
  */
 
+@NonNullForAll
 public interface ObservableSortedKeyedList<K, E extends Keyed<? extends K>>
         extends ObservableKeyedList<K, E>, SortedKeyedList<K, E> {
 }

ui/src/main/java/com/wireguard/android/viewmodel/ConfigProxy.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.viewmodel;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.ObservableArrayList;
 import androidx.databinding.ObservableList;
 import android.os.Parcel;
@@ -17,6 +19,7 @@ import com.wireguard.config.Peer;
 import java.util.ArrayList;
 import java.util.Collection;
 
+@NonNullForAll
 public class ConfigProxy implements Parcelable {
     public static final Parcelable.Creator<ConfigProxy> CREATOR = new ConfigProxyCreator();
 

ui/src/main/java/com/wireguard/android/viewmodel/InterfaceProxy.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.viewmodel;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.BaseObservable;
 import androidx.databinding.Bindable;
 import androidx.databinding.ObservableArrayList;
@@ -26,6 +28,7 @@ import java.util.List;
 import java9.util.stream.Collectors;
 import java9.util.stream.StreamSupport;
 
+@NonNullForAll
 public class InterfaceProxy extends BaseObservable implements Parcelable {
     public static final Parcelable.Creator<InterfaceProxy> CREATOR = new InterfaceProxyCreator();
 

ui/src/main/java/com/wireguard/android/viewmodel/PeerProxy.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.viewmodel;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.databinding.BaseObservable;
 import androidx.databinding.Bindable;
 import androidx.databinding.Observable;
@@ -32,6 +34,7 @@ import java9.util.Sets;
 import java9.util.stream.Collectors;
 import java9.util.stream.Stream;
 
+@NonNullForAll
 public class PeerProxy extends BaseObservable implements Parcelable {
     public static final Parcelable.Creator<PeerProxy> CREATOR = new PeerProxyCreator();
     private static final Set<String> IPV4_PUBLIC_NETWORKS = new LinkedHashSet<>(Lists.of(

ui/src/main/java/com/wireguard/android/widget/KeyInputFilter.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.widget;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 import android.text.InputFilter;
 import android.text.SpannableStringBuilder;
@@ -16,6 +18,7 @@ import com.wireguard.crypto.Key;
  * InputFilter for entering WireGuard private/public keys encoded with base64.
  */
 
+@NonNullForAll
 public class KeyInputFilter implements InputFilter {
     private static boolean isAllowed(final char c) {
         return Character.isLetterOrDigit(c) || c == '+' || c == '/';

ui/src/main/java/com/wireguard/android/widget/MultiselectableRelativeLayout.java

@@ -5,12 +5,15 @@
 
 package com.wireguard.android.widget;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.util.AttributeSet;
 import android.widget.RelativeLayout;
 
 import com.wireguard.android.R;
 
+@NonNullForAll
 public class MultiselectableRelativeLayout extends RelativeLayout {
     private static final int[] STATE_MULTISELECTED = {R.attr.state_multiselected};
     private boolean multiselected;

ui/src/main/java/com/wireguard/android/widget/NameInputFilter.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.android.widget;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 import android.text.InputFilter;
 import android.text.SpannableStringBuilder;
@@ -16,6 +18,7 @@ import com.wireguard.android.backend.Tunnel;
  * InputFilter for entering WireGuard configuration names (Linux interface names).
  */
 
+@NonNullForAll
 public class NameInputFilter implements InputFilter {
     private static boolean isAllowed(final char c) {
         return Character.isLetterOrDigit(c) || "_=+.-".indexOf(c) >= 0;

ui/src/main/java/com/wireguard/android/widget/SlashDrawable.java

@@ -6,6 +6,8 @@
 
 package com.wireguard.android.widget;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.animation.ObjectAnimator;
 import android.animation.ValueAnimator;
 import android.content.res.ColorStateList;
@@ -29,6 +31,7 @@ import androidx.annotation.RequiresApi;
 import android.util.FloatProperty;
 
 @RequiresApi(Build.VERSION_CODES.N)
+@NonNullForAll
 public class SlashDrawable extends Drawable {
 
     private static final float CENTER_X = 10.65f;

ui/src/main/java/com/wireguard/android/widget/ToggleSwitch.java

@@ -6,12 +6,15 @@
 
 package com.wireguard.android.widget;
 
+import com.wireguard.util.NonNullForAll;
+
 import android.content.Context;
 import android.os.Parcelable;
 import androidx.annotation.Nullable;
 import android.util.AttributeSet;
 import android.widget.Switch;
 
+@NonNullForAll
 public class ToggleSwitch extends Switch {
     private boolean isRestoringState;
     @Nullable private OnBeforeCheckedChangeListener listener;

ui/src/main/java/com/wireguard/util/Keyed.java

@@ -5,10 +5,13 @@
 
 package com.wireguard.util;
 
+import com.wireguard.util.NonNullForAll;
+
 /**
  * Interface for objects that have a identifying key of the given type.
  */
 
+@NonNullForAll
 public interface Keyed<K> {
     K getKey();
 }

ui/src/main/java/com/wireguard/util/KeyedList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import java.util.Collection;
@@ -15,6 +17,7 @@ import java.util.List;
  * {@code null} elements.
  */
 
+@NonNullForAll
 public interface KeyedList<K, E extends Keyed<? extends K>> extends List<E> {
     boolean containsAllKeys(Collection<K> keys);
 

ui/src/main/java/com/wireguard/util/SortedKeyedList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.util;
 
+import com.wireguard.util.NonNullForAll;
+
 import androidx.annotation.Nullable;
 
 import java.util.Collection;
@@ -16,6 +18,7 @@ import java.util.Set;
  * applied to their keys.
  */
 
+@NonNullForAll
 public interface SortedKeyedList<K, E extends Keyed<? extends K>> extends KeyedList<K, E> {
     Comparator<? super K> comparator();