global: Add nullity annotations

Signed-off-by: Eric Kuck <eric@bluelinelabs.com>

6 files changed, 28 insertions, 26 deletions

diff --git a/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java b/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
index b8c0c4fa..70d97fb1 100644
--- a/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
+++ b/app/src/main/java/com/wireguard/android/util/ExceptionLoggers.java
@@ -6,8 +6,9 @@
 
 package com.wireguard.android.util;
 
-import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.Log;
+
 import java9.util.concurrent.CompletionException;
 import java9.util.function.BiConsumer;
 
@@ -34,7 +35,6 @@ public enum ExceptionLoggers implements BiConsumer<Object, Throwable> {
         return throwable;
     }
 
-    @NonNull
     public static String unwrapMessage(Throwable throwable) {
         throwable = unwrap(throwable);
         final String message = throwable.getMessage();
@@ -44,7 +44,7 @@ public enum ExceptionLoggers implements BiConsumer<Object, Throwable> {
     }
 
     @Override
-    public void accept(final Object result, final Throwable throwable) {
+    public void accept(final Object result, @Nullable final Throwable throwable) {
         if (throwable != null)
             Log.println(Log.ERROR, TAG, Log.getStackTraceString(throwable));
         else if (priority <= Log.DEBUG)
diff --git a/app/src/main/java/com/wireguard/android/util/ObservableKeyedArrayList.java b/app/src/main/java/com/wireguard/android/util/ObservableKeyedArrayList.java
index 1e064e42..0be3c005 100644
--- a/app/src/main/java/com/wireguard/android/util/ObservableKeyedArrayList.java
+++ b/app/src/main/java/com/wireguard/android/util/ObservableKeyedArrayList.java
@@ -7,7 +7,7 @@
 package com.wireguard.android.util;
 
 import android.databinding.ObservableArrayList;
-import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import com.wireguard.util.Keyed;
 
@@ -25,28 +25,28 @@ import java.util.Objects;
 public class ObservableKeyedArrayList<K, E extends Keyed<? extends K>>
         extends ObservableArrayList<E> implements ObservableKeyedList<K, E> {
     @Override
-    public boolean add(final E e) {
+    public boolean add(@Nullable final E e) {
         if (e == null)
             throw new NullPointerException("Trying to add a null element");
         return super.add(e);
     }
 
     @Override
-    public void add(final int index, final E e) {
+    public void add(final int index, @Nullable final E e) {
         if (e == null)
             throw new NullPointerException("Trying to add a null element");
         super.add(index, e);
     }
 
     @Override
-    public boolean addAll(@NonNull final Collection<? extends E> c) {
+    public boolean addAll(final Collection<? extends E> c) {
         if (c.contains(null))
             throw new NullPointerException("Trying to add a collection with null element(s)");
         return super.addAll(c);
     }
 
     @Override
-    public boolean addAll(final int index, @NonNull final Collection<? extends E> c) {
+    public boolean addAll(final int index, final Collection<? extends E> c) {
         if (c.contains(null))
             throw new NullPointerException("Trying to add a collection with null element(s)");
         return super.addAll(index, c);
@@ -65,13 +65,13 @@ public class ObservableKeyedArrayList<K, E extends Keyed<? extends K>>
         return indexOfKey(key) >= 0;
     }
 
-    @Override
+    @Override @Nullable
     public E get(final K key) {
         final int index = indexOfKey(key);
         return index >= 0 ? get(index) : null;
     }
 
-    @Override
+    @Override @Nullable
     public E getLast(final K key) {
         final int index = lastIndexOfKey(key);
         return index >= 0 ? get(index) : null;
@@ -100,7 +100,7 @@ public class ObservableKeyedArrayList<K, E extends Keyed<? extends K>>
     }
 
     @Override
-    public E set(final int index, final E e) {
+    public E set(final int index, @Nullable final E e) {
         if (e == null)
             throw new NullPointerException("Trying to set a null key");
         return super.set(index, e);
diff --git a/app/src/main/java/com/wireguard/android/util/ObservableSortedKeyedArrayList.java b/app/src/main/java/com/wireguard/android/util/ObservableSortedKeyedArrayList.java
index 4ff3a771..239520c4 100644
--- a/app/src/main/java/com/wireguard/android/util/ObservableSortedKeyedArrayList.java
+++ b/app/src/main/java/com/wireguard/android/util/ObservableSortedKeyedArrayList.java
@@ -6,7 +6,7 @@
 
 package com.wireguard.android.util;
 
-import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import com.wireguard.util.Keyed;
 import com.wireguard.util.SortedKeyedList;
@@ -29,6 +29,7 @@ import java.util.Spliterator;
 
 public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
         extends ObservableKeyedArrayList<K, E> implements ObservableSortedKeyedList<K, E> {
+    @Nullable
     private final Comparator<? super K> comparator;
     private final transient KeyList<K, E> keyList = new KeyList<>(this);
 
@@ -75,7 +76,7 @@ public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
     }
 
     @Override
-    public boolean addAll(@NonNull final Collection<? extends E> c) {
+    public boolean addAll(final Collection<? extends E> c) {
         boolean didChange = false;
         for (final E e : c)
             if (add(e))
@@ -84,12 +85,13 @@ public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
     }
 
     @Override
-    public boolean addAll(int index, @NonNull final Collection<? extends E> c) {
+    public boolean addAll(int index, final Collection<? extends E> c) {
         for (final E e : c)
             add(index++, e);
         return true;
     }
 
+    @Nullable
     @Override
     public Comparator<? super K> comparator() {
         return comparator;
@@ -128,7 +130,6 @@ public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
     }
 
     @Override
-    @NonNull
     public Set<K> keySet() {
         return keyList;
     }
@@ -168,7 +169,6 @@ public class ObservableSortedKeyedArrayList<K, E extends Keyed<? extends K>>
     }
 
     @Override
-    @NonNull
     public Collection<E> values() {
         return this;
     }
diff --git a/app/src/main/java/com/wireguard/android/util/RootShell.java b/app/src/main/java/com/wireguard/android/util/RootShell.java
index 9293dff9..18e04102 100644
--- a/app/src/main/java/com/wireguard/android/util/RootShell.java
+++ b/app/src/main/java/com/wireguard/android/util/RootShell.java
@@ -7,6 +7,7 @@
 package com.wireguard.android.util;
 
 import android.content.Context;
+import android.support.annotation.Nullable;
 import android.util.Log;
 
 import com.wireguard.android.R;
@@ -34,10 +35,10 @@ public class RootShell {
     private final File localTemporaryDir;
     private final Object lock = new Object();
     private final String preamble;
-    private Process process;
-    private BufferedReader stderr;
-    private OutputStreamWriter stdin;
-    private BufferedReader stdout;
+    @Nullable private Process process;
+    @Nullable private BufferedReader stderr;
+    @Nullable private OutputStreamWriter stdin;
+    @Nullable private BufferedReader stdout;
 
     public RootShell(final Context context) {
         deviceNotRootedMessage = context.getString(R.string.error_root);
@@ -80,7 +81,7 @@ public class RootShell {
      * @param command Command to run as root.
      * @return The exit value of the command.
      */
-    public int run(final Collection<String> output, final String command)
+    public int run(@Nullable final Collection<String> output, final String command)
             throws IOException, NoRootException {
         synchronized (lock) {
             /* Start inside synchronized block to prevent a concurrent call to stop(). */
diff --git a/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java b/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java
index e0bb579d..997dd45c 100644
--- a/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java
+++ b/app/src/main/java/com/wireguard/android/util/SharedLibraryLoader.java
@@ -19,8 +19,7 @@ import java.util.zip.ZipFile;
 public final class SharedLibraryLoader {
     private static final String TAG = "WireGuard/" + SharedLibraryLoader.class.getSimpleName();
 
-    private SharedLibraryLoader() {
-    }
+    private SharedLibraryLoader() { }
 
     public static void loadSharedLibrary(final Context context, final String libName) {
         Throwable noAbiException;
diff --git a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
index 9cdb6a59..16c906eb 100644
--- a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
+++ b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
@@ -7,6 +7,7 @@
 package com.wireguard.android.util;
 
 import android.content.Context;
+import android.support.annotation.Nullable;
 import android.system.OsConstants;
 import android.util.Log;
 
@@ -39,20 +40,21 @@ public final class ToolsInstaller {
             new File("/system/xbin"),
             new File("/system/bin"),
     };
-    private static final File INSTALL_DIR = getInstallDir();
+    @Nullable private static final File INSTALL_DIR = getInstallDir();
     private static final String TAG = "WireGuard/" + ToolsInstaller.class.getSimpleName();
 
     private final File localBinaryDir;
     private final Object lock = new Object();
     private final File nativeLibraryDir;
-    private Boolean areToolsAvailable;
-    private Boolean installAsMagiskModule;
+    @Nullable private Boolean areToolsAvailable;
+    @Nullable private Boolean installAsMagiskModule;
 
     public ToolsInstaller(final Context context) {
         localBinaryDir = new File(context.getCacheDir(), "bin");
         nativeLibraryDir = new File(context.getApplicationInfo().nativeLibraryDir);
     }
 
+    @Nullable
     private static File getInstallDir() {
         final String path = System.getenv("PATH");
         if (path == null)