android/annotations: add Nullable and NonNull from AOSP

src/api-impl/android/annotation/NonNull.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2013 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 android.annotation;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Denotes that a parameter, field or method return value can never be null.
+ * <p>
+ * This is a marker annotation and it has no specific attributes.
+ *
+ * @paramDoc This value cannot be {@code null}.
+ * @returnDoc This value cannot be {@code null}.
+ * @hide
+ */
+@Retention(CLASS)
+@Target({METHOD, PARAMETER, FIELD})
+public @interface NonNull {
+}

src/api-impl/android/annotation/Nullable.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2013 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 android.annotation;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.CLASS;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Denotes that a parameter, field or method return value can be null.
+ * <p>
+ * When decorating a method call parameter, this denotes that the parameter can
+ * legitimately be null and the method will gracefully deal with it. Typically
+ * used on optional parameters.
+ * <p>
+ * When decorating a method, this denotes the method might legitimately return
+ * null.
+ * <p>
+ * This is a marker annotation and it has no specific attributes.
+ *
+ * @paramDoc This value may be {@code null}.
+ * @returnDoc This value may be {@code null}.
+ * @hide
+ */
+@Retention(CLASS)
+@Target({METHOD, PARAMETER, FIELD})
+public @interface Nullable {
+}

src/api-impl/meson.build

@@ -15,6 +15,8 @@ srcs = [
 	'android/animation/TimeInterpolator.java',
 	'android/animation/TypeEvaluator.java',
 	'android/animation/ValueAnimator.java',
+	'android/annotation/NonNull.java',
+	'android/annotation/Nullable.java',
 	'android/annotation/PrivateApi.java',
 	'android/annotation/SdkConstant.java',
 	'android/annotation/SuppressLint.java',