diff --git a/core/java/android/view/Gravity.java b/core/java/android/view/Gravity.java
index defa58e10e6ef..c8bfd36b2b484 100644
--- a/core/java/android/view/Gravity.java
+++ b/core/java/android/view/Gravity.java
@@ -15,8 +15,13 @@
  */
 
 package android.view;
+
+import android.annotation.IntDef;
 import android.graphics.Rect;
 
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
 /**
  * Standard constants and tools for placing an object within a potentially
  * larger container.
@@ -122,6 +127,32 @@ public class Gravity
      */
     public static final int RELATIVE_HORIZONTAL_GRAVITY_MASK = START | END;
 
+
+    /**
+     * @hide
+     */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(flag = true, value = {
+        Gravity.FILL,
+        Gravity.FILL_HORIZONTAL,
+        Gravity.FILL_VERTICAL,
+        Gravity.START,
+        Gravity.END,
+        Gravity.LEFT,
+        Gravity.RIGHT,
+        Gravity.TOP,
+        Gravity.BOTTOM,
+        Gravity.CENTER,
+        Gravity.CENTER_HORIZONTAL,
+        Gravity.CENTER_VERTICAL,
+        Gravity.DISPLAY_CLIP_HORIZONTAL,
+        Gravity.DISPLAY_CLIP_VERTICAL,
+        Gravity.CLIP_HORIZONTAL,
+        Gravity.CLIP_VERTICAL,
+        Gravity.NO_GRAVITY
+    })
+    public @interface GravityFlags {}
+
     /**
      * Apply a gravity constant to an object. This supposes that the layout direction is LTR.
      * 
diff --git a/core/java/android/view/WindowManager.java b/core/java/android/view/WindowManager.java
index ef2153e074e7c..b9afbc95de0d4 100644
--- a/core/java/android/view/WindowManager.java
+++ b/core/java/android/view/WindowManager.java
@@ -104,6 +104,7 @@ import android.os.Parcelable;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.proto.ProtoOutputStream;
+import android.view.Gravity.GravityFlags;
 import android.view.View.OnApplyWindowInsetsListener;
 import android.view.WindowInsets.Side;
 import android.view.WindowInsets.Side.InsetsSide;
@@ -2572,6 +2573,7 @@ public interface WindowManager extends ViewManager {
          *
          * @see Gravity
          */
+        @GravityFlags
         public int gravity;
 
         /**
diff --git a/core/proto/android/view/windowlayoutparams.proto b/core/proto/android/view/windowlayoutparams.proto
index 4bb56f8acfa4d..062485d304c34 100644
--- a/core/proto/android/view/windowlayoutparams.proto
+++ b/core/proto/android/view/windowlayoutparams.proto
@@ -35,7 +35,7 @@ message WindowLayoutParamsProto {
     optional int32 height = 5;
     optional float horizontal_margin = 6;
     optional float vertical_margin = 7;
-    optional int32 gravity = 8;
+    optional int32 gravity = 8 [(.android.typedef) = "android.view.Gravity.GravityFlags"];
     optional int32 soft_input_mode = 9 [(.android.typedef) = "android.view.WindowManager.LayoutParams.SoftInputModeFlags"];
     optional .android.graphics.PixelFormatProto.Format format = 10;
     optional int32 window_animations = 11;