From 86413b57e1a1c1c273da24b023dceb7765af5b49 Mon Sep 17 00:00:00 2001
From: Siarhei Vishniakou <svv@google.com>
Date: Wed, 11 Jan 2023 13:26:44 -0800
Subject: [PATCH] Add MotionPredictor API

This API will provide access to motion predictions.

Bug: 167946763
Test: atest InputTests
Change-Id: Ib8bc0debd9714e76520baae6ab8122762525716d
---
 core/api/current.txt                        |  7 +++++++
 core/java/android/view/MotionPredictor.java | 11 ++++++++---
 tests/MotionPrediction/Android.bp           |  3 +--
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/core/api/current.txt b/core/api/current.txt
index c147be9b3caf0..fcff8bb7afe1d 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -50628,6 +50628,13 @@ package android.view {
     field public int toolType;
   }
 
+  public final class MotionPredictor {
+    ctor public MotionPredictor(@NonNull android.content.Context);
+    method public boolean isPredictionAvailable(int, int);
+    method @NonNull public java.util.List<android.view.MotionEvent> predict(long);
+    method public void record(@NonNull android.view.MotionEvent);
+  }
+
   public interface OnReceiveContentListener {
     method @Nullable public android.view.ContentInfo onReceiveContent(@NonNull android.view.View, @NonNull android.view.ContentInfo);
   }
diff --git a/core/java/android/view/MotionPredictor.java b/core/java/android/view/MotionPredictor.java
index 3e58a31745dee..fa86a4c73fb20 100644
--- a/core/java/android/view/MotionPredictor.java
+++ b/core/java/android/view/MotionPredictor.java
@@ -25,10 +25,15 @@ import java.util.Arrays;
 import java.util.List;
 
 /**
- * Calculates motion predictions.
+ * Calculate motion predictions.
  *
- * Add motions here to get predicted events!
- * @hide
+ * Feed motion events to this class in order to generate the predicted events. The prediction
+ * functionality may not be available on all devices. Check if a specific source is supported on a
+ * given input device using #isPredictionAvailable.
+ *
+ * Send all of the events that were received from the system here in order to generate complete,
+ * accurate predictions. When processing the returned predictions, make sure to consider all of the
+ * {@link MotionEvent#getHistoricalAxisValue historical samples}.
  */
 // Acts as a pass-through to the native MotionPredictor object.
 // Do not store any state in this Java layer, or add any business logic here. All of the
diff --git a/tests/MotionPrediction/Android.bp b/tests/MotionPrediction/Android.bp
index b9d01da263aae..6cda8f050987b 100644
--- a/tests/MotionPrediction/Android.bp
+++ b/tests/MotionPrediction/Android.bp
@@ -26,6 +26,5 @@ package {
 android_app {
     name: "MotionPrediction",
     srcs: ["**/*.kt"],
-    platform_apis: true,
-    certificate: "platform",
+    sdk_version: "current",
 }