From 35ca6c8129209d2f9e57e8630141ddd3943ede02 Mon Sep 17 00:00:00 2001
From: Sean Stout <sstout@google.com>
Date: Mon, 25 Jan 2021 19:36:23 -0800
Subject: [PATCH] Add DisplayGroupListener interface

This interface can be used to listen for addition, removal, or
modification of DisplayGroups.

Bug: 138328918
Test: make
Change-Id: I3a2f39838ab00808816366d2484190b401aabed0
---
 .../display/DisplayManagerInternal.java       | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/core/java/android/hardware/display/DisplayManagerInternal.java b/core/java/android/hardware/display/DisplayManagerInternal.java
index 5a03adee4eabd..95f1d124b9a1c 100644
--- a/core/java/android/hardware/display/DisplayManagerInternal.java
+++ b/core/java/android/hardware/display/DisplayManagerInternal.java
@@ -465,4 +465,46 @@ public abstract class DisplayManagerInternal {
     public interface DisplayTransactionListener {
         void onDisplayTransaction(Transaction t);
     }
+
+    /**
+     * Called when there are changes to {@link com.android.server.display.DisplayGroup
+     * DisplayGroups}.
+     */
+    public interface DisplayGroupListener {
+        /**
+         * A new display group with the provided {@code groupId} was added.
+         *
+         * <ol>
+         *     <li>The {@code groupId} is applied to all appropriate {@link Display displays}.
+         *     <li>This method is called.
+         *     <li>{@link android.hardware.display.DisplayManager.DisplayListener DisplayListeners}
+         *     are informed of any corresponding changes.
+         * </ol>
+         */
+        void onDisplayGroupAdded(int groupId);
+
+        /**
+         * The display group with the provided {@code groupId} was removed.
+         *
+         * <ol>
+         *     <li>All affected {@link Display displays} have their group IDs updated appropriately.
+         *     <li>{@link android.hardware.display.DisplayManager.DisplayListener DisplayListeners}
+         *     are informed of any corresponding changes.
+         *     <li>This method is called.
+         * </ol>
+         */
+        void onDisplayGroupRemoved(int groupId);
+
+        /**
+         * The display group with the provided {@code groupId} has changed.
+         *
+         * <ol>
+         *     <li>All affected {@link Display displays} have their group IDs updated appropriately.
+         *     <li>{@link android.hardware.display.DisplayManager.DisplayListener DisplayListeners}
+         *     are informed of any corresponding changes.
+         *     <li>This method is called.
+         * </ol>
+         */
+        void onDisplayGroupChanged(int groupId);
+    }
 }