From 0214ed9b119cdbc87cfc12908635deaf16603fe5 Mon Sep 17 00:00:00 2001
From: Andrii Kulian <akulian@google.com>
Date: Tue, 16 May 2017 13:44:05 -0700
Subject: [PATCH] Don't report displays that are going to be removed

When display is removed from system, it is immediately removed from
AM, but removal can be deferred in WM if there is an active animation
on that display. If AM then requests display ids in focus order from
WM, it might get a display that was already deleted in AM.
This CL skips displays marked for deferred removal.

Bug: 38166277
Test: DisplayContentTests#testDontReportDeferredRemoval
Change-Id: I49544963f476fc58a609094781ed46541af8a238
---
 .../com/android/server/wm/DisplayContent.java |  5 +++++
 .../server/wm/RootWindowContainer.java        |  7 ++++++-
 .../server/wm/DisplayContentTests.java        | 21 ++++++++++++++++++-
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 257f2856213e2..5ace9a02b6c92 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1892,6 +1892,11 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
         return true;
     }
 
+    /** @return 'true' if removal of this display content is deferred due to active animation. */
+    boolean isRemovalDeferred() {
+        return mDeferredRemoval;
+    }
+
     boolean animateForIme(float interpolatedValue, float animationTarget,
             float dividerAnimationTarget) {
         boolean updated = false;
diff --git a/services/core/java/com/android/server/wm/RootWindowContainer.java b/services/core/java/com/android/server/wm/RootWindowContainer.java
index be3558b3f52f6..233e75bbfec70 100644
--- a/services/core/java/com/android/server/wm/RootWindowContainer.java
+++ b/services/core/java/com/android/server/wm/RootWindowContainer.java
@@ -181,7 +181,12 @@ class RootWindowContainer extends WindowContainer<DisplayContent> {
 
         final int size = mChildren.size();
         for (int i = 0; i < size; ++i) {
-            displaysInFocusOrder.put(i, mChildren.get(i).getDisplayId());
+            final DisplayContent displayContent = mChildren.get(i);
+            if (displayContent.isRemovalDeferred()) {
+                // Don't report displays that are going to be removed soon.
+                continue;
+            }
+            displaysInFocusOrder.put(i, displayContent.getDisplayId());
         }
     }
 
diff --git a/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java b/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java
index f9254ad8180b2..856e94055ed51 100644
--- a/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java
+++ b/services/tests/servicestests/src/com/android/server/wm/DisplayContentTests.java
@@ -34,6 +34,7 @@ import android.content.res.Configuration;
 import android.platform.test.annotations.Presubmit;
 import android.support.test.filters.SmallTest;
 import android.support.test.runner.AndroidJUnit4;
+import android.util.SparseIntArray;
 
 import java.util.Arrays;
 import java.util.LinkedList;
@@ -239,7 +240,7 @@ public class DisplayContentTests extends WindowTestsBase {
     @Test
     @Ignore
     public void testFocusedWindowMultipleDisplays() throws Exception {
-        // Create a focusable window and check that focus is calcualted correctly
+        // Create a focusable window and check that focus is calculated correctly
         final WindowState window1 =
                 createWindow(null, TYPE_BASE_APPLICATION, mDisplayContent, "window1");
         assertEquals(window1, sWm.mRoot.computeFocusedWindow());
@@ -310,6 +311,24 @@ public class DisplayContentTests extends WindowTestsBase {
         assertEquals(afterStackCount - 1, mDisplayContent.getStaskPosById(PINNED_STACK_ID));
     }
 
+    /**
+     * Test that WM does not report displays to AM that are pending to be removed.
+     */
+    @Test
+    public void testDontReportDeferredRemoval() {
+        // Create a display and add an animating window to it.
+        final DisplayContent dc = createNewDisplay();
+        final WindowState window = createWindow(null /* parent */, TYPE_BASE_APPLICATION, dc, "w");
+        window.mAnimatingExit = true;
+        // Request display removal, it should be deferred.
+        dc.removeIfPossible();
+        // Request ordered display ids from WM.
+        final SparseIntArray orderedDisplayIds = new SparseIntArray();
+        sWm.getDisplaysInFocusOrder(orderedDisplayIds);
+        // Make sure that display that is marked for removal is not reported.
+        assertEquals(-1, orderedDisplayIds.indexOfValue(dc.getDisplayId()));
+    }
+
     private static void verifySizes(DisplayContent displayContent, int expectedBaseWidth,
                              int expectedBaseHeight, int expectedBaseDensity) {
         assertEquals(displayContent.mBaseDisplayWidth, expectedBaseWidth);