From bb28587195be2fa9d8c201cfffccbb456d953427 Mon Sep 17 00:00:00 2001
From: Wale Ogunwale <ogunwale@google.com>
Date: Thu, 1 Mar 2018 13:05:30 -0800
Subject: [PATCH] Move primary-split-screen stack forward in some cases.

If we are moving a stack in split-screen seconardy mode forward, we
need to make sure we move the primary split-screen stack forward in
the case it is current behind a fulscreen stack so both halves of the
split-screen appear on-top and the fullscreen stack isn't cutting
between them.
Mostly a workaround until fix can fix b/70677280 where we would have
a stack as a parent of another stack.

Change-Id: I7d030b80c12771e0370a1fea8e1abf96560a9029
Fixes: 71899050
Bug: 70677280
Test: atest ActivityStackTests#testSplitScreenMoveToFront
---
 .../com/android/server/am/ActivityStack.java  | 21 ++++++++++++++-
 .../android/server/am/ActivityStackTests.java | 27 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index 728c07d02d461..a3044f8899536 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -989,13 +989,32 @@ class ActivityStack<T extends StackWindowController> extends ConfigurationContai
             return;
         }
 
+        final ActivityDisplay display = getDisplay();
+
+        if (inSplitScreenSecondaryWindowingMode()) {
+            // If the stack is in split-screen seconardy mode, we need to make sure we move the
+            // primary split-screen stack forward in the case it is currently behind a fullscreen
+            // stack so both halves of the split-screen appear on-top and the fullscreen stack isn't
+            // cutting between them.
+            // TODO(b/70677280): This is a workaround until we can fix as part of b/70677280.
+            final ActivityStack topFullScreenStack =
+                    display.getTopStackInWindowingMode(WINDOWING_MODE_FULLSCREEN);
+            if (topFullScreenStack != null) {
+                final ActivityStack primarySplitScreenStack = display.getSplitScreenPrimaryStack();
+                if (display.getIndexOf(topFullScreenStack)
+                        > display.getIndexOf(primarySplitScreenStack)) {
+                    primarySplitScreenStack.moveToFront(reason + " splitScreenToTop");
+                }
+            }
+        }
+
         if (!isActivityTypeHome() && returnsToHomeStack()) {
             // Make sure the home stack is behind this stack since that is where we should return to
             // when this stack is no longer visible.
             mStackSupervisor.moveHomeStackToFront(reason + " returnToHome");
         }
 
-        getDisplay().positionChildAtTop(this);
+        display.positionChildAtTop(this);
         mStackSupervisor.setFocusStackUnchecked(reason, this);
         if (task != null) {
             insertTaskAtTop(task, null);
diff --git a/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java b/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java
index c62820e8e3c31..a98d5a161f808 100644
--- a/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java
+++ b/services/tests/servicestests/src/com/android/server/am/ActivityStackTests.java
@@ -47,7 +47,7 @@ import org.junit.Test;
  * Tests for the {@link ActivityStack} class.
  *
  * Build/Install/Run:
- *  atest ActivityStackTests
+ *  atest FrameworksServicesTests:com.android.server.am.ActivityStackTests
  */
 @SmallTest
 @Presubmit
@@ -425,6 +425,31 @@ public class ActivityStackTests extends ActivityTestsBase {
         assertTrue(display.getStackAboveHome() == fullscreenStack2);
     }
 
+    @Test
+    public void testSplitScreenMoveToFront() throws Exception {
+        final ActivityDisplay display = mService.mStackSupervisor.getDefaultDisplay();
+        final TestActivityStack splitScreenPrimary = createStackForShouldBeVisibleTest(display,
+                WINDOWING_MODE_SPLIT_SCREEN_PRIMARY, ACTIVITY_TYPE_STANDARD, true /* onTop */);
+        final TestActivityStack splitScreenSecondary = createStackForShouldBeVisibleTest(display,
+                WINDOWING_MODE_SPLIT_SCREEN_SECONDARY, ACTIVITY_TYPE_STANDARD, true /* onTop */);
+        final TestActivityStack assistantStack = createStackForShouldBeVisibleTest(display,
+                WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_ASSISTANT, true /* onTop */);
+
+        splitScreenPrimary.setIsTranslucent(false);
+        splitScreenSecondary.setIsTranslucent(false);
+        assistantStack.setIsTranslucent(false);
+
+        assertFalse(splitScreenPrimary.shouldBeVisible(null /* starting */));
+        assertFalse(splitScreenSecondary.shouldBeVisible(null /* starting */));
+        assertTrue(assistantStack.shouldBeVisible(null /* starting */));
+
+        splitScreenSecondary.moveToFront("testSplitScreenMoveToFront");
+
+        assertTrue(splitScreenPrimary.shouldBeVisible(null /* starting */));
+        assertTrue(splitScreenSecondary.shouldBeVisible(null /* starting */));
+        assertFalse(assistantStack.shouldBeVisible(null /* starting */));
+    }
+
     private <T extends ActivityStack> T createStackForShouldBeVisibleTest(
             ActivityDisplay display, int windowingMode, int activityType, boolean onTop) {
         final T stack = display.createStack(windowingMode, activityType, onTop);