From ce07b079f0a9503e13c9da11063a4d04029f1c84 Mon Sep 17 00:00:00 2001
From: Louis Chang <louischang@google.com>
Date: Tue, 26 Oct 2021 17:12:41 +0800
Subject: [PATCH] Making activity invisible when occluded by one of the
 adjacent TF

Multiple TaskFragments can be added in a leaf Task for activity
embedding use case. Unlike split-screen use case, the adjacent
TaskFragments are not always positioned next to each other.
There could have a TaskFragment positioned in between two adjacent
TaskFragments.

Bug: 204185619
Test: atest SplitActivityLifecycleTest

Change-Id: I27295a8176c61044bd8e92d70cb1aa422e3e88f6
---
 .../java/com/android/server/wm/TaskFragment.java   | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/services/core/java/com/android/server/wm/TaskFragment.java b/services/core/java/com/android/server/wm/TaskFragment.java
index 99f6f341e9771..f08ebba7839ed 100644
--- a/services/core/java/com/android/server/wm/TaskFragment.java
+++ b/services/core/java/com/android/server/wm/TaskFragment.java
@@ -778,6 +778,7 @@ class TaskFragment extends WindowContainer<WindowContainer> {
         boolean gotOpaqueSplitScreenPrimary = false;
         boolean gotOpaqueSplitScreenSecondary = false;
         boolean gotTranslucentFullscreen = false;
+        boolean gotTranslucentAdjacent = false;
         boolean gotTranslucentSplitScreenPrimary = false;
         boolean gotTranslucentSplitScreenSecondary = false;
         boolean shouldBeVisible = true;
@@ -806,6 +807,18 @@ class TaskFragment extends WindowContainer<WindowContainer> {
 
             final boolean hasRunningActivities = hasRunningActivity(other);
             if (other == this) {
+                if (!adjacentTaskFragments.isEmpty() && !gotTranslucentAdjacent) {
+                    // The z-order of this TaskFragment is in middle of two adjacent TaskFragments
+                    // and it cannot be visible if the TaskFragment on top is not translucent and
+                    // is fully occluding this one.
+                    for (int j = adjacentTaskFragments.size() - 1; j >= 0; --j) {
+                        final TaskFragment taskFragment = adjacentTaskFragments.get(j);
+                        if (!taskFragment.isTranslucent(starting)
+                                && taskFragment.getBounds().contains(this.getBounds())) {
+                            return TASK_FRAGMENT_VISIBILITY_INVISIBLE;
+                        }
+                    }
+                }
                 // Should be visible if there is no other fragment occluding it, unless it doesn't
                 // have any running activities, not starting one and not home stack.
                 shouldBeVisible = hasRunningActivities
@@ -875,6 +888,7 @@ class TaskFragment extends WindowContainer<WindowContainer> {
                             || otherTaskFrag.mAdjacentTaskFragment.isTranslucent(starting)) {
                         // Can be visible behind a translucent adjacent TaskFragments.
                         gotTranslucentFullscreen = true;
+                        gotTranslucentAdjacent = true;
                         continue;
                     }
                     // Can not be visible behind adjacent TaskFragments.