From d66df0deb4462b1345291b8513383d0d4b638034 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Tue, 6 Sep 2022 15:23:20 -0600
Subject: [PATCH] Remove unnecessary calculation of display configuration

Since hierarchy unifying, ideally the configuration is already
synced if there is no orientation change. These code still remain
because the display config change from decor window relies on it:

Since [1] and [2], the height of navigation bar is no longer read
from resources. The height can be changed according to the layout
parameter. That may cause the display not to compute the latest
configuration when display density or navigation mode is changed.
And the display config change will happen at random timing when
calling updateOrientation (usually from resuming activity).

But after [3] and [4], the new display config can be sent if the
decor insets provider windows are changed. So now these code
are redundant, especially the computeScreenConfiguration is not a
cheap method, and it will be called twice from resumeTopActivity,
which adds extra unnecessary latency (20%).

[1]: If8ec79b3cb3b989eed578c44e8749b13fd2e8592
[2]: I04af809b5ff1ea43772a41d36ed6d97fb80ee02e
[3]: If966bcc8125300d47d5cd631f7db17ff027e5261
[4]: If6c28a89939372e6362b92f469ef7d793e8ec215

Bug: 234585256
Bug: 159103089
Test: CtsWindowManagerDeviceTestCases
Change-Id: Id7b7f4f7a647edd51b4d3255131eb2052f403784
---
 .../com/android/server/wm/DisplayContent.java  | 18 ------------------
 .../android/server/wm/ActivityRecordTests.java |  1 +
 .../wm/ActivityTaskManagerServiceTests.java    |  5 +----
 3 files changed, 2 insertions(+), 22 deletions(-)

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 720b08285f174..ca02e7d9cca58 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1614,24 +1614,6 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
             }
             config = new Configuration();
             computeScreenConfiguration(config);
-        } else if (!(mTransitionController.isCollecting(this)
-                // If waiting for a remote display change, don't prematurely update configuration.
-                || mRemoteDisplayChangeController.isWaitingForRemoteDisplayChange())) {
-            // No obvious action we need to take, but if our current state mismatches the
-            // activity manager's, update it, disregarding font scale, which should remain set
-            // to the value of the previous configuration.
-            // Here we're calling Configuration#unset() instead of setToDefaults() because we
-            // need to keep override configs clear of non-empty values (e.g. fontSize).
-            final Configuration currentConfig = getRequestedOverrideConfiguration();
-            mTmpConfiguration.unset();
-            mTmpConfiguration.updateFrom(currentConfig);
-            computeScreenConfiguration(mTmpConfiguration);
-            if (currentConfig.diff(mTmpConfiguration) != 0) {
-                mWaitingForConfig = true;
-                setLayoutNeeded();
-                mDisplayRotation.prepareNormalRotationAnimation();
-                config = new Configuration(mTmpConfiguration);
-            }
         }
 
         return config;
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java
index bbd7695fc8cd7..95e9f20011d00 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java
@@ -2993,6 +2993,7 @@ public class ActivityRecordTests extends WindowTestsBase {
         // Add a decor insets provider window.
         final WindowState navbar = createNavBarWithProvidedInsets(squareDisplay);
         squareDisplay.getDisplayPolicy().updateDecorInsetsInfoIfNeeded(navbar);
+        squareDisplay.sendNewConfiguration();
         final Task task = new TaskBuilder(mSupervisor).setDisplay(squareDisplay).build();
 
         // create a fixed portrait activity
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java
index 20b1120d7d3e9..2fccd64bcecac 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java
@@ -220,10 +220,7 @@ public class ActivityTaskManagerServiceTests extends WindowTestsBase {
         // Check that changes are reported
         Configuration c = new Configuration(newDisp1.getRequestedOverrideConfiguration());
         c.windowConfiguration.setBounds(new Rect(0, 0, 1000, 1300));
-        newDisp1.onRequestedOverrideConfigurationChanged(c);
-        mAtm.mRootWindowContainer.ensureVisibilityAndConfig(null /* starting */,
-                newDisp1.mDisplayId, false /* markFrozenIfConfigChanged */,
-                false /* deferResume */);
+        newDisp1.performDisplayOverrideConfigUpdate(c);
         assertEquals(0, added.size());
         assertEquals(1, changed.size());
         assertEquals(0, removed.size());