From 5e9e3e488b0cf9529549bbc388f2a7c5d9aa300b Mon Sep 17 00:00:00 2001
From: Lyn Han <lynhan@google.com>
Date: Wed, 20 Apr 2022 16:32:32 -0400
Subject: [PATCH] Fix stack height jump during lockscreen=>shade and aod<=>ls

Fixes: 229882633
Test: NotificationPanelViewControllerTest
Test: press power button to wakeup and sleep
      swipedown from lockscreen to go to shade
      => observe no stack height jump
Change-Id: I6575f733b17d6c8905150c0a7854d752dd0a5cfe
---
 .../NotificationPanelViewController.java      | 11 ++++++-
 .../NotificationPanelViewControllerTest.java  | 31 +++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java
index adf70a255b4ff..0b46f07f8e8bb 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelViewController.java
@@ -1233,6 +1233,11 @@ public class NotificationPanelViewController extends PanelViewController {
         mKeyguardBottomArea.initQRCodeScanner(mQRCodeScannerController);
     }
 
+    @VisibleForTesting
+    void setMaxDisplayedNotifications(int maxAllowed) {
+        mMaxAllowedKeyguardNotifications = maxAllowed;
+    }
+
     private void updateMaxDisplayedNotifications(boolean recompute) {
         if (recompute) {
             mMaxAllowedKeyguardNotifications = Math.max(computeMaxKeyguardNotifications(), 1);
@@ -1463,7 +1468,11 @@ public class NotificationPanelViewController extends PanelViewController {
     /**
      * @return the maximum keyguard notifications that can fit on the screen
      */
-    private int computeMaxKeyguardNotifications() {
+    @VisibleForTesting
+    int computeMaxKeyguardNotifications() {
+        if (mAmbientState.getFractionToShade() > 0 || mAmbientState.getDozeAmount() > 0) {
+            return mMaxAllowedKeyguardNotifications;
+        }
         float topPadding = mNotificationStackScrollLayoutController.getTopPadding();
         float shelfIntrinsicHeight =
                 mNotificationShelfController.getVisibility() == View.GONE
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java
index 71f1f0b0f7cf0..cad603c85bbcb 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/phone/NotificationPanelViewControllerTest.java
@@ -557,6 +557,37 @@ public class NotificationPanelViewControllerTest extends SysuiTestCase {
         mMainHandler.removeCallbacksAndMessages(null);
     }
 
+    @Test
+    public void computeMaxKeyguardNotifications_lockscreenToShade_returnsExistingMax() {
+        when(mAmbientState.getFractionToShade()).thenReturn(0.5f);
+        mNotificationPanelViewController.setMaxDisplayedNotifications(-1);
+
+        // computeMaxKeyguardNotifications sets maxAllowed to 0 at minimum if it updates the value
+        assertThat(mNotificationPanelViewController.computeMaxKeyguardNotifications())
+                .isEqualTo(-1);
+    }
+
+    @Test
+    public void computeMaxKeyguardNotifications_dozeAmountNotZero_returnsExistingMax() {
+        when(mAmbientState.getDozeAmount()).thenReturn(0.5f);
+        mNotificationPanelViewController.setMaxDisplayedNotifications(-1);
+
+        // computeMaxKeyguardNotifications sets maxAllowed to 0 at minimum if it updates the value
+        assertThat(mNotificationPanelViewController.computeMaxKeyguardNotifications())
+                .isEqualTo(-1);
+    }
+
+    @Test
+    public void computeMaxKeyguardNotifications_noTransition_updatesMax() {
+        when(mAmbientState.getFractionToShade()).thenReturn(0f);
+        when(mAmbientState.getDozeAmount()).thenReturn(0f);
+        mNotificationPanelViewController.setMaxDisplayedNotifications(-1);
+
+        // computeMaxKeyguardNotifications sets maxAllowed to 0 at minimum if it updates the value
+        assertThat(mNotificationPanelViewController.computeMaxKeyguardNotifications())
+                .isNotEqualTo(-1);
+    }
+
     @Test
     public void testSetPanelScrimMinFraction() {
         mNotificationPanelViewController.setPanelScrimMinFraction(0.5f);