From bef187f9180fa8744fe608637f5e25a029e1eee5 Mon Sep 17 00:00:00 2001
From: Lyn Han <lynhan@google.com>
Date: Wed, 25 May 2022 15:29:43 -0700
Subject: [PATCH] Remove divider height before first view in shade

to save vertical space on lockscreen.

Bug: 214257536
Test: NotificationStackSizeCalculatorTest
Change-Id: I3132cf4bad09983661e1cd5b3eef8b3caf81799b
---
 .../stack/NotificationStackSizeCalculator.kt  | 26 ++++++++++++-------
 .../NotificationStackSizeCalculatorTest.kt    | 12 ++++-----
 2 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt
index 6287857e7be97..22234b1ef17d2 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculator.kt
@@ -58,7 +58,7 @@ constructor(
     private var maxKeyguardNotifications by notNull<Int>()
 
     /** Minimum space between two notifications, see [calculateGapAndDividerHeight]. */
-    private var dividerHeight by notNull<Int>()
+    private var dividerHeight by notNull<Float>()
 
     init {
         updateResources()
@@ -142,9 +142,13 @@ constructor(
                 if (i == children.lastIndex) {
                     0f // No shelf needed.
                 } else {
+                    val firstViewInShelfIndex = i + 1
                     val spaceBeforeShelf =
                         calculateGapAndDividerHeight(
-                            stack, previous = currentNotification, current = children[i + 1], i)
+                            stack,
+                            previous = currentNotification,
+                            current = children[firstViewInShelfIndex],
+                            currentIndex = firstViewInShelfIndex)
                     spaceBeforeShelf + shelfIntrinsicHeight
                 }
 
@@ -156,16 +160,17 @@ constructor(
         maxKeyguardNotifications =
             infiniteIfNegative(resources.getInteger(R.integer.keyguard_max_notification_count))
 
-        dividerHeight = max(1, resources.getDimensionPixelSize(R.dimen.notification_divider_height))
+        dividerHeight =
+            max(1f, resources.getDimensionPixelSize(R.dimen.notification_divider_height).toFloat())
     }
 
     private val NotificationStackScrollLayout.childrenSequence: Sequence<ExpandableView>
         get() = children.map { it as ExpandableView }
 
     @VisibleForTesting
-    fun onLockscreen() : Boolean {
-        return statusBarStateController.state == KEYGUARD
-                && lockscreenShadeTransitionController.fractionToShade == 0f
+    fun onLockscreen(): Boolean {
+        return statusBarStateController.state == KEYGUARD &&
+            lockscreenShadeTransitionController.fractionToShade == 0f
     }
 
     @VisibleForTesting
@@ -207,11 +212,12 @@ constructor(
         stack: NotificationStackScrollLayout,
         previous: ExpandableView?,
         current: ExpandableView?,
-        visibleIndex: Int
+        currentIndex: Int
     ): Float {
-        var height = stack.calculateGapHeight(previous, current, visibleIndex)
-        height += dividerHeight
-        return height
+        if (currentIndex == 0) {
+            return 0f
+        }
+        return stack.calculateGapHeight(previous, current, currentIndex) + dividerHeight
     }
 
     private fun NotificationStackScrollLayout.showableChildren() =
diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculatorTest.kt b/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculatorTest.kt
index 663490ebfde0f..ef680210e3fe2 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculatorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackSizeCalculatorTest.kt
@@ -125,8 +125,7 @@ class NotificationStackSizeCalculatorTest : SysuiTestCase() {
         // Each row in separate section.
         setGapHeight(gapHeight)
         val spaceUsed =
-            listOf(
-                    dividerHeight + rowHeight,
+            listOf(rowHeight,
                     dividerHeight + gapHeight + rowHeight,
                     dividerHeight + gapHeight + shelfHeight)
                 .sum()
@@ -149,9 +148,8 @@ class NotificationStackSizeCalculatorTest : SysuiTestCase() {
         val rowHeight = rowHeight
         val shelfHeight = shelfHeight
         val spaceUsed =
-            listOf(
-                dividerHeight + rowHeight,
-                dividerHeight + shelfHeight)
+            listOf(rowHeight,
+                    dividerHeight + shelfHeight)
                 .sum()
         val availableSpace = spaceUsed + 1
         val rows = listOf(createMockRow(rowHeight), createMockRow(rowHeight))
@@ -195,7 +193,7 @@ class NotificationStackSizeCalculatorTest : SysuiTestCase() {
 
         val space = sizeCalculator.spaceNeeded(expandableView, visibleIndex = 0,
                 previousView = null, stack = stackLayout, onLockscreen = true)
-        assertThat(space).isEqualTo(5 + dividerHeight)
+        assertThat(space).isEqualTo(5)
     }
 
     @Test
@@ -209,7 +207,7 @@ class NotificationStackSizeCalculatorTest : SysuiTestCase() {
 
         val space = sizeCalculator.spaceNeeded(expandableView, visibleIndex = 0,
                 previousView = null, stack = stackLayout, onLockscreen = false)
-        assertThat(space).isEqualTo(10 + dividerHeight)
+        assertThat(space).isEqualTo(10)
     }
 
     private fun computeMaxKeyguardNotifications(