Fix missing HUN Outro animations

The disappear animation was broken, because we were setting some wrong
values on the HUN animating away:
 - a bottom clipping, which made it to immediately disappear at the start of the animation
 - an yTranslation, which made it to jump around on split shade
 - a wrong height, which made it to flicker during the animation (note: the height flickering only happened if there were other HUNs moving into the shade in the meantime -> the avalanche is the typical use case)

Fixes: b/282624825
Test: atest StackScrollAlgorithmTest
Test: atest create HUNs and observe the animations

Change-Id: If0c1e4f439a3011b5ea499edc2128aa417279ec8

packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java

@@ -315,7 +315,8 @@ public class StackScrollAlgorithm {
             float newNotificationEnd = newYTranslation + newHeight;
             boolean isHeadsUp = (child instanceof ExpandableNotificationRow) && child.isPinned();
             if (mClipNotificationScrollToTop
-                    && ((isHeadsUp && !firstHeadsUp) || child.isHeadsUpAnimatingAway())
+                    && !firstHeadsUp
+                    && (isHeadsUp || child.isHeadsUpAnimatingAway())
                     && newNotificationEnd > firstHeadsUpEnd
                     && !ambientState.isShadeExpanded()) {
                 // The bottom of this view is peeking out from under the previous view.
@@ -619,13 +620,12 @@ public class StackScrollAlgorithm {
                     updateViewWithShelf(view, viewState, shelfStart);
                 }
             }
-            // Avoid pulsing notification flicker during AOD to LS
-            // A pulsing notification is already expanded, no need to expand it again with animation
-            if (ambientState.isPulsingRow(view)) {
-                expansionFraction = 1.0f;
+            viewState.height = getMaxAllowedChildHeight(view);
+            if (!view.isPinned() && !view.isHeadsUpAnimatingAway()
+                    && !ambientState.isPulsingRow(view)) {
+                // The expansion fraction should not affect HUNs or pulsing notifications.
+                viewState.height *= expansionFraction;
             }
-            // Clip height of view right before shelf.
-            viewState.height = (int) (getMaxAllowedChildHeight(view) * expansionFraction);
         }
 
         algorithmState.mCurrentYPosition +=
@@ -785,6 +785,8 @@ public class StackScrollAlgorithm {
                 }
             }
             if (row.isPinned()) {
+                // Make sure row yTranslation is at maximum the HUN yTranslation,
+                // which accounts for AmbientState.stackTopMargin in split-shade.
                 childState.setYTranslation(
                         Math.max(childState.getYTranslation(), headsUpTranslation));
                 childState.height = Math.max(row.getIntrinsicHeight(), childState.height);
@@ -809,7 +811,11 @@ public class StackScrollAlgorithm {
                 }
             }
             if (row.isHeadsUpAnimatingAway()) {
-                childState.setYTranslation(Math.max(childState.getYTranslation(), mHeadsUpInset));
+                // Make sure row yTranslation is at maximum the HUN yTranslation,
+                // which accounts for AmbientState.stackTopMargin in split-shade.
+                childState.setYTranslation(
+                        Math.max(childState.getYTranslation(), headsUpTranslation));
+                // keep it visible for the animation
                 childState.hidden = false;
             }
         }

packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithmTest.kt

@@ -35,7 +35,6 @@ import org.mockito.Mockito.`when` as whenever
 @SmallTest
 class StackScrollAlgorithmTest : SysuiTestCase() {
 
-
     @JvmField @Rule
     var expect: Expect = Expect.create()
 
@@ -82,26 +81,58 @@ class StackScrollAlgorithmTest : SysuiTestCase() {
     fun resetViewStates_defaultHun_yTranslationIsInset() {
         whenever(notificationRow.isPinned).thenReturn(true)
         whenever(notificationRow.isHeadsUp).thenReturn(true)
-
-        stackScrollAlgorithm.resetViewStates(ambientState, 0)
-
-        assertThat(notificationRow.viewState.yTranslation)
-                .isEqualTo(stackScrollAlgorithm.mHeadsUpInset)
+        resetViewStates_hunYTranslationIsInset()
     }
 
     @Test
-    fun resetViewStates_stackMargin_changesHunYTranslation() {
+    fun resetViewStates_defaultHunWithStackMargin_changesHunYTranslation() {
         whenever(notificationRow.isPinned).thenReturn(true)
         whenever(notificationRow.isHeadsUp).thenReturn(true)
-        val minHeadsUpTranslation = context.resources
-                .getDimensionPixelSize(R.dimen.notification_side_paddings)
+        resetViewStates_stackMargin_changesHunYTranslation()
+    }
 
-        // split shade case with top margin introduced by shade's status bar
-        ambientState.stackTopMargin = 100
-        stackScrollAlgorithm.resetViewStates(ambientState, 0)
+    @Test
+    fun resetViewStates_hunAnimatingAway_yTranslationIsInset() {
+        whenever(notificationRow.isHeadsUpAnimatingAway).thenReturn(true)
+        resetViewStates_hunYTranslationIsInset()
+    }
 
-        // top margin presence should decrease heads up translation up to minHeadsUpTranslation
-        assertThat(notificationRow.viewState.yTranslation).isEqualTo(minHeadsUpTranslation)
+    @Test
+    fun resetViewStates_hunAnimatingAway_StackMarginChangesHunYTranslation() {
+        whenever(notificationRow.isHeadsUpAnimatingAway).thenReturn(true)
+        resetViewStates_stackMargin_changesHunYTranslation()
+    }
+
+    @Test
+    fun resetViewStates_hunAnimatingAway_bottomNotClipped() {
+        whenever(notificationRow.isHeadsUpAnimatingAway).thenReturn(true)
+
+        stackScrollAlgorithm.resetViewStates(ambientState, /* speedBumpIndex= */ 0)
+
+        assertThat(notificationRow.viewState.clipBottomAmount).isEqualTo(0)
+    }
+
+    @Test
+    fun resetViewStates_hunsOverlapping_bottomHunClipped() {
+        val topHun = mockExpandableNotificationRow()
+        val bottomHun = mockExpandableNotificationRow()
+        whenever(topHun.isHeadsUp).thenReturn(true)
+        whenever(topHun.isPinned).thenReturn(true)
+        whenever(bottomHun.isHeadsUp).thenReturn(true)
+        whenever(bottomHun.isPinned).thenReturn(true)
+
+        resetViewStates_hunsOverlapping_bottomHunClipped(topHun, bottomHun)
+    }
+
+    @Test
+    fun resetViewStates_hunsOverlappingAndBottomHunAnimatingAway_bottomHunClipped() {
+        val topHun = mockExpandableNotificationRow()
+        val bottomHun = mockExpandableNotificationRow()
+        whenever(topHun.isHeadsUp).thenReturn(true)
+        whenever(topHun.isPinned).thenReturn(true)
+        whenever(bottomHun.isHeadsUpAnimatingAway).thenReturn(true)
+
+        resetViewStates_hunsOverlapping_bottomHunClipped(topHun, bottomHun)
     }
 
     @Test
@@ -855,6 +886,57 @@ class StackScrollAlgorithmTest : SysuiTestCase() {
         ambientState.stackHeight = ambientState.stackEndHeight * fraction
     }
 
+    private fun resetViewStates_hunYTranslationIsInset() {
+        stackScrollAlgorithm.resetViewStates(ambientState, 0)
+
+        assertThat(notificationRow.viewState.yTranslation)
+                .isEqualTo(stackScrollAlgorithm.mHeadsUpInset)
+    }
+
+    private fun resetViewStates_stackMargin_changesHunYTranslation() {
+        val stackTopMargin = 50
+        val headsUpTranslationY = stackScrollAlgorithm.mHeadsUpInset - stackTopMargin
+
+        // we need the shelf to mock the real-life behaviour of StackScrollAlgorithm#updateChild
+        ambientState.shelf = notificationShelf
+
+        // split shade case with top margin introduced by shade's status bar
+        ambientState.stackTopMargin = stackTopMargin
+        stackScrollAlgorithm.resetViewStates(ambientState, 0)
+
+        // heads up translation should be decreased by the top margin
+        assertThat(notificationRow.viewState.yTranslation).isEqualTo(headsUpTranslationY)
+    }
+
+    private fun resetViewStates_hunsOverlapping_bottomHunClipped(
+            topHun: ExpandableNotificationRow,
+            bottomHun: ExpandableNotificationRow
+    ) {
+        val topHunHeight = mContext.resources.getDimensionPixelSize(
+                R.dimen.notification_content_min_height)
+        val bottomHunHeight = mContext.resources.getDimensionPixelSize(
+                R.dimen.notification_max_heads_up_height)
+        whenever(topHun.intrinsicHeight).thenReturn(topHunHeight)
+        whenever(bottomHun.intrinsicHeight).thenReturn(bottomHunHeight)
+
+        // we need the shelf to mock the real-life behaviour of StackScrollAlgorithm#updateChild
+        ambientState.shelf = notificationShelf
+
+        // add two overlapping HUNs
+        hostView.removeAllViews()
+        hostView.addView(topHun)
+        hostView.addView(bottomHun)
+
+        stackScrollAlgorithm.resetViewStates(ambientState, /* speedBumpIndex= */ 0)
+
+        // the height shouldn't change
+        assertThat(topHun.viewState.height).isEqualTo(topHunHeight)
+        assertThat(bottomHun.viewState.height).isEqualTo(bottomHunHeight)
+        // the HUN at the bottom should be clipped
+        assertThat(topHun.viewState.clipBottomAmount).isEqualTo(0)
+        assertThat(bottomHun.viewState.clipBottomAmount).isEqualTo(bottomHunHeight - topHunHeight)
+    }
+
     private fun resetViewStates_expansionChanging_notificationAlphaUpdated(
             expansionFraction: Float,
             expectedAlpha: Float,