Merge "Fix alpha not fading on notifications after the first shade expansion" into tm-qpr-dev

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

@@ -163,7 +163,7 @@ public class StackScrollAlgorithm {
                 // which is more expensive.
                 if (shelfState.hidden) {
                     // When the shelf is hidden, it won't clip views, so we don't hide rows
-                    return;
+                    continue;
                 }
 
                 final float shelfTop = shelfState.yTranslation;

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

@@ -179,7 +179,28 @@ class StackScrollAlgorithmTest : SysuiTestCase() {
     }
 
     @Test
-    fun resetViewStates_hiddenShelf_viewAlphaDoesNotChange() {
+    fun resetViewStates_hiddenShelf_allRowsBecomesTransparent() {
+        hostView.removeAllViews()
+        val row1 = mockExpandableNotificationRow()
+        hostView.addView(row1)
+        val row2 = mockExpandableNotificationRow()
+        hostView.addView(row2)
+
+        ambientState.setStatusBarState(StatusBarState.KEYGUARD)
+        ambientState.hideAmount = 0.25f
+        notificationShelf.viewState.hidden = true
+        ambientState.shelf = notificationShelf
+        stackScrollAlgorithm.initView(context)
+
+        stackScrollAlgorithm.resetViewStates(ambientState, /* speedBumpIndex= */ 0)
+
+        val expected = 1f - ambientState.hideAmount
+        assertThat(row1.viewState.alpha).isEqualTo(expected)
+        assertThat(row2.viewState.alpha).isEqualTo(expected)
+    }
+
+    @Test
+    fun resetViewStates_hiddenShelf_shelfAlphaDoesNotChange() {
         val expected = notificationShelf.viewState.alpha
         notificationShelf.viewState.hidden = true
         ambientState.shelf = notificationShelf
@@ -459,3 +480,9 @@ class StackScrollAlgorithmTest : SysuiTestCase() {
         assertEquals(1f, currentRoundness)
     }
 }
+
+private fun mockExpandableNotificationRow(): ExpandableNotificationRow {
+    return mock(ExpandableNotificationRow::class.java).apply {
+        whenever(viewState).thenReturn(ExpandableViewState())
+    }
+}