Fade in notifications on wakeup.

We will be adding better expansion/translation animations here, but this is better than the current state of things, where notifs just suddenly appear.

Bug: 181020504
Test: manual
Change-Id: Ic350c6b59077d717b23d21ed5dff9f6f7301a658
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationShelf.java b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationShelf.java
index 3daa2b3..f57fd21 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/NotificationShelf.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/NotificationShelf.java
@@ -173,7 +173,7 @@
                     getFullyClosedTranslation());
             viewState.zTranslation = ambientState.getBaseZHeight();
             viewState.clipTopAmount = 0;
-            viewState.alpha = 1;
+            viewState.alpha = 1f - ambientState.getHideAmount();
             viewState.belowSpeedBump = mHostLayoutController.getSpeedBumpIndex() == 0;
             viewState.hideSensitive = false;
             viewState.xTranslation = getTranslationX();
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayout.java b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayout.java
index f6c1b1c..40c0b89 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayout.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayout.java
@@ -1245,7 +1245,7 @@
         }
 
         if (mAmbientState.isHiddenAtAll()) {
-            clipToOutline = true;
+            clipToOutline = false;
             invalidateOutline();
             if (isFullyHidden()) {
                 setClipBounds(null);
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java
index d7a98bd..bbdbe80 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/notification/stack/StackScrollAlgorithm.java
@@ -320,6 +320,7 @@
         }
         int childHeight = getMaxAllowedChildHeight(child);
         childViewState.yTranslation = currentYPosition;
+        childViewState.alpha = 1f - ambientState.getHideAmount();
 
         boolean isFooterView = child instanceof FooterView;
         boolean isEmptyShadeView = child instanceof EmptyShadeView;