From b923d1e1f01a3a135d3e708af609a626c9c26368 Mon Sep 17 00:00:00 2001
From: JianYang Liu <jianyliu@google.com>
Date: Thu, 24 Oct 2019 17:19:44 -0700
Subject: [PATCH] Changed Notification shade's background alpha initial and
 final values to be configurable.

Bug: 143372960
Test: manual - took before and after videos
Merged-In: Ia0b6a56859889d538e21f807a88bc5217d89e64a
Change-Id: Ia0b6a56859889d538e21f807a88bc5217d89e64a
---
 packages/CarSystemUI/res/values/config.xml         | 15 +++++++++
 .../systemui/statusbar/car/CarStatusBar.java       | 39 ++++++++++++++++++----
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/packages/CarSystemUI/res/values/config.xml b/packages/CarSystemUI/res/values/config.xml
index 467c4a41893d..cbf22870af96 100644
--- a/packages/CarSystemUI/res/values/config.xml
+++ b/packages/CarSystemUI/res/values/config.xml
@@ -40,4 +40,19 @@
          slots that may be reused for things like IME control. -->
     <integer name="config_maxNotificationIcons">0</integer>
 
+    <!--
+        Initial alpha percent value for the background when the notification
+        shade is open. Should be a number between, and inclusive, 0 and 100.
+        If the number is 0, then the background alpha starts off fully
+        transparent. If the number if 100, then the background alpha starts off
+        fully opaque. -->
+    <integer name="config_initialNotificationBackgroundAlpha">0</integer>
+    <!--
+        Final alpha percent value for the background when the notification
+        shade is fully open. Should be a number between, and inclusive, 0 and
+        100. If this value is smaller than
+        config_initialNotificationBackgroundAlpha, the background will default
+        to a constant alpha percent value using the initial alpha. -->
+    <integer name="config_finalNotificationBackgroundAlpha">100</integer>
+
 </resources>
diff --git a/packages/CarSystemUI/src/com/android/systemui/statusbar/car/CarStatusBar.java b/packages/CarSystemUI/src/com/android/systemui/statusbar/car/CarStatusBar.java
index b7aa496b3d5d..80a824020c78 100644
--- a/packages/CarSystemUI/src/com/android/systemui/statusbar/car/CarStatusBar.java
+++ b/packages/CarSystemUI/src/com/android/systemui/statusbar/car/CarStatusBar.java
@@ -101,6 +101,9 @@ public class CarStatusBar extends StatusBar implements CarBatteryController.Batt
     private float mOpeningVelocity = DEFAULT_FLING_VELOCITY;
     private float mClosingVelocity = DEFAULT_FLING_VELOCITY;
 
+    private float mBackgroundAlphaDiff;
+    private float mInitialBackgroundAlpha;
+
     private TaskStackListenerImpl mTaskStackListener;
 
     private FullscreenUserSwitcher mFullscreenUserSwitcher;
@@ -214,6 +217,25 @@ public class CarStatusBar extends StatusBar implements CarBatteryController.Batt
         // created.
         mHvacController = new HvacController(mContext);
 
+      	// Notification bar related setup.
+        mInitialBackgroundAlpha = (float) mContext.getResources().getInteger(
+            R.integer.config_initialNotificationBackgroundAlpha) / 100;
+        if (mInitialBackgroundAlpha < 0 || mInitialBackgroundAlpha > 100) {
+            throw new RuntimeException(
+              "Unable to setup notification bar due to incorrect initial background alpha"
+                      + " percentage");
+        }
+        float finalBackgroundAlpha = Math.max(
+            mInitialBackgroundAlpha,
+            (float) mContext.getResources().getInteger(
+                R.integer.config_finalNotificationBackgroundAlpha) / 100);
+        if (finalBackgroundAlpha < 0 || finalBackgroundAlpha > 100) {
+            throw new RuntimeException(
+              "Unable to setup notification bar due to incorrect final background alpha"
+                      + " percentage");
+        }
+        mBackgroundAlphaDiff = finalBackgroundAlpha - mInitialBackgroundAlpha;
+
         super.start();
         mTaskStackListener = new TaskStackListenerImpl();
         mActivityManagerWrapper = ActivityManagerWrapper.getInstance();
@@ -1155,17 +1177,22 @@ public class CarStatusBar extends StatusBar implements CarBatteryController.Batt
             mHandleBar.setTranslationY(height - mHandleBar.getHeight() - lp.bottomMargin);
         }
         if (mNotificationView.getHeight() > 0) {
-            // Calculates the alpha value for the background based on how much of the notification
-            // shade is visible to the user. When the notification shade is completely open then
-            // alpha value will be 1.
-            float alpha = (float) height / mNotificationView.getHeight();
             Drawable background = mNotificationView.getBackground().mutate();
-
-            background.setAlpha((int) (alpha * 255));
+            background.setAlpha((int) (getBackgroundAlpha(height) * 255));
             mNotificationView.setBackground(background);
         }
     }
 
+    /**
+     * Calculates the alpha value for the background based on how much of the notification
+     * shade is visible to the user. When the notification shade is completely open then
+     * alpha value will be 1.
+     */
+    private float getBackgroundAlpha(int height) {
+        return mInitialBackgroundAlpha +
+            ((float) height / mNotificationView.getHeight() * mBackgroundAlphaDiff);
+    }
+
     private void calculatePercentageFromBottom(float height) {
         if (mNotificationView.getHeight() > 0) {
             mPercentageFromBottom = (int) Math.abs(
-- 
2.11.0