From c8b63cf556910faa85d6f2d920d1ad43dd4e3dd5 Mon Sep 17 00:00:00 2001
From: Tiger <tigerhuang@google.com>
Date: Fri, 16 Dec 2022 19:13:59 +0800
Subject: [PATCH] Make navigation bar color transparent by default

This CL only changes the default color from black to transparent. If an
app specifies the navigation color from the resource or programatically,
its color will still be applied.

This feature is only enabled when config_navBarDefaultTransparent is
enabled.

Fix: 232195501
Test: Open Pixel Logger or NetGrapher with the combinations of:
      1. gesture navigation or 3-button navigation
      2. light theme or dark theme
Change-Id: I9f1fd67e1c42cc732accba2260e0374cbc495041
---
 .../android/internal/policy/PhoneWindow.java    | 17 ++++++++++++++---
 core/res/res/values/colors.xml                  |  6 ++++++
 core/res/res/values/config.xml                  |  4 ++++
 core/res/res/values/symbols.xml                 |  3 +++
 core/res/res/values/themes.xml                  |  2 +-
 core/res/res/values/themes_material.xml         |  4 ++--
 6 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/core/java/com/android/internal/policy/PhoneWindow.java b/core/java/com/android/internal/policy/PhoneWindow.java
index 1875ecf69ea03..a14e9a7cf516d 100644
--- a/core/java/com/android/internal/policy/PhoneWindow.java
+++ b/core/java/com/android/internal/policy/PhoneWindow.java
@@ -2507,12 +2507,23 @@ public class PhoneWindow extends Window implements MenuBuilder.Callback {
         final boolean targetPreQ = targetSdk < Build.VERSION_CODES.Q;
 
         if (!mForcedStatusBarColor) {
-            mStatusBarColor = a.getColor(R.styleable.Window_statusBarColor, 0xFF000000);
+            mStatusBarColor = a.getColor(R.styleable.Window_statusBarColor, Color.BLACK);
         }
         if (!mForcedNavigationBarColor) {
-            mNavigationBarColor = a.getColor(R.styleable.Window_navigationBarColor, 0xFF000000);
+            final int navBarCompatibleColor = context.getColor(R.color.navigation_bar_compatible);
+            final int navBarDefaultColor = context.getColor(R.color.navigation_bar_default);
+            final int navBarColor = a.getColor(R.styleable.Window_navigationBarColor,
+                    navBarDefaultColor);
+
+            mNavigationBarColor =
+                    navBarColor == navBarDefaultColor
+                            && !context.getResources().getBoolean(
+                                    R.bool.config_navBarDefaultTransparent)
+                    ? navBarCompatibleColor
+                    : navBarColor;
+
             mNavigationBarDividerColor = a.getColor(R.styleable.Window_navigationBarDividerColor,
-                    0x00000000);
+                    Color.TRANSPARENT);
         }
         if (!targetPreQ) {
             mEnsureStatusBarContrastWhenTransparent = a.getBoolean(
diff --git a/core/res/res/values/colors.xml b/core/res/res/values/colors.xml
index 0c2fc1d4af297..e8922b0c870c1 100644
--- a/core/res/res/values/colors.xml
+++ b/core/res/res/values/colors.xml
@@ -573,4 +573,10 @@
     <color name="side_fps_toast_background">#F7F9FA</color>
     <color name="side_fps_text_color">#191C1D</color>
     <color name="side_fps_button_color">#00677E</color>
+
+    <!-- Color for system bars -->
+    <color name="navigation_bar_compatible">@android:color/black</color>
+    <!-- This uses non-regular transparent intentionally. It is used to tell if the transparent
+         color is set by the framework or not. -->
+    <color name="navigation_bar_default">#00808080</color>
 </resources>
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 8e5ae9cf21ae7..76bb2760c5414 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -3876,6 +3876,10 @@
          This should only be set when the device has gestural navigation enabled by default. -->
     <bool name="config_showGesturalNavigationHints">false</bool>
 
+    <!-- Controls whether the navigation bar background color provided by the app is transparent by
+         default. This should be controlled in developer options. -->
+    <bool name="config_navBarDefaultTransparent">false</bool>
+
     <!-- Controls the free snap mode for the docked stack divider. In this mode, the divider can be
          snapped to any position between the first target and the last target. -->
     <bool name="config_dockedStackDividerFreeSnapMode">false</bool>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index dcd7a31b6e4c5..9faf1439d9c7f 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -2996,6 +2996,9 @@
   <java-symbol type="array" name="config_backGestureInsetScales" />
   <java-symbol type="color" name="system_bar_background_semi_transparent" />
   <java-symbol type="bool" name="config_showGesturalNavigationHints" />
+  <java-symbol type="bool" name="config_navBarDefaultTransparent" />
+  <java-symbol type="color" name="navigation_bar_default"/>
+  <java-symbol type="color" name="navigation_bar_compatible"/>
 
   <!-- EditText suggestion popup. -->
   <java-symbol type="id" name="suggestionWindowContainer" />
diff --git a/core/res/res/values/themes.xml b/core/res/res/values/themes.xml
index a60862b74e15c..e96de582022a8 100644
--- a/core/res/res/values/themes.xml
+++ b/core/res/res/values/themes.xml
@@ -191,7 +191,7 @@ please see themes_device_defaults.xml.
         <item name="windowTranslucentNavigation">false</item>
         <item name="windowDrawsSystemBarBackgrounds">false</item>
         <item name="statusBarColor">@color/black</item>
-        <item name="navigationBarColor">@color/black</item>
+        <item name="navigationBarColor">@color/navigation_bar_default</item>
         <item name="windowActionBarFullscreenDecorLayout">@layout/screen_action_bar</item>
         <item name="windowContentTransitions">false</item>
         <item name="windowActivityTransitions">false</item>
diff --git a/core/res/res/values/themes_material.xml b/core/res/res/values/themes_material.xml
index e516a6cf9d2b5..cd4c0d62523ec 100644
--- a/core/res/res/values/themes_material.xml
+++ b/core/res/res/values/themes_material.xml
@@ -175,7 +175,7 @@ please see themes_device_defaults.xml.
         <item name="windowDrawsSystemBarBackgrounds">true</item>
         <item name="windowActionBarFullscreenDecorLayout">@layout/screen_toolbar</item>
         <item name="statusBarColor">?attr/colorPrimaryDark</item>
-        <item name="navigationBarColor">@color/black</item>
+        <item name="navigationBarColor">@color/navigation_bar_default</item>
         <item name="windowEnterTransition">@transition/fade</item>
         <item name="windowSharedElementEnterTransition">@transition/move</item>
         <item name="windowSharedElementExitTransition">@transition/move</item>
@@ -548,7 +548,7 @@ please see themes_device_defaults.xml.
         <item name="windowDrawsSystemBarBackgrounds">true</item>
         <item name="windowActionBarFullscreenDecorLayout">@layout/screen_toolbar</item>
         <item name="statusBarColor">?attr/colorPrimaryDark</item>
-        <item name="navigationBarColor">@color/black</item>
+        <item name="navigationBarColor">@color/navigation_bar_default</item>
         <item name="windowEnterTransition">@transition/fade</item>
         <item name="windowSharedElementEnterTransition">@transition/move</item>
         <item name="windowSharedElementExitTransition">@transition/move</item>