GestureNav: Fix broken split screen navbar

With gesture navigation, it no longer makes sense to force the navigation bar
to black in split screen, instead we can show the respective navbar backgrounds of
the applications.

Fixes: 130913061
Test: enable gesture navigation, enter splitscreen, observe that navigation bar backgrounds are properly drawn, also verify the same if IME is open.
Change-Id: If1464dd9cf0c5499c7c33caab06eb430fb59cb30

core/java/com/android/internal/policy/DecorView.java

@@ -1160,16 +1160,17 @@ public class DecorView extends FrameLayout implements RootViewSurfaceTaker, Wind
         // Note: We don't need to check for IN_SCREEN or INSET_DECOR because unlike the status bar,
         // these flags wouldn't make the window draw behind the navigation bar, unless
         // LAYOUT_HIDE_NAVIGATION was set.
+        boolean hideNavigation = (sysUiVisibility & SYSTEM_UI_FLAG_HIDE_NAVIGATION) != 0;
         boolean forceConsumingNavBar = (mForceWindowDrawsBarBackgrounds
                         && (attrs.flags & FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS) == 0
                         && (sysUiVisibility & SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION) == 0
-                        && (sysUiVisibility & SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0)
-                || mLastShouldAlwaysConsumeSystemBars;
+                        && !hideNavigation)
+                || (mLastShouldAlwaysConsumeSystemBars && hideNavigation);
 
         boolean consumingNavBar =
                 ((attrs.flags & FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS) != 0
                         && (sysUiVisibility & SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION) == 0
-                        && (sysUiVisibility & SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0)
+                        && !hideNavigation)
                 || forceConsumingNavBar;
 
         // If we didn't request fullscreen layout, but we still got it because of the

core/res/res/values/config.xml

@@ -3279,7 +3279,8 @@
          various workspace stacks.
          0 - Nav bar is always opaque when either the freeform stack or docked stack is visible.
          1 - Nav bar is always translucent when the freeform stack is visible, otherwise always
-         opaque.
+             opaque.
+         2 - Nav bar is never forced opaque.
          -->
     <integer name="config_navBarOpacityMode">0</integer>
 

packages/overlays/NavigationBarModeGesturalOverlay/res/values/config.xml

@@ -37,6 +37,15 @@
      {@link Window#setEnsuringNavigationBarContrastWhenTransparent}. -->
     <bool name="config_navBarNeedsScrim">false</bool>
 
+    <!-- Controls the opacity of the navigation bar depending on the visibility of the
+     various workspace stacks.
+     0 - Nav bar is always opaque when either the freeform stack or docked stack is visible.
+     1 - Nav bar is always translucent when the freeform stack is visible, otherwise always
+         opaque.
+     2 - Nav bar is never forced opaque.
+     -->
+    <integer name="config_navBarOpacityMode">2</integer>
+
     <!-- Controls whether seamless rotation should be allowed even though the navbar can move
          (which normally prevents seamless rotation). -->
     <bool name="config_allowSeamlessRotationDespiteNavBarMoving">true</bool>

services/core/java/com/android/server/wm/DisplayPolicy.java

@@ -198,6 +198,8 @@ public class DisplayPolicy {
     private static final int NAV_BAR_OPAQUE_WHEN_FREEFORM_OR_DOCKED = 0;
     // Nav bar is always translucent when the freeform stack is visible, otherwise always opaque.
     private static final int NAV_BAR_TRANSLUCENT_WHEN_FREEFORM_OPAQUE_OTHERWISE = 1;
+    // Nav bar is never forced opaque.
+    private static final int NAV_BAR_FORCE_TRANSPARENT = 2;
 
     /**
      * These are the system UI flags that, when changing, can cause the layout
@@ -3288,8 +3290,10 @@ public class DisplayPolicy {
                 : mTopFullscreenOpaqueWindowState;
         vis = mStatusBarController.applyTranslucentFlagLw(fullscreenTransWin, vis, oldVis);
         vis = mNavigationBarController.applyTranslucentFlagLw(fullscreenTransWin, vis, oldVis);
-        final int dockedVis = mStatusBarController.applyTranslucentFlagLw(
+        int dockedVis = mStatusBarController.applyTranslucentFlagLw(
                 mTopDockedOpaqueWindowState, 0, 0);
+        dockedVis = mNavigationBarController.applyTranslucentFlagLw(
+                mTopDockedOpaqueWindowState, dockedVis, 0);
 
         final boolean fullscreenDrawsStatusBarBackground =
                 drawsStatusBarBackground(vis, mTopFullscreenOpaqueWindowState);
@@ -3297,6 +3301,8 @@ public class DisplayPolicy {
                 drawsStatusBarBackground(dockedVis, mTopDockedOpaqueWindowState);
         final boolean fullscreenDrawsNavBarBackground =
                 drawsNavigationBarBackground(vis, mTopFullscreenOpaqueWindowState);
+        final boolean dockedDrawsNavigationBarBackground =
+                drawsNavigationBarBackground(dockedVis, mTopDockedOpaqueWindowState);
 
         // prevent status bar interaction from clearing certain flags
         int type = win.getAttrs().type;
@@ -3321,7 +3327,7 @@ public class DisplayPolicy {
         }
 
         vis = configureNavBarOpacity(vis, dockedStackVisible, freeformStackVisible, resizing,
-                fullscreenDrawsNavBarBackground);
+                fullscreenDrawsNavBarBackground, dockedDrawsNavigationBarBackground);
 
         // update status bar
         boolean immersiveSticky =
@@ -3439,8 +3445,14 @@ public class DisplayPolicy {
      */
     private int configureNavBarOpacity(int visibility, boolean dockedStackVisible,
             boolean freeformStackVisible, boolean isDockedDividerResizing,
-            boolean fullscreenDrawsBackground) {
-        if (mNavBarOpacityMode == NAV_BAR_OPAQUE_WHEN_FREEFORM_OR_DOCKED) {
+            boolean fullscreenDrawsBackground, boolean dockedDrawsNavigationBarBackground) {
+        if (mNavBarOpacityMode == NAV_BAR_FORCE_TRANSPARENT) {
+            if (fullscreenDrawsBackground && dockedDrawsNavigationBarBackground) {
+                visibility = setNavBarTransparentFlag(visibility);
+            } else if (dockedStackVisible) {
+                visibility = setNavBarOpaqueFlag(visibility);
+            }
+        } else if (mNavBarOpacityMode == NAV_BAR_OPAQUE_WHEN_FREEFORM_OR_DOCKED) {
             if (dockedStackVisible || freeformStackVisible || isDockedDividerResizing) {
                 visibility = setNavBarOpaqueFlag(visibility);
             } else if (fullscreenDrawsBackground) {