From a6be960c2fd4741a6c7ebb6e5722e8a261af349d Mon Sep 17 00:00:00 2001
From: Amir Hardon <amirh@users.noreply.github.com>
Date: Mon, 15 Jul 2019 16:51:36 -0700
Subject: [PATCH] Make the virtual display's window translucent
 (flutter/engine#9828)

By default alpha is not preserved for the VD's contents.
We make the window translucent as a side effect of doing so is preserving alpha.
There should not be extra performance cost for setting the window to be translucent as there is only a single window within the VD.

Fixes flutter/flutter#33756
---
 .../plugin/platform/SingleViewPresentation.java     | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/SingleViewPresentation.java b/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/SingleViewPresentation.java
index 7acd66b3b4..3fd1e04577 100644
--- a/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/SingleViewPresentation.java
+++ b/engine/src/flutter/shell/platform/android/io/flutter/plugin/platform/SingleViewPresentation.java
@@ -96,7 +96,11 @@ class SingleViewPresentation extends Presentation {
             Object createParams,
             OnFocusChangeListener focusChangeListener
     ) {
-        super(outerContext, display);
+        // By default alpha is not preserved for the VD's contents.
+        // We make the window translucent as a side effect of doing so is preserving alpha.
+        // There should not be extra performance cost for setting the window to be translucent as
+        // there is only a single window within the VD.
+        super(outerContext, display, android.R.style.Theme_Translucent_NoTitleBar_Fullscreen);
         this.viewFactory = viewFactory;
         this.accessibilityEventsDelegate = accessibilityEventsDelegate;
         this.viewId = viewId;
@@ -109,6 +113,7 @@ class SingleViewPresentation extends Presentation {
         );
     }
 
+
     /**
      * Creates a presentation that will attach an already existing view as
      * its root view.
@@ -124,7 +129,11 @@ class SingleViewPresentation extends Presentation {
             OnFocusChangeListener focusChangeListener,
             boolean startFocused
     ) {
-        super(outerContext, display);
+        // By default alpha is not preserved for the VD's contents.
+        // We make the window translucent as a side effect of doing so is preserving alpha.
+        // There should not be extra performance cost for setting the window to be translucent as
+        // there is only a single window within the VD.
+        super(outerContext, display, android.R.style.Theme_Translucent_NoTitleBar_Fullscreen);
         this.accessibilityEventsDelegate = accessibilityEventsDelegate;
         viewFactory = null;
         this.state = state;