From ac9ad70086ca80fe865c49ace2159f342bd00b9b Mon Sep 17 00:00:00 2001
From: Phil Weaver <pweaver@google.com>
Date: Wed, 27 Jul 2016 18:03:10 -0700
Subject: [PATCH] Prevent a11y seeing behind tasks w/modal windows.

Bug: 30279147
Change-Id: Iee714031894bec0d5b25e0d0feaf918536e5b124
---
 .../server/wm/AccessibilityController.java        | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/wm/AccessibilityController.java b/services/core/java/com/android/server/wm/AccessibilityController.java
index 8be5dfb3c7fda..d2d5c28788895 100644
--- a/services/core/java/com/android/server/wm/AccessibilityController.java
+++ b/services/core/java/com/android/server/wm/AccessibilityController.java
@@ -1071,14 +1071,15 @@ final class AccessibilityController {
                                 Region.Op.REVERSE_DIFFERENCE);
                     }
 
-                    // We figured out what is touchable for the entire screen - done.
-                    if (unaccountedSpace.isEmpty()) {
-                        break;
-                    }
-
                     // If a window is modal it prevents other windows from being touched
                     if ((flags & (WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                             | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL)) == 0) {
+                        // Account for all space in the task, whether the windows in it are
+                        // touchable or not. The modal window blocks all touches from the task's
+                        // area.
+                        unaccountedSpace.op(windowState.getDisplayFrameLw(), unaccountedSpace,
+                                Region.Op.REVERSE_DIFFERENCE);
+
                         if (task != null) {
                             // If the window is associated with a particular task, we can skip the
                             // rest of the windows for that task.
@@ -1090,6 +1091,10 @@ final class AccessibilityController {
                             break;
                         }
                     }
+                    // We figured out what is touchable for the entire screen - done.
+                    if (unaccountedSpace.isEmpty()) {
+                        break;
+                    }
                 }
 
                 // Always report the focused window.