Exclude unnecessary window early in DisplayWindowsObserver

Previously, some windows are excluded from the final list of
accessibility windows in populateReportedWindowLocked().
This is done after we compute touchable region to decide which windows
are touchable and to be exposed.
Thus, there are some corner cases where an unwanted window joins in
touchable region computation and occludes an important window,
resulting in missing window info.

With this change, unnecessary windows are excluded when we compute
touchable regions.

This is a retry of abandoned CL [1] with a cleaner approach behind
the computeWindowChangesOnA11y flag.

[1] Iacff5b7e67a9e7e989671dc85ad884b0e9f2f2f0

Bug: 240885392
Bug: 254581919
Test: android.autofillservice.cts.servicebehavior.SettingsIntentTest
Test: android.autofillservice.cts.inline.InlineTooltipTest
Test: CtsAccessibilityServiceTestCases CtsAccessibilityTestCases AccessibilityWindowManagerWithAccessibilityWindowTest
Change-Id: Id4b24284db40feaa744c9a5598d0067566fa3963

2 files changed, 63 insertions, 13 deletions

diff --git a/services/accessibility/java/com/android/server/accessibility/AccessibilityWindowManager.java b/services/accessibility/java/com/android/server/accessibility/AccessibilityWindowManager.java
index 3a946f07f7b3..c570d65d8f57 100644
--- a/services/accessibility/java/com/android/server/accessibility/AccessibilityWindowManager.java
+++ b/services/accessibility/java/com/android/server/accessibility/AccessibilityWindowManager.java
@@ -527,14 +527,19 @@ public class AccessibilityWindowManager {
             final Region unaccountedSpace = new Region(0, 0, screenSize.x, screenSize.y);
             for (final AccessibilityWindow a11yWindow : visibleWindows) {
                 a11yWindow.getTouchableRegionInWindow(regionInWindow);
-                if (windowMattersToAccessibility(a11yWindow, regionInWindow, unaccountedSpace)) {
-                    final WindowInfo window = a11yWindow.getWindowInfo();
-                    if (window.token != null) {
+
+                final WindowInfo window = a11yWindow.getWindowInfo();
+                final int windowId = window.token != null
+                        ? findWindowIdLocked(userId, window.token)
+                        : AccessibilityWindowInfo.UNDEFINED_WINDOW_ID;
+
+                if (windowMattersToAccessibilityLocked(a11yWindow, windowId, regionInWindow,
+                        unaccountedSpace)) {
+                    if (windowId >= 0) {
                         // Even if token is null, the window will be used in calculating visible
                         // windows, but is excluded from the accessibility window list.
                         window.regionInScreen.set(regionInWindow);
                         window.layer = addedWindows.size();
-                        final int windowId = findWindowIdLocked(userId, window.token);
                         updateWindowWithWindowAttributes(window, mWindowAttributes.get(windowId));
 
                         windows.add(window);
@@ -585,8 +590,8 @@ public class AccessibilityWindowManager {
             return windows;
         }
 
-        private static boolean windowMattersToAccessibility(AccessibilityWindow a11yWindow,
-                Region regionInScreen, Region unaccountedSpace) {
+        private boolean windowMattersToAccessibilityLocked(AccessibilityWindow a11yWindow,
+                int windowId, Region regionInScreen, Region unaccountedSpace) {
             if (a11yWindow.ignoreRecentsAnimationForAccessibility()) {
                 return false;
             }
@@ -603,6 +608,10 @@ public class AccessibilityWindowManager {
                 return false;
             }
 
+            if (isEmbeddedHierarchyWindowsLocked(windowId)) {
+                return false;
+            }
+
             // If the window is completely covered by other windows - ignore.
             if (unaccountedSpace.quickReject(regionInScreen)) {
                 return false;
@@ -983,14 +992,19 @@ public class AccessibilityWindowManager {
         private AccessibilityWindowInfo populateReportedWindowLocked(int userId,
                 WindowInfo window, SparseArray<AccessibilityWindowInfo> oldWindowsById) {
             final int windowId = findWindowIdLocked(userId, window.token);
-            if (windowId < 0) {
-                return null;
-            }
 
-            // Don't need to add the embedded hierarchy windows into the accessibility windows list.
-            if (isEmbeddedHierarchyWindowsLocked(windowId)) {
-                return null;
+            // With the flag enabled, createWindowInfoListLocked() already removes invalid windows.
+            if (!Flags.computeWindowChangesOnA11y()) {
+                if (windowId < 0) {
+                    return null;
+                }
+
+                // Don't need to add the embedded hierarchy windows into the a11y windows list.
+                if (isEmbeddedHierarchyWindowsLocked(windowId)) {
+                    return null;
+                }
             }
+
             final AccessibilityWindowInfo reportedWindow = AccessibilityWindowInfo.obtain();
 
             reportedWindow.setId(windowId);
@@ -1609,7 +1623,7 @@ public class AccessibilityWindowManager {
                 return getWindowTokensForUserLocked(userId).keyAt(userIndex);
             }
         }
-        return -1;
+        return AccessibilityWindowInfo.UNDEFINED_WINDOW_ID;
     }
 
     /**
diff --git a/services/tests/servicestests/src/com/android/server/accessibility/AccessibilityWindowManagerWithAccessibilityWindowTest.java b/services/tests/servicestests/src/com/android/server/accessibility/AccessibilityWindowManagerWithAccessibilityWindowTest.java
index f6dc2f0f05b2..6e8d6dc3c120 100644
--- a/services/tests/servicestests/src/com/android/server/accessibility/AccessibilityWindowManagerWithAccessibilityWindowTest.java
+++ b/services/tests/servicestests/src/com/android/server/accessibility/AccessibilityWindowManagerWithAccessibilityWindowTest.java
@@ -47,6 +47,7 @@ import static org.mockito.Mockito.when;
 
 import android.annotation.Nullable;
 import android.graphics.Point;
+import android.graphics.Rect;
 import android.graphics.Region;
 import android.os.IBinder;
 import android.os.LocaleList;
@@ -434,6 +435,41 @@ public class AccessibilityWindowManagerWithAccessibilityWindowTest {
     }
 
     @Test
+    public void onWindowsChanged_embeddedWindows_shouldOnlyReportHost() throws RemoteException {
+        final Rect embeddingBounds = new Rect(0, 0, 200, 100);
+
+        // The embedded window comes front of the host window.
+        final IBinder embeddedWindowLeashToken = Mockito.mock(IBinder.class);
+        final int embeddedWindowId = addAccessibilityInteractionConnection(Display.DEFAULT_DISPLAY,
+                false, embeddedWindowLeashToken, USER_SYSTEM_ID);
+        final AccessibilityWindow embeddedWindow = createMockAccessibilityWindow(
+                mA11yWindowTokens.get(embeddedWindowId), Display.DEFAULT_DISPLAY);
+        setRegionForMockAccessibilityWindow(embeddedWindow, new Region(embeddingBounds));
+        mWindows.get(Display.DEFAULT_DISPLAY).set(0, embeddedWindow);
+
+        final IBinder hostWindowLeashToken = Mockito.mock(IBinder.class);
+        final int hostWindowId = addAccessibilityInteractionConnection(Display.DEFAULT_DISPLAY,
+                false, hostWindowLeashToken, USER_SYSTEM_ID);
+        final AccessibilityWindow hostWindow = createMockAccessibilityWindow(
+                mA11yWindowTokens.get(hostWindowId), Display.DEFAULT_DISPLAY);
+        setRegionForMockAccessibilityWindow(hostWindow, new Region(embeddingBounds));
+        mWindows.get(Display.DEFAULT_DISPLAY).set(1, hostWindow);
+
+        mA11yWindowManager.associateEmbeddedHierarchyLocked(
+                hostWindowLeashToken, embeddedWindowLeashToken);
+
+        onAccessibilityWindowsChanged(Display.DEFAULT_DISPLAY, SEND_ON_WINDOW_CHANGES);
+
+        final List<AccessibilityWindowInfo> a11yWindows =
+                mA11yWindowManager.getWindowListLocked(Display.DEFAULT_DISPLAY);
+        assertThat(a11yWindows, not(hasItem(windowId(embeddedWindowId))));
+        assertThat(a11yWindows.get(0), windowId(hostWindowId));
+        final Rect bounds = new Rect();
+        a11yWindows.get(0).getBoundsInScreen(bounds);
+        assertEquals(bounds, embeddingBounds);
+    }
+
+    @Test
     public void onWindowsChangedAndForceSend_shouldUpdateWindows() {
         assertNotEquals("new title",
                 toString(mA11yWindowManager.getWindowListLocked(Display.DEFAULT_DISPLAY)