DisplayCutout: Only dispatch to apps requesting it

Fixes a compatibility issues, where apps that were not expecting
a cutout were dispatched one anyway, which caused the WindowInsets
dispatch to continue down the hierarchy even though the SystemInsets
were consumed by the app.

To avoid this, we pre-emptively consume the cutout for any apps that
did not request to be laid out in the cutout area. This is safe,
because for apps that don't request it, the status bar will take care
of consuming it, or they won't be laid out in the cutout at all.

If apps still need to know where the cutout is, they can query for it
via View.getRootWindowInsets().

Fixes: 65689439
Bug: 70490585
Test: atest android.view.cts.DisplayCutoutTest
Change-Id: If06674c619f095d4105be1b3a511fb5823b63d2b

1 files changed, 10 insertions, 1 deletions

diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 6d4998b05c48..73a235959578 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -20,6 +20,7 @@ import static android.view.Display.INVALID_DISPLAY;
 import static android.view.View.PFLAG_DRAW_ANIMATION;
 import static android.view.WindowCallbacks.RESIZE_MODE_DOCKED_DIVIDER;
 import static android.view.WindowCallbacks.RESIZE_MODE_FREEFORM;
+import static android.view.WindowManager.LayoutParams.FLAG2_LAYOUT_IN_DISPLAY_CUTOUT_AREA;
 import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_FORCE_DECOR_VIEW_VISIBILITY;
 import static android.view.WindowManager.LayoutParams.TYPE_INPUT_METHOD;
 import static android.view.WindowManager.LayoutParams.TYPE_STATUS_BAR_PANEL;
@@ -1578,7 +1579,15 @@ public final class ViewRootImpl implements ViewParent,
     }
 
     void dispatchApplyInsets(View host) {
-        host.dispatchApplyWindowInsets(getWindowInsets(true /* forceConstruct */));
+        WindowInsets insets = getWindowInsets(true /* forceConstruct */);
+        final boolean layoutInCutout =
+                (mWindowAttributes.flags2 & FLAG2_LAYOUT_IN_DISPLAY_CUTOUT_AREA) != 0;
+        if (!layoutInCutout) {
+            // Window is either not laid out in cutout or the status bar inset takes care of
+            // clearing the cutout, so we don't need to dispatch the cutout to the hierarchy.
+            insets = insets.consumeCutout();
+        }
+        host.dispatchApplyWindowInsets(insets);
     }
 
     private static boolean shouldUseDisplaySize(final WindowManager.LayoutParams lp) {