2 files changed, 39 insertions, 0 deletions

diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 4504887f265b..91677a12338d 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -939,6 +939,26 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
      */
     private static boolean sAcceptZeroSizeDragShadow;
 
+    /**
+     * Prior to Q, {@link #dispatchApplyWindowInsets} had some issues:
+     * <ul>
+     *     <li>The modified insets changed by {@link #onApplyWindowInsets} were passed to the
+     *     entire view hierarchy in prefix order, including siblings as well as siblings of parents
+     *     further down the hierarchy. This violates the basic concepts of the view hierarchy, and
+     *     thus, the hierarchical dispatching mechanism was hard to use for apps.</li>
+     *
+     *     <li>Dispatch was stopped after the insets were fully consumed. This is somewhat confusing
+     *     for developers, but more importantly, by adding more granular information to
+     *     {@link WindowInsets} it becomes really cumbersome to define what consumed actually means
+     *     </li>
+     * </ul>
+     *
+     * In order to make window inset dispatching work properly, we dispatch window insets
+     * in the view hierarchy in a proper hierarchical manner and don't stop dispatching if the
+     * insets are consumed if this flag is set to {@code false}.
+     */
+    static boolean sBrokenInsetsDispatch;
+
     /** @hide */
     @IntDef({NOT_FOCUSABLE, FOCUSABLE, FOCUSABLE_AUTO})
     @Retention(RetentionPolicy.SOURCE)
@@ -5108,6 +5128,9 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
 
             sAcceptZeroSizeDragShadow = targetSdkVersion < Build.VERSION_CODES.P;
 
+            sBrokenInsetsDispatch = !ViewRootImpl.USE_NEW_INSETS
+                    || targetSdkVersion < Build.VERSION_CODES.Q;
+
             sCompatibilityDone = true;
         }
     }
diff --git a/core/java/android/view/ViewGroup.java b/core/java/android/view/ViewGroup.java
index 8372032593b0..9d11397498cf 100644
--- a/core/java/android/view/ViewGroup.java
+++ b/core/java/android/view/ViewGroup.java
@@ -7111,6 +7111,14 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
     @Override
     public WindowInsets dispatchApplyWindowInsets(WindowInsets insets) {
         insets = super.dispatchApplyWindowInsets(insets);
+        if (View.sBrokenInsetsDispatch) {
+            return brokenDispatchApplyWindowInsets(insets);
+        } else {
+            return newDispatchApplyWindowInsets(insets);
+        }
+    }
+
+    private WindowInsets brokenDispatchApplyWindowInsets(WindowInsets insets) {
         if (!insets.isConsumed()) {
             final int count = getChildCount();
             for (int i = 0; i < count; i++) {
@@ -7123,6 +7131,14 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager
         return insets;
     }
 
+    private WindowInsets newDispatchApplyWindowInsets(WindowInsets insets) {
+        final int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            getChildAt(i).dispatchApplyWindowInsets(insets);
+        }
+        return insets;
+    }
+
     /**
      * Returns the animation listener to which layout animation events are
      * sent.