[Search] Block keyboard focus on other views when SearchView is open

PiperOrigin-RevId: 814296973

Author: imhappi

docs/components/Search.md

@@ -301,6 +301,18 @@ so that screen readers such as TalkBack are able to announce their purpose or
 action. Text rendered in these components are automatically provided to
 accessibility services, so additional content labels are usually unnecessary.
 
+`SearchView` also automatically handles its siblings' accessibility when shown,
+i.e., setting views that are not nested within the SearchView as not important
+for accessibility. These values are restored when the `SearchView` is hidden.
+
+**Note** `SearchView` handles its siblings' accessibility by saving the original
+values when `SearchView` is shown, and restoring them when it's hidden. If
+changing the view hierarchy of the `SearchView`'s root view, make sure to call
+`setModalForAccessibility(false)` to restore the original a11y values. Eg. if
+removing the `SearchView` when open, you must call
+`setModalForAccessibility(false)` before removal to ensure that the original
+a11y values are restored since `SearchView.hide()` will never be called.
+
 ### Transition listeners
 
 If you want to get callbacks for when the `SearchView` transitions between its

lib/java/com/google/android/material/search/SearchView.java

@@ -41,6 +41,7 @@
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.ViewTreeObserver.OnTouchModeChangeListener;
 import android.view.Window;
 import android.view.WindowManager;
 import android.view.accessibility.AccessibilityEvent;
@@ -171,6 +172,17 @@ public class SearchView extends FrameLayout
   private boolean statusBarSpacerEnabledOverride;
   @NonNull private TransitionState currentTransitionState = TransitionState.HIDDEN;
   private Map<View, Integer> childImportantForAccessibilityMap;
+  private final OnTouchModeChangeListener touchModeChangeListener =
+      new OnTouchModeChangeListener() {
+        @Override
+        public void onTouchModeChanged(boolean isInTouchMode) {
+          // If we enter non touch mode and the SearchView is showing in the currently focused
+          // window, request focus on the EditText to prevent focusing views behind SearchView.
+          if (!isInTouchMode && hasWindowFocus() && isShowing() && editText != null) {
+            editText.post(editText::requestFocus);
+          }
+        }
+      };
 
   public SearchView(@NonNull Context context) {
     this(context, null);
@@ -271,6 +283,7 @@ protected void onAttachedToWindow() {
     TransitionState state = getCurrentTransitionState();
     updateModalForAccessibility(state);
     updateListeningForBackCallbacks(state);
+    getViewTreeObserver().addOnTouchModeChangeListener(touchModeChangeListener);
   }
 
   @Override
@@ -279,6 +292,7 @@ protected void onDetachedFromWindow() {
 
     setModalForAccessibility(/* isSearchViewModal= */ false);
     backOrchestrator.stopListeningForBackCallbacks();
+    getViewTreeObserver().removeOnTouchModeChangeListener(touchModeChangeListener);
   }
 
   @Override

lib/java/com/google/android/material/search/res/layout/mtrl_search_view.xml

@@ -31,6 +31,8 @@
       android:layout_height="match_parent"
       android:focusable="true"
       android:focusableInTouchMode="true"
+      android:touchscreenBlocksFocus="true"
+      android:keyboardNavigationCluster="true"
       android:visibility="gone">
 
     <LinearLayout