QA Rich Card: filter scrolling events

Explicitly stop the propagation of scroll events (including key and
mouse events) that aren't handled by the pretarget handler when the
rich answers view is visible. Specifically update behavior to disallow
scrolling of anything *other* than the rich answers card. Scrolling
behavior of the rich answers card will be updated later.

This is necessary to make event handling consistent with the existing
quick answers view (e.g. not allowing scrolling of other windows while
the card is visible.)

Tests: tested on DUT
Bug: b/274503679
Change-Id: I4c216049c2d1140bd300aebe71a95fadc2b98335
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4363407
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Commit-Queue: Angela Xiao <angelaxiao@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1122027}

chrome/browser/ui/quick_answers/ui/rich_answers_pre_target_handler.cc

@@ -35,9 +35,24 @@ void RichAnswersPreTargetHandler::OnKeyEvent(ui::KeyEvent* key_event) {
   }
 
   auto key_code = key_event->key_code();
-  if (key_code == ui::VKEY_ESCAPE) {
-    QuickAnswersController::Get()->DismissQuickAnswers(
-        quick_answers::QuickAnswersExitPoint::kUnspecified);
+  switch (key_code) {
+    case ui::VKEY_ESCAPE: {
+      QuickAnswersController::Get()->DismissQuickAnswers(
+          quick_answers::QuickAnswersExitPoint::kUnspecified);
+      return;
+    }
+    case ui::VKEY_SPACE:
+    case ui::VKEY_UP:
+    case ui::VKEY_DOWN:
+    case ui::VKEY_LEFT:
+    case ui::VKEY_RIGHT: {
+      // TODO(b/275106457): Handle key navigation of focus on the
+      // rich answers card view.
+      key_event->StopPropagation();
+      return;
+    }
+    default:
+      return;
   }
 }
 
@@ -52,6 +67,23 @@ void RichAnswersPreTargetHandler::OnMouseEvent(ui::MouseEvent* mouse_event) {
     QuickAnswersController::Get()->DismissQuickAnswers(
         quick_answers::QuickAnswersExitPoint::kUnspecified);
   }
+
+  // While the rich answers view is visible, do not pass on unhandled
+  // mouse events up the hierarchy. The rich answers view should be dismissed
+  // before allowing mouse event handling by other windows and views.
+  if (mouse_event->cancelable()) {
+    mouse_event->StopPropagation();
+  }
+}
+
+void RichAnswersPreTargetHandler::OnScrollEvent(ui::ScrollEvent* scroll_event) {
+  // TODO(b/265255821): handle scrolling of the rich answers view card.
+  // Limit scroll events to the rich answers card while it is visible.
+  // This means other windows and views will not be scrollable until the rich
+  // answers view is dismissed.
+  if (scroll_event->cancelable()) {
+    scroll_event->StopPropagation();
+  }
 }
 
 }  // namespace quick_answers

chrome/browser/ui/quick_answers/ui/rich_answers_pre_target_handler.h

@@ -29,6 +29,7 @@ class RichAnswersPreTargetHandler : public ui::EventHandler {
   // ui::EventHandler:
   void OnKeyEvent(ui::KeyEvent* key_event) override;
   void OnMouseEvent(ui::MouseEvent* mouse_event) override;
+  void OnScrollEvent(ui::ScrollEvent* scroll_event) override;
 
  private:
   // Associated view handled by this class.