Makes magnifier observe AXEventManager for focus changes

Bug: 865575
Change-Id: I8d8328a459d7621d6fc0a0d65e0f24f788b9767f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1852414
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#704854}

chrome/browser/chromeos/accessibility/magnification_manager.cc

@@ -26,6 +26,7 @@
 #include "content/public/browser/notification_source.h"
 #include "content/public/common/service_manager_connection.h"
 #include "services/service_manager/public/cpp/connector.h"
+#include "ui/views/accessibility/ax_event_manager.h"
 
 namespace chromeos {
 
@@ -94,6 +95,18 @@ double MagnificationManager::GetSavedScreenMagnifierScale() const {
       ash::prefs::kAccessibilityScreenMagnifierScale);
 }
 
+void MagnificationManager::OnViewEvent(views::View* view,
+                                       ax::mojom::Event event_type) {
+  if (!fullscreen_magnifier_enabled_ && !IsDockedMagnifierEnabled())
+    return;
+
+  if (event_type != ax::mojom::Event::kFocus &&
+      event_type != ax::mojom::Event::kSelection)
+    return;
+
+  HandleFocusChanged(view->GetBoundsInScreen(), false);
+}
+
 void MagnificationManager::SetProfileForTest(Profile* profile) {
   SetProfile(profile);
 }
@@ -108,10 +121,12 @@ MagnificationManager::MagnificationManager() {
   registrar_.Add(this, content::NOTIFICATION_FOCUS_CHANGED_IN_PAGE,
                  content::NotificationService::AllSources());
   user_manager::UserManager::Get()->AddSessionStateObserver(this);
+  views::AXEventManager::Get()->AddObserver(this);
 }
 
 MagnificationManager::~MagnificationManager() {
   CHECK(this == g_magnification_manager);
+  views::AXEventManager::Get()->RemoveObserver(this);
   user_manager::UserManager::Get()->RemoveSessionStateObserver(this);
 }
 
@@ -280,17 +295,22 @@ void MagnificationManager::HandleFocusChangedInPage(
   if (node_details->is_editable_node)
     return;
 
-  const gfx::Rect& bounds_in_screen = node_details->node_bounds_in_screen;
+  HandleFocusChanged(node_details->node_bounds_in_screen,
+                     node_details->is_editable_node);
+}
+
+void MagnificationManager::HandleFocusChanged(const gfx::Rect& bounds_in_screen,
+                                              bool is_editable) {
   if (bounds_in_screen.IsEmpty())
     return;
 
   // Fullscreen magnifier and docked magnifier are mutually exclusive.
   if (fullscreen_magnifier_enabled_) {
     ash::Shell::Get()->magnification_controller()->HandleFocusedNodeChanged(
-        node_details->is_editable_node, node_details->node_bounds_in_screen);
+        is_editable, bounds_in_screen);
     return;
   }
-  DCHECK(docked_magnifier_enabled);
+  DCHECK(IsDockedMagnifierEnabled());
   ash::DockedMagnifierController::Get()->CenterOnPoint(
       bounds_in_screen.CenterPoint());
 }

chrome/browser/chromeos/accessibility/magnification_manager.h

@@ -10,6 +10,7 @@
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "ui/views/accessibility/ax_event_observer.h"
 
 class PrefChangeRegistrar;
 class Profile;
@@ -30,7 +31,8 @@ namespace chromeos {
 // either Fullscreen or Docked magnifier is enabled.
 class MagnificationManager
     : public content::NotificationObserver,
-      public user_manager::UserManager::UserSessionStateObserver {
+      public user_manager::UserManager::UserSessionStateObserver,
+      public views::AXEventObserver {
  public:
   // Creates an instance of MagnificationManager. This should be called once.
   static void Initialize();
@@ -59,6 +61,9 @@ class MagnificationManager
   // Loads the Fullscreen magnifier scale from the pref.
   double GetSavedScreenMagnifierScale() const;
 
+  // views::AXEventObserver:
+  void OnViewEvent(views::View* view, ax::mojom::Event event_type) override;
+
   void SetProfileForTest(Profile* profile);
 
  private:
@@ -85,6 +90,9 @@ class MagnificationManager
   // Called when received content::NOTIFICATION_FOCUS_CHANGED_IN_PAGE.
   void HandleFocusChangedInPage(const content::NotificationDetails& details);
 
+  // Called in response to AXEventObserver.
+  void HandleFocusChanged(const gfx::Rect& bounds_in_screen, bool is_editable);
+
   Profile* profile_ = nullptr;
 
   bool fullscreen_magnifier_enabled_ = false;