Support focus highlight in Android window

chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/arc/accessibility/arc_accessibility_helper_bridge.h"
+
+#include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
+#include "components/arc/arc_bridge_service.h"
+#include "components/exo/wm_helper.h"
+#include "ui/aura/window.h"
+#include "ui/gfx/geometry/rect.h"
+
+namespace arc {
+
+ArcAccessibilityHelperBridge::ArcAccessibilityHelperBridge(
+    ArcBridgeService* bridge_service)
+    : ArcService(bridge_service), binding_(this) {
+  arc_bridge_service()->accessibility_helper()->AddObserver(this);
+}
+
+ArcAccessibilityHelperBridge::~ArcAccessibilityHelperBridge() {
+  arc_bridge_service()->accessibility_helper()->RemoveObserver(this);
+}
+
+void ArcAccessibilityHelperBridge::OnInstanceReady() {
+  auto* instance = ARC_GET_INSTANCE_FOR_METHOD(
+      arc_bridge_service()->accessibility_helper(), Init);
+  DCHECK(instance);
+  instance->Init(binding_.CreateInterfacePtrAndBind());
+}
+
+void ArcAccessibilityHelperBridge::OnAccessibilityEvent(
+    mojom::AccessibilityEventType eventType,
+    mojom::AccessibilityNodeInfoDataPtr eventSource) {
+  if (eventType != mojom::AccessibilityEventType::VIEW_FOCUSED ||
+      eventSource.is_null()) {

[dcheng, 2017/01/24 09:36:56]

Is |event_source| actually nullable? The IDL doesn't define as optional.

[yawano, 2017/01/24 11:18:09]

Yes, this can be nullable. For example TYPE_WINDOWS_CHANGED accessibility event
doesn't provide getSource(). (See TYPE_WINDOWS_CHANGED section in
https://developer.android.com/reference/android/view/accessibility/Accessibil...)
Updated the mojom file.

+    return;
+  }
+
+  chromeos::AccessibilityManager* accessibility_manager =
+      chromeos::AccessibilityManager::Get();
+
+  if (!accessibility_manager ||
+      !accessibility_manager->IsFocusHighlightEnabled()) {
+    return;
+  }
+
+  exo::WMHelper* wmHelper = exo::WMHelper::GetInstance();
+
+  aura::Window* focused_window = wmHelper->GetFocusedWindow();
+  if (!focused_window)
+    return;
+
+  aura::Window* toplevel_window = focused_window->GetToplevelWindow();
+
+  gfx::Rect bounds_in_screen = gfx::ScaleToEnclosingRect(
+      eventSource.get()->boundsInScreen,
+      1.0f / toplevel_window->layer()->device_scale_factor());
+
+  accessibility_manager->OnViewFocusedInArc(bounds_in_screen);
+}
+
+}  // namespace arc