Fix arrow button issue in tablet mode

Changes:
Only reset views::FocusManager::arrow_key_traversal_enabled_ when power
button menu is shown before.

Bug: 898716
Change-Id: I01de4fe8b9438e75d1104997aa0e90c61ae52dd2
Reviewed-on: https://chromium-review.googlesource.com/c/1300685
Commit-Queue: Weidong Guo <weidongg@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Michael Wasserman <msw@chromium.org>
Reviewed-by: Min Chen <minch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#603589}

ash/app_list/views/app_list_view.cc

@@ -289,8 +289,6 @@ AppListView::AppListView(AppListViewDelegate* delegate)
           std::make_unique<HideViewAnimationObserver>()),
       transition_animation_observer_(
           std::make_unique<TransitionAnimationObserver>(this)),
-      previous_arrow_key_traversal_enabled_(
-          views::FocusManager::arrow_key_traversal_enabled()),
       state_animation_metrics_reporter_(
           std::make_unique<StateAnimationMetricsReporter>()),
       is_home_launcher_enabled_(app_list_features::IsHomeLauncherEnabled()),
@@ -298,18 +296,12 @@ AppListView::AppListView(AppListViewDelegate* delegate)
           app_list_features::IsNewStyleLauncherEnabled()),
       weak_ptr_factory_(this) {
   CHECK(delegate);
-
-  // Enable arrow key in FocusManager. Arrow left/right and up/down triggers
-  // the same focus movement as tab/shift+tab.
-  views::FocusManager::set_arrow_key_traversal_enabled(true);
 }
 
 AppListView::~AppListView() {
   hide_view_animation_observer_.reset();
   // Remove child views first to ensure no remaining dependencies on delegate_.
   RemoveAllChildViews(true);
-  views::FocusManager::set_arrow_key_traversal_enabled(
-      previous_arrow_key_traversal_enabled_);
 }
 
 // static
@@ -592,6 +584,11 @@ void AppListView::InitializeFullscreen(gfx::NativeView parent) {
   fullscreen_widget_->GetNativeView()->SetBounds(
       GetPreferredWidgetBoundsForState(AppListViewState::CLOSED));
 
+  // Enable arrow key in FocusManager. Arrow left/right and up/down triggers
+  // the same focus movement as tab/shift+tab.
+  fullscreen_widget_->GetFocusManager()
+      ->set_arrow_key_traversal_enabled_for_widget(true);
+
   widget_observer_ = std::make_unique<FullscreenWidgetObserver>(this);
 }
 

ash/app_list/views/app_list_view.h

@@ -409,9 +409,6 @@ class APP_LIST_EXPORT AppListView : public views::WidgetDelegateView {
   // Accessibility announcement dialogue.
   base::string16 state_announcement_;
 
-  // Whether FocusManager can handle arrow key before this class is constructed.
-  const bool previous_arrow_key_traversal_enabled_;
-
   // Metric reporter for state change animations.
   const std::unique_ptr<ui::AnimationMetricsReporter>
       state_animation_metrics_reporter_;

ash/system/power/power_button_controller.cc

@@ -76,6 +76,11 @@ std::unique_ptr<views::Widget> CreateMenuWidget() {
   gfx::Rect widget_bounds =
       display::Screen::GetScreen()->GetPrimaryDisplay().bounds();
   menu_widget->SetBounds(widget_bounds);
+
+  // Enable arrow key in FocusManager. Arrow right/left and down/up triggers
+  // the same focus movement as tab/shift+tab.
+  menu_widget->GetFocusManager()->set_arrow_key_traversal_enabled_for_widget(
+      true);
   return menu_widget;
 }
 
@@ -143,9 +148,7 @@ class PowerButtonController::ActiveWindowWidgetController
 
 PowerButtonController::PowerButtonController(
     BacklightsForcedOffSetter* backlights_forced_off_setter)
-    : arrow_key_traversal_initially_enabled_(
-          views::FocusManager::arrow_key_traversal_enabled()),
-      backlights_forced_off_setter_(backlights_forced_off_setter),
+    : backlights_forced_off_setter_(backlights_forced_off_setter),
       lock_state_controller_(Shell::Get()->lock_state_controller()),
       tick_clock_(base::DefaultTickClock::GetInstance()),
       backlights_forced_off_observer_(this),
@@ -347,8 +350,6 @@ void PowerButtonController::DismissMenu() {
 
   show_menu_animation_done_ = false;
   active_window_widget_controller_.reset();
-  views::FocusManager::set_arrow_key_traversal_enabled(
-      arrow_key_traversal_initially_enabled_);
 }
 
 void PowerButtonController::StopForcingBacklightsOff() {
@@ -521,9 +522,6 @@ void PowerButtonController::LockScreenIfRequired() {
 
 void PowerButtonController::SetShowMenuAnimationDone() {
   show_menu_animation_done_ = true;
-  // Enable arrow key in FocusManager. Arrow right/left and down/up triggers
-  // the same focus movement as tab/shift+tab.
-  views::FocusManager::set_arrow_key_traversal_enabled(true);
   pre_shutdown_timer_.Start(FROM_HERE, kStartShutdownAnimationTimeout, this,
                             &PowerButtonController::OnPreShutdownTimeout);
 }

ash/system/power/power_button_controller.h

@@ -237,9 +237,6 @@ class ASH_EXPORT PowerButtonController
   // True if the next button release event should force the display off.
   bool force_off_on_button_up_ = false;
 
-  // Whether FocusManager can handle arrow key before showing the power menu.
-  const bool arrow_key_traversal_initially_enabled_;
-
   // Used to force backlights off, when needed.
   BacklightsForcedOffSetter* backlights_forced_off_setter_;  // Not owned.
 

ui/views/focus/focus_manager.cc

@@ -68,8 +68,11 @@ bool FocusManager::OnKeyEvent(const ui::KeyEvent& event) {
       return false;
     }
 
-    if (arrow_key_traversal_enabled_ && ProcessArrowKeyTraversal(event))
+    if ((arrow_key_traversal_enabled_ ||
+         arrow_key_traversal_enabled_for_widget_) &&
+        ProcessArrowKeyTraversal(event)) {
       return false;
+    }
 
     // Intercept arrow key messages to switch between grouped views.
     bool is_left = key_code == ui::VKEY_LEFT || key_code == ui::VKEY_UP;

ui/views/focus/focus_manager.h

@@ -75,7 +75,7 @@ namespace ui {
 class Accelerator;
 class AcceleratorTarget;
 class KeyEvent;
-}
+}  // namespace ui
 
 namespace views {
 
@@ -176,9 +176,7 @@ class VIEWS_EXPORT FocusManager : public ViewObserver {
   }
 
   // Get the reason why the focus most recently changed.
-  FocusChangeReason focus_change_reason() const {
-    return focus_change_reason_;
-  }
+  FocusChangeReason focus_change_reason() const { return focus_change_reason_; }
 
   // Clears the focused view. The window associated with the top root view gets
   // the native focus (so we still get keyboard events).
@@ -297,6 +295,13 @@ class VIEWS_EXPORT FocusManager : public ViewObserver {
     return arrow_key_traversal_enabled_;
   }
 
+  // TODO(weidongg): converts compatible usages of
+  // |arrow_key_traversal_enabled_| to this (https://crbug.com/899431).
+  // Similar to above, but only for the widget that owns this FocusManager.
+  void set_arrow_key_traversal_enabled_for_widget(bool enabled) {
+    arrow_key_traversal_enabled_for_widget_ = enabled;
+  }
+
   // Returns the next focusable view. Traversal starts at |starting_view|. If
   // |starting_view| is NULL |starting_widget| is consuled to determine which
   // Widget to start from. See
@@ -334,9 +339,13 @@ class VIEWS_EXPORT FocusManager : public ViewObserver {
   // ViewObserver:
   void OnViewIsDeleting(View* view) override;
 
-  // Whether arrow key traversal is enabled.
+  // Whether arrow key traversal is enabled globally.
   static bool arrow_key_traversal_enabled_;
 
+  // Whether arrow key traversal is enabled for all widgets under the top-level
+  // widget that owns the FocusManager.
+  bool arrow_key_traversal_enabled_for_widget_ = false;
+
   // The top-level Widget this FocusManager is associated with.
   Widget* widget_;