Ash Tray: Update status area collapse state when state changes.

The collapse state of the status area should be updated when the shelf state or
bounds change or when a tray item is shown or hidden.

Note that the actual calculation for which trays should be hidden or visible is
unimplemented and will be finished in a future CL.

TEST=unit test
BUG=982511

Change-Id: Ie4a46be7d03435bf8927062af0c7726f5cc090a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1904165
Commit-Queue: Tim Song <tengs@chromium.org>
Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714798}

ash/public/cpp/ash_switches.cc

@@ -58,6 +58,10 @@ const char kAshEnableWaylandServer[] = "enable-wayland-server";
 // Enables the stylus tools next to the status area.
 const char kAshForceEnableStylusTools[] = "force-enable-stylus-tools";
 
+// Forces the status area to allow collapse/expand regardless of the current
+// state.
+const char kAshForceStatusAreaCollapsible[] = "force-status-area-collapsible";
+
 // Power button position includes the power button's physical display side and
 // the percentage for power button center position to the display's
 // width/height in landscape_primary screen orientation. The value is a JSON

ash/public/cpp/ash_switches.h

@@ -30,6 +30,7 @@ ASH_PUBLIC_EXPORT extern const char kAshEnablePaletteOnAllDisplays[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableTabletMode[];
 ASH_PUBLIC_EXPORT extern const char kAshEnableWaylandServer[];
 ASH_PUBLIC_EXPORT extern const char kAshForceEnableStylusTools[];
+ASH_PUBLIC_EXPORT extern const char kAshForceStatusAreaCollapsible[];
 ASH_PUBLIC_EXPORT extern const char kAshPowerButtonPosition[];
 ASH_PUBLIC_EXPORT extern const char kAshUiMode[];
 ASH_PUBLIC_EXPORT extern const char kAshUiModeClamshell[];

ash/shelf/shelf_widget.cc

@@ -353,6 +353,7 @@ void ShelfWidget::DelegateView::UpdateDragHandle() {
 
 void ShelfWidget::DelegateView::OnBoundsChanged(const gfx::Rect& old_bounds) {
   UpdateOpaqueBackground();
+  shelf_widget_->status_area_widget()->UpdateCollapseState();
 }
 
 views::View* ShelfWidget::DelegateView::GetDefaultFocusableChild() {

ash/system/status_area_widget.cc

@@ -5,6 +5,8 @@
 #include "ash/system/status_area_widget.h"
 
 #include "ash/keyboard/ui/keyboard_ui_controller.h"
+#include "ash/public/cpp/ash_switches.h"
+#include "ash/public/cpp/shelf_config.h"
 #include "ash/session/session_controller_impl.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shell.h"
@@ -18,7 +20,10 @@
 #include "ash/system/tray/status_area_overflow_button_tray.h"
 #include "ash/system/unified/unified_system_tray.h"
 #include "ash/system/virtual_keyboard/virtual_keyboard_tray.h"
+#include "ash/wm/tablet_mode/tablet_mode_controller.h"
+#include "base/command_line.h"
 #include "base/i18n/time_formatting.h"
+#include "chromeos/constants/chromeos_switches.h"
 #include "ui/display/display.h"
 #include "ui/native_theme/native_theme_dark_aura.h"
 
@@ -145,6 +150,36 @@ void StatusAreaWidget::SetSystemTrayVisibility(bool visible) {
   }
 }
 
+void StatusAreaWidget::UpdateCollapseState() {
+  // The status area is only collapsible in tablet mode. Otherwise, we just show
+  // all trays.
+  if (!Shell::Get()->tablet_mode_controller())
+    return;
+
+  bool is_collapsible =
+      chromeos::switches::ShouldShowShelfHotseat() &&
+      Shell::Get()->tablet_mode_controller()->InTabletMode() &&
+      ShelfConfig::Get()->is_in_app();
+
+  bool force_collapsible = base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kAshForceStatusAreaCollapsible);
+
+  is_collapsible |= force_collapsible;
+
+  // If the status area is already collapsed/expanded, we should not update the
+  // state again.
+  if (is_collapsible && collapse_state_ == CollapseState::NOT_COLLAPSIBLE)
+    collapse_state_ = CollapseState::COLLAPSED;
+  else if (!is_collapsible)
+    collapse_state_ = CollapseState::NOT_COLLAPSIBLE;
+
+  // TODO(tengs): Right now we simply show the overflow button in the collpase
+  // state. The full calculation of which trays overflow will be done in a
+  // future CL.
+  overflow_button_tray_->SetVisiblePreferred(
+      force_collapsible && collapse_state_ != CollapseState::NOT_COLLAPSIBLE);
+}
+
 TrayBackgroundView* StatusAreaWidget::GetSystemTrayAnchor() const {
   // Use the target visibility of the layer instead of the visibility of the
   // view because the view is still visible when fading away, but we do not want

ash/system/status_area_widget.h

@@ -55,6 +55,10 @@ class ASH_EXPORT StatusAreaWidget : public views::Widget {
   // notification tray.
   void UpdateAfterLoginStatusChange(LoginStatus login_status);
 
+  // Updates the collapse state of the status area after the state of the shelf
+  // changes.
+  void UpdateCollapseState();
+
   // Sets system tray visibility. Shows or hides widget if needed.
   void SetSystemTrayVisibility(bool visible);
 

ash/system/status_area_widget_unittest.cc

@@ -24,6 +24,7 @@
 #include "ash/system/session/logout_button_tray.h"
 #include "ash/system/status_area_widget_test_api.h"
 #include "ash/system/status_area_widget_test_helper.h"
+#include "ash/system/tray/status_area_overflow_button_tray.h"
 #include "ash/system/tray/system_tray_notifier.h"
 #include "ash/system/unified/unified_system_tray.h"
 #include "ash/system/virtual_keyboard/virtual_keyboard_tray.h"
@@ -365,13 +366,13 @@ class StatusAreaWidgetCollapseStateTest : public AshTestBase {
   void SetUp() override {
     AshTestBase::SetUp();
 
-    StatusAreaWidget* status_area =
-        StatusAreaWidgetTestHelper::GetStatusAreaWidget();
-    virtual_keyboard_ = status_area->virtual_keyboard_tray_for_testing();
-    ime_menu_ = status_area->ime_menu_tray();
-    palette_ = status_area->palette_tray();
-    dictation_button_ = status_area->dictation_button_tray();
-    select_to_speak_ = status_area->select_to_speak_tray();
+    status_area_ = StatusAreaWidgetTestHelper::GetStatusAreaWidget();
+    overflow_button_ = status_area_->overflow_button_tray();
+    virtual_keyboard_ = status_area_->virtual_keyboard_tray_for_testing();
+    ime_menu_ = status_area_->ime_menu_tray();
+    palette_ = status_area_->palette_tray();
+    dictation_button_ = status_area_->dictation_button_tray();
+    select_to_speak_ = status_area_->select_to_speak_tray();
 
     virtual_keyboard_->SetVisiblePreferred(true);
     ime_menu_->SetVisiblePreferred(true);
@@ -381,8 +382,7 @@ class StatusAreaWidgetCollapseStateTest : public AshTestBase {
   }
 
   void SetCollapseState(StatusAreaWidget::CollapseState collapse_state) {
-    StatusAreaWidgetTestApi test_api(
-        StatusAreaWidgetTestHelper::GetStatusAreaWidget());
+    StatusAreaWidgetTestApi test_api(status_area_);
     test_api.SetCollapseState(collapse_state);
 
     virtual_keyboard_->UpdateAfterStatusAreaCollapseChange();
@@ -392,6 +392,8 @@ class StatusAreaWidgetCollapseStateTest : public AshTestBase {
     select_to_speak_->UpdateAfterStatusAreaCollapseChange();
   }
 
+  StatusAreaWidget* status_area_;
+  TrayBackgroundView* overflow_button_;
   TrayBackgroundView* virtual_keyboard_;
   TrayBackgroundView* ime_menu_;
   TrayBackgroundView* palette_;
@@ -444,4 +446,12 @@ TEST_F(StatusAreaWidgetCollapseStateTest, ImeMenuShownWithVirtualKeyboard) {
   EXPECT_FALSE(select_to_speak_->GetVisible());
 }
 
+TEST_F(StatusAreaWidgetCollapseStateTest, OverflowButtonShownWhenCollapsible) {
+  EXPECT_FALSE(overflow_button_->GetVisible());
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kAshForceStatusAreaCollapsible);
+  status_area_->UpdateCollapseState();
+  EXPECT_TRUE(overflow_button_->GetVisible());
+}
+
 }  // namespace ash

ash/system/tray/tray_background_view.cc

@@ -204,8 +204,13 @@ void TrayBackgroundView::InitializeBubbleAnimations(
 }
 
 void TrayBackgroundView::SetVisiblePreferred(bool visible_preferred) {
+  if (visible_preferred_ == visible_preferred)
+    return;
   visible_preferred_ = visible_preferred;
   SetVisible(GetEffectiveVisibility());
+
+  // We need to update which trays overflow after showing or hiding a tray.
+  shelf_->GetStatusAreaWidget()->UpdateCollapseState();
 }
 
 void TrayBackgroundView::SetVisible(bool visible) {