shelf: Show shelf in overview even when auto hide is on.

Test: ash_unittests ShelfLayoutManagerTest.VisibleInOverview
Bug: 881153
Change-Id: I2b5b8122831b5c71bc4ee4fcf4360d7626e11f0b
Reviewed-on: https://chromium-review.googlesource.com/1211741
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589422}

ash/shelf/shelf_layout_manager.cc

@@ -272,6 +272,9 @@ void ShelfLayoutManager::UpdateVisibilityState() {
     SetState(SHELF_VISIBLE);
   } else if (Shell::Get()->screen_pinning_controller()->IsPinned()) {
     SetState(SHELF_HIDDEN);
+  } else if (Shell::Get()->window_selector_controller() &&
+             Shell::Get()->window_selector_controller()->IsSelecting()) {
+    SetState(SHELF_VISIBLE);
   } else {
     // TODO(zelidrag): Verify shelf drag animation still shows on the device
     // when we are in SHELF_AUTO_HIDE_ALWAYS_HIDDEN.
@@ -497,6 +500,16 @@ void ShelfLayoutManager::OnAppListVisibilityChanged(bool shown,
   MaybeUpdateShelfBackground(AnimationChangeType::IMMEDIATE);
 }
 
+void ShelfLayoutManager::OnOverviewModeStarting() {
+  UpdateVisibilityState();
+  MaybeUpdateShelfBackground(AnimationChangeType::ANIMATE);
+}
+
+void ShelfLayoutManager::OnOverviewModeEnded() {
+  UpdateVisibilityState();
+  MaybeUpdateShelfBackground(AnimationChangeType::ANIMATE);
+}
+
 void ShelfLayoutManager::OnSplitViewModeStarted() {
   MaybeUpdateShelfBackground(AnimationChangeType::ANIMATE);
 }
@@ -559,6 +572,11 @@ ShelfBackgroundType ShelfLayoutManager::GetShelfBackgroundType() const {
     return SHELF_BACKGROUND_OVERLAP;
   }
 
+  if (Shell::Get()->window_selector_controller() &&
+      Shell::Get()->window_selector_controller()->IsSelecting()) {
+    return SHELF_BACKGROUND_OVERLAP;
+  }
+
   // If split view mode is active, make the shelf fully opapue.
   if (Shell::Get()->IsSplitViewModeActive())
     return SHELF_BACKGROUND_SPLIT_VIEW;

ash/shelf/shelf_layout_manager.h

@@ -155,6 +155,8 @@ class ASH_EXPORT ShelfLayoutManager
   void OnPinnedStateChanged(aura::Window* pinned_window) override;
   void OnAppListVisibilityChanged(bool shown,
                                   aura::Window* root_window) override;
+  void OnOverviewModeStarting() override;
+  void OnOverviewModeEnded() override;
   void OnSplitViewModeStarted() override;
   void OnSplitViewModeEnded() override;
 

ash/shelf/shelf_layout_manager_unittest.cc

@@ -35,6 +35,7 @@
 #include "ash/wallpaper/wallpaper_controller.h"
 #include "ash/window_factory.h"
 #include "ash/wm/lock_state_controller.h"
+#include "ash/wm/overview/window_selector_controller.h"
 #include "ash/wm/splitview/split_view_controller.h"
 #include "ash/wm/tablet_mode/tablet_mode_controller.h"
 #include "ash/wm/window_state.h"
@@ -1006,6 +1007,36 @@ TEST_F(ShelfLayoutManagerTest, VisibleWhenLockScreenShowing) {
   EXPECT_EQ(SHELF_BACKGROUND_OVERLAP, GetShelfWidget()->GetBackgroundType());
 }
 
+// Tests that the shelf should be visible when in overview mode.
+TEST_F(ShelfLayoutManagerTest, VisibleInOverview) {
+  std::unique_ptr<aura::Window> window(CreateTestWindow());
+  window->Show();
+  Shelf* shelf = GetPrimaryShelf();
+  shelf->SetAutoHideBehavior(SHELF_AUTO_HIDE_BEHAVIOR_ALWAYS);
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_HIDDEN, shelf->GetAutoHideState());
+
+  // LayoutShelf() forces the animation to completion, at which point the
+  // shelf should go off the screen.
+  GetShelfLayoutManager()->LayoutShelf();
+  display::Display display = display::Screen::GetScreen()->GetPrimaryDisplay();
+  EXPECT_EQ(display.bounds().bottom() - kShelfAutoHideSize,
+            GetShelfWidget()->GetWindowBoundsInScreen().y());
+
+  WindowSelectorController* window_selector_controller =
+      Shell::Get()->window_selector_controller();
+  // Tests that the shelf is visible when in overview mode and its color is
+  // overlap.
+  window_selector_controller->ToggleOverview();
+  EXPECT_EQ(SHELF_VISIBLE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_BACKGROUND_OVERLAP, GetShelfWidget()->GetBackgroundType());
+
+  // Test that on exiting overview mode, the shelf returns to auto hide state.
+  window_selector_controller->ToggleOverview();
+  EXPECT_EQ(SHELF_AUTO_HIDE, shelf->GetVisibilityState());
+  EXPECT_EQ(SHELF_AUTO_HIDE_HIDDEN, shelf->GetAutoHideState());
+}
+
 // Assertions around SetAutoHideBehavior.
 TEST_F(ShelfLayoutManagerTest, SetAutoHideBehavior) {
   Shelf* shelf = GetPrimaryShelf();