overview: Keep no recent items centered.

Test: manual
Bug: 818373
Change-Id: I05efc0528fbee5d088947fc2893267d4a601ba93
Reviewed-on: https://chromium-review.googlesource.com/951633Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541860}

ash/wm/overview/window_grid.cc

@@ -173,21 +173,28 @@ class WindowGrid::ShieldView : public views::View {
     label_container_->SetVisible(visible);
   }
 
-  bool IsLabelVisible() const { return label_container_->visible(); }
-
- protected:
-  // views::View:
-  void Layout() override {
-    background_view_->SetBoundsRect(GetLocalBounds());
+  gfx::Rect GetLabelBounds() const {
+    return label_container_->GetBoundsInScreen();
+  }
 
+  // ShieldView takes up the whole workspace since it changes opacity of the
+  // whole wallpaper. The bounds of the grid may be smaller in some cases of
+  // splitview. The label should be centered in the bounds of the grid.
+  void SetGridBounds(const gfx::Rect& bounds) {
     const int label_width = label_->GetPreferredSize().width() +
                             2 * kNoItemsIndicatorHorizontalPaddingDp;
-    gfx::Rect label_container_bounds = GetLocalBounds();
+    gfx::Rect label_container_bounds = bounds;
     label_container_bounds.ClampToCenteredSize(
         gfx::Size(label_width, kNoItemsIndicatorHeightDp));
     label_container_->SetBoundsRect(label_container_bounds);
   }
 
+  bool IsLabelVisible() const { return label_container_->visible(); }
+
+ protected:
+  // views::View:
+  void Layout() override { background_view_->SetBoundsRect(GetLocalBounds()); }
+
  private:
   // Owned by views heirarchy.
   views::View* background_view_ = nullptr;
@@ -509,6 +516,8 @@ void WindowGrid::AddItem(aura::Window* window) {
   window_list_.push_back(
       std::make_unique<WindowSelectorItem>(window, window_selector_, this));
   window_list_.back()->PrepareForOverview();
+  if (shield_view_)
+    shield_view_->SetLabelVisibility(false);
 
   PositionWindows(/*animate=*/true);
 }
@@ -524,6 +533,8 @@ void WindowGrid::RemoveItem(WindowSelectorItem* selector_item) {
     window_state_observer_.Remove(
         wm::GetWindowState(selector_item->GetWindow()));
     window_list_.erase(iter);
+    if (shield_view_)
+      shield_view_->SetLabelVisibility(empty());
   }
 }
 
@@ -555,6 +566,8 @@ void WindowGrid::WindowClosing(WindowSelectorItem* window) {
 
 void WindowGrid::SetBoundsAndUpdatePositions(const gfx::Rect& bounds) {
   bounds_ = bounds;
+  if (shield_view_)
+    shield_view_->SetGridBounds(bounds_);
   PositionWindows(/*animate=*/true);
 }
 
@@ -562,6 +575,8 @@ void WindowGrid::SetBoundsAndUpdatePositionsIgnoringWindow(
     const gfx::Rect& bounds,
     WindowSelectorItem* ignored_item) {
   bounds_ = bounds;
+  if (shield_view_)
+    shield_view_->SetGridBounds(bounds_);
   PositionWindows(/*animate=*/true, ignored_item);
 }
 
@@ -672,6 +687,13 @@ bool WindowGrid::IsNoItemsIndicatorLabelVisibleForTesting() {
   return shield_view_ && shield_view_->IsLabelVisible();
 }
 
+gfx::Rect WindowGrid::GetNoItemsIndicatorLabelBoundsForTesting() const {
+  if (!shield_view_)
+    return gfx::Rect();
+
+  return shield_view_->GetLabelBounds();
+}
+
 void WindowGrid::SetWindowListAnimationStates(
     WindowSelectorItem* selected_item,
     WindowSelector::OverviewTransition transition) {
@@ -771,6 +793,7 @@ void WindowGrid::InitShieldWidget() {
     shield_view_ = new ShieldView();
     shield_view_->SetBackgroundColor(shield_color);
     shield_view_->SetLabelVisibility(empty());
+    shield_view_->SetGridBounds(bounds_);
     shield_widget_->SetContentsView(shield_view_);
     shield_widget_->SetOpacity(initial_opacity);
   }

ash/wm/overview/window_grid.h

@@ -162,6 +162,8 @@ class ASH_EXPORT WindowGrid : public aura::WindowObserver,
 
   bool IsNoItemsIndicatorLabelVisibleForTesting();
 
+  gfx::Rect GetNoItemsIndicatorLabelBoundsForTesting() const;
+
   WindowSelector* window_selector() { return window_selector_; }
 
   void set_window_animation_observer(

ash/wm/overview/window_selector_unittest.cc

@@ -19,6 +19,7 @@
 #include "ash/public/cpp/window_properties.h"
 #include "ash/screen_util.h"
 #include "ash/shelf/shelf.h"
+#include "ash/shelf/shelf_constants.h"
 #include "ash/shelf/shelf_view_test_api.h"
 #include "ash/shell.h"
 #include "ash/shell_test_api.h"
@@ -2060,6 +2061,53 @@ TEST_F(WindowSelectorTest, OverviewNoWindowsIndicator) {
                   ->IsNoItemsIndicatorLabelVisibleForTesting());
 }
 
+// Verify that the overview no windows indicator position is as expected.
+TEST_F(WindowSelectorTest, OverviewNoWindowsIndicatorPosition) {
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kAshEnableNewOverviewUi);
+
+  UpdateDisplay("400x300");
+  // Midpoint of height minus shelf.
+  const int expected_y = (300 - kShelfSize) / 2;
+
+  // Helper to check points. Uses EXPECT_NEAR on each coordinate to account for
+  // rounding.
+  auto check_point = [](const gfx::Point& expected, const gfx::Point& actual) {
+    EXPECT_NEAR(expected.x(), actual.x(), 1);
+    EXPECT_NEAR(expected.y(), actual.y(), 1);
+  };
+
+  ToggleOverview();
+  ASSERT_TRUE(window_selector());
+
+  // Verify that originally the label is in the center of the workspace.
+  WindowGrid* grid = window_selector()->grid_list_for_testing()[0].get();
+  check_point(gfx::Point(200, expected_y),
+              grid->GetNoItemsIndicatorLabelBoundsForTesting().CenterPoint());
+
+  // Verify that when grid bounds are on the left, the label is centered on the
+  // left side of the workspace.
+  grid->SetBoundsAndUpdatePositions(gfx::Rect(0, 0, 200, 300 - kShelfSize));
+  check_point(gfx::Point(100, expected_y),
+              grid->GetNoItemsIndicatorLabelBoundsForTesting().CenterPoint());
+
+  // Verify that when grid bounds are on the right, the label is centered on the
+  // right side of the workspace.
+  grid->SetBoundsAndUpdatePositions(gfx::Rect(200, 0, 200, 300 - kShelfSize));
+  check_point(gfx::Point(300, expected_y),
+              grid->GetNoItemsIndicatorLabelBoundsForTesting().CenterPoint());
+
+  // Verify that after rotating the display, the label is centered in the
+  // workspace 300x(400-shelf).
+  display::Screen* screen = display::Screen::GetScreen();
+  const display::Display& display = screen->GetPrimaryDisplay();
+  display_manager()->SetDisplayRotation(
+      display.id(), display::Display::ROTATE_90,
+      display::Display::RotationSource::ACTIVE);
+  check_point(gfx::Point(150, (400 - kShelfSize) / 2),
+              grid->GetNoItemsIndicatorLabelBoundsForTesting().CenterPoint());
+}
+
 // Verify that when opening overview mode with multiple displays, the no items
 // indicator appears on the grid(s) if it has no windows.
 TEST_F(WindowSelectorTest, OverviewNoWindowsIndicatorMultiDisplay) {