text: // Copyright (c) 2012 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 "ash/wm/drag_window_resizer.h"
  
  #include "ash/display/mouse_cursor_event_filter.h"
  #include "ash/public/cpp/shelf_config.h"
  #include "ash/public/cpp/shell_window_ids.h"
  #include "ash/root_window_controller.h"
  #include "ash/shelf/shelf_layout_manager.h"
  #include "ash/shell.h"
  #include "ash/test/ash_test_base.h"
  #include "ash/wm/desks/desks_util.h"
  #include "ash/wm/drag_window_controller.h"
  #include "ash/wm/window_positioning_utils.h"
  #include "ash/wm/window_util.h"
  #include "base/strings/string_number_conversions.h"
  #include "base/strings/stringprintf.h"
  #include "third_party/abseil-cpp/absl/types/optional.h"
  #include "ui/aura/client/aura_constants.h"
  #include "ui/aura/env.h"
  #include "ui/aura/test/test_window_delegate.h"
  #include "ui/aura/window.h"
  #include "ui/base/cursor/cursor.h"
  #include "ui/base/hit_test.h"
  #include "ui/base/ui_base_types.h"
  #include "ui/compositor/layer.h"
  #include "ui/compositor/layer_delegate.h"
  #include "ui/compositor/layer_tree_owner.h"
  #include "ui/compositor_extra/shadow.h"
  #include "ui/display/display_layout.h"
  #include "ui/display/display_layout_builder.h"
  #include "ui/display/manager/display_manager.h"
  #include "ui/gfx/geometry/insets.h"
  #include "ui/views/widget/widget.h"
  #include "ui/wm/core/cursor_manager.h"
  #include "ui/wm/core/window_util.h"
  
  namespace ash {
  namespace {
  
  const int kRootHeight = 600;
  
  // Used to test if the OnPaintLayer is called by DragWindowLayerDelegate.
  class TestLayerDelegate : public ui::LayerDelegate {
   public:
    TestLayerDelegate() = default;
  
    TestLayerDelegate(const TestLayerDelegate&) = delete;
    TestLayerDelegate& operator=(const TestLayerDelegate&) = delete;
  
    ~TestLayerDelegate() override = default;
  
    int paint_count() const { return paint_count_; }
  
   private:
    // Paint content for the layer to the specified context.
    void OnPaintLayer(const ui::PaintContext& context) override {
      paint_count_++;
    }
    void OnDeviceScaleFactorChanged(float old_device_scale_factor,
                                    float new_device_scale_factor) override {}
  
    int paint_count_ = 0;
  };
  
  }  // namespace
  
  class DragWindowResizerTest : public AshTestBase {
   public:
    DragWindowResizerTest() : transient_child_(nullptr) {}
  
    DragWindowResizerTest(const DragWindowResizerTest&) = delete;
    DragWindowResizerTest& operator=(const DragWindowResizerTest&) = delete;
  
    ~DragWindowResizerTest() override = default;
  
    void SetUp() override {
      AshTestBase::SetUp();
  
      UpdateDisplay(base::StringPrintf("800x%d", kRootHeight));
  
      aura::Window* root = Shell::GetPrimaryRootWindow();
      gfx::Rect root_bounds(root->bounds());
      EXPECT_EQ(kRootHeight, root_bounds.height());
      EXPECT_EQ(800, root_bounds.width());
      window_ = std::make_unique<aura::Window>(&delegate_);
      window_->SetType(aura::client::WINDOW_TYPE_NORMAL);
      window_->Init(ui::LAYER_NOT_DRAWN);
      ParentWindowInPrimaryRootWindow(window_.get());
      window_->SetId(1);
  
      always_on_top_window_ = std::make_unique<aura::Window>(&delegate2_);
      always_on_top_window_->SetType(aura::client::WINDOW_TYPE_NORMAL);
      always_on_top_window_->SetProperty(aura::client::kZOrderingKey,
                                         ui::ZOrderLevel::kFloatingWindow);
      always_on_top_window_->Init(ui::LAYER_NOT_DRAWN);
      ParentWindowInPrimaryRootWindow(always_on_top_window_.get());
      always_on_top_window_->SetId(2);
  
      system_modal_window_ = std::make_unique<aura::Window>(&delegate3_);
      system_modal_window_->SetType(aura::client::WINDOW_TYPE_NORMAL);
      system_modal_window_->SetProperty(aura::client::kModalKey,
                                        ui::MODAL_TYPE_SYSTEM);
      system_modal_window_->Init(ui::LAYER_NOT_DRAWN);
      ParentWindowInPrimaryRootWindow(system_modal_window_.get());
      system_modal_window_->SetId(3);
  
      transient_child_ = new aura::Window(&delegate4_);
      transient_child_->SetType(aura::client::WINDOW_TYPE_NORMAL);
      transient_child_->Init(ui::LAYER_NOT_DRAWN);
      ParentWindowInPrimaryRootWindow(transient_child_);
      transient_child_->SetId(4);
  
      transient_parent_ = std::make_unique<aura::Window>(&delegate5_);
      transient_parent_->SetType(aura::client::WINDOW_TYPE_NORMAL);
      transient_parent_->Init(ui::LAYER_NOT_DRAWN);
      ParentWindowInPrimaryRootWindow(transient_parent_.get());
      ::wm::AddTransientChild(transient_parent_.get(), transient_child_);
      transient_parent_->SetId(5);
    }
  
    void TearDown() override {
      window_.reset();
      always_on_top_window_.reset();
      system_modal_window_.reset();
      transient_parent_.reset();
      AshTestBase::TearDown();
    }
  
   protected:
    gfx::PointF CalculateDragPoint(const WindowResizer& resizer,
                                   int delta_x,
                                   int delta_y) const {
      gfx::PointF location = resizer.GetInitialLocation();
      location.set_x(location.x() + delta_x);
      location.set_y(location.y() + delta_y);
      return location;
    }
  
    ShelfLayoutManager* shelf_layout_manager() {
      return Shell::GetPrimaryRootWindowController()->GetShelfLayoutManager();
    }
  
    static WindowResizer* CreateDragWindowResizer(
        aura::Window* window,
        const gfx::Point& point_in_parent,
        int window_component) {
      return CreateWindowResizer(window, gfx::PointF(point_in_parent),
                                 window_component, ::wm::WINDOW_MOVE_SOURCE_MOUSE)
          .release();
    }
  
    bool TestIfMouseWarpsAt(const gfx::Point& point_in_screen) {
      return AshTestBase::TestIfMouseWarpsAt(GetEventGenerator(),
                                             point_in_screen);
    }
  
    aura::test::TestWindowDelegate delegate_;
    aura::test::TestWindowDelegate delegate2_;
    aura::test::TestWindowDelegate delegate3_;
    aura::test::TestWindowDelegate delegate4_;
    aura::test::TestWindowDelegate delegate5_;
    aura::test::TestWindowDelegate delegate6_;
  
    std::unique_ptr<aura::Window> window_;
    std::unique_ptr<aura::Window> always_on_top_window_;
    std::unique_ptr<aura::Window> system_modal_window_;
    aura::Window* transient_child_;
    std::unique_ptr<aura::Window> transient_parent_;
  };
  
  // Verifies a window can be moved from the primary display to another.
  TEST_F(DragWindowResizerTest, WindowDragWithMultiDisplays) {
    // Prevent snapping |window_|. We will drag within 25px of a display edge, for
    // the purpose of testing that a minimum visibility of 25px is enforced. When
    // a drag ends at that distance (or up to 32px) from a left or right display
    // edge, the dragged window is snapped. As that would only distract from the
    // purposes of the test, we avoid it by making |window_| unsnappable.
    // TODO: Remove this code after adding functionality where the mouse has to
    // dwell in the snap region before the dragged window can get snapped.
    window_->SetProperty(aura::client::kResizeBehaviorKey,
                         aura::client::kResizeBehaviorNone);
    ASSERT_FALSE(WindowState::Get(window_.get())->CanSnap());
  
    // The secondary display is logically on the right, but on the system (e.g. X)
    // layer, it's below the primary one. See UpdateDisplay() in ash_test_base.cc.
    UpdateDisplay("800x600,400x300");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
    ASSERT_EQ(2U, root_windows.size());
  
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    {
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      // Drag the pointer to the right. Once it reaches the right edge of the
      // primary display, it warps to the secondary.
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      Shell::Get()->cursor_manager()->SetDisplay(
          display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]));
      resizer->Drag(CalculateDragPoint(*resizer, 800, 10), 0);
      resizer->CompleteDrag();
      // The whole window is on the secondary display now. The parent should be
      // changed.
      EXPECT_EQ(root_windows[1], window_->GetRootWindow());
      EXPECT_EQ("0,10 50x60", window_->bounds().ToString());
    }
  
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    {
      // Grab (0, 0) of the window and move the pointer to (795, 10).
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      Shell::Get()->cursor_manager()->SetDisplay(
          display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[0]));
      resizer->Drag(CalculateDragPoint(*resizer, 795, 10), 0);
      // Window should be adjusted for minimum visibility (25px) during the drag.
      EXPECT_EQ("775,10 50x60", window_->bounds().ToString());
      resizer->CompleteDrag();
      // Since the pointer is still on the primary root window, the parent should
      // not be changed.
      // Window origin should be adjusted for minimum visibility (25px).
      EXPECT_EQ(root_windows[0], window_->GetRootWindow());
      EXPECT_EQ("775,10 50x60", window_->bounds().ToString());
    }
  
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    {
      // Grab the top-right edge of the window and move the pointer to (0, 10)
      // in the secondary root window's coordinates.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(49, 0), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      Shell::Get()->cursor_manager()->SetDisplay(
          display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]));
      resizer->Drag(CalculateDragPoint(*resizer, 751, 10), ui::EF_CONTROL_DOWN);
      resizer->CompleteDrag();
      // Since the pointer is on the secondary, the parent should be changed
      // even though only small fraction of the window is within the secondary
      // root window's bounds.
      EXPECT_EQ(root_windows[1], window_->GetRootWindow());
      // Window origin should be adjusted for minimum visibility (25px).
      int expected_x = -50 + kMinimumOnScreenArea;
  
      EXPECT_EQ(base::NumberToString(expected_x) + ",10 50x60",
                window_->bounds().ToString());
    }
    // Dropping a window that is larger than the destination work area
    // will shrink to fit to the work area.
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 700, 500),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    const int shelf_inset = 300 - ShelfConfig::Get()->shelf_size();
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    {
      // Grab the top-right edge of the window and move the pointer to (0, 10)
      // in the secondary root window's coordinates.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(699, 0), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 101, 10), ui::EF_CONTROL_DOWN);
      resizer->CompleteDrag();
      EXPECT_EQ(root_windows[1], window_->GetRootWindow());
      // Window size should be adjusted to fit to the work area
      EXPECT_EQ(gfx::Size(400, shelf_inset).ToString(),
                window_->bounds().size().ToString());
      gfx::Rect window_bounds_in_screen = window_->GetBoundsInScreen();
      gfx::Rect intersect(window_->GetRootWindow()->GetBoundsInScreen());
      intersect.Intersect(window_bounds_in_screen);
  
      EXPECT_LE(10, intersect.width());
      EXPECT_LE(10, intersect.height());
      EXPECT_TRUE(window_bounds_in_screen.Contains(gfx::Point(800, 10)));
    }
  
    // Dropping a window that is larger than the destination work area
    // will shrink to fit to the work area.
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 700, 500),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    {
      // Grab the top-left edge of the window and move the pointer to (150, 10)
      // in the secondary root window's coordinates. Make sure the window is
      // shrink in such a way that it keeps the cursor within.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(0, 0), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 799, 10), ui::EF_CONTROL_DOWN);
      resizer->Drag(CalculateDragPoint(*resizer, 850, 10), ui::EF_CONTROL_DOWN);
      resizer->CompleteDrag();
      EXPECT_EQ(root_windows[1], window_->GetRootWindow());
      // Window size should be adjusted to fit to the work area
      EXPECT_EQ(gfx::Size(400, shelf_inset).ToString(),
                window_->bounds().size().ToString());
      gfx::Rect window_bounds_in_screen = window_->GetBoundsInScreen();
      gfx::Rect intersect(window_->GetRootWindow()->GetBoundsInScreen());
      intersect.Intersect(window_bounds_in_screen);
      EXPECT_LE(10, intersect.width());
      EXPECT_LE(10, intersect.height());
      EXPECT_TRUE(window_bounds_in_screen.Contains(gfx::Point(850, 10)));
    }
  }
  
  // Verifies that dragging the active window to another display makes the new
  // root window the active root window.
  TEST_F(DragWindowResizerTest, WindowDragWithMultiDisplaysActiveRoot) {
    // The secondary display is logically on the right, but on the system (e.g. X)
    // layer, it's below the primary one. See UpdateDisplay() in ash_test_base.cc.
    UpdateDisplay("800x600,800x600");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
    ASSERT_EQ(2U, root_windows.size());
  
    aura::test::TestWindowDelegate delegate;
    std::unique_ptr<aura::Window> window =
        std::make_unique<aura::Window>(&delegate);
    window->SetType(aura::client::WINDOW_TYPE_NORMAL);
    window->Init(ui::LAYER_TEXTURED);
    ParentWindowInPrimaryRootWindow(window.get());
    window->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                              display::Screen::GetScreen()->GetPrimaryDisplay());
    window->Show();
    EXPECT_TRUE(wm::CanActivateWindow(window.get()));
    wm::ActivateWindow(window.get());
    EXPECT_EQ(root_windows[0], window->GetRootWindow());
    EXPECT_EQ(root_windows[0], Shell::GetRootWindowForNewWindows());
    {
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window.get(), gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      // Drag the pointer to the right. Once it reaches the right edge of the
      // primary display, it warps to the secondary.
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      Shell::Get()->cursor_manager()->SetDisplay(
          display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]));
      resizer->Drag(CalculateDragPoint(*resizer, 800, 10), 0);
      resizer->CompleteDrag();
      // The whole window is on the secondary display now. The parent should be
      // changed.
      EXPECT_EQ(root_windows[1], window->GetRootWindow());
      EXPECT_EQ(root_windows[1], Shell::GetRootWindowForNewWindows());
    }
  }
  
  // Verifies a window can be moved from the secondary display to primary.
  TEST_F(DragWindowResizerTest, WindowDragWithMultiDisplaysRightToLeft) {
    // See comment on similar code at beginning of |WindowDragWithMultiDisplays|.
    // TODO: Same TODO as with that other comment.
    window_->SetProperty(aura::client::kResizeBehaviorKey,
                         aura::client::kResizeBehaviorNone);
    ASSERT_FALSE(WindowState::Get(window_.get())->CanSnap());
  
    UpdateDisplay("800x600,800x600");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
    ASSERT_EQ(2U, root_windows.size());
  
    window_->SetBoundsInScreen(
        gfx::Rect(800, 00, 50, 60),
        display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]));
    EXPECT_EQ(root_windows[1], window_->GetRootWindow());
    {
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      // Move the mouse near the right edge, (798, 0), of the primary display.
      resizer->Drag(CalculateDragPoint(*resizer, -2, 0), ui::EF_CONTROL_DOWN);
      resizer->CompleteDrag();
      EXPECT_EQ(root_windows[0], window_->GetRootWindow());
      // Window origin should be adjusted for minimum visibility (25px).
      EXPECT_EQ("775,0 50x60", window_->bounds().ToString());
    }
  }
  
  // Verifies the drag window is shown correctly.
  TEST_F(DragWindowResizerTest, DragWindowController) {
    UpdateDisplay("800x600,800x600");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
    ASSERT_EQ(2U, root_windows.size());
  
    TestLayerDelegate delegate;
    window_->layer()->set_delegate(&delegate);
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
    {
      // Hold the center of the window so that the window doesn't stick to the
      // edge when dragging around the edge of the display.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(25, 30), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      DragWindowResizer* drag_resizer = DragWindowResizer::instance_;
      ASSERT_TRUE(drag_resizer);
      EXPECT_FALSE(drag_resizer->drag_window_controller_.get());
  
      // The pointer is inside the primary root. The drag window controller
      // should be NULL.
      ASSERT_EQ(display::Screen::GetScreen()
                    ->GetDisplayNearestWindow(root_windows[0])
                    .id(),
                Shell::Get()->cursor_manager()->GetDisplay().id());
      resizer->Drag(CalculateDragPoint(*resizer, 10, 10), 0);
      DragWindowController* controller =
          drag_resizer->drag_window_controller_.get();
      EXPECT_EQ(0, controller->GetDragWindowsCountForTest());
  
      // The window spans both root windows.
      resizer->Drag(CalculateDragPoint(*resizer, 773, 10), 0);
      EXPECT_EQ(1, controller->GetDragWindowsCountForTest());
      const aura::Window* drag_window = controller->GetDragWindowForTest(0);
      ASSERT_TRUE(drag_window);
  
      const ui::Layer* drag_layer = drag_window->layer();
      ASSERT_TRUE(drag_layer);
      // Check if |resizer->layer_| is properly set to the drag widget.
      EXPECT_FALSE(drag_layer->children().empty());
  
      // The paint request on a drag window should reach the original delegate.
      controller->RequestLayerPaintForTest();
      EXPECT_EQ(1, delegate.paint_count());
  
      // Invalidating the delegate on the original layer should prevent
      // calling the OnPaintLayer on the original delegate from new delegate.
      window_->layer()->set_delegate(nullptr);
      controller->RequestLayerPaintForTest();
      EXPECT_EQ(1, delegate.paint_count());
  
      // |window_| should be opaque since the pointer is still on the primary
      // root window. The drag window should be semi-transparent.
      EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
      EXPECT_GT(1.0f, drag_layer->opacity());
  
      // Enter the pointer to the secondary display.
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      Shell::Get()->cursor_manager()->SetDisplay(
          display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]));
      resizer->Drag(CalculateDragPoint(*resizer, 775, 10), 0);
      EXPECT_EQ(1, controller->GetDragWindowsCountForTest());
      // |window_| should be transparent, and the drag window should be opaque.
      EXPECT_GT(1.0f, window_->layer()->opacity());
      EXPECT_FLOAT_EQ(1.0f, drag_layer->opacity());
  
      resizer->CompleteDrag();
      EXPECT_EQ(root_windows[1], window_->GetRootWindow());
      EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
    }
  
    // Do the same test with RevertDrag().
    window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60),
                               display::Screen::GetScreen()->GetPrimaryDisplay());
    EXPECT_EQ(root_windows[0], window_->GetRootWindow());
    EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
    {
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      DragWindowResizer* drag_resizer = DragWindowResizer::instance_;
      DragWindowController* controller =
          drag_resizer->drag_window_controller_.get();
      ASSERT_TRUE(drag_resizer);
      EXPECT_FALSE(controller);
  
      resizer->Drag(CalculateDragPoint(*resizer, 0, 610), 0);
      resizer->RevertDrag();
      EXPECT_EQ(root_windows[0], window_->GetRootWindow());
      EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
    }
  }
  
  TEST_F(DragWindowResizerTest, DragWindowControllerAcrossThreeDisplays) {
    UpdateDisplay("400x600,400x600,800x600");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
  
    // Layout so that all three displays touch each other.
    display::DisplayIdList list = display_manager()->GetCurrentDisplayIdList();
    ASSERT_EQ(3u, list.size());
    ASSERT_EQ(display::Screen::GetScreen()->GetPrimaryDisplay().id(), list[0]);
    display::DisplayLayoutBuilder builder(list[0]);
    builder.AddDisplayPlacement(list[1], list[0],
                                display::DisplayPlacement::RIGHT, 0);
    builder.AddDisplayPlacement(list[2], list[0],
                                display::DisplayPlacement::BOTTOM, 0);
    display_manager()->SetLayoutForCurrentDisplays(builder.Build());
    // Sanity check.
    ASSERT_EQ(gfx::Rect(0, 000, 400, 600),
              display_manager()->GetDisplayForId(list[0]).bounds());
    ASSERT_EQ(gfx::Rect(400, 0, 400, 600),
              display_manager()->GetDisplayForId(list[1]).bounds());
    ASSERT_EQ(gfx::Rect(0, 600, 800, 600),
              display_manager()->GetDisplayForId(list[2]).bounds());
  
    // Create a window on 2nd display.
    window_->SetBoundsInScreen(gfx::Rect(400, 0, 100, 100),
                               display_manager()->GetDisplayForId(list[1]));
    ASSERT_EQ(root_windows[1], window_->GetRootWindow());
  
    // Hold the center of the window so that the window doesn't stick to the edge
    // when dragging around the edge of the display.
    std::unique_ptr<WindowResizer> resizer(
        CreateDragWindowResizer(window_.get(), gfx::Point(50, 50), HTCAPTION));
    ASSERT_TRUE(resizer.get());
    DragWindowResizer* drag_resizer = DragWindowResizer::instance_;
    ASSERT_TRUE(drag_resizer);
    EXPECT_FALSE(drag_resizer->drag_window_controller_.get());
    // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
    // without having to call |CursorManager::SetDisplay|.
    Shell::Get()->cursor_manager()->SetDisplay(
        display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]));
    resizer->Drag(CalculateDragPoint(*resizer, -50, 0), 0);
    DragWindowController* controller =
        drag_resizer->drag_window_controller_.get();
    ASSERT_TRUE(controller);
    ASSERT_EQ(1, controller->GetDragWindowsCountForTest());
    const aura::Window* drag_window0 = controller->GetDragWindowForTest(0);
    ASSERT_TRUE(drag_window0);
    const ui::Layer* drag_layer0 = drag_window0->layer();
    EXPECT_EQ(root_windows[0], drag_window0->GetRootWindow());
  
    // |window_| should be opaque since the pointer is still on the primary
    // root window. The drag window should be semi-transparent.
    EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
    EXPECT_GT(1.0f, drag_layer0->opacity());
  
    // The window spans across 3 displays, dragging to 3rd display.
    resizer->Drag(CalculateDragPoint(*resizer, -50, 549), 0);
    ASSERT_EQ(2, controller->GetDragWindowsCountForTest());
    drag_window0 = controller->GetDragWindowForTest(0);
    const aura::Window* drag_window1 = controller->GetDragWindowForTest(1);
    drag_layer0 = drag_window0->layer();
    const ui::Layer* drag_layer1 = drag_window1->layer();
    EXPECT_EQ(root_windows[0], drag_window0->GetRootWindow());
    EXPECT_EQ(root_windows[2], drag_window1->GetRootWindow());
  
    // |window_| should be opaque since the pointer is still on the 2nd
    // root window. The drag window should be semi-transparent.
    EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
    EXPECT_GT(1.0f, drag_layer0->opacity());
    EXPECT_GT(1.0f, drag_layer1->opacity());
  
    // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
    // without having to call |CursorManager::SetDisplay|.
    Shell::Get()->cursor_manager()->SetDisplay(
        display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[0]));
    resizer->Drag(CalculateDragPoint(*resizer, -51, 549), 0);
    ASSERT_EQ(2, controller->GetDragWindowsCountForTest());
    drag_window0 = controller->GetDragWindowForTest(0);
    drag_window1 = controller->GetDragWindowForTest(1);
    drag_layer0 = drag_window0->layer();
    drag_layer1 = drag_window1->layer();
    EXPECT_EQ(root_windows[0], drag_window0->GetRootWindow());
    EXPECT_EQ(root_windows[2], drag_window1->GetRootWindow());
  
    // |window_| should be transparent since the pointer is still on the primary
    // root window. The drag window should be semi-transparent.
    EXPECT_GT(1.0f, window_->layer()->opacity());
    EXPECT_FLOAT_EQ(1.0f, drag_layer0->opacity());
    EXPECT_GT(1.0f, drag_layer1->opacity());
  
    // Enter the pointer to the 3rd. Since it's bottom, the window snaps and
    // no drag windwos are created.
    // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
    // without having to call |CursorManager::SetDisplay|.
    Shell::Get()->cursor_manager()->SetDisplay(
        display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[2]));
    resizer->Drag(CalculateDragPoint(*resizer, -51, 551), 0);
    ASSERT_EQ(1, controller->GetDragWindowsCountForTest());
    drag_window0 = controller->GetDragWindowForTest(0);
    drag_layer0 = drag_window0->layer();
    EXPECT_EQ(root_windows[2], drag_window0->GetRootWindow());
  
    // |window_| should be transparent, and the drag window should be opaque.
    EXPECT_FLOAT_EQ(0.0f, window_->layer()->opacity());
    EXPECT_FLOAT_EQ(1.0f, drag_layer0->opacity());
  
    resizer->CompleteDrag();
    EXPECT_EQ(root_windows[2], window_->GetRootWindow());
    EXPECT_FLOAT_EQ(1.0f, window_->layer()->opacity());
  }
  
  TEST_F(DragWindowResizerTest, DragWindowControllerWithCustomShadowBounds) {
    UpdateDisplay("400x600,400x600,800x600");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
  
    // Layout so that all three displays touch each other.
    display::DisplayIdList list = display_manager()->GetCurrentDisplayIdList();
    ASSERT_EQ(3u, list.size());
    ASSERT_EQ(display::Screen::GetScreen()->GetPrimaryDisplay().id(), list[0]);
    display::DisplayLayoutBuilder builder(list[0]);
    builder.AddDisplayPlacement(list[1], list[0],
                                display::DisplayPlacement::RIGHT, 0);
    builder.AddDisplayPlacement(list[2], list[0],
                                display::DisplayPlacement::BOTTOM, 0);
    display_manager()->SetLayoutForCurrentDisplays(builder.Build());
    const display::Display& display0 =
        display_manager()->GetDisplayForId(list[0]);
    const display::Display& display1 =
        display_manager()->GetDisplayForId(list[1]);
    const display::Display& display2 =
        display_manager()->GetDisplayForId(list[2]);
    // Sanity check.
    ASSERT_EQ(gfx::Rect(0, 000, 400, 600), display0.bounds());
    ASSERT_EQ(gfx::Rect(400, 0, 400, 600), display1.bounds());
    ASSERT_EQ(gfx::Rect(0, 600, 800, 600), display2.bounds());
  
    const gfx::Rect shadow_bounds(10, 10, 200, 200);
    const auto update_controller_and_check_root_and_shadow =
        [&shadow_bounds](DragWindowController* controller,
                         aura::Window* root_window) {
          controller->Update();
          ASSERT_EQ(1, controller->GetDragWindowsCountForTest());
          EXPECT_EQ(root_window,
                    controller->GetDragWindowForTest(0)->GetRootWindow());
          const ui::Shadow* shadow = controller->GetDragWindowShadowForTest(0);
          ASSERT_TRUE(shadow);
          ASSERT_TRUE(shadow->layer());
          EXPECT_TRUE(shadow->layer()->visible());
          EXPECT_EQ(shadow_bounds, shadow->content_bounds());
        };
    // Test mouse dragging.
    {
      wm::CursorManager* cursor_manager = Shell::Get()->cursor_manager();
      // Start on |display1|.
      cursor_manager->SetDisplay(display1);
      window_->SetBoundsInScreen(gfx::Rect(420, 20, 100, 100), display1);
      DragWindowController controller(window_.get(), /*is_touch_dragging=*/false,
                                      absl::make_optional(shadow_bounds));
      // Move to |display0|.
      cursor_manager->SetDisplay(display0);
      window_->SetBoundsInScreen(gfx::Rect(20, 20, 100, 100), display0);
      update_controller_and_check_root_and_shadow(&controller, root_windows[0]);
      // Move to |display2|.
      cursor_manager->SetDisplay(display2);
      window_->SetBoundsInScreen(gfx::Rect(20, 620, 100, 100), display2);
      update_controller_and_check_root_and_shadow(&controller, root_windows[2]);
    }
    // Test touch dragging.
    {
      // Start on |display0|.
      window_->SetBoundsInScreen(gfx::Rect(20, 20, 100, 100), display0);
      DragWindowController controller(window_.get(), /*is_touch_dragging=*/true,
                                      absl::make_optional(shadow_bounds));
      // Move the window so some is visible on |display1|.
      window_->SetBoundsInScreen(gfx::Rect(380, 20, 100, 100), display0);
      update_controller_and_check_root_and_shadow(&controller, root_windows[1]);
      // Move the window so some is visible on |display2|.
      window_->SetBoundsInScreen(gfx::Rect(20, 580, 100, 100), display0);
      update_controller_and_check_root_and_shadow(&controller, root_windows[2]);
    }
  }
  
  // Verifies if the resizer sets and resets
  // MouseCursorEventFilter::mouse_warp_mode_ as expected.
  TEST_F(DragWindowResizerTest, WarpMousePointer) {
    MouseCursorEventFilter* event_filter = Shell::Get()->mouse_cursor_filter();
    ASSERT_TRUE(event_filter);
    window_->SetBounds(gfx::Rect(0, 0, 50, 60));
  
    EXPECT_TRUE(event_filter->mouse_warp_enabled_);
    {
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      // While dragging a window, warp should be allowed.
      EXPECT_TRUE(event_filter->mouse_warp_enabled_);
      resizer->CompleteDrag();
    }
    EXPECT_TRUE(event_filter->mouse_warp_enabled_);
  
    {
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      EXPECT_TRUE(event_filter->mouse_warp_enabled_);
      resizer->RevertDrag();
    }
    EXPECT_TRUE(event_filter->mouse_warp_enabled_);
  
    {
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTRIGHT));
      // While resizing a window, warp should NOT be allowed.
      EXPECT_FALSE(event_filter->mouse_warp_enabled_);
      resizer->CompleteDrag();
    }
    EXPECT_TRUE(event_filter->mouse_warp_enabled_);
  
    {
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTRIGHT));
      EXPECT_FALSE(event_filter->mouse_warp_enabled_);
      resizer->RevertDrag();
    }
    EXPECT_TRUE(event_filter->mouse_warp_enabled_);
  }
  
  // Verifies cursor's device scale factor is updated whe a window is moved across
  // root windows with different device scale factors (http://crbug.com/154183).
  TEST_F(DragWindowResizerTest, CursorDeviceScaleFactor) {
    // The secondary display is logically on the right, but on the system (e.g. X)
    // layer, it's below the primary one. See UpdateDisplay() in ash_test_base.cc.
    UpdateDisplay("600x400,1000x800*2");
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
    ASSERT_EQ(2U, root_windows.size());
    const display::Display display0 =
        display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[0]);
    const display::Display display1 =
        display::Screen::GetScreen()->GetDisplayNearestWindow(root_windows[1]);
  
    auto* cursor_manager = Shell::Get()->cursor_manager();
    // Move window from the root window with 1.0 device scale factor to the root
    // window with 2.0 device scale factor.
    {
      window_->SetBoundsInScreen(gfx::Rect(0, 0, 50, 60), display0);
      EXPECT_EQ(root_windows[0], window_->GetRootWindow());
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      EXPECT_EQ(1.0f, cursor_manager->GetCursor().image_scale_factor());
      ASSERT_TRUE(resizer.get());
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      cursor_manager->SetDisplay(display1);
      resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
      TestIfMouseWarpsAt(gfx::Point(399, 200));
      EXPECT_EQ(2.0f, cursor_manager->GetCursor().image_scale_factor());
      resizer->CompleteDrag();
      EXPECT_EQ(2.0f, cursor_manager->GetCursor().image_scale_factor());
    }
  
    // Move window from the root window with 2.0 device scale factor to the root
    // window with 1.0 device scale factor.
    {
      window_->SetBoundsInScreen(gfx::Rect(600, 0, 50, 60), display1);
      EXPECT_EQ(root_windows[1], window_->GetRootWindow());
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window_.get(), gfx::Point(), HTCAPTION));
      EXPECT_EQ(2.0f, cursor_manager->GetCursor().image_scale_factor());
      ASSERT_TRUE(resizer.get());
      // TODO(crbug.com/990589): Unit tests should be able to simulate mouse input
      // without having to call |CursorManager::SetDisplay|.
      cursor_manager->SetDisplay(display0);
      resizer->Drag(CalculateDragPoint(*resizer, -200, 200), 0);
      TestIfMouseWarpsAt(gfx::Point(400, 200));
      EXPECT_EQ(1.0f, cursor_manager->GetCursor().image_scale_factor());
      resizer->CompleteDrag();
      EXPECT_EQ(1.0f, cursor_manager->GetCursor().image_scale_factor());
    }
  }
  
  // Verifies several kinds of windows can be moved across displays.
  TEST_F(DragWindowResizerTest, MoveWindowAcrossDisplays) {
    // The secondary display is logically on the right, but on the system (e.g. X)
    // layer, it's below the primary one. See UpdateDisplay() in ash_test_base.cc.
    UpdateDisplay("400x300,400x300");
  
    aura::Window::Windows root_windows = Shell::GetAllRootWindows();
    ASSERT_EQ(2U, root_windows.size());
  
    // Normal window can be moved across display.
    {
      aura::Window* window = window_.get();
      window->SetBoundsInScreen(
          gfx::Rect(0, 0, 50, 60),
          display::Screen::GetScreen()->GetPrimaryDisplay());
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window, gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
      EXPECT_TRUE(TestIfMouseWarpsAt(gfx::Point(399, 200)));
      EXPECT_EQ("401,200",
                aura::Env::GetInstance()->last_mouse_location().ToString());
      resizer->CompleteDrag();
    }
  
    // Always on top window can be moved across display.
    {
      aura::Window* window = always_on_top_window_.get();
      window->SetBoundsInScreen(
          gfx::Rect(0, 0, 50, 60),
          display::Screen::GetScreen()->GetPrimaryDisplay());
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window, gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
      EXPECT_TRUE(TestIfMouseWarpsAt(gfx::Point(399, 200)));
      EXPECT_EQ("401,200",
                aura::Env::GetInstance()->last_mouse_location().ToString());
      resizer->CompleteDrag();
    }
  
    // System modal window can be moved across display.
    {
      aura::Window* window = system_modal_window_.get();
      window->SetBoundsInScreen(
          gfx::Rect(0, 0, 50, 60),
          display::Screen::GetScreen()->GetPrimaryDisplay());
      aura::Env::GetInstance()->SetLastMouseLocation(gfx::Point(0, 0));
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window, gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
      EXPECT_TRUE(TestIfMouseWarpsAt(gfx::Point(399, 200)));
      EXPECT_EQ("401,200",
                aura::Env::GetInstance()->last_mouse_location().ToString());
      resizer->CompleteDrag();
    }
  
    // Transient window cannot be moved across display.
    {
      aura::Window* window = transient_child_;
      window->SetBoundsInScreen(
          gfx::Rect(0, 0, 50, 60),
          display::Screen::GetScreen()->GetPrimaryDisplay());
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window, gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
      EXPECT_FALSE(TestIfMouseWarpsAt(gfx::Point(399, 200)));
      EXPECT_EQ("399,200",
                aura::Env::GetInstance()->last_mouse_location().ToString());
      resizer->CompleteDrag();
    }
  
    // The parent of transient window can be moved across display.
    {
      aura::Window* window = transient_parent_.get();
      window->SetBoundsInScreen(
          gfx::Rect(0, 0, 50, 60),
          display::Screen::GetScreen()->GetPrimaryDisplay());
      // Grab (0, 0) of the window.
      std::unique_ptr<WindowResizer> resizer(
          CreateDragWindowResizer(window, gfx::Point(), HTCAPTION));
      ASSERT_TRUE(resizer.get());
      resizer->Drag(CalculateDragPoint(*resizer, 399, 200), 0);
      EXPECT_TRUE(TestIfMouseWarpsAt(gfx::Point(399, 200)));
      EXPECT_EQ("401,200",
                aura::Env::GetInstance()->last_mouse_location().ToString());
      resizer->CompleteDrag();
    }
  }
  
  }  // namespace ash
  