partial_split: Fix tablet menu layout error cases

This disables the 1/3 option and enables the 2/3 option on the
tablet menu partial button based on the window minimum size.

UX deck: https://www.figma.com/file/mqbkvuR7RNSPqUKyHWeqyg/Window-layout-menu-error-cases?node-id=0%3A1&t=46Q46fDKkFg5ou0c-0

TabletModeMultitaskMenuEventHandlerTest.WindowMinimumSizes

Test: ash_unittests
Bug: b/259414511
Change-Id: Ifac3beaee7ac2a99da4118d4c36cf2ec000ef5ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4160253
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Sophie Wen <sophiewen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1094604}

ash/frame/caption_buttons/frame_size_button_unittest.cc

@@ -804,7 +804,7 @@ TEST_F(MultitaskMenuTest, TestMultitaskMenuPartialSplit) {
   ShowMultitaskMenu();
   generator->MoveMouseTo(multitask_menu()
                              ->multitask_menu_view_for_testing()
-                             ->partial_button_for_testing()
+                             ->partial_button()
                              ->GetBoundsInScreen()
                              .left_center());
   generator->ClickLeftButton();
@@ -822,7 +822,7 @@ TEST_F(MultitaskMenuTest, TestMultitaskMenuPartialSplit) {
   ShowMultitaskMenu();
   gfx::Rect partial_bounds(multitask_menu()
                                ->multitask_menu_view_for_testing()
-                               ->partial_button_for_testing()
+                               ->partial_button()
                                ->GetBoundsInScreen());
   gfx::Point secondary_center(
       gfx::Point(partial_bounds.x() + partial_bounds.width() * 0.67f,

ash/wm/tablet_mode/tablet_mode_multitask_menu.cc

@@ -12,8 +12,11 @@
 #include "ash/wm/splitview/split_view_controller.h"
 #include "ash/wm/tablet_mode/tablet_mode_multitask_menu_event_handler.h"
 #include "ash/wm/window_state.h"
+#include "chromeos/ui/base/display_util.h"
 #include "chromeos/ui/frame/multitask_menu/multitask_menu_view.h"
+#include "chromeos/ui/frame/multitask_menu/split_button_view.h"
 #include "chromeos/ui/wm/window_util.h"
+#include "ui/aura/window_delegate.h"
 #include "ui/base/metadata/metadata_impl_macros.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_type.h"
@@ -71,17 +74,44 @@ class TabletModeMultitaskMenuView : public views::View {
     uint8_t buttons = chromeos::MultitaskMenuView::kFullscreen;
     if (SplitViewController::Get(window)->CanSnapWindow(window)) {
       buttons |= chromeos::MultitaskMenuView::kHalfSplit;
+    }
+
+    // TODO(sophiewen): Refactor from SplitViewController.
+    DCHECK(window->delegate());
+    const bool horizontal = chromeos::IsDisplayLayoutHorizontal(
+        display::Screen::GetScreen()->GetDisplayNearestWindow(window));
+    const gfx::Size min_size = window->delegate()->GetMinimumSize();
+    const int min_length = horizontal ? min_size.width() : min_size.height();
+    const gfx::Rect work_area = display::Screen::GetScreen()
+                                    ->GetDisplayNearestWindow(window)
+                                    .work_area();
+    const int work_area_length =
+        horizontal ? work_area.width() : work_area.height();
+    if (min_length <= work_area_length * chromeos::kTwoThirdSnapRatio) {
+      // If `min_length` <= 2/3, it can fit into 2/3 split, so ensure that
+      // we show the full partial button.
       buttons |= chromeos::MultitaskMenuView::kPartialSplit;
     }
+
     if (chromeos::wm::CanFloatWindow(window))
       buttons |= chromeos::MultitaskMenuView::kFloat;
 
-    menu_view_for_testing_ =
+    menu_view_base_ =
         AddChildView(std::make_unique<chromeos::MultitaskMenuView>(
             window, std::move(callback), buttons));
 
-    auto* layout = menu_view_for_testing_->SetLayoutManager(
-        std::make_unique<views::BoxLayout>(
+    if (menu_view_base_->partial_button() &&
+        min_length > work_area_length * chromeos::kOneThirdSnapRatio) {
+      // If `min_length` > 1/3, it can't fit into 1/3 split, so disable
+      // the 1/3 option in the partial button. Note that `GetRightBottomButton`
+      // must be disabled after `partial_button` is initialized to update the
+      // color in `SplitButton::OnPaintBackground()`.
+      menu_view_base_->partial_button()->GetRightBottomButton()->SetEnabled(
+          false);
+    }
+
+    auto* layout =
+        menu_view_base_->SetLayoutManager(std::make_unique<views::BoxLayout>(
             views::BoxLayout::Orientation::kHorizontal, kInsideBorderInsets,
             kBetweenButtonSpacing));
     layout->set_main_axis_alignment(
@@ -103,14 +133,12 @@ class TabletModeMultitaskMenuView : public views::View {
       delete;
   ~TabletModeMultitaskMenuView() override = default;
 
+  chromeos::MultitaskMenuView* menu_view_base() { return menu_view_base_; }
+
   SystemShadow* shadow() { return shadow_.get(); }
 
-  chromeos::MultitaskMenuView* menu_view_for_testing() {
-    return menu_view_for_testing_;
-  }
-
  private:
-  raw_ptr<chromeos::MultitaskMenuView> menu_view_for_testing_ = nullptr;
+  raw_ptr<chromeos::MultitaskMenuView> menu_view_base_ = nullptr;
 
   std::unique_ptr<SystemShadow> shadow_;
 };
@@ -303,7 +331,7 @@ void TabletModeMultitaskMenu::OnDisplayMetricsChanged(
 chromeos::MultitaskMenuView*
 TabletModeMultitaskMenu::GetMultitaskMenuViewForTesting() {
   return static_cast<TabletModeMultitaskMenuView*>(menu_view_)
-      ->menu_view_for_testing();  // IN-TEST
+      ->menu_view_base();  // IN-TEST
 }
 
 }  // namespace ash

ash/wm/tablet_mode/tablet_mode_multitask_menu_event_handler_unittest.cc

@@ -134,7 +134,7 @@ class TabletModeMultitaskMenuEventHandlerTest : public AshTestBase {
   void PressPartialPrimary(const aura::Window& window) {
     ShowMultitaskMenu(window);
     GetEventGenerator()->GestureTapAt(GetMultitaskMenuView(GetMultitaskMenu())
-                                          ->partial_button_for_testing()
+                                          ->partial_button()
                                           ->GetBoundsInScreen()
                                           .left_center());
   }
@@ -142,7 +142,7 @@ class TabletModeMultitaskMenuEventHandlerTest : public AshTestBase {
   void PressPartialSecondary(const aura::Window& window) {
     ShowMultitaskMenu(window);
     gfx::Rect partial_bounds(GetMultitaskMenuView(GetMultitaskMenu())
-                                 ->partial_button_for_testing()
+                                 ->partial_button()
                                  ->GetBoundsInScreen());
     gfx::Point secondary_center(
         gfx::Point(partial_bounds.x() + partial_bounds.width() * 0.67f,
@@ -248,7 +248,7 @@ TEST_F(TabletModeMultitaskMenuEventHandlerTest, BasicShowMenu) {
       GetMultitaskMenuView(multitask_menu);
   ASSERT_TRUE(multitask_menu_view);
   EXPECT_TRUE(multitask_menu_view->half_button_for_testing());
-  EXPECT_TRUE(multitask_menu_view->partial_button_for_testing());
+  EXPECT_TRUE(multitask_menu_view->partial_button());
   EXPECT_TRUE(multitask_menu_view->full_button_for_testing());
   EXPECT_TRUE(multitask_menu_view->float_button_for_testing());
 
@@ -561,6 +561,53 @@ TEST_F(TabletModeMultitaskMenuEventHandlerTest, AdjustedMenuBounds) {
             GetMultitaskMenu()->widget()->GetWindowBoundsInScreen().x());
 }
 
+// Tests that the split buttons are enabled/disabled based on min sizes.
+TEST_F(TabletModeMultitaskMenuEventHandlerTest, WindowMinimumSizes) {
+  UpdateDisplay("800x600");
+  aura::test::TestWindowDelegate delegate;
+  std::unique_ptr<aura::Window> window(CreateTestWindowInShellWithDelegate(
+      &delegate, /*id=*/-1, gfx::Rect(800, 600)));
+
+  const gfx::Rect work_area_bounds =
+      display::Screen::GetScreen()->GetPrimaryDisplay().work_area();
+
+  // Set the min width to 0.4 of the work area. Since 1/3 < minWidth <= 1/2,
+  // only the 1/3 option is disabled.
+  delegate.set_minimum_size(
+      gfx::Size(work_area_bounds.width() * 0.4f, work_area_bounds.height()));
+  ShowMultitaskMenu(*window);
+  chromeos::MultitaskMenuView* multitask_menu_view =
+      GetMultitaskMenuView(GetMultitaskMenu());
+  EXPECT_TRUE(multitask_menu_view->half_button_for_testing());
+  EXPECT_TRUE(multitask_menu_view->partial_button()->GetEnabled());
+  ASSERT_FALSE(multitask_menu_view->partial_button()
+                   ->GetRightBottomButton()
+                   ->GetEnabled());
+  GetMultitaskMenu()->Reset();
+
+  // Set the min width to 0.6 of the work area. Since 1/2 < minWidth <= 2/3, the
+  // half button is hidden and only the 2/3 option is enabled.
+  delegate.set_minimum_size(
+      gfx::Size(work_area_bounds.width() * 0.6f, work_area_bounds.height()));
+  ShowMultitaskMenu(*window);
+  multitask_menu_view = GetMultitaskMenuView(GetMultitaskMenu());
+  EXPECT_FALSE(multitask_menu_view->half_button_for_testing());
+  EXPECT_TRUE(multitask_menu_view->partial_button()->GetEnabled());
+  ASSERT_FALSE(multitask_menu_view->partial_button()
+                   ->GetRightBottomButton()
+                   ->GetEnabled());
+  GetMultitaskMenu()->Reset();
+
+  // Set the min width to 0.7 of the work area. Since minWidth > 2/3, both the
+  // split buttons are hidden.
+  delegate.set_minimum_size(
+      gfx::Size(work_area_bounds.width() * 0.7f, work_area_bounds.height()));
+  ShowMultitaskMenu(*window);
+  multitask_menu_view = GetMultitaskMenuView(GetMultitaskMenu());
+  EXPECT_FALSE(multitask_menu_view->half_button_for_testing());
+  EXPECT_FALSE(multitask_menu_view->partial_button());
+}
+
 // Tests that tap outside the menu will close the menu.
 TEST_F(TabletModeMultitaskMenuEventHandlerTest, CloseMultitaskMenuOnTap) {
   // Create a display and window that is bigger than the menu.
@@ -596,7 +643,7 @@ TEST_F(TabletModeMultitaskMenuEventHandlerTest, HiddenButtons) {
       GetMultitaskMenuView(multitask_menu);
   ASSERT_TRUE(multitask_menu_view);
   EXPECT_FALSE(multitask_menu_view->half_button_for_testing());
-  EXPECT_FALSE(multitask_menu_view->partial_button_for_testing());
+  EXPECT_FALSE(multitask_menu_view->partial_button());
   EXPECT_TRUE(multitask_menu_view->full_button_for_testing());
   EXPECT_FALSE(multitask_menu_view->float_button_for_testing());
 }

chromeos/ui/frame/multitask_menu/multitask_menu_view.cc

@@ -90,7 +90,7 @@ MultitaskMenuView::MultitaskMenuView(
         base::BindRepeating(&MultitaskMenuView::PartialButtonPressed,
                             base::Unretained(this)),
         window, is_portrait_mode);
-    partial_button_for_testing_ = partial_button.get();
+    partial_button_ = partial_button.get();
     AddChildView(CreateButtonContainer(std::move(partial_button),
                                        IDS_MULTITASK_MENU_PARTIAL_BUTTON_NAME));
   }

chromeos/ui/frame/multitask_menu/multitask_menu_view.h

@@ -47,9 +47,7 @@ class COMPONENT_EXPORT(CHROMEOS_UI_FRAME) MultitaskMenuView
   SplitButtonView* half_button_for_testing() {
     return half_button_for_testing_.get();
   }
-  SplitButtonView* partial_button_for_testing() {
-    return partial_button_for_testing_.get();
-  }
+  SplitButtonView* partial_button() { return partial_button_.get(); }
   MultitaskButton* full_button_for_testing() {
     return full_button_for_testing_.get();
   }
@@ -66,7 +64,7 @@ class COMPONENT_EXPORT(CHROMEOS_UI_FRAME) MultitaskMenuView
 
   // Saved for testing purpose.
   raw_ptr<SplitButtonView> half_button_for_testing_ = nullptr;
-  raw_ptr<SplitButtonView> partial_button_for_testing_ = nullptr;
+  raw_ptr<SplitButtonView> partial_button_ = nullptr;
   raw_ptr<MultitaskButton> full_button_for_testing_ = nullptr;
   raw_ptr<MultitaskButton> float_button_for_testing_ = nullptr;
 

chromeos/ui/frame/multitask_menu/split_button_view.cc

@@ -81,7 +81,8 @@ class SplitButtonView::SplitButton : public views::Button {
   void OnPaintBackground(gfx::Canvas* canvas) override {
     cc::PaintFlags pattern_flags;
     pattern_flags.setAntiAlias(true);
-    pattern_flags.setColor(button_color_);
+    pattern_flags.setColor(GetEnabled() ? button_color_
+                                        : kMultitaskButtonDisabledColor);
     pattern_flags.setStyle(cc::PaintFlags::kFill_Style);
     gfx::Rect pattern_bounds = GetLocalBounds();
     pattern_bounds.Inset(insets_);
@@ -160,6 +161,10 @@ SplitButtonView::SplitButtonView(SplitButtonType type,
           : gfx::Size(right_bottom_width, kMultitaskHalfButtonHeight));
 }
 
+views::Button* SplitButtonView::GetRightBottomButton() {
+  return static_cast<views::Button*>(right_bottom_button_);
+}
+
 void SplitButtonView::OnButtonHoveredOrPressed() {
   border_color_ = kMultitaskButtonPrimaryHoverColor;
   fill_color_ = kMultitaskButtonViewHoverColor;

chromeos/ui/frame/multitask_menu/split_button_view.h

@@ -38,16 +38,18 @@ class SplitButtonView : public views::BoxLayoutView {
 
   ~SplitButtonView() override = default;
 
+  views::Button* GetRightBottomButton();
+
  private:
   class SplitButton;
 
+  // Called when either button is hovered or pressed. Updates button colors.
+  void OnButtonHoveredOrPressed();
+
   // views::View:
   void OnPaint(gfx::Canvas* canvas) override;
   void OnThemeChanged() override;
 
-  // Called when either button is hovered or pressed. Updates button colors.
-  void OnButtonHoveredOrPressed();
-
   // Pointers to the buttons that are owned by the views hierarchy. The names
   // refer to the physical location of the button, which do not change in RTL
   // languages.