path: root/chromium/ui/views/controls/menu/menu_scroll_view_container.cc

// 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 "ui/views/controls/menu/menu_scroll_view_container.h"

#include <algorithm>
#include <memory>

#include "base/macros.h"
#include "build/build_config.h"
#include "cc/paint/paint_flags.h"
#include "third_party/skia/include/core/SkPath.h"
#include "ui/accessibility/ax_enums.mojom.h"
#include "ui/accessibility/ax_node_data.h"
#include "ui/base/dragdrop/drag_drop_types.h"
#include "ui/base/dragdrop/mojom/drag_drop_types.mojom.h"
#include "ui/base/metadata/metadata_header_macros.h"
#include "ui/base/metadata/metadata_impl_macros.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/color_palette.h"
#include "ui/views/border.h"
#include "ui/views/bubble/bubble_border.h"
#include "ui/views/controls/menu/menu_config.h"
#include "ui/views/controls/menu/menu_controller.h"
#include "ui/views/controls/menu/menu_item_view.h"
#include "ui/views/controls/menu/submenu_view.h"
#include "ui/views/layout/flex_layout.h"
#include "ui/views/round_rect_painter.h"
#include "ui/views/view.h"
#include "ui/views/view_class_properties.h"

using ui::NativeTheme;

namespace views {

namespace {

static constexpr int kBorderPaddingDueToRoundedCorners = 1;

// MenuScrollButton ------------------------------------------------------------

// MenuScrollButton is used for the scroll buttons when not all menu items fit
// on screen. MenuScrollButton forwards appropriate events to the
// MenuController.

class MenuScrollButton : public View {
 public:
  METADATA_HEADER(MenuScrollButton);
  MenuScrollButton(SubmenuView* host, bool is_up)
      : host_(host),
        is_up_(is_up),
        // Make our height the same as that of other MenuItemViews.
        pref_height_(MenuItemView::pref_menu_height()) {}
  MenuScrollButton(const MenuScrollButton&) = delete;
  MenuScrollButton& operator=(const MenuScrollButton&) = delete;

  gfx::Size CalculatePreferredSize() const override {
    return gfx::Size(MenuConfig::instance().scroll_arrow_height * 2 - 1,
                     pref_height_);
  }

  void OnThemeChanged() override {
    View::OnThemeChanged();
    arrow_color_ = GetNativeTheme()->GetSystemColor(
        ui::NativeTheme::kColorId_EnabledMenuItemForegroundColor);
  }

  bool CanDrop(const OSExchangeData& data) override {
    DCHECK(host_->GetMenuItem()->GetMenuController());
    return true;  // Always return true so that drop events are targeted to us.
  }

  void OnDragEntered(const ui::DropTargetEvent& event) override {
    DCHECK(host_->GetMenuItem()->GetMenuController());
    host_->GetMenuItem()->GetMenuController()->OnDragEnteredScrollButton(
        host_, is_up_);
  }

  int OnDragUpdated(const ui::DropTargetEvent& event) override {
    return ui::DragDropTypes::DRAG_NONE;
  }

  void OnDragExited() override {
    DCHECK(host_->GetMenuItem()->GetMenuController());
    host_->GetMenuItem()->GetMenuController()->OnDragExitedScrollButton(host_);
  }

  ui::mojom::DragOperation OnPerformDrop(
      const ui::DropTargetEvent& event) override {
    return ui::mojom::DragOperation::kNone;
  }

  void OnPaint(gfx::Canvas* canvas) override {
    const MenuConfig& config = MenuConfig::instance();

    // The background.
    gfx::Rect item_bounds(0, 0, width(), height());
    NativeTheme::ExtraParams extra;
    GetNativeTheme()->Paint(canvas->sk_canvas(),
                            NativeTheme::kMenuItemBackground,
                            NativeTheme::kNormal, item_bounds, extra);

    // Then the arrow.
    int x = width() / 2;
    int y = (height() - config.scroll_arrow_height) / 2;

    int x_left = x - config.scroll_arrow_height;
    int x_right = x + config.scroll_arrow_height;
    int y_bottom;

    if (!is_up_) {
      y_bottom = y;
      y = y_bottom + config.scroll_arrow_height;
    } else {
      y_bottom = y + config.scroll_arrow_height;
    }
    SkPath path;
    path.setFillType(SkPathFillType::kWinding);
    path.moveTo(SkIntToScalar(x), SkIntToScalar(y));
    path.lineTo(SkIntToScalar(x_left), SkIntToScalar(y_bottom));
    path.lineTo(SkIntToScalar(x_right), SkIntToScalar(y_bottom));
    path.lineTo(SkIntToScalar(x), SkIntToScalar(y));
    cc::PaintFlags flags;
    flags.setStyle(cc::PaintFlags::kFill_Style);
    flags.setAntiAlias(true);
    flags.setColor(arrow_color_);
    canvas->DrawPath(path, flags);
  }

 private:
  // SubmenuView we were created for.
  SubmenuView* host_;

  // Direction of the button.
  bool is_up_;

  // Preferred height.
  int pref_height_;

  // Color for the arrow to scroll.
  SkColor arrow_color_;
};

BEGIN_METADATA(MenuScrollButton, View)
END_METADATA

}  // namespace

// MenuScrollView --------------------------------------------------------------

// MenuScrollView is a viewport for the SubmenuView. It's reason to exist is so
// that ScrollRectToVisible works.
//
// NOTE: It is possible to use ScrollView directly (after making it deal with
// null scrollbars), but clicking on a child of ScrollView forces the window to
// become active, which we don't want. As we really only need a fraction of
// what ScrollView does, so we use a one off variant.

class MenuScrollViewContainer::MenuScrollView : public View {
 public:
  METADATA_HEADER(MenuScrollView);
  MenuScrollView(View* child, MenuScrollViewContainer* owner) : owner_(owner) {
    AddChildView(child);
  }
  MenuScrollView(const MenuScrollView&) = delete;
  MenuScrollView& operator=(const MenuScrollView&) = delete;

  void ScrollRectToVisible(const gfx::Rect& rect) override {
    // NOTE: this assumes we only want to scroll in the y direction.

    // If the rect is already visible, do not scroll.
    if (GetLocalBounds().Contains(rect))
      return;

    // Scroll just enough so that the rect is visible.
    int dy = 0;
    if (rect.bottom() > GetLocalBounds().bottom())
      dy = rect.bottom() - GetLocalBounds().bottom();
    else
      dy = rect.y();

    // Convert rect.y() to view's coordinates and make sure we don't show past
    // the bottom of the view.
    View* child = GetContents();
    int old_y = child->y();
    int y = -std::max(
        0, std::min(child->GetPreferredSize().height() - this->height(),
                    dy - child->y()));
    child->SetY(y);

    const int min_y = 0;
    const int max_y = -(child->GetPreferredSize().height() - this->height());

    if (old_y == min_y && old_y != y)
      owner_->DidScrollAwayFromTop();
    if (old_y == max_y && old_y != y)
      owner_->DidScrollAwayFromBottom();

    if (y == min_y)
      owner_->DidScrollToTop();
    if (y == max_y)
      owner_->DidScrollToBottom();
  }

  // Returns the contents, which is the SubmenuView.
  View* GetContents() { return children().front(); }
  const View* GetContents() const { return children().front(); }

 private:
  MenuScrollViewContainer* owner_;
};

BEGIN_METADATA(MenuScrollViewContainer, MenuScrollView, View)
END_METADATA

// MenuScrollViewContainer ----------------------------------------------------

MenuScrollViewContainer::MenuScrollViewContainer(SubmenuView* content_view)
    : content_view_(content_view) {
  auto* layout = SetLayoutManager(std::make_unique<views::FlexLayout>());
  layout->SetOrientation(views::LayoutOrientation::kVertical);

  scroll_up_button_ =
      AddChildView(std::make_unique<MenuScrollButton>(content_view, true));

  scroll_view_ =
      AddChildView(std::make_unique<MenuScrollView>(content_view, this));
  scroll_view_->SetProperty(
      views::kFlexBehaviorKey,
      views::FlexSpecification(views::MinimumFlexSizeRule::kScaleToMinimum,
                               views::MaximumFlexSizeRule::kUnbounded));

  scroll_down_button_ =
      AddChildView(std::make_unique<MenuScrollButton>(content_view, false));

  arrow_ = BubbleBorderTypeFromAnchor(
      content_view_->GetMenuItem()->GetMenuController()->GetAnchorPosition());

  // The correct insets must be set before returning, since the menu creation
  // code needs to know the final size of the menu.  Calling CreateBorder() is
  // the easiest way to do that.
  CreateBorder();
}

bool MenuScrollViewContainer::HasBubbleBorder() const {
  return arrow_ != BubbleBorder::NONE;
}

MenuItemView* MenuScrollViewContainer::GetFootnote() const {
  MenuItemView* const footnote = content_view_->GetLastItem();
  return (footnote && footnote->GetType() == MenuItemView::Type::kHighlighted)
             ? footnote
             : nullptr;
}

gfx::Size MenuScrollViewContainer::CalculatePreferredSize() const {
  gfx::Size prefsize = scroll_view_->GetContents()->GetPreferredSize();
  gfx::Insets insets = GetInsets();
  prefsize.Enlarge(insets.width(), insets.height());
  const MenuConfig& config = MenuConfig::instance();
  // Leave space for the menu border, below the footnote.
  if (GetFootnote() && config.use_outer_border && !HasBubbleBorder())
    prefsize.Enlarge(0, 1);
  return prefsize;
}

void MenuScrollViewContainer::OnThemeChanged() {
  View::OnThemeChanged();
  CreateBorder();
}

void MenuScrollViewContainer::OnPaintBackground(gfx::Canvas* canvas) {
  if (background()) {
    View::OnPaintBackground(canvas);
    return;
  }

  gfx::Rect bounds(0, 0, width(), height());
  NativeTheme::ExtraParams extra;
  const MenuConfig& menu_config = MenuConfig::instance();
  extra.menu_background.corner_radius = menu_config.CornerRadiusForMenu(
      content_view_->GetMenuItem()->GetMenuController());
  GetNativeTheme()->Paint(canvas->sk_canvas(),
                          NativeTheme::kMenuPopupBackground,
                          NativeTheme::kNormal, bounds, extra);
}

void MenuScrollViewContainer::GetAccessibleNodeData(ui::AXNodeData* node_data) {
  // Get the name from the submenu view.
  content_view_->GetAccessibleNodeData(node_data);

  // On macOS, NSMenus are not supposed to have anything wrapped around them. To
  // allow VoiceOver to recognize this as a menu and to read aloud the total
  // number of items inside it, we ignore the MenuScrollViewContainer (which
  // holds the menu itself: the SubmenuView).
#if defined(OS_MAC)
  node_data->role = ax::mojom::Role::kNone;
#else
  node_data->role = ax::mojom::Role::kMenuBar;
#endif
}

void MenuScrollViewContainer::OnBoundsChanged(
    const gfx::Rect& previous_bounds) {
  // When the bounds on the MenuScrollViewContainer itself change, the scroll
  // offset is always reset to 0, so always hide the scroll-up control, and only
  // show the scroll-down control if it's going to be useful.
  scroll_up_button_->SetVisible(false);
  scroll_down_button_->SetVisible(
      scroll_view_->GetContents()->GetPreferredSize().height() > height());

  const bool any_scroll_button_visible =
      scroll_up_button_->GetVisible() || scroll_down_button_->GetVisible();

  MenuItemView* const footnote = GetFootnote();
  if (footnote)
    footnote->SetCornerRadius(any_scroll_button_visible ? 0 : corner_radius_);
  InvalidateLayout();
}

void MenuScrollViewContainer::DidScrollToTop() {
  scroll_up_button_->SetVisible(false);
}

void MenuScrollViewContainer::DidScrollToBottom() {
  scroll_down_button_->SetVisible(false);
}

void MenuScrollViewContainer::DidScrollAwayFromTop() {
  scroll_up_button_->SetVisible(true);
}

void MenuScrollViewContainer::DidScrollAwayFromBottom() {
  scroll_down_button_->SetVisible(true);
}

void MenuScrollViewContainer::CreateBorder() {
  if (HasBubbleBorder())
    CreateBubbleBorder();
  else
    CreateDefaultBorder();
}

void MenuScrollViewContainer::CreateDefaultBorder() {
  DCHECK_EQ(arrow_, BubbleBorder::NONE);
  bubble_border_ = nullptr;

  const MenuConfig& menu_config = MenuConfig::instance();
  corner_radius_ = menu_config.CornerRadiusForMenu(
      content_view_->GetMenuItem()->GetMenuController());
  int padding = menu_config.use_outer_border && corner_radius_ > 0
                    ? kBorderPaddingDueToRoundedCorners
                    : 0;

  const int vertical_inset =
      (corner_radius_ ? corner_radius_
                      : menu_config.menu_vertical_border_size) +
      padding;
  const int horizontal_inset =
      menu_config.menu_horizontal_border_size + padding;

  int bottom_inset = GetFootnote() ? 0 : vertical_inset;

  if (menu_config.use_outer_border) {
    SkColor color = GetWidget() ? GetNativeTheme()->GetSystemColor(
                                      ui::NativeTheme::kColorId_MenuBorderColor)
                                : gfx::kPlaceholderColor;
    SetBorder(views::CreateBorderPainter(
        std::make_unique<views::RoundRectPainter>(color, corner_radius_),
        gfx::Insets(vertical_inset, horizontal_inset, bottom_inset,
                    horizontal_inset)));
  } else {
    SetBorder(CreateEmptyBorder(vertical_inset, horizontal_inset, bottom_inset,
                                horizontal_inset));
  }
}

void MenuScrollViewContainer::CreateBubbleBorder() {
  const SkColor color = GetWidget()
                            ? GetNativeTheme()->GetSystemColor(
                                  ui::NativeTheme::kColorId_MenuBackgroundColor)
                            : gfx::kPlaceholderColor;
  bubble_border_ =
      new BubbleBorder(arrow_, BubbleBorder::STANDARD_SHADOW, color);
  if (content_view_->GetMenuItem()
          ->GetMenuController()
          ->use_touchable_layout()) {
    const MenuConfig& menu_config = MenuConfig::instance();
    bubble_border_->SetCornerRadius(menu_config.touchable_corner_radius);
    bubble_border_->set_md_shadow_elevation(
        menu_config.touchable_menu_shadow_elevation);
    gfx::Insets insets(menu_config.vertical_touchable_menu_item_padding, 0);
    if (GetFootnote())
      insets.Set(menu_config.vertical_touchable_menu_item_padding, 0, 0, 0);
    scroll_view_->GetContents()->SetBorder(CreateEmptyBorder(insets));
  }

  corner_radius_ = bubble_border_->corner_radius();

  SetBorder(std::unique_ptr<Border>(bubble_border_));
  SetBackground(std::make_unique<BubbleBackground>(bubble_border_));
}

BubbleBorder::Arrow MenuScrollViewContainer::BubbleBorderTypeFromAnchor(
    MenuAnchorPosition anchor) {
  switch (anchor) {
    case MenuAnchorPosition::kBubbleAbove:
    case MenuAnchorPosition::kBubbleBelow:
    case MenuAnchorPosition::kBubbleLeft:
    case MenuAnchorPosition::kBubbleRight:
      return BubbleBorder::FLOAT;
    default:
      return BubbleBorder::NONE;
  }
}

BEGIN_METADATA(MenuScrollViewContainer, View)
END_METADATA

}  // namespace views