ui/views/controls/menu/submenu

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This source file includes following definitions.
prefix_selector_
GetMenuItemCount
GetMenuItemAt
ChildPreferredSizeChanged
Layout
GetPreferredSize
GetAccessibleState
GetTextInputClient
PaintChildren
GetDropFormats
AreDropTypesRequired
CanDrop
OnDragEntered
OnDragUpdated
OnDragExited
OnPerformDrop
OnMouseWheel
OnGestureEvent
GetRowCount
GetSelectedRow
SetSelectedRow
GetTextForRow
IsShowing
ShowAt
Reposition
Close
Hide
ReleaseCapture
SkipDefaultKeyEventProcessing
GetMenuItem
SetDropMenuItem
GetShowSelection
GetScrollViewContainer
MenuHostDestroyed
GetClassName
OnBoundsChanged
PaintDropIndicator
SchedulePaintForDropIndicator
CalculateDropIndicatorBounds
OnScroll
// 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/submenu_view.h"

#include <algorithm>

#include "base/compiler_specific.h"
#include "ui/accessibility/ax_view_state.h"
#include "ui/events/event.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/geometry/safe_integer_conversions.h"
#include "ui/views/controls/menu/menu_config.h"
#include "ui/views/controls/menu/menu_controller.h"
#include "ui/views/controls/menu/menu_host.h"
#include "ui/views/controls/menu/menu_scroll_view_container.h"
#include "ui/views/widget/root_view.h"
#include "ui/views/widget/widget.h"

namespace {

// Height of the drop indicator. This should be an even number.
const int kDropIndicatorHeight = 2;

// Color of the drop indicator.
const SkColor kDropIndicatorColor = SK_ColorBLACK;

}  // namespace

namespace views {

// static
const char SubmenuView::kViewClassName[] = "SubmenuView";

SubmenuView::SubmenuView(MenuItemView* parent)
    : parent_menu_item_(parent),
      host_(NULL),
      drop_item_(NULL),
      drop_position_(MenuDelegate::DROP_NONE),
      scroll_view_container_(NULL),
      max_minor_text_width_(0),
      minimum_preferred_width_(0),
      resize_open_menu_(false),
      scroll_animator_(new ScrollAnimator(this)),
      roundoff_error_(0),
      prefix_selector_(this) {
  DCHECK(parent);
  // We'll delete ourselves, otherwise the ScrollView would delete us on close.
  set_owned_by_client();
}

SubmenuView::~SubmenuView() {
  // The menu may not have been closed yet (it will be hidden, but not
  // necessarily closed).
  Close();

  delete scroll_view_container_;
}

int SubmenuView::GetMenuItemCount() {
  int count = 0;
  for (int i = 0; i < child_count(); ++i) {
    if (child_at(i)->id() == MenuItemView::kMenuItemViewID)
      count++;
  }
  return count;
}

MenuItemView* SubmenuView::GetMenuItemAt(int index) {
  for (int i = 0, count = 0; i < child_count(); ++i) {
    if (child_at(i)->id() == MenuItemView::kMenuItemViewID &&
        count++ == index) {
      return static_cast<MenuItemView*>(child_at(i));
    }
  }
  NOTREACHED();
  return NULL;
}

void SubmenuView::ChildPreferredSizeChanged(View* child) {
  if (!resize_open_menu_)
    return;

  MenuItemView *item = GetMenuItem();
  MenuController* controller = item->GetMenuController();

  if (controller) {
    bool dir;
    gfx::Rect bounds = controller->CalculateMenuBounds(item, false, &dir);
    Reposition(bounds);
  }
}

void SubmenuView::Layout() {
  // We're in a ScrollView, and need to set our width/height ourselves.
  if (!parent())
    return;

  // Use our current y, unless it means part of the menu isn't visible anymore.
  int pref_height = GetPreferredSize().height();
  int new_y;
  if (pref_height > parent()->height())
    new_y = std::max(parent()->height() - pref_height, y());
  else
    new_y = 0;
  SetBounds(x(), new_y, parent()->width(), pref_height);

  gfx::Insets insets = GetInsets();
  int x = insets.left();
  int y = insets.top();
  int menu_item_width = width() - insets.width();
  for (int i = 0; i < child_count(); ++i) {
    View* child = child_at(i);
    if (child->visible()) {
      gfx::Size child_pref_size = child->GetPreferredSize();
      child->SetBounds(x, y, menu_item_width, child_pref_size.height());
      y += child_pref_size.height();
    }
  }
}

gfx::Size SubmenuView::GetPreferredSize() {
  if (!has_children())
    return gfx::Size();

  max_minor_text_width_ = 0;
  // The maximum width of items which contain maybe a label and multiple views.
  int max_complex_width = 0;
  // The max. width of items which contain a label and maybe an accelerator.
  int max_simple_width = 0;
  int height = 0;
  for (int i = 0; i < child_count(); ++i) {
    View* child = child_at(i);
    if (!child->visible())
      continue;
    if (child->id() == MenuItemView::kMenuItemViewID) {
      MenuItemView* menu = static_cast<MenuItemView*>(child);
      const MenuItemView::MenuItemDimensions& dimensions =
          menu->GetDimensions();
      max_simple_width = std::max(
          max_simple_width, dimensions.standard_width);
      max_minor_text_width_ =
          std::max(max_minor_text_width_, dimensions.minor_text_width);
      max_complex_width = std::max(max_complex_width,
          dimensions.standard_width + dimensions.children_width);
      height += dimensions.height;
    } else {
      gfx::Size child_pref_size =
          child->visible() ? child->GetPreferredSize() : gfx::Size();
      max_complex_width = std::max(max_complex_width, child_pref_size.width());
      height += child_pref_size.height();
    }
  }
  if (max_minor_text_width_ > 0) {
    max_minor_text_width_ +=
        GetMenuItem()->GetMenuConfig().label_to_minor_text_padding;
  }
  gfx::Insets insets = GetInsets();
  return gfx::Size(
      std::max(max_complex_width,
               std::max(max_simple_width + max_minor_text_width_ +
                        insets.width(),
               minimum_preferred_width_ - 2 * insets.width())),
      height + insets.height());
}

void SubmenuView::GetAccessibleState(ui::AXViewState* state) {
  // Inherit most of the state from the parent menu item, except the role.
  if (GetMenuItem())
    GetMenuItem()->GetAccessibleState(state);
  state->role = ui::AX_ROLE_MENU_LIST_POPUP;
}

ui::TextInputClient* SubmenuView::GetTextInputClient() {
  return &prefix_selector_;
}

void SubmenuView::PaintChildren(gfx::Canvas* canvas) {
  View::PaintChildren(canvas);

  if (drop_item_ && drop_position_ != MenuDelegate::DROP_ON)
    PaintDropIndicator(canvas, drop_item_, drop_position_);
}

bool SubmenuView::GetDropFormats(
      int* formats,
      std::set<OSExchangeData::CustomFormat>* custom_formats) {
  DCHECK(GetMenuItem()->GetMenuController());
  return GetMenuItem()->GetMenuController()->GetDropFormats(this, formats,
                                                            custom_formats);
}

bool SubmenuView::AreDropTypesRequired() {
  DCHECK(GetMenuItem()->GetMenuController());
  return GetMenuItem()->GetMenuController()->AreDropTypesRequired(this);
}

bool SubmenuView::CanDrop(const OSExchangeData& data) {
  DCHECK(GetMenuItem()->GetMenuController());
  return GetMenuItem()->GetMenuController()->CanDrop(this, data);
}

void SubmenuView::OnDragEntered(const ui::DropTargetEvent& event) {
  DCHECK(GetMenuItem()->GetMenuController());
  GetMenuItem()->GetMenuController()->OnDragEntered(this, event);
}

int SubmenuView::OnDragUpdated(const ui::DropTargetEvent& event) {
  DCHECK(GetMenuItem()->GetMenuController());
  return GetMenuItem()->GetMenuController()->OnDragUpdated(this, event);
}

void SubmenuView::OnDragExited() {
  DCHECK(GetMenuItem()->GetMenuController());
  GetMenuItem()->GetMenuController()->OnDragExited(this);
}

int SubmenuView::OnPerformDrop(const ui::DropTargetEvent& event) {
  DCHECK(GetMenuItem()->GetMenuController());
  return GetMenuItem()->GetMenuController()->OnPerformDrop(this, event);
}

bool SubmenuView::OnMouseWheel(const ui::MouseWheelEvent& e) {
  gfx::Rect vis_bounds = GetVisibleBounds();
  int menu_item_count = GetMenuItemCount();
  if (vis_bounds.height() == height() || !menu_item_count) {
    // All menu items are visible, nothing to scroll.
    return true;
  }

  // Find the index of the first menu item whose y-coordinate is >= visible
  // y-coordinate.
  int i = 0;
  while ((i < menu_item_count) && (GetMenuItemAt(i)->y() < vis_bounds.y()))
    ++i;
  if (i == menu_item_count)
    return true;
  int first_vis_index = std::max(0,
      (GetMenuItemAt(i)->y() == vis_bounds.y()) ? i : i - 1);

  // If the first item isn't entirely visible, make it visible, otherwise make
  // the next/previous one entirely visible. If enough wasn't scrolled to show
  // any new rows, then just scroll the amount so that smooth scrolling using
  // the trackpad is possible.
  int delta = abs(e.y_offset() / ui::MouseWheelEvent::kWheelDelta);
  if (delta == 0)
    return OnScroll(0, e.y_offset());
  for (bool scroll_up = (e.y_offset() > 0); delta != 0; --delta) {
    int scroll_target;
    if (scroll_up) {
      if (GetMenuItemAt(first_vis_index)->y() == vis_bounds.y()) {
        if (first_vis_index == 0)
          break;
        first_vis_index--;
      }
      scroll_target = GetMenuItemAt(first_vis_index)->y();
    } else {
      if (first_vis_index + 1 == menu_item_count)
        break;
      scroll_target = GetMenuItemAt(first_vis_index + 1)->y();
      if (GetMenuItemAt(first_vis_index)->y() == vis_bounds.y())
        first_vis_index++;
    }
    ScrollRectToVisible(gfx::Rect(gfx::Point(0, scroll_target),
                                  vis_bounds.size()));
    vis_bounds = GetVisibleBounds();
  }

  return true;
}

void SubmenuView::OnGestureEvent(ui::GestureEvent* event) {
  bool handled = true;
  switch (event->type()) {
    case ui::ET_GESTURE_SCROLL_BEGIN:
      scroll_animator_->Stop();
      break;
    case ui::ET_GESTURE_SCROLL_UPDATE:
      handled = OnScroll(0, event->details().scroll_y());
      break;
    case ui::ET_GESTURE_SCROLL_END:
      break;
    case ui::ET_SCROLL_FLING_START:
      if (event->details().velocity_y() != 0.0f)
        scroll_animator_->Start(0, event->details().velocity_y());
      break;
    case ui::ET_GESTURE_TAP_DOWN:
    case ui::ET_SCROLL_FLING_CANCEL:
      if (scroll_animator_->is_scrolling())
        scroll_animator_->Stop();
      else
        handled = false;
      break;
    default:
      handled = false;
      break;
  }
  if (handled)
    event->SetHandled();
}

int SubmenuView::GetRowCount() {
  return GetMenuItemCount();
}

int SubmenuView::GetSelectedRow() {
  int row = 0;
  for (int i = 0; i < child_count(); ++i) {
    if (child_at(i)->id() != MenuItemView::kMenuItemViewID)
      continue;

    if (static_cast<MenuItemView*>(child_at(i))->IsSelected())
      return row;

    row++;
  }

  return -1;
}

void SubmenuView::SetSelectedRow(int row) {
  GetMenuItem()->GetMenuController()->SetSelection(
      GetMenuItemAt(row),
      MenuController::SELECTION_DEFAULT);
}

base::string16 SubmenuView::GetTextForRow(int row) {
  return GetMenuItemAt(row)->title();
}

bool SubmenuView::IsShowing() {
  return host_ && host_->IsMenuHostVisible();
}

void SubmenuView::ShowAt(Widget* parent,
                         const gfx::Rect& bounds,
                         bool do_capture) {
  if (host_) {
    host_->ShowMenuHost(do_capture);
  } else {
    host_ = new MenuHost(this);
    // Force construction of the scroll view container.
    GetScrollViewContainer();
    // Force a layout since our preferred size may not have changed but our
    // content may have.
    InvalidateLayout();
    host_->InitMenuHost(parent, bounds, scroll_view_container_, do_capture);
  }

  GetScrollViewContainer()->NotifyAccessibilityEvent(
      ui::AX_EVENT_MENU_START,
      true);
  NotifyAccessibilityEvent(
      ui::AX_EVENT_MENU_POPUP_START,
      true);
}

void SubmenuView::Reposition(const gfx::Rect& bounds) {
  if (host_)
    host_->SetMenuHostBounds(bounds);
}

void SubmenuView::Close() {
  if (host_) {
    NotifyAccessibilityEvent(ui::AX_EVENT_MENU_POPUP_END, true);
    GetScrollViewContainer()->NotifyAccessibilityEvent(
        ui::AX_EVENT_MENU_END, true);

    host_->DestroyMenuHost();
    host_ = NULL;
  }
}

void SubmenuView::Hide() {
  if (host_)
    host_->HideMenuHost();
  if (scroll_animator_->is_scrolling())
    scroll_animator_->Stop();
}

void SubmenuView::ReleaseCapture() {
  if (host_)
    host_->ReleaseMenuHostCapture();
}

bool SubmenuView::SkipDefaultKeyEventProcessing(const ui::KeyEvent& e) {
  return views::FocusManager::IsTabTraversalKeyEvent(e);
}

MenuItemView* SubmenuView::GetMenuItem() const {
  return parent_menu_item_;
}

void SubmenuView::SetDropMenuItem(MenuItemView* item,
                                  MenuDelegate::DropPosition position) {
  if (drop_item_ == item && drop_position_ == position)
    return;
  SchedulePaintForDropIndicator(drop_item_, drop_position_);
  drop_item_ = item;
  drop_position_ = position;
  SchedulePaintForDropIndicator(drop_item_, drop_position_);
}

bool SubmenuView::GetShowSelection(MenuItemView* item) {
  if (drop_item_ == NULL)
    return true;
  // Something is being dropped on one of this menus items. Show the
  // selection if the drop is on the passed in item and the drop position is
  // ON.
  return (drop_item_ == item && drop_position_ == MenuDelegate::DROP_ON);
}

MenuScrollViewContainer* SubmenuView::GetScrollViewContainer() {
  if (!scroll_view_container_) {
    scroll_view_container_ = new MenuScrollViewContainer(this);
    // Otherwise MenuHost would delete us.
    scroll_view_container_->set_owned_by_client();
  }
  return scroll_view_container_;
}

void SubmenuView::MenuHostDestroyed() {
  host_ = NULL;
  GetMenuItem()->GetMenuController()->Cancel(MenuController::EXIT_DESTROYED);
}

const char* SubmenuView::GetClassName() const {
  return kViewClassName;
}

void SubmenuView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
  SchedulePaint();
}

void SubmenuView::PaintDropIndicator(gfx::Canvas* canvas,
                                     MenuItemView* item,
                                     MenuDelegate::DropPosition position) {
  if (position == MenuDelegate::DROP_NONE)
    return;

  gfx::Rect bounds = CalculateDropIndicatorBounds(item, position);
  canvas->FillRect(bounds, kDropIndicatorColor);
}

void SubmenuView::SchedulePaintForDropIndicator(
    MenuItemView* item,
    MenuDelegate::DropPosition position) {
  if (item == NULL)
    return;

  if (position == MenuDelegate::DROP_ON) {
    item->SchedulePaint();
  } else if (position != MenuDelegate::DROP_NONE) {
    SchedulePaintInRect(CalculateDropIndicatorBounds(item, position));
  }
}

gfx::Rect SubmenuView::CalculateDropIndicatorBounds(
    MenuItemView* item,
    MenuDelegate::DropPosition position) {
  DCHECK(position != MenuDelegate::DROP_NONE);
  gfx::Rect item_bounds = item->bounds();
  switch (position) {
    case MenuDelegate::DROP_BEFORE:
      item_bounds.Offset(0, -kDropIndicatorHeight / 2);
      item_bounds.set_height(kDropIndicatorHeight);
      return item_bounds;

    case MenuDelegate::DROP_AFTER:
      item_bounds.Offset(0, item_bounds.height() - kDropIndicatorHeight / 2);
      item_bounds.set_height(kDropIndicatorHeight);
      return item_bounds;

    default:
      // Don't render anything for on.
      return gfx::Rect();
  }
}

bool SubmenuView::OnScroll(float dx, float dy) {
  const gfx::Rect& vis_bounds = GetVisibleBounds();
  const gfx::Rect& full_bounds = bounds();
  int x = vis_bounds.x();
  float y_f = vis_bounds.y() - dy - roundoff_error_;
  int y = gfx::ToRoundedInt(y_f);
  roundoff_error_ = y - y_f;
  // clamp y to [0, full_height - vis_height)
  y = std::min(y, full_bounds.height() - vis_bounds.height() - 1);
  y = std::max(y, 0);
  gfx::Rect new_vis_bounds(x, y, vis_bounds.width(), vis_bounds.height());
  if (new_vis_bounds != vis_bounds) {
    ScrollRectToVisible(new_vis_bounds);
    return true;
  }
  return false;
}

}  // namespace views
/* [<][>][^][v][top][bottom][index][help] */
root/ui/views/controls/menu/submenu_view.cc

DEFINITIONS
