Add the button style for combobox

ui/views/controls/combobox/combobox.cc

Index: ui/views/controls/combobox/combobox.cc
diff --git a/ui/views/controls/combobox/combobox.cc b/ui/views/controls/combobox/combobox.cc
index 5e487d27dcb36922868e4b49334caf2a333ee177..41e9938461f3bc23ee69f2a9847ace0ac9d6fbc3 100644
--- a/ui/views/controls/combobox/combobox.cc
+++ b/ui/views/controls/combobox/combobox.cc
@@ -12,17 +12,24 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/events/event.h"
 #include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/gfx/animation/throb_animation.h"
 #include "ui/gfx/canvas.h"
+#include "ui/gfx/image/image.h"
+#include "ui/gfx/scoped_canvas.h"
 #include "ui/native_theme/native_theme.h"
 #include "ui/views/background.h"
 #include "ui/views/color_constants.h"
+#include "ui/views/controls/button/custom_button.h"
+#include "ui/views/controls/button/label_button.h"
 #include "ui/views/controls/combobox/combobox_listener.h"
 #include "ui/views/controls/focusable_border.h"
 #include "ui/views/controls/menu/menu_runner.h"
+#include "ui/views/controls/menu/menu_runner_handler.h"
 #include "ui/views/controls/menu/submenu_view.h"
 #include "ui/views/controls/prefix_selector.h"
 #include "ui/views/ime/input_method.h"
 #include "ui/views/mouse_constants.h"
+#include "ui/views/painter.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
@@ -40,6 +47,8 @@ const int kMinComboboxWidth = 25;
 // Size of the combobox arrow margins
 const int kDisclosureArrowLeftPadding = 7;
 const int kDisclosureArrowRightPadding = 7;
+const int kDisclosureArrowButtonLeftPadding = 11;
+const int kDisclosureArrowButtonRightPadding = 12;
 
 // Define the id of the first item in the menu (since it needs to be > 0)
 const int kFirstMenuItemId = 1000;
@@ -49,6 +58,19 @@ const SkColor kInvalidTextColor = SK_ColorWHITE;
 // Used to indicate that no item is currently selected by the user.
 const int kNoSelection = -1;
 
+const int kBodyButtonImages[] = IMAGE_GRID(IDR_COMBOBOX_BUTTON);
+const int kHoveredBodyButtonImages[] = IMAGE_GRID(IDR_COMBOBOX_BUTTON_H);
+const int kPressedBodyButtonImages[] = IMAGE_GRID(IDR_COMBOBOX_BUTTON_P);
+
+#define MENU_IMAGE_GRID(x) { \
+    x ## _MENU_TOP, x ## _MENU_CENTER, x ## _MENU_BOTTOM, }
+
+const int kMenuButtonImages[] = MENU_IMAGE_GRID(IDR_COMBOBOX_BUTTON);
+const int kHoveredMenuButtonImages[] = MENU_IMAGE_GRID(IDR_COMBOBOX_BUTTON_H);
+const int kPressedMenuButtonImages[] = MENU_IMAGE_GRID(IDR_COMBOBOX_BUTTON_P);
+
+#undef MENU_IMAGE_GRID
+
 // The background to use for invalid comboboxes.
 class InvalidBackground : public Background {
  public:
@@ -67,6 +89,23 @@ class InvalidBackground : public Background {
   DISALLOW_COPY_AND_ASSIGN(InvalidBackground);
 };
 
+// The transparent button which holds a button state but is not rendered.
+class TransparentButton : public CustomButton {
+ public:
+  TransparentButton(ButtonListener* listener)
+      : CustomButton(listener) {
+    SetAnimationDuration(LabelButton::kHoverAnimationDurationMs);
+  }
+  virtual ~TransparentButton() {}
+
+  double GetAnimationValue() const {
+    return hover_animation_->GetCurrentValue();
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TransparentButton);
+};
+
 // Returns the next or previous valid index (depending on |increment|'s value).
 // Skips separator or disabled indices. Returns -1 if there is no valid adjacent
 // index.
@@ -82,6 +121,102 @@ int GetAdjacentIndex(ui::ComboboxModel* model, int increment, int index) {
   return kNoSelection;
 }
 
+// Returns the image resource ids of an array for the body button.
+//
+// TODO(hajimehoshi): This function should return the images for the 'disabled'
+// status. (crbug/270052)
+//
+// TODO(hajimehoshi): Currently, |focused| is ignored. This should return the
+// images for the 'focused' status. (crbug/270052)
+const int* GetBodyButtonImageIds(bool focused,
+                                 Button::ButtonState state,
+                                 size_t* num) {
+  DCHECK(num);
+  *num = 9;
+  switch (state) {
+    case Button::STATE_DISABLED:
+      return kBodyButtonImages;
+    case Button::STATE_NORMAL:
+      return kBodyButtonImages;
+    case Button::STATE_HOVERED:
+      return kHoveredBodyButtonImages;
+    case Button::STATE_PRESSED:
+      return kPressedBodyButtonImages;
+    default:
+      NOTREACHED();
+  }
+  return NULL;
+}
+
+// Returns the image resource ids of an array for the menu button.
+const int* GetMenuButtonImageIds(bool focused,
+                                 Button::ButtonState state,
+                                 size_t* num) {
+  DCHECK(num);
+  *num = 3;
+  switch (state) {
+    case Button::STATE_DISABLED:
+      return kMenuButtonImages;
+    case Button::STATE_NORMAL:
+      return kMenuButtonImages;
+    case Button::STATE_HOVERED:
+      return kHoveredMenuButtonImages;
+    case Button::STATE_PRESSED:
+      return kPressedMenuButtonImages;
+    default:
+      NOTREACHED();
+  }
+  return NULL;
+}
+
+// Returns the images for the menu buttons.
+std::vector<const gfx::ImageSkia*> GetMenuButtonImages(
+    bool focused,
+    Button::ButtonState state) {
+  const int* ids;
+  size_t num_ids;
+  ids = GetMenuButtonImageIds(focused, state, &num_ids);
+  std::vector<const gfx::ImageSkia*> images;
+  images.reserve(num_ids);
+  ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
+  for (size_t i = 0; i < num_ids; i++)
+    images.push_back(rb.GetImageSkiaNamed(ids[i]));
+  return images;
+}
+
+// Paints three images in a column at the given location. The center image is
+// stretched so as to fit the given height.
+void PaintImagesVertically(gfx::Canvas* canvas,
+                           const gfx::ImageSkia& top_image,
+                           const gfx::ImageSkia& center_image,
+                           const gfx::ImageSkia& bottom_image,
+                           int x, int y, int width, int height) {
+  canvas->DrawImageInt(top_image,
+                       0, 0, top_image.width(), top_image.height(),
+                       x, y, width, top_image.height(), false);
+  y += top_image.height();
+  int center_height = height - top_image.height() - bottom_image.height();
+  canvas->DrawImageInt(center_image,
+                       0, 0, center_image.width(), center_image.height(),
+                       x, y, width, center_height, false);
+  y += center_height;
+  canvas->DrawImageInt(bottom_image,
+                       0, 0, bottom_image.width(), bottom_image.height(),
+                       x, y, width, bottom_image.height(), false);
+}
+
+// Paints the arrow button.
+void PaintArrowButton(
+    gfx::Canvas* canvas,
+    const std::vector<const gfx::ImageSkia*>& arrow_button_images,
+    int x, int height) {
+  PaintImagesVertically(canvas,
+                        *arrow_button_images[0],
+                        *arrow_button_images[1],
+                        *arrow_button_images[2],
+                        x, 0, arrow_button_images[0]->width(), height);
+}
+
 }  // namespace
 
 // static
@@ -92,17 +227,46 @@ const char Combobox::kViewClassName[] = "views/Combobox";
 
 Combobox::Combobox(ui::ComboboxModel* model)
     : model_(model),
+      style_(STYLE_SHOW_DROP_DOWN_ON_CLICK),
       listener_(NULL),
       selected_index_(model_->GetDefaultIndex()),
       invalid_(false),
-      text_border_(new FocusableBorder()),
       disclosure_arrow_(ui::ResourceBundle::GetSharedInstance().GetImageNamed(
           IDR_MENU_DROPARROW).ToImageSkia()),
-      dropdown_open_(false) {
+      dropdown_open_(false),
+      text_button_(new TransparentButton(this)),
+      arrow_button_(new TransparentButton(this)) {
   model_->AddObserver(this);
   UpdateFromModel();
   set_focusable(true);
-  set_border(text_border_);
+  UpdateBorder();
+
+  // Initialize the button images.
+  Button::ButtonState button_states[] = {
+    Button::STATE_DISABLED,
+    Button::STATE_NORMAL,
+    Button::STATE_HOVERED,
+    Button::STATE_PRESSED,
+  };
+  for (int i = 0; i < 2; i++) {
+    for (size_t state_index = 0; state_index < arraysize(button_states);
+         state_index++) {
+      Button::ButtonState state = button_states[state_index];
+      size_t num;
+      bool focused = !!i;
+      const int* ids = GetBodyButtonImageIds(focused, state, &num);
+      body_button_painters_[focused][state].reset(
+          Painter::CreateImageGridPainter(ids));
+      menu_button_images_[focused][state] = GetMenuButtonImages(focused, state);
+    }
+  }
+
+  text_button_->SetVisible(true);
+  arrow_button_->SetVisible(true);
+  text_button_->set_focusable(false);
+  arrow_button_->set_focusable(false);
+  AddChildView(text_button_);
+  AddChildView(arrow_button_);
 }
 
 Combobox::~Combobox() {
@@ -115,6 +279,16 @@ const gfx::Font& Combobox::GetFont() {
   return rb.GetFont(ui::ResourceBundle::BaseFont);
 }
 
+void Combobox::SetStyle(Style style) {
+  if (style_ == style)
+    return;
+
+  style_ = style;
+
+  UpdateBorder();
+  PreferredSizeChanged();
+}
+
 void Combobox::ModelChanged() {
   selected_index_ = std::min(0, model_->GetItemCount());
   UpdateFromModel();
@@ -145,13 +319,9 @@ void Combobox::SetInvalid(bool invalid) {
     return;
 
   invalid_ = invalid;
-  if (invalid_) {
-    text_border_->SetColor(kWarningColor);
-    set_background(new InvalidBackground());
-  } else {
-    text_border_->UseDefaultColor();
-    set_background(NULL);
-  }
+
+  set_background(invalid_ ? new InvalidBackground() : NULL);
+  UpdateBorder();
   SchedulePaint();
 }
 
@@ -161,6 +331,30 @@ ui::TextInputClient* Combobox::GetTextInputClient() {
   return selector_.get();
 }
 
+void Combobox::Layout() {
+  PrefixDelegate::Layout();
+
+  gfx::Insets insets = GetInsets();
+  int text_button_width = 0;
+  int arrow_button_width = 0;
+
+  switch (style_) {
+    case STYLE_SHOW_DROP_DOWN_ON_CLICK: {
+      arrow_button_width = width();
+      break;
+    }
+    case STYLE_NOTIFY_ON_CLICK: {
+      arrow_button_width = GetDisclosureArrowLeftPadding() +
+          disclosure_arrow_->width() + GetDisclosureArrowRightPadding();
+      text_button_width = width() - arrow_button_width;
+      break;
+    }
+  }
+
+  int arrow_button_x = std::max(0, text_button_width);
+  text_button_->SetBounds(0, 0, std::max(0, text_button_width), height());
+  arrow_button_->SetBounds(arrow_button_x, 0, arrow_button_width, height());
+}
 
 bool Combobox::IsItemChecked(int id) const {
   return false;
@@ -206,9 +400,8 @@ gfx::Size Combobox::GetPreferredSize() {
   // the minimum width for the dropdown list.
   gfx::Insets insets = GetInsets();
   int total_width = std::max(kMinComboboxWidth, content_size_.width()) +
-      insets.width() + kDisclosureArrowLeftPadding +
-      disclosure_arrow_->width() + kDisclosureArrowRightPadding;
-
+      insets.width() + GetDisclosureArrowLeftPadding() +
+      disclosure_arrow_->width() + GetDisclosureArrowRightPadding();
   return gfx::Size(total_width, content_size_.height() + insets.height());
 }
 
@@ -225,22 +418,6 @@ bool Combobox::SkipDefaultKeyEventProcessing(const ui::KeyEvent& e) {
   return dropdown_open_;
 }
 
-bool Combobox::OnMousePressed(const ui::MouseEvent& mouse_event) {
-  RequestFocus();
-  const base::TimeDelta delta = base::Time::Now() - closed_time_;
-  if (mouse_event.IsLeftMouseButton() &&
-      (delta.InMilliseconds() > kMinimumMsBetweenButtonClicks)) {
-    UpdateFromModel();
-    ShowDropDownMenu(ui::MENU_SOURCE_MOUSE);
-  }
-
-  return true;
-}
-
-bool Combobox::OnMouseDragged(const ui::MouseEvent& mouse_event) {
-  return true;
-}
-
 bool Combobox::OnKeyPressed(const ui::KeyEvent& e) {
   // TODO(oshima): handle IME.
   DCHECK_EQ(e.type(), ui::ET_KEY_PRESSED);
@@ -285,6 +462,20 @@ bool Combobox::OnKeyPressed(const ui::KeyEvent& e) {
       new_index = GetAdjacentIndex(model(), -1, selected_index_);
       break;
 
+    // Click the button only when the button style mode.
+    case ui::VKEY_SPACE:
+      if (style_ == STYLE_NOTIFY_ON_CLICK) {
+        // When pressing space, the click event will be raised after the key is
+        // released.
+        text_button_->SetState(Button::STATE_PRESSED);
+      }
+      break;
+
+    // Click the button only when the button style mode.
+    case ui::VKEY_RETURN:
+      HandleClickEvent();
+      break;
+
     default:
       return false;
   }
@@ -302,23 +493,29 @@ bool Combobox::OnKeyPressed(const ui::KeyEvent& e) {
 }
 
 bool Combobox::OnKeyReleased(const ui::KeyEvent& e) {
-  return false;  // crbug.com/127520
-}
+  if (style_ != STYLE_NOTIFY_ON_CLICK)
+    return false;  // crbug.com/127520
 
-void Combobox::OnGestureEvent(ui::GestureEvent* gesture) {
-  if (gesture->type() == ui::ET_GESTURE_TAP) {
-    UpdateFromModel();
-    ShowDropDownMenu(ui::MENU_SOURCE_TOUCH);
-    gesture->StopPropagation();
-    return;
-  }
-  View::OnGestureEvent(gesture);
+  if (e.key_code() == ui::VKEY_SPACE)
+    HandleClickEvent();
+
+  return false;
 }
 
 void Combobox::OnPaint(gfx::Canvas* canvas) {
-  OnPaintBackground(canvas);
-  PaintText(canvas);
-  OnPaintBorder(canvas);
+  switch (style_) {
+    case STYLE_SHOW_DROP_DOWN_ON_CLICK: {
+      OnPaintBackground(canvas);
+      PaintText(canvas);
+      OnPaintBorder(canvas);
+      break;
+    }
+    case STYLE_NOTIFY_ON_CLICK: {
+      PaintButtons(canvas);
+      PaintText(canvas);
+      break;
+    }
+  }
 }
 
 void Combobox::OnFocus() {
@@ -348,6 +545,28 @@ void Combobox::OnModelChanged() {
   ModelChanged();
 }
 
+void Combobox::ButtonPressed(Button* sender, const ui::Event& event) {
+  RequestFocus();
+
+  if (sender == text_button_) {
+    HandleClickEvent();
+  } else {
+    DCHECK_EQ(arrow_button_, sender);
+    // TODO(hajimehoshi): Fix the problem that the arrow button blinks when
+    // cliking this while the dropdown menu is opened.
+    const base::TimeDelta delta = base::Time::Now() - closed_time_;
+    if (delta.InMilliseconds() <= kMinimumMsBetweenButtonClicks)
+      return;
+
+    ui::MenuSourceType source_type = ui::MENU_SOURCE_MOUSE;
+    if (event.IsKeyEvent())
+      source_type = ui::MENU_SOURCE_KEYBOARD;
+    else if (event.IsGestureEvent() || event.IsTouchEvent())
+      source_type = ui::MENU_SOURCE_TOUCH;
+    ShowDropDownMenu(source_type);
+  }
+}
+
 void Combobox::UpdateFromModel() {
   int max_width = 0;
   const gfx::Font& font = Combobox::GetFont();
@@ -376,6 +595,15 @@ void Combobox::UpdateFromModel() {
   content_size_.SetSize(max_width, font.GetHeight());
 }
 
+void Combobox::UpdateBorder() {
+  FocusableBorder* border = new FocusableBorder();
+  if (style_ == STYLE_NOTIFY_ON_CLICK)
+    border->SetInsets(8, 13, 8, 13);
+  if (invalid_)
+    border->SetColor(kWarningColor);
+  set_border(border);
+}
+
 void Combobox::AdjustBoundsForRTLUI(gfx::Rect* rect) const {
   rect->set_x(GetMirroredXForRect(*rect));
 }
@@ -383,7 +611,7 @@ void Combobox::AdjustBoundsForRTLUI(gfx::Rect* rect) const {
 void Combobox::PaintText(gfx::Canvas* canvas) {
   gfx::Insets insets = GetInsets();
 
-  canvas->Save();
+  gfx::ScopedCanvas scoped_canvas(canvas);
   canvas->ClipRect(GetContentsBounds());
 
   int x = insets.left();
@@ -399,8 +627,8 @@ void Combobox::PaintText(gfx::Canvas* canvas) {
     selected_index_ = 0;
   string16 text = model()->GetItemAt(selected_index_);
 
-  int disclosure_arrow_offset = width() - disclosure_arrow_->width()
-      - kDisclosureArrowLeftPadding - kDisclosureArrowRightPadding;
+  int disclosure_arrow_offset = width() - disclosure_arrow_->width() -
+      GetDisclosureArrowLeftPadding() - GetDisclosureArrowRightPadding();
 
   const gfx::Font& font = Combobox::GetFont();
   int text_width = font.GetStringWidth(text);
@@ -411,7 +639,8 @@ void Combobox::PaintText(gfx::Canvas* canvas) {
   AdjustBoundsForRTLUI(&text_bounds);
   canvas->DrawStringInt(text, font, text_color, text_bounds);
 
-  gfx::Rect arrow_bounds(disclosure_arrow_offset + kDisclosureArrowLeftPadding,
+  int arrow_x = disclosure_arrow_offset + GetDisclosureArrowLeftPadding();
+  gfx::Rect arrow_bounds(arrow_x,
                          height() / 2 - disclosure_arrow_->height() / 2,
                          disclosure_arrow_->width(),
                          disclosure_arrow_->height());
@@ -423,8 +652,63 @@ void Combobox::PaintText(gfx::Canvas* canvas) {
     paint.setXfermodeMode(SkXfermode::kDstOut_Mode);
   canvas->DrawImageInt(*disclosure_arrow_, arrow_bounds.x(), arrow_bounds.y(),
                        paint);
+}
+
+void Combobox::PaintButtons(gfx::Canvas* canvas) {
+  DCHECK(style_ == STYLE_NOTIFY_ON_CLICK);
+
+  gfx::ScopedCanvas scoped_canvas(canvas);
+  if (base::i18n::IsRTL()) {
+    canvas->Translate(gfx::Vector2d(width(), 0));
+    canvas->Scale(-1, 1);
+  }
 
-  canvas->Restore();
+  bool focused = HasFocus();
+  const std::vector<const gfx::ImageSkia*>& arrow_button_images =
+      menu_button_images_[focused][
+          arrow_button_->state() == Button::STATE_HOVERED ?
+          Button::STATE_NORMAL : arrow_button_->state()];
+
+  int text_button_hover_alpha =
+      text_button_->state() == Button::STATE_PRESSED ? 0 :
+      static_cast<int>(static_cast<TransparentButton*>(text_button_)->
+                       GetAnimationValue() * 255);
+  if (text_button_hover_alpha < 255) {
+    canvas->SaveLayerAlpha(255 - text_button_hover_alpha);
+    Painter* text_button_painter =
+        body_button_painters_[focused][
+            text_button_->state() == Button::STATE_HOVERED ?
+            Button::STATE_NORMAL : text_button_->state()].get();
+    Painter::PaintPainterAt(canvas, text_button_painter,
+                            gfx::Rect(0, 0, text_button_->width(), height()));
+    canvas->Restore();
+  }
+  if (0 < text_button_hover_alpha) {
+    canvas->SaveLayerAlpha(text_button_hover_alpha);
+    Painter* text_button_hovered_painter =
+        body_button_painters_[focused][Button::STATE_HOVERED].get();
+    Painter::PaintPainterAt(canvas, text_button_hovered_painter,
+                            gfx::Rect(0, 0, text_button_->width(), height()));
+    canvas->Restore();
+  }
+
+  int arrow_button_hover_alpha =
+      arrow_button_->state() == Button::STATE_PRESSED ? 0 :
+      static_cast<int>(static_cast<TransparentButton*>(arrow_button_)->
+                       GetAnimationValue() * 255);
+  if (arrow_button_hover_alpha < 255) {
+    canvas->SaveLayerAlpha(255 - arrow_button_hover_alpha);
+    PaintArrowButton(canvas, arrow_button_images, arrow_button_->x(), height());
+    canvas->Restore();
+  }
+  if (0 < arrow_button_hover_alpha) {
+    canvas->SaveLayerAlpha(arrow_button_hover_alpha);
+    const std::vector<const gfx::ImageSkia*>& arrow_button_hovered_images =
+        menu_button_images_[focused][Button::STATE_HOVERED];
+    PaintArrowButton(canvas, arrow_button_hovered_images,
+                     arrow_button_->x(), height());
+    canvas->Restore();
+  }
 }
 
 void Combobox::ShowDropDownMenu(ui::MenuSourceType source_type) {
@@ -434,8 +718,8 @@ void Combobox::ShowDropDownMenu(ui::MenuSourceType source_type) {
   // Extend the menu to the width of the combobox.
   MenuItemView* menu = dropdown_list_menu_runner_->GetMenu();
   SubmenuView* submenu = menu->CreateSubmenu();
-  submenu->set_minimum_preferred_width(size().width() -
-                                (kMenuBorderWidthLeft + kMenuBorderWidthRight));
+  submenu->set_minimum_preferred_width(
+      size().width() - (kMenuBorderWidthLeft + kMenuBorderWidthRight));
 
   gfx::Rect lb = GetLocalBounds();
   gfx::Point menu_position(lb.origin());
@@ -448,16 +732,25 @@ void Combobox::ShowDropDownMenu(ui::MenuSourceType source_type) {
 
   View::ConvertPointToScreen(this, &menu_position);
   if (menu_position.x() < 0)
-      menu_position.set_x(0);
+    menu_position.set_x(0);
 
   gfx::Rect bounds(menu_position, lb.size());
 
+  Button::ButtonState original_state = Button::STATE_NORMAL;
+  if (arrow_button_) {
+    original_state = arrow_button_->state();
+    arrow_button_->SetState(Button::STATE_PRESSED);
+  }
   dropdown_open_ = true;
   if (dropdown_list_menu_runner_->RunMenuAt(GetWidget(), NULL, bounds,
-          MenuItemView::TOPLEFT, source_type, MenuRunner::COMBOBOX) ==
-      MenuRunner::MENU_DELETED)
+                                            MenuItemView::TOPLEFT, source_type,
+                                            MenuRunner::COMBOBOX) ==
+      MenuRunner::MENU_DELETED) {
     return;
+  }
   dropdown_open_ = false;
+  if (arrow_button_)
+    arrow_button_->SetState(original_state);
   closed_time_ = base::Time::Now();
 
   // Need to explicitly clear mouse handler so that events get sent
@@ -482,4 +775,34 @@ int Combobox::MenuCommandToIndex(int menu_command_id) const {
   return index;
 }
 
+int Combobox::GetDisclosureArrowLeftPadding() const {
+  switch (style_) {
+    case STYLE_SHOW_DROP_DOWN_ON_CLICK:
+      return kDisclosureArrowLeftPadding;
+    case STYLE_NOTIFY_ON_CLICK:
+      return kDisclosureArrowButtonLeftPadding;
+  }
+  NOTREACHED();
+  return 0;
+}
+
+int Combobox::GetDisclosureArrowRightPadding() const {
+  switch (style_) {
+    case STYLE_SHOW_DROP_DOWN_ON_CLICK:
+      return kDisclosureArrowRightPadding;
+    case STYLE_NOTIFY_ON_CLICK:
+      return kDisclosureArrowButtonRightPadding;
+  }
+  NOTREACHED();
+  return 0;
+}
+
+void Combobox::HandleClickEvent() {
+  if (style_ != STYLE_NOTIFY_ON_CLICK)
+    return;
+
+  if (listener_)
+    listener_->OnComboboxTextButtonClicked(this);
+}
+
 }  // namespace views