Add the button style for combobox

ui/views/controls/button/multi_target_button.cc

Index: ui/views/controls/button/multi_target_button.cc
diff --git a/ui/views/controls/button/multi_target_button.cc b/ui/views/controls/button/multi_target_button.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c041f218430ec55be9c5ca5179f257e7dd00e704
--- /dev/null
+++ b/ui/views/controls/button/multi_target_button.cc
@@ -0,0 +1,52 @@
+// Copyright 2013 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/button/multi_target_button.h"
+
+#include "grit/ui_resources.h"
+#include "ui/base/models/menu_model.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/views/controls/button/label_button.h"
+#include "ui/views/controls/button/label_button_border.h"
+#include "ui/views/controls/button/menu_button.h"
+#include "ui/views/controls/menu/menu_runner.h"
+#include "ui/views/layout/box_layout.h"
+
+namespace views {
+
+MultiTargetButton::MultiTargetButton(ui::MenuModel* menu_model)
+    : menu_model_(menu_model) {
+  SetLayoutManager(
+      new views::BoxLayout(views::BoxLayout::kHorizontal, 0, 0, -4));

[hajimehoshi, 2013/11/05 10:10:26]

-4 is to remove the space between two buttons. Would you tell me where such kind
of width is defined?

+
+  button_ = new views::LabelButton(this, menu_model->GetLabelAt(0));

[sky, 2013/11/05 16:29:37]

Using two buttons side by side is problematic because the borders aren't always
going to line up. This should be a single button. In fact you likely want to
subclass an existing button and customize the painting to get the effect you're
after.

+  button_->SetStyle(Button::STYLE_NATIVE_TEXTBUTTON);
+  AddChildView(button_);
+
+  drop_arrow_button_ = new MenuButton(NULL, string16(), this, true);
+  drop_arrow_button_->set_focusable(true);
+  drop_arrow_button_->set_border(
+      new views::LabelButtonBorder(Button::STYLE_BUTTON));
+  AddChildView(drop_arrow_button_);
+}
+
+MultiTargetButton::~MultiTargetButton() {
+}
+
+void MultiTargetButton::ButtonPressed(Button* sender, const ui::Event& event) {
+  menu_model_->ActivatedAt(0);
+}
+
+void MultiTargetButton::OnMenuButtonClicked(
+    View* source, const gfx::Point& point) {
+  DCHECK_EQ(drop_arrow_button_, source);
+  menu_runner_.reset(new MenuRunner(menu_model_));
+  ignore_result(menu_runner_->RunMenuAt(source->GetWidget(), drop_arrow_button_,
+                                        gfx::Rect(point, gfx::Size()),
+                                        MenuItemView::TOPRIGHT,
+                                        ui::MenuSourceType::MENU_SOURCE_MOUSE,
+                                        MenuRunner::HAS_MNEMONICS));
+}
+
+}  // namespace views