Views: factor out Combobox background and const-ify style

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 278b4c3bada9a75727e048a8048ef91c1d21e97d..1ae342435582aa359a3ec83c984f47abf6c21bb0 100644
--- a/ui/views/controls/combobox/combobox.cc
+++ b/ui/views/controls/combobox/combobox.cc
@@ -46,6 +46,10 @@ namespace views {
 
 namespace {
 
+// Action style shoulder padding widths
+const int kActionLeftPadding = 12;
+const int kActionRightPadding = 11;
+
 // Menu border widths
 const int kMenuBorderWidthLeft = 1;
 const int kMenuBorderWidthTop = 1;
@@ -54,12 +58,6 @@ const int kMenuBorderWidthRight = 1;
 // Limit how small a combobox can be.
 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;
 
@@ -89,6 +87,22 @@ const int kFocusedPressedMenuButtonImages[] =
 
 #undef MENU_IMAGE_GRID
 
+gfx::Rect PositionArrowWithinShoulder(const gfx::Rect& shoulder_bounds,

[sky, 2016/05/17 16:49:21]

similar comment about naming.

[Elly Fong-Jones, 2016/05/17 17:35:05]

-> PositionArrowWithinContainer

+                                      const gfx::Size& arrow_size,
+                                      Combobox::Style style) {
+  gfx::Rect bounds(shoulder_bounds);
+  if (style == Combobox::STYLE_ACTION) {
+    // This positions the arrow horizontally. The later call to
+    // ClampToCenteredSize will position it vertically without touching the
+    // horizontal position.
+    bounds.Inset(kActionLeftPadding, 0, kActionRightPadding, 0);
+    DCHECK_EQ(bounds.width(), arrow_size.width());
+  }
+
+  bounds.ClampToCenteredSize(arrow_size);
+  return bounds;
+}
+
 // The transparent button which holds a button state but is not rendered.
 class TransparentButton : public CustomButton {
  public:
@@ -343,9 +357,9 @@ class Combobox::ComboboxMenuModelAdapter : public ui::MenuModel,
 ////////////////////////////////////////////////////////////////////////////////
 // Combobox, public:
 
-Combobox::Combobox(ui::ComboboxModel* model)
+Combobox::Combobox(ui::ComboboxModel* model, Style style)
     : model_(model),
-      style_(STYLE_NORMAL),
+      style_(style),
       listener_(NULL),
       selected_index_(model_->GetDefaultIndex()),
       invalid_(false),
@@ -353,6 +367,9 @@ Combobox::Combobox(ui::ComboboxModel* model)
       text_button_(new TransparentButton(this)),
       arrow_button_(new TransparentButton(this)),
       weak_ptr_factory_(this) {
+  if (style_ == STYLE_ACTION)

[sky, 2016/05/17 16:49:21]

nit: move to initializer on 364.

[Elly Fong-Jones, 2016/05/17 17:35:05]

Done.

+    selected_index_ = 0;
+
   ModelChanged();
 #if defined(OS_MACOSX)
   SetFocusBehavior(FocusBehavior::ACCESSIBLE_ONLY);
@@ -361,8 +378,10 @@ Combobox::Combobox(ui::ComboboxModel* model)
 #endif
 
   UpdateBorder();
+  arrow_image_ = PlatformStyle::CreateComboboxArrow(enabled(), style);
   // set_background() takes ownership but takes a raw pointer.
-  std::unique_ptr<Background> b = PlatformStyle::CreateComboboxBackground();
+  std::unique_ptr<Background> b =
+      PlatformStyle::CreateComboboxBackground(GetShoulderWidth());
   set_background(b.release());
 
   // Initialize the button images.
@@ -404,19 +423,6 @@ const gfx::FontList& Combobox::GetFontList() {
   return rb.GetFontListWithDelta(ui::kLabelFontSizeDelta);
 }
 
-void Combobox::SetStyle(Style style) {
-  if (style_ == style)
-    return;
-
-  style_ = style;
-  if (style_ == STYLE_ACTION)
-    selected_index_ = 0;
-
-  UpdateBorder();
-  content_size_ = GetContentSize();
-  PreferredSizeChanged();
-}
-
 void Combobox::ModelChanged() {
   // If the selection is no longer valid (or the model is empty), restore the
   // default index.
@@ -465,12 +471,6 @@ void Combobox::SetInvalid(bool invalid) {
   SchedulePaint();
 }
 
-int Combobox::GetArrowButtonWidth() const {
-  return GetDisclosureArrowLeftPadding() +
-         ArrowSize().width() +
-         GetDisclosureArrowRightPadding();
-}
-
 void Combobox::Layout() {
   PrefixDelegate::Layout();
 
@@ -484,9 +484,7 @@ void Combobox::Layout() {
       break;
     }
     case STYLE_ACTION: {
-      arrow_button_width = GetDisclosureArrowLeftPadding() +
-          ArrowSize().width() +
-          GetDisclosureArrowRightPadding();
+      arrow_button_width = GetShoulderWidth();
       text_button_width = width() - arrow_button_width;
       break;
     }
@@ -497,6 +495,11 @@ void Combobox::Layout() {
   arrow_button_->SetBounds(arrow_button_x, 0, arrow_button_width, height());
 }
 
+void Combobox::OnEnabledChanged() {
+  PrefixDelegate::OnEnabledChanged();
+  arrow_image_ = PlatformStyle::CreateComboboxArrow(enabled(), style_);
+}
+
 int Combobox::GetRowCount() {
   return model()->GetItemCount();
 }
@@ -529,8 +532,7 @@ gfx::Size Combobox::GetPreferredSize() const {
                         Textfield::kTextPadding,
                         Textfield::kTextPadding);
   int total_width = std::max(kMinComboboxWidth, content_size_.width()) +
-                    insets.width() + GetDisclosureArrowLeftPadding() +
-                    ArrowSize().width() + GetDisclosureArrowRightPadding();
+                    insets.width() + GetShoulderWidth();
   return gfx::Size(total_width, content_size_.height() + insets.height());
 }
 
@@ -738,8 +740,7 @@ void Combobox::PaintText(gfx::Canvas* canvas) {
   base::string16 text = model()->GetItemAt(selected_index_);
 
   gfx::Size arrow_size = ArrowSize();
-  int disclosure_arrow_offset = width() - arrow_size.width() -
-      GetDisclosureArrowLeftPadding() - GetDisclosureArrowRightPadding();
+  int disclosure_arrow_offset = width() - GetShoulderWidth();
 
   const gfx::FontList& font_list = Combobox::GetFontList();
   int text_width = gfx::GetStringWidth(text, font_list);
@@ -750,26 +751,18 @@ void Combobox::PaintText(gfx::Canvas* canvas) {
   AdjustBoundsForRTLUI(&text_bounds);
   canvas->DrawStringRect(text, font_list, text_color, text_bounds);
 
-  int arrow_x = disclosure_arrow_offset + GetDisclosureArrowLeftPadding();
-  gfx::Rect arrow_bounds(arrow_x,
-                         height() / 2 - arrow_size.height() / 2,
-                         arrow_size.width(),
-                         arrow_size.height());
+  gfx::Rect arrow_bounds(disclosure_arrow_offset, 0, GetShoulderWidth(),
+                         height());
+  arrow_bounds = PositionArrowWithinShoulder(arrow_bounds, ArrowSize(), style_);
   AdjustBoundsForRTLUI(&arrow_bounds);
 
-  gfx::ImageSkia arrow_image = PlatformStyle::CreateComboboxArrow(
-      enabled(), style_);
-  canvas->DrawImageInt(arrow_image, arrow_bounds.x(), arrow_bounds.y());
+  canvas->DrawImageInt(arrow_image_, arrow_bounds.x(), arrow_bounds.y());
 }
 
 void Combobox::PaintButtons(gfx::Canvas* canvas) {
   DCHECK(style_ == STYLE_ACTION);
 
-  gfx::ScopedCanvas scoped_canvas(canvas);
-  if (base::i18n::IsRTL()) {
-    canvas->Translate(gfx::Vector2d(width(), 0));
-    canvas->Scale(-1, 1);
-  }
+  gfx::ScopedRTLFlipCanvas scoped_canvas(canvas, bounds());
 
   bool focused = HasFocus();
   const std::vector<const gfx::ImageSkia*>& arrow_button_images =
@@ -877,30 +870,8 @@ void Combobox::OnPerformAction() {
     selected_index_ = 0;
 }
 
-int Combobox::GetDisclosureArrowLeftPadding() const {
-  switch (style_) {
-    case STYLE_NORMAL:
-      return kDisclosureArrowLeftPadding;
-    case STYLE_ACTION:
-      return kDisclosureArrowButtonLeftPadding;
-  }
-  NOTREACHED();
-  return 0;
-}
-
-int Combobox::GetDisclosureArrowRightPadding() const {
-  switch (style_) {
-    case STYLE_NORMAL:
-      return kDisclosureArrowRightPadding;
-    case STYLE_ACTION:
-      return kDisclosureArrowButtonRightPadding;
-  }
-  NOTREACHED();
-  return 0;
-}
-
 gfx::Size Combobox::ArrowSize() const {
-  return PlatformStyle::CreateComboboxArrow(enabled(), style_).size();
+  return arrow_image_.size();
 }
 
 gfx::Size Combobox::GetContentSize() const {
@@ -926,4 +897,12 @@ PrefixSelector* Combobox::GetPrefixSelector() {
   return selector_.get();
 }
 
+int Combobox::GetShoulderWidth() const {
+  const int kNormalPadding = 7;
+  int padding = style_ == STYLE_NORMAL ?
+                          kNormalPadding * 2 :
+                          kActionLeftPadding + kActionRightPadding;
+  return ArrowSize().width() + padding;
+}
+
 }  // namespace views