Relayout new tab button when MD mode changes

BUG=737995,881371
TBR=pkasting

Change-Id: Ifd8b41626747ae8e52fd7db67e86af5d87b9994f
Reviewed-on: https://chromium-review.googlesource.com/1255594Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#595600}

chrome/browser/ui/views/tabs/new_tab_button.cc

@@ -34,11 +34,8 @@
 #include "chrome/browser/ui/views/feature_promos/new_tab_promo_bubble_view.h"
 #endif
 
-namespace {
-
-constexpr gfx::Size kButtonSize(28, 28);
-
-}  // namespace
+// static
+const gfx::Size NewTabButton::kButtonSize{28, 28};
 
 NewTabButton::NewTabButton(TabStrip* tab_strip, views::ButtonListener* listener)
     : views::ImageButton(listener), tab_strip_(tab_strip) {
@@ -57,14 +54,6 @@ NewTabButton::NewTabButton(TabStrip* tab_strip, views::ButtonListener* listener)
 
   SetFocusPainter(nullptr);
   SetInstallFocusRingOnFocus(true);
-
-  // The button is placed vertically exactly in the center of the tabstrip.
-  const int extra_vertical_space = GetLayoutConstant(TAB_HEIGHT) -
-                                   GetLayoutConstant(TABSTRIP_TOOLBAR_OVERLAP) -
-                                   kButtonSize.height();
-  constexpr int kHorizontalInset = 8;
-  SetBorder(views::CreateEmptyBorder(gfx::Insets(
-      extra_vertical_space / 2, kHorizontalInset, 0, kHorizontalInset)));
 }
 
 NewTabButton::~NewTabButton() {

chrome/browser/ui/views/tabs/new_tab_button.h

@@ -25,6 +25,8 @@ class NewTabButton : public views::ImageButton,
                      public views::MaskedTargeterDelegate,
                      public views::WidgetObserver {
  public:
+  static const gfx::Size kButtonSize;
+
   NewTabButton(TabStrip* tab_strip, views::ButtonListener* listener);
   ~NewTabButton() override;
 

chrome/browser/ui/views/tabs/tab_strip.cc

@@ -266,6 +266,7 @@ TabStrip::TabStrip(std::unique_ptr<TabStripController> controller)
     : controller_(std::move(controller)) {
   Init();
   SetEventTargeter(std::make_unique<views::ViewTargeter>(this));
+  md_observer_.Add(ui::MaterialDesignController::GetInstance());
 }
 
 TabStrip::~TabStrip() {
@@ -1464,6 +1465,7 @@ void TabStrip::Init() {
       std::make_unique<views::ViewTargeter>(new_tab_button_));
   AddChildView(new_tab_button_);
 
+  UpdateNewTabButtonBorder();
   new_tab_button_bounds_.set_size(new_tab_button_->GetPreferredSize());
 
   if (g_drop_indicator_width == 0) {
@@ -2433,6 +2435,16 @@ void TabStrip::SetResetToShrinkOnExit(bool value) {
     RemoveMessageLoopObserver();
 }
 
+void TabStrip::UpdateNewTabButtonBorder() {
+  // The button is placed vertically exactly in the center of the tabstrip.
+  const int extra_vertical_space = GetLayoutConstant(TAB_HEIGHT) -
+                                   GetLayoutConstant(TABSTRIP_TOOLBAR_OVERLAP) -
+                                   NewTabButton::kButtonSize.height();
+  constexpr int kHorizontalInset = 8;
+  new_tab_button_->SetBorder(views::CreateEmptyBorder(gfx::Insets(
+      extra_vertical_space / 2, kHorizontalInset, 0, kHorizontalInset)));
+}
+
 void TabStrip::SingleTabModeChanged() {
   const int active_tab_index = controller_->GetActiveIndex();
   if (IsValidModelIndex(active_tab_index))
@@ -2597,3 +2609,10 @@ views::View* TabStrip::TargetForRect(views::View* root, const gfx::Rect& rect) {
   }
   return this;
 }
+
+void TabStrip::OnMdModeChanged() {
+  UpdateNewTabButtonBorder();
+  new_tab_button_bounds_.set_size(new_tab_button_->GetPreferredSize());
+  new_tab_button_->SetBoundsRect(new_tab_button_bounds_);
+  StopAnimating(true);
+}

chrome/browser/ui/views/tabs/tab_strip.h

@@ -13,12 +13,14 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
+#include "base/scoped_observer.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/ui/tabs/tab_utils.h"
 #include "chrome/browser/ui/views/frame/browser_root_view.h"
 #include "chrome/browser/ui/views/tabs/tab.h"
 #include "chrome/browser/ui/views/tabs/tab_controller.h"
 #include "chrome/browser/ui/views/tabs/tab_strip.h"
+#include "ui/base/material_design/material_design_controller_observer.h"
 #include "ui/gfx/animation/animation_container.h"
 #include "ui/gfx/color_palette.h"
 #include "ui/gfx/geometry/point.h"
@@ -63,7 +65,8 @@ class TabStrip : public views::View,
                  public views::MouseWatcherListener,
                  public views::ViewTargeterDelegate,
                  public TabController,
-                 public BrowserRootView::DropTarget {
+                 public BrowserRootView::DropTarget,
+                 public ui::MaterialDesignControllerObserver {
  public:
   explicit TabStrip(std::unique_ptr<TabStripController> controller);
   ~TabStrip() override;
@@ -559,10 +562,14 @@ class TabStrip : public views::View,
   // layout is reset.
   void SetResetToShrinkOnExit(bool value);
 
-  // views::ButtonListener implementation:
+  // Updates the border padding for |new_tab_button_|.  This should be called
+  // whenever any input of the computation of the border's sizing changes.
+  void UpdateNewTabButtonBorder();
+
+  // views::ButtonListener:
   void ButtonPressed(views::Button* sender, const ui::Event& event) override;
 
-  // View overrides.
+  // views::View:
   const views::View* GetViewByID(int id) const override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   bool OnMouseDragged(const ui::MouseEvent& event) override;
@@ -571,12 +578,15 @@ class TabStrip : public views::View,
   void OnMouseMoved(const ui::MouseEvent& event) override;
   void OnMouseEntered(const ui::MouseEvent& event) override;
 
-  // ui::EventHandler overrides.
+  // ui::EventHandler:
   void OnGestureEvent(ui::GestureEvent* event) override;
 
   // views::ViewTargeterDelegate:
   views::View* TargetForRect(views::View* root, const gfx::Rect& rect) override;
 
+  // ui::MaterialDesignControllerObserver:
+  void OnMdModeChanged() override;
+
   // -- Member Variables ------------------------------------------------------
 
   base::ObserverList<TabStripObserver>::Unchecked observers_;
@@ -688,6 +698,10 @@ class TabStrip : public views::View,
 
   SkColor separator_color_ = gfx::kPlaceholderColor;
 
+  ScopedObserver<ui::MaterialDesignController,
+                 ui::MaterialDesignControllerObserver>
+      md_observer_{this};
+
   DISALLOW_COPY_AND_ASSIGN(TabStrip);
 };