app_list: Make min page switcher button width and spacing smaller.

ui/app_list/page_switcher.cc

 // 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/app_list/page_switcher.h"
 
 #include <algorithm>
 
 #include "third_party/skia/include/core/SkPath.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/base/animation/throb_animation.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/views/controls/button/custom_button.h"
 #include "ui/views/layout/box_layout.h"
 
 namespace {
 
 const int kPreferredHeight = 57;
 
-const int kButtonSpacing = 18;
+const int kMaxButtonSpacing = 18;
+const int kMinButtonSpacing = 4;
 const int kMaxButtonWidth = 68;
-const int kMinButtonWidth = 44;
+const int kMinButtonWidth = 28;
 const int kButtonHeight = 6;
 const int kButtonCornerRadius = 2;
+const int kButtonStripPadding = 20;
 
 const SkColor kHoverColor = SkColorSetRGB(0xB4, 0xB4, 0xB4);
 
 const SkColor kNormalColor = SkColorSetRGB(0xE2, 0xE2, 0xE2);
 
 const SkColor kSelectedColor = SkColorSetRGB(0x46, 0x8F, 0xFC);
 
 class PageSwitcherButton : public views::CustomButton {
  public:
   explicit PageSwitcherButton(views::ButtonListener* listener)
@@ skipping 81 matching lines @@
   return static_cast<PageSwitcherButton*>(buttons->child_at(index));
 }
 
 }  // namespace
 
 namespace app_list {
 
 PageSwitcher::PageSwitcher(PaginationModel* model)
     : model_(model),
       buttons_(new views::View) {
-  buttons_->SetLayoutManager(new views::BoxLayout(
-      views::BoxLayout::kHorizontal, 0, 0, kButtonSpacing));
   AddChildView(buttons_);
 
   TotalPagesChanged();
   SelectedPageChanged(-1, model->selected_page());
   model_->AddObserver(this);
 }
 
 PageSwitcher::~PageSwitcher() {
   model_->RemoveObserver(this);
 }
 
 gfx::Size PageSwitcher::GetPreferredSize() {
   // Always return a size with correct height so that container resize is not
   // needed when more pages are added.
   return gfx::Size(buttons_->GetPreferredSize().width(),
                    kPreferredHeight);
 }
 
 void PageSwitcher::Layout() {
   gfx::Rect rect(GetContentsBounds());
 
-  CalculateButtonWidth(rect.width());
+  CalculateButtonWidthAndSpacing(rect.width());
 
   // Makes |buttons_| horizontally center and vertically fill.
   gfx::Size buttons_size(buttons_->GetPreferredSize());
   gfx::Rect buttons_bounds(rect.CenterPoint().x() - buttons_size.width() / 2,
                            rect.y(),
                            buttons_size.width(),
                            rect.height());
   buttons_->SetBoundsRect(rect.Intersect(buttons_bounds));
 }
 
-void PageSwitcher::CalculateButtonWidth(int contents_width) {
+void PageSwitcher::CalculateButtonWidthAndSpacing(int contents_width) {
   int button_count = buttons_->child_count();
   if (!button_count)
     return;
 
-  int button_width = contents_width / button_count - kButtonSpacing;
+  contents_width -= 2 * kButtonStripPadding;
+
+  int button_width = kMinButtonWidth;
+  int button_spacing = kMinButtonSpacing;
+  if (button_count > 1) {
+    button_spacing = (contents_width - button_width * button_count) /
+        (button_count - 1);
+    button_spacing = std::min(kMaxButtonSpacing,
+                              std::max(kMinButtonSpacing, button_spacing));
+  }
+
+  button_width = (contents_width - (button_count - 1) * button_spacing) /
+      button_count;
   button_width = std::min(kMaxButtonWidth,
                           std::max(kMinButtonWidth, button_width));
 
+  buttons_->SetLayoutManager(new views::BoxLayout(
+      views::BoxLayout::kHorizontal, kButtonStripPadding, 0, button_spacing));
   for (int i = 0; i < button_count; ++i) {
     PageSwitcherButton* button =
         static_cast<PageSwitcherButton*>(buttons_->child_at(i));
     button->set_button_width(button_width);
   }
 }
 
 void PageSwitcher::ButtonPressed(views::Button* sender,
                                  const ui::Event& event) {
   for (int i = 0; i < buttons_->child_count(); ++i) {
@@ skipping 33 matching lines @@
     remaining = -remaining;
     progress = -progress;
   }
 
   GetButtonByIndex(buttons_, current_page)->SetSelectedRange(remaining);
   if (model_->is_valid_page(target_page))
     GetButtonByIndex(buttons_, target_page)->SetSelectedRange(progress);
 }
 
 }  // namespace app_list