Skeleton for app_list on OSX, and refactoring for enable_app_list=1 on OS=="mac".

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 kMaxButtonSpacing = 18;
-const int kMinButtonSpacing = 4;
-const int kMaxButtonWidth = 68;
-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)
-      : views::CustomButton(listener),
-        button_width_(kMaxButtonWidth),
-        selected_range_(0) {
-  }
-  virtual ~PageSwitcherButton() {}
-
-  void SetSelectedRange(double selected_range) {
-    if (selected_range_ == selected_range)
-      return;
-
-    selected_range_ = selected_range;
-    SchedulePaint();
-  }
-
-  void set_button_width(int button_width) { button_width_ = button_width; }
-
-  // Overridden from views::View:
-  virtual gfx::Size GetPreferredSize() OVERRIDE {
-    return gfx::Size(button_width_, kButtonHeight);
-  }
-
-  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
-    if (state() == STATE_HOVERED) {
-      PaintButton(canvas, kHoverColor);
-    } else {
-      PaintButton(canvas, kNormalColor);
-    }
-  }
-
- private:
-  // Paints a button that has two rounded corner at bottom.
-  void PaintButton(gfx::Canvas* canvas, SkColor base_color) {
-    gfx::Rect rect(GetContentsBounds());
-    rect.ClampToCenteredSize(gfx::Size(button_width_, kButtonHeight));
-
-    SkPath path;
-    path.addRoundRect(gfx::RectToSkRect(rect),
-                      SkIntToScalar(kButtonCornerRadius),
-                      SkIntToScalar(kButtonCornerRadius));
-
-    SkPaint paint;
-    paint.setAntiAlias(true);
-    paint.setStyle(SkPaint::kFill_Style);
-    paint.setColor(base_color);
-    canvas->DrawPath(path, paint);
-
-    int selected_start_x = 0;
-    int selected_width = 0;
-    if (selected_range_ > 0) {
-      selected_width = selected_range_ * rect.width();
-    } else if (selected_range_ < 0) {
-      selected_width =  -selected_range_ * rect.width();
-      selected_start_x = rect.right() - selected_width;
-    }
-
-    if (selected_width) {
-      gfx::Rect selected_rect(rect);
-      selected_rect.set_x(selected_start_x);
-      selected_rect.set_width(selected_width);
-
-      SkPath selected_path;
-      selected_path.addRoundRect(gfx::RectToSkRect(selected_rect),
-                                 SkIntToScalar(kButtonCornerRadius),
-                                 SkIntToScalar(kButtonCornerRadius));
-      paint.setColor(kSelectedColor);
-      canvas->DrawPath(selected_path, paint);
-    }
-  }
-
-  int button_width_;
-
-  // [-1, 1] range that represents the portion of the button that should be
-  // painted with kSelectedColor. Positive range starts from left side and
-  // negative range starts from the right side.
-  double selected_range_;
-
-  DISALLOW_COPY_AND_ASSIGN(PageSwitcherButton);
-};
-
-// Gets PageSwitcherButton at |index| in |buttons|.
-PageSwitcherButton* GetButtonByIndex(views::View* buttons, int index) {
-  return static_cast<PageSwitcherButton*>(buttons->child_at(index));
-}
-
-}  // namespace
-
-namespace app_list {
-
-PageSwitcher::PageSwitcher(PaginationModel* model)
-    : model_(model),
-      buttons_(new views::View) {
-  AddChildView(buttons_);
-
-  TotalPagesChanged();
-  SelectedPageChanged(-1, model->selected_page());
-  model_->AddObserver(this);
-}
-
-PageSwitcher::~PageSwitcher() {
-  model_->RemoveObserver(this);
-}
-
-int PageSwitcher::GetPageForPoint(const gfx::Point& point) const {
-  if (!buttons_->bounds().Contains(point))
-    return -1;
-
-  gfx::Point buttons_point(point);
-  views::View::ConvertPointToTarget(this, buttons_, &buttons_point);
-
-  for (int i = 0; i < buttons_->child_count(); ++i) {
-    const views::View* button = buttons_->child_at(i);
-    if (button->bounds().Contains(buttons_point))
-      return i;
-  }
-
-  return -1;
-}
-
-void PageSwitcher::UpdateUIForDragPoint(const gfx::Point& point) {
-  int page = GetPageForPoint(point);
-
-  const int button_count = buttons_->child_count();
-  if (page >= 0 && page < button_count) {
-    PageSwitcherButton* button =
-        static_cast<PageSwitcherButton*>(buttons_->child_at(page));
-    button->SetState(views::CustomButton::STATE_HOVERED);
-    return;
-  }
-
-  for (int i = 0; i < button_count; ++i) {
-    PageSwitcherButton* button =
-        static_cast<PageSwitcherButton*>(buttons_->child_at(i));
-    button->SetState(views::CustomButton::STATE_NORMAL);
-  }
-}
-
-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());
-
-  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(gfx::IntersectRects(rect, buttons_bounds));
-}
-
-void PageSwitcher::CalculateButtonWidthAndSpacing(int contents_width) {
-  const int button_count = buttons_->child_count();
-  if (!button_count)
-    return;
-
-  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) {
-    if (sender == static_cast<views::Button*>(buttons_->child_at(i))) {
-      model_->SelectPage(i, true /* animate */);
-      break;
-    }
-  }
-}
-
-void PageSwitcher::TotalPagesChanged() {
-  buttons_->RemoveAllChildViews(true);
-  for (int i = 0; i < model_->total_pages(); ++i) {
-    PageSwitcherButton* button = new PageSwitcherButton(this);
-    button->SetSelectedRange(i == model_->selected_page() ? 1 : 0);
-    buttons_->AddChildView(button);
-  }
-  buttons_->SetVisible(model_->total_pages() > 1);
-  Layout();
-}
-
-void PageSwitcher::SelectedPageChanged(int old_selected, int new_selected) {
-  if (old_selected >= 0 && old_selected < buttons_->child_count())
-    GetButtonByIndex(buttons_, old_selected)->SetSelectedRange(0);
-  if (new_selected >= 0 && new_selected < buttons_->child_count())
-    GetButtonByIndex(buttons_, new_selected)->SetSelectedRange(1);
-}
-
-void PageSwitcher::TransitionChanged() {
-  const int current_page = model_->selected_page();
-  const int target_page = model_->transition().target_page;
-
-  double progress = model_->transition().progress;
-  double remaining = progress - 1;
-
-  if (current_page > target_page) {
-    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