Adding a Views scrollbar implementation.

views/controls/scrollbar/native_scroll_bar_views.cc

+// Copyright (c) 2011 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 "views/controls/scrollbar/native_scroll_bar_views.h"
+
+#include "base/logging.h"
+#include "ui/base/keycodes/keyboard_codes.h"
+#include "ui/gfx/canvas.h"
+#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/path.h"
+#include "views/controls/button/custom_button.h"
+#include "views/controls/focusable_border.h"
+#include "views/controls/scrollbar/native_scroll_bar.h"
+#include "views/controls/scrollbar/scroll_bar.h"
+#include "views/controls/scrollbar/base_scroll_bar_button.h"
+#include "views/controls/scrollbar/base_scroll_bar_thumb.h"
+
+namespace views {
+
+namespace {
+
+// Wrapper for the scroll buttons.
+class ScrollBarButton : public BaseScrollBarButton {
+ public:
+  enum Type {
+    UP,
+    DOWN,
+    LEFT,
+    RIGHT,
+  };
+
+  ScrollBarButton(ButtonListener* listener, Type type);
+  virtual ~ScrollBarButton();
+
+  virtual gfx::Size GetPreferredSize() OVERRIDE;
+
+ protected:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
+ private:
+  gfx::NativeTheme::ExtraParams GetNativeThemeParams() const;
+  gfx::NativeTheme::Part GetNativeThemePart() const;
+  gfx::NativeTheme::State GetNativeThemeState() const;
+
+  Type type_;
+};
+
+// Wrapper for the scroll thumb
+class ScrollBarThumb : public BaseScrollBarThumb {
+ public:
+  explicit ScrollBarThumb(BaseScrollBar* scroll_bar);
+  virtual ~ScrollBarThumb();
+
+  virtual gfx::Size GetPreferredSize() OVERRIDE;
+
+ protected:
+  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+
+ private:
+  gfx::NativeTheme::ExtraParams GetNativeThemeParams() const;
+  gfx::NativeTheme::Part GetNativeThemePart() const;
+  gfx::NativeTheme::State GetNativeThemeState() const;
+
+  ScrollBar* scroll_bar_;
+};
+
+/////////////////////////////////////////////////////////////////////////////
+// ScrollBarButton
+
+ScrollBarButton::ScrollBarButton(
+    ButtonListener* listener,
+    Type type)
+    : BaseScrollBarButton(listener),
+      type_(type) {
+}
+
+ScrollBarButton::~ScrollBarButton() {
+}
+
+gfx::Size ScrollBarButton::GetPreferredSize() {
+  const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
+  return native_theme->GetPartSize(GetNativeThemePart(),
+                                   GetNativeThemeState(),
+                                   GetNativeThemeParams());
+}
+
+void ScrollBarButton::OnPaint(gfx::Canvas* canvas) {
+  const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
+  gfx::Rect bounds;
+  bounds.set_size(GetPreferredSize());
+
+  native_theme->Paint(canvas->AsCanvasSkia(),
+                      GetNativeThemePart(),
+                      GetNativeThemeState(),
+                      bounds,
+                      GetNativeThemeParams());
+}
+
+gfx::NativeTheme::ExtraParams
+    ScrollBarButton::GetNativeThemeParams() const {
+  gfx::NativeTheme::ExtraParams params;
+
+  switch (state_) {
+    case CustomButton::BS_HOT:
+      params.scrollbar_arrow.is_hovering = true;
+      break;
+    default:
+      params.scrollbar_arrow.is_hovering = false;
+      break;
+  }
+
+  return params;
+}
+
+gfx::NativeTheme::Part
+    ScrollBarButton::GetNativeThemePart() const {
+  switch (type_) {
+    case UP:
+      return gfx::NativeTheme::kScrollbarUpArrow;
+    case DOWN:
+      return gfx::NativeTheme::kScrollbarDownArrow;
+    case LEFT:
+      return gfx::NativeTheme::kScrollbarLeftArrow;
+    case RIGHT:
+      return gfx::NativeTheme::kScrollbarRightArrow;
+    default:
+      return gfx::NativeTheme::kScrollbarUpArrow;
+  }
+}
+
+gfx::NativeTheme::State
+    ScrollBarButton::GetNativeThemeState() const {
+  gfx::NativeTheme::State state;
+
+  switch (state_) {
+    case CustomButton::BS_HOT:
+      state = gfx::NativeTheme::kHovered;
+      break;
+    case CustomButton::BS_PUSHED:
+      state = gfx::NativeTheme::kPressed;
+      break;
+    case CustomButton::BS_DISABLED:
+      state = gfx::NativeTheme::kDisabled;
+      break;
+    case CustomButton::BS_NORMAL:
+    default:
+      state = gfx::NativeTheme::kNormal;
+      break;
+  }
+
+  return state;
+}
+
+/////////////////////////////////////////////////////////////////////////////
+// ScrollBarThumb
+
+ScrollBarThumb::ScrollBarThumb(BaseScrollBar* scroll_bar)
+    : BaseScrollBarThumb(scroll_bar),
+      scroll_bar_(scroll_bar) {
+}
+
+ScrollBarThumb::~ScrollBarThumb() {
+}
+
+gfx::Size ScrollBarThumb::GetPreferredSize() {
+  const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
+  return native_theme->GetPartSize(GetNativeThemePart(),
+                                   GetNativeThemeState(),
+                                   GetNativeThemeParams());
+}
+
+void ScrollBarThumb::OnPaint(gfx::Canvas* canvas) {
+  const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
+
+  native_theme->Paint(canvas->AsCanvasSkia(),
+                      GetNativeThemePart(),
+                      GetNativeThemeState(),
+                      GetLocalBounds(),
+                      GetNativeThemeParams());
+}
+
+gfx::NativeTheme::ExtraParams
+    ScrollBarThumb::GetNativeThemeParams() const {
+  gfx::NativeTheme::ExtraParams params;
+
+  switch (GetState()) {
+    case CustomButton::BS_HOT:
+      params.scrollbar_thumb.is_hovering = true;
+      break;
+    default:
+      params.scrollbar_thumb.is_hovering = false;
+      break;
+  }
+
+  return params;
+}
+
+gfx::NativeTheme::Part ScrollBarThumb::GetNativeThemePart() const {
+  if (scroll_bar_->IsHorizontal())
+    return gfx::NativeTheme::kScrollbarHorizontalThumb;
+  return gfx::NativeTheme::kScrollbarVerticalThumb;
+}
+
+gfx::NativeTheme::State ScrollBarThumb::GetNativeThemeState() const {
+  gfx::NativeTheme::State state;
+
+  switch (GetState()) {
+    case CustomButton::BS_HOT:
+      state = gfx::NativeTheme::kHovered;
+      break;
+    case CustomButton::BS_PUSHED:
+      state = gfx::NativeTheme::kPressed;
+      break;
+    case CustomButton::BS_DISABLED:
+      state = gfx::NativeTheme::kDisabled;
+      break;
+    case CustomButton::BS_NORMAL:
+    default:
+      state = gfx::NativeTheme::kNormal;
+      break;
+  }
+
+  return state;
+}
+
+}  // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+// NativeScrollBarViews, public:
+
+NativeScrollBarViews::NativeScrollBarViews(NativeScrollBar* scroll_bar)
+    : BaseScrollBar(scroll_bar->IsHorizontal(),
+                    new ScrollBarThumb(this)),
+      native_scroll_bar_(scroll_bar) {
+  SetController(native_scroll_bar_->GetController());
+
+  if (native_scroll_bar_->IsHorizontal()) {
+    prev_button_ = new ScrollBarButton(this, ScrollBarButton::LEFT);
+    next_button_ = new ScrollBarButton(this, ScrollBarButton::RIGHT);
+
+    part_ = gfx::NativeTheme::kScrollbarHorizontalTrack;
+  } else {
+    prev_button_ = new ScrollBarButton(this, ScrollBarButton::UP);
+    next_button_ = new ScrollBarButton(this, ScrollBarButton::DOWN);
+
+    part_ = gfx::NativeTheme::kScrollbarVerticalTrack;
+  }
+
+  state_ = gfx::NativeTheme::kNormal;
+
+  AddChildView(prev_button_);
+  AddChildView(next_button_);
+
+  prev_button_->set_context_menu_controller(this);
+  next_button_->set_context_menu_controller(this);
+}
+
+NativeScrollBarViews::~NativeScrollBarViews() {
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// NativeScrollBarViews, View overrides:
+
+void NativeScrollBarViews::Layout() {
+  SetBoundsRect(native_scroll_bar_->GetLocalBounds());
+
+  gfx::Size size = prev_button_->GetPreferredSize();
+  prev_button_->SetBounds(0, 0, size.width(), size.height());
+
+  if (native_scroll_bar_->IsHorizontal()) {
+    next_button_->SetBounds(width() - size.width(), 0,
+                            size.width(), size.height());
+  } else {
+    next_button_->SetBounds(0, height() - size.height(),
+                            size.width(), size.height());
+  }
+
+  GetThumb()->SetBoundsRect(GetTrackBounds());
+}
+
+void NativeScrollBarViews::OnPaint(gfx::Canvas* canvas) {
+  const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
+  gfx::Rect bounds = GetTrackBounds();
+
+  params_.scrollbar_track.track_x = bounds.x();
+  params_.scrollbar_track.track_y = bounds.y();
+  params_.scrollbar_track.track_width = bounds.width();
+  params_.scrollbar_track.track_height = bounds.height();
+
+
+  native_theme->Paint(canvas->AsCanvasSkia(),
+                      part_,
+                      state_,
+                      bounds,
+                      params_);
+}
+
+gfx::Size NativeScrollBarViews::GetPreferredSize() {
+  if (native_scroll_bar_->IsHorizontal())
+    return gfx::Size(0, GetHorizontalScrollBarHeight());
+  return gfx::Size(GetVerticalScrollBarWidth(), 0);
+}
+
+int NativeScrollBarViews::GetLayoutSize() const {
+  gfx::Size size = prev_button_->GetPreferredSize();
+  return IsHorizontal() ? size.height() : size.width();
+}
+
+void NativeScrollBarViews::ScrollToPosition(int position) {
+  GetController()->ScrollToPosition(native_scroll_bar_, position);
+}
+
+int NativeScrollBarViews::GetScrollIncrement(bool is_page,
+                                             bool is_positive) {
+  return GetController()->GetScrollIncrement(native_scroll_bar_,
+                                             is_page,
+                                             is_positive);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// BaseButton::ButtonListener overrides:
+
+void NativeScrollBarViews::ButtonPressed(Button* sender,
+                                         const views::Event& event) {
+  if (sender == prev_button_) {
+    ScrollByAmount(SCROLL_PREV_LINE);
+  } else if (sender == next_button_) {
+    ScrollByAmount(SCROLL_NEXT_LINE);
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// NativeScrollBarViews, NativeScrollBarWrapper overrides:
+
+int NativeScrollBarViews::GetPosition() const {
+  return BaseScrollBar::GetPosition();
+}
+
+View* NativeScrollBarViews::GetView() {
+  return this;
+}
+
+void NativeScrollBarViews::Update(int viewport_size,
+                                  int content_size,
+                                  int current_pos) {
+  BaseScrollBar::Update(viewport_size, content_size, current_pos);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// NativeScrollBarViews, private:
+
+gfx::Rect NativeScrollBarViews::GetTrackBounds() const {
+  gfx::Rect bounds = GetLocalBounds();
+  gfx::Size size = prev_button_->GetPreferredSize();
+  BaseScrollBarThumb* thumb = GetThumb();
+
+  if (native_scroll_bar_->IsHorizontal()) {
+    bounds.set_x(bounds.x() + size.width());
+    bounds.set_width(bounds.width() - 2 * size.width());
+    bounds.set_height(thumb->GetPreferredSize().height());
+  } else {
+    bounds.set_y(bounds.y() + size.height());
+    bounds.set_height(bounds.height() - 2 * size.height());
+    bounds.set_width(thumb->GetPreferredSize().width());
+  }
+
+  return bounds;
+}
+
+}  // namespace views