ash: Add launcher overflow bubble.

ash/launcher/overflow_bubble.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 "ash/launcher/overflow_bubble.h"
+
+#include <algorithm>
+
+#include "ash/launcher/launcher_types.h"
+#include "ash/launcher/launcher_view.h"
+#include "ui/gfx/screen.h"
+#include "ui/views/bubble/bubble_delegate.h"
+#include "ui/views/bubble/bubble_frame_view.h"
+
+namespace ash {
+namespace internal {
+
+namespace {
+
+// This should be the same color as the darkest launcher bar.
+const SkColor kLauncherColor = SkColorSetARGB(0x80, 0, 0, 0);
+
+// Max bubble size to screen size ratio.
+const float kMaxBubbleSizeToScreenRatio = 0.5f;
+
+// Inner padding in pixels for launcher view inside bubble.
+const int kPadding = 2;
+
+// Padding space in pixels between LauncherView's left/top edge to its contents.
+const int kLauncherViewLeadingInset = 8;
+
+// Gets arrow location based on shelf alignment.
+views::BubbleBorder::ArrowLocation GetBubbleArrowLocation(
+    ShelfAlignment shelf_alignment) {
+  switch (shelf_alignment) {
+    case ash::SHELF_ALIGNMENT_BOTTOM:
+      return views::BubbleBorder::BOTTOM_LEFT;
+    case ash::SHELF_ALIGNMENT_LEFT:
+      return views::BubbleBorder::LEFT_TOP;
+    case ash::SHELF_ALIGNMENT_RIGHT:
+      return views::BubbleBorder::RIGHT_TOP;
+    default:
+      NOTREACHED() << "Unknown shelf alignment " << shelf_alignment;
+      return views::BubbleBorder::BOTTOM_LEFT;
+  }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// OverflowBubbleView
+// OverflowBubbleView hosts a LauncherView to display overflown items.
+
+class OverflowBubbleView : public views::BubbleDelegateView {
+ public:
+  OverflowBubbleView();
+  virtual ~OverflowBubbleView();
+
+  void InitOverflowBubble(LauncherDelegate* delegate,
+                          LauncherModel* model,
+                          views::View* anchor,
+                          ShelfAlignment shelf_alignment,
+                          int overflow_start_index);
+
+ private:
+  bool is_horizontal_alignment() const {
+    return shelf_alignment_ == SHELF_ALIGNMENT_BOTTOM;
+  }
+
+  const gfx::Size GetContentsSize() const {
+    return static_cast<views::View*>(launcher_view_)->GetPreferredSize();
+  }
+
+  void ScrollByXOffset(int x_offset);
+  void ScrollByYOffset(int y_offset);
+
+  // views::View overrides:
+  virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual void Layout() OVERRIDE;
+  virtual void ChildPreferredSizeChanged(views::View* child) OVERRIDE;
+  virtual bool OnMouseWheel(const views::MouseWheelEvent& event) OVERRIDE;
+  virtual bool OnScrollEvent(const views::ScrollEvent & event) OVERRIDE;
+
+  // views::BubbleDelegate overrides:
+  virtual gfx::Rect GetBubbleBounds() OVERRIDE;
+
+  ShelfAlignment shelf_alignment_;
+  LauncherView* launcher_view_;  // Owned by views hierarchy.
+  gfx::Point scroll_offset_;
+
+  DISALLOW_COPY_AND_ASSIGN(OverflowBubbleView);
+};
+
+OverflowBubbleView::OverflowBubbleView()
+    : shelf_alignment_(SHELF_ALIGNMENT_BOTTOM),
+      launcher_view_(NULL) {
+}
+
+OverflowBubbleView::~OverflowBubbleView() {
+}
+
+void OverflowBubbleView::InitOverflowBubble(LauncherDelegate* delegate,
+                                            LauncherModel* model,
+                                            views::View* anchor,
+                                            ShelfAlignment shelf_alignment,
+                                            int overflow_start_index) {
+  shelf_alignment_ = shelf_alignment;
+
+  // Makes bubble view has a layer and clip its children layers.
+  SetPaintToLayer(true);
+  SetFillsBoundsOpaquely(false);
+  layer()->SetMasksToBounds(true);
+
+  launcher_view_ = new LauncherView(model, delegate, NULL);
+  launcher_view_->set_first_visible_index(overflow_start_index);
+  launcher_view_->set_leading_inset(kLauncherViewLeadingInset);
+  launcher_view_->Init();
+  launcher_view_->SetAlignment(shelf_alignment);
+  AddChildView(launcher_view_);
+
+  set_anchor_view(anchor);
+  set_arrow_location(GetBubbleArrowLocation(shelf_alignment));
+  set_background(NULL);
+  set_color(kLauncherColor);
+  set_margin(kPadding);
+  set_move_with_anchor(true);
+  views::BubbleDelegateView::CreateBubble(this);
+}
+
+void OverflowBubbleView::ScrollByXOffset(int x_offset) {
+  const gfx::Rect visible_bounds(GetContentsBounds());
+  const gfx::Size contents_size(GetContentsSize());
+
+  int x = std::min(contents_size.width() - visible_bounds.width(),
+                   std::max(0, scroll_offset_.x() + x_offset));
+  scroll_offset_.set_x(x);
+}
+
+void OverflowBubbleView::ScrollByYOffset(int y_offset) {
+  const gfx::Rect visible_bounds(GetContentsBounds());
+  const gfx::Size contents_size(GetContentsSize());
+
+  int y = std::min(contents_size.height() - visible_bounds.height(),
+                   std::max(0, scroll_offset_.y() + y_offset));
+  scroll_offset_.set_y(y);
+}
+
+gfx::Size OverflowBubbleView::GetPreferredSize() {
+  gfx::Size preferred_size = GetContentsSize();
+
+  const gfx::Rect monitor_rect = gfx::Screen::GetDisplayNearestPoint(
+      GetAnchorRect().CenterPoint()).work_area();
+  if (!monitor_rect.IsEmpty()) {
+    if (is_horizontal_alignment()) {
+      preferred_size.set_width(std::min(
+          preferred_size.width(),
+          static_cast<int>(monitor_rect.width() *
+                           kMaxBubbleSizeToScreenRatio)));
+    } else {
+      preferred_size.set_height(std::min(
+          preferred_size.height(),
+          static_cast<int>(monitor_rect.height() *
+                           kMaxBubbleSizeToScreenRatio)));
+    }
+  }
+
+  return preferred_size;
+}
+
+void OverflowBubbleView::Layout() {
+  const gfx::Point origin(-scroll_offset_.x(), -scroll_offset_.y());
+  launcher_view_->SetBoundsRect(gfx::Rect(origin, GetContentsSize()));
+}
+
+void OverflowBubbleView::ChildPreferredSizeChanged(views::View* child) {
+  // Ensures |launch_view_| is still visible.
+  ScrollByXOffset(0);
+  ScrollByYOffset(0);
+  Layout();
+
+  SizeToContents();
+}
+
+bool OverflowBubbleView::OnMouseWheel(const views::MouseWheelEvent& event) {
+  if (is_horizontal_alignment())
+    ScrollByXOffset(-event.offset());
+  else
+    ScrollByYOffset(-event.offset());
+  Layout();
+
+  return true;
+}
+
+bool OverflowBubbleView::OnScrollEvent(const views::ScrollEvent & event) {
+  ScrollByXOffset(-event.x_offset());
+  ScrollByYOffset(-event.y_offset());
+  Layout();
+  return true;
+}
+
+gfx::Rect OverflowBubbleView::GetBubbleBounds() {
+  views::BubbleBorder* border = GetBubbleFrameView()->bubble_border();
+  gfx::Insets bubble_insets;
+  border->GetInsets(&bubble_insets);
+
+  const int border_size =
+      views::BubbleBorder::is_arrow_on_horizontal(arrow_location()) ?
+      bubble_insets.left() : bubble_insets.top();
+  const int arrow_offset = border_size + kPadding + kLauncherViewLeadingInset +
+      kLauncherPreferredSize / 2;
+
+  const gfx::Size content_size = GetPreferredSize();
+  border->SetArrowOffset(arrow_offset, content_size);
+
+  const gfx::Rect anchor_rect = GetAnchorRect();
+  gfx::Rect bubble_rect = GetBubbleFrameView()->GetUpdatedWindowBounds(
+      anchor_rect,
+      content_size,
+      false);
+
+  gfx::Rect monitor_rect = gfx::Screen::GetDisplayNearestPoint(
+      anchor_rect.CenterPoint()).work_area();
+
+  int offset = 0;
+  if (views::BubbleBorder::is_arrow_on_horizontal(arrow_location())) {
+    if (bubble_rect.x() < monitor_rect.x())
+      offset = monitor_rect.x() - bubble_rect.x();
+    else if (bubble_rect.right() > monitor_rect.right())
+      offset = monitor_rect.right() - bubble_rect.right();
+
+    bubble_rect.Offset(offset, 0);
+    border->SetArrowOffset(anchor_rect.CenterPoint().x() - bubble_rect.x(),
+                           content_size);
+  } else {
+    if (bubble_rect.y() < monitor_rect.y())
+      offset = monitor_rect.y() - bubble_rect.y();
+    else if (bubble_rect.bottom() > monitor_rect.bottom())
+      offset =  monitor_rect.bottom() - bubble_rect.bottom();
+
+    bubble_rect.Offset(0, offset);
+    border->SetArrowOffset(anchor_rect.CenterPoint().y() - bubble_rect.y(),
+                           content_size);
+  }
+
+  GetBubbleFrameView()->SchedulePaint();
+  return bubble_rect;
+}
+
+}  // namespace
+
+OverflowBubble::OverflowBubble()
+    : bubble_(NULL) {
+}
+
+OverflowBubble::~OverflowBubble() {
+  Hide();
+}
+
+void OverflowBubble::Show(LauncherDelegate* delegate,
+                          LauncherModel* model,
+                          views::View* anchor,
+                          ShelfAlignment shelf_alignment,
+                          int overflow_start_index) {
+  Hide();
+
+  OverflowBubbleView* bubble_view = new OverflowBubbleView();
+  bubble_view->InitOverflowBubble(delegate,
+                                  model,
+                                  anchor,
+                                  shelf_alignment,
+                                  overflow_start_index);
+
+  bubble_ = bubble_view;
+  bubble_->GetWidget()->AddObserver(this);
+  bubble_->GetWidget()->Show();
+}
+
+void OverflowBubble::Hide() {
+  if (!IsShowing())
+    return;
+
+  bubble_->GetWidget()->RemoveObserver(this);
+  bubble_->GetWidget()->Close();
+  bubble_ = NULL;
+}
+
+void OverflowBubble::OnWidgetClosing(views::Widget* widget) {
+  DCHECK(widget == bubble_->GetWidget());
+  bubble_ = NULL;
+}
+
+}  // namespace internal
+}  // namespace ash