Adds UI components for desktop notifications, including balloon view classes to display toasts on the screen, and manager for controlling the layout of the balloons.

BUG=none
TEST=none yet (part of larger patch)

Review URL: http://codereview.chromium.org/338051

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@30471 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 554 insertions, 200 deletions

diff --git a/chrome/browser/notifications/balloon.cc b/chrome/browser/notifications/balloon.cc
new file mode 100644
index 0000000..71abe66
--- /dev/null
+++ b/chrome/browser/notifications/balloon.cc
@@ -0,0 +1,43 @@
+// Copyright (c) 2009 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 "chrome/browser/notifications/balloon.h"
+
+#include "base/gfx/rect.h"
+#include "base/logging.h"
+#include "chrome/browser/notifications/balloon_collection.h"
+#include "chrome/browser/renderer_host/site_instance.h"
+
+Balloon::Balloon(const Notification& notification, Profile* profile,
+                 BalloonCloseListener* listener)
+    : profile_(profile),
+      notification_(notification),
+      close_listener_(listener) {
+}
+
+Balloon::~Balloon() {
+}
+
+void Balloon::SetPosition(const gfx::Point& upper_left, bool reposition) {
+  position_ = upper_left;
+  if (reposition && balloon_view_.get())
+    balloon_view_->RepositionToBalloon();
+}
+
+void Balloon::set_view(BalloonView* balloon_view) {
+  balloon_view_.reset(balloon_view);
+}
+
+void Balloon::Show() {
+  notification_.Display();
+  if (balloon_view_.get()) {
+    balloon_view_->Show(this);
+  }
+}
+
+void Balloon::Close(bool by_user) {
+  notification_.Close(by_user);
+  if (close_listener_)
+    close_listener_->OnBalloonClosed(this);
+}
diff --git a/chrome/browser/notifications/balloon.h b/chrome/browser/notifications/balloon.h
new file mode 100644
index 0000000..5559f09
--- /dev/null
+++ b/chrome/browser/notifications/balloon.h
@@ -0,0 +1,91 @@
+// Copyright (c) 2009 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.
+
+// Handles the visible notification (or balloons).
+
+#ifndef CHROME_BROWSER_NOTIFICATIONS_BALLOON_H_
+#define CHROME_BROWSER_NOTIFICATIONS_BALLOON_H_
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/gfx/point.h"
+#include "base/gfx/rect.h"
+#include "base/gfx/size.h"
+#include "base/scoped_ptr.h"
+#include "chrome/browser/notifications/notification.h"
+
+class Balloon;
+class Profile;
+class SiteInstance;
+
+// Interface for a view that displays a balloon.
+class BalloonView {
+ public:
+  virtual ~BalloonView() { }
+
+  // Show the view on the screen.
+  virtual void Show(Balloon* balloon) = 0;
+
+  // Reposition the view to match the position of its balloon.
+  virtual void RepositionToBalloon() = 0;
+
+  // Close the view.
+  virtual void Close() = 0;
+};
+
+// Represents a Notification on the screen.
+class Balloon {
+ public:
+  class BalloonCloseListener {
+   public:
+    virtual ~BalloonCloseListener() {}
+
+    // Called when a balloon is closed.
+    virtual void OnBalloonClosed(Balloon* source) = 0;
+  };
+
+  // |listener| may be null in unit tests w/o actual UI.
+  Balloon(const Notification& notification,
+          Profile* profile,
+          BalloonCloseListener* listener);
+  virtual ~Balloon();
+
+  const Notification& notification() const { return notification_; }
+  Profile* profile() const { return profile_; }
+
+  const gfx::Point& position() const { return position_; }
+  void SetPosition(const gfx::Point& upper_left, bool reposition);
+
+  const gfx::Size& size() const { return size_; }
+  void set_size(const gfx::Size& size) { size_ = size; }
+
+  // Provides a view for this balloon.  Ownership transfers
+  // to this object.
+  void set_view(BalloonView* balloon_view);
+
+  virtual void Show();
+  virtual void Close(bool by_user);
+
+ private:
+  // Non-owned pointer to the profile.
+  Profile* profile_;
+
+  // The notification being shown in this balloon.
+  Notification notification_;
+
+  // A listener to be called when the balloon closes.
+  BalloonCloseListener* close_listener_;
+
+  // The actual UI element for the balloon.
+  scoped_ptr<BalloonView> balloon_view_;
+
+  // Position and size of the balloon on the screen.
+  gfx::Point position_;
+  gfx::Size size_;
+
+  DISALLOW_COPY_AND_ASSIGN(Balloon);
+};
+
+#endif  // CHROME_BROWSER_NOTIFICATIONS_BALLOON_H_
diff --git a/chrome/browser/notifications/balloon_collection.cc b/chrome/browser/notifications/balloon_collection.cc
new file mode 100644
index 0000000..d979ddd
--- /dev/null
+++ b/chrome/browser/notifications/balloon_collection.cc
@@ -0,0 +1,172 @@
+// Copyright (c) 2009 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 "chrome/browser/notifications/balloon_collection.h"
+
+#include "base/gfx/rect.h"
+#include "base/logging.h"
+#include "base/stl_util-inl.h"
+#include "chrome/browser/notifications/balloon.h"
+
+namespace {
+
+// Portion of the screen allotted for notifications. When notification balloons
+// extend over this, no new notifications are shown until some are closed.
+const double kPercentBalloonFillFactor = 0.7;
+
+// Allow at least this number of balloons on the screen.
+const int kMinAllowedBalloonCount = 2;
+
+}  // namespace
+
+// static
+BalloonCollectionImpl::Layout::Placement
+    BalloonCollectionImpl::Layout::placement_ =
+        Layout::VERTICALLY_FROM_BOTTOM_RIGHT;
+
+BalloonCollectionImpl::BalloonCollectionImpl()
+    : space_change_listener_(NULL) {
+}
+
+BalloonCollectionImpl::~BalloonCollectionImpl() {
+  STLDeleteElements(&balloons_);
+}
+
+void BalloonCollectionImpl::Add(const Notification& notification,
+                                Profile* profile) {
+  Balloon* new_balloon = MakeBalloon(notification, profile);
+  balloons_.push_back(new_balloon);
+  PositionBalloons(false);
+  new_balloon->Show();
+
+  // There may be no listener in a unit test.
+  if (space_change_listener_)
+    space_change_listener_->OnBalloonSpaceChanged();
+}
+
+bool BalloonCollectionImpl::HasSpace() const {
+  if (count() < kMinAllowedBalloonCount)
+    return true;
+
+  int max_balloon_size = 0;
+  int total_size = 0;
+  layout_.GetMaxLinearSize(&max_balloon_size, &total_size);
+
+  int current_max_size = max_balloon_size * count();
+  int max_allowed_size = static_cast<int>(total_size *
+                                          kPercentBalloonFillFactor);
+  return current_max_size < max_allowed_size - max_balloon_size;
+}
+
+void BalloonCollectionImpl::OnBalloonClosed(Balloon* source) {
+  // We want to free the balloon when finished.
+  scoped_ptr<Balloon> closed(source);
+  for (Balloons::iterator it = balloons_.begin(); it != balloons_.end(); ++it) {
+    if (*it == source) {
+      balloons_.erase(it);
+      break;
+    }
+  }
+  PositionBalloons(true);
+
+  // There may be no listener in a unit test.
+  if (space_change_listener_)
+    space_change_listener_->OnBalloonSpaceChanged();
+}
+
+void BalloonCollectionImpl::PositionBalloons(bool reposition) {
+  gfx::Point origin = layout_.GetLayoutOrigin();
+  for (Balloons::iterator it = balloons_.begin(); it != balloons_.end(); ++it) {
+    gfx::Point upper_left = layout_.NextPosition((*it)->size(), &origin);
+    (*it)->SetPosition(upper_left, reposition);
+  }
+}
+
+BalloonCollectionImpl::Layout::Layout() {
+  RefreshSystemMetrics();
+}
+
+const void BalloonCollectionImpl::Layout::GetMaxLinearSize(
+    int* max_balloon_size,
+    int* total_size) const {
+  DCHECK(max_balloon_size && total_size);
+
+  switch (placement_) {
+    case HORIZONTALLY_FROM_BOTTOM_LEFT:
+    case HORIZONTALLY_FROM_BOTTOM_RIGHT:
+      *total_size = work_area_.width();
+      *max_balloon_size = max_balloon_width();
+      break;
+    case VERTICALLY_FROM_TOP_RIGHT:
+    case VERTICALLY_FROM_BOTTOM_RIGHT:
+      *total_size = work_area_.height();
+      *max_balloon_size = max_balloon_height();
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
+gfx::Point BalloonCollectionImpl::Layout::GetLayoutOrigin() const {
+  int x = 0;
+  int y = 0;
+  switch (placement_) {
+    case HORIZONTALLY_FROM_BOTTOM_LEFT:
+      x = work_area_.x();
+      y = work_area_.bottom();
+      break;
+    case HORIZONTALLY_FROM_BOTTOM_RIGHT:
+      x = work_area_.right();
+      y = work_area_.bottom();
+      break;
+    case VERTICALLY_FROM_TOP_RIGHT:
+      x = work_area_.right();
+      y = work_area_.y();
+      break;
+    case VERTICALLY_FROM_BOTTOM_RIGHT:
+      x = work_area_.right();
+      y = work_area_.bottom();
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+  return gfx::Point(x, y);
+}
+
+gfx::Point BalloonCollectionImpl::Layout::NextPosition(
+    const gfx::Size& balloon_size,
+    gfx::Point* position_iterator) const {
+  DCHECK(position_iterator);
+
+  int x = 0;
+  int y = 0;
+  switch (placement_) {
+    case HORIZONTALLY_FROM_BOTTOM_LEFT:
+      x = position_iterator->x();
+      y = position_iterator->y() - balloon_size.height();
+      position_iterator->set_x(position_iterator->x() + balloon_size.width());
+      break;
+    case HORIZONTALLY_FROM_BOTTOM_RIGHT:
+      position_iterator->set_x(position_iterator->x() - balloon_size.width());
+      x = position_iterator->x();
+      y = position_iterator->y() - balloon_size.height();
+      break;
+    case VERTICALLY_FROM_TOP_RIGHT:
+      x = position_iterator->x() - balloon_size.width();
+      y = position_iterator->y();
+      position_iterator->set_y(position_iterator->y() + balloon_size.height());
+      break;
+    case VERTICALLY_FROM_BOTTOM_RIGHT:
+      position_iterator->set_y(position_iterator->y() - balloon_size.height());
+      x = position_iterator->x() - balloon_size.width();
+      y = position_iterator->y();
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+  return gfx::Point(x, y);
+}
diff --git a/chrome/browser/notifications/balloon_collection.h b/chrome/browser/notifications/balloon_collection.h
new file mode 100644
index 0000000..a756936
--- /dev/null
+++ b/chrome/browser/notifications/balloon_collection.h
@@ -0,0 +1,151 @@
+// Copyright (c) 2009 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.
+
+// Handles the visible notification (or balloons).
+
+#ifndef CHROME_BROWSER_NOTIFICATIONS_BALLOON_COLLECTION_H_
+#define CHROME_BROWSER_NOTIFICATIONS_BALLOON_COLLECTION_H_
+
+#include <deque>
+
+#include "base/gfx/point.h"
+#include "base/gfx/rect.h"
+#include "base/gfx/size.h"
+#include "chrome/browser/notifications/balloon.h"
+#include "chrome/browser/notifications/notification.h"
+
+class Balloon;
+class Profile;
+
+class BalloonCollection {
+ public:
+  virtual ~BalloonCollection() {}
+
+  // Adds a new balloon for the specified notification.
+  virtual void Add(const Notification& notification,
+                   Profile* profile) = 0;
+
+  // Is there room to add another notification?
+  virtual bool HasSpace() const = 0;
+};
+
+// A balloon collection represents a set of notification balloons being
+// shown on the screen.  It positions new notifications according to
+// a layout, and monitors for balloons being closed, which it reports
+// up to its parent, the notification UI manager.
+class BalloonCollectionImpl : public BalloonCollection,
+                              public Balloon::BalloonCloseListener {
+ public:
+  class BalloonSpaceChangeListener {
+   public:
+    virtual ~BalloonSpaceChangeListener() {}
+
+    // Called when there is more or less space for balloons due to
+    // monitor size changes or balloons disappearing.
+    virtual void OnBalloonSpaceChanged() = 0;
+  };
+
+  BalloonCollectionImpl();
+  virtual ~BalloonCollectionImpl();
+
+  BalloonSpaceChangeListener* space_change_listener() {
+    return space_change_listener_;
+  }
+  void set_space_change_listener(BalloonSpaceChangeListener* listener) {
+    space_change_listener_ = listener;
+  }
+
+  // BalloonCollectionInterface overrides
+  virtual void Add(const Notification& notification,
+                   Profile* profile);
+  virtual bool HasSpace() const;
+
+  // Balloon::BalloonCloseListener interface
+  virtual void OnBalloonClosed(Balloon* source);
+
+ protected:
+  // Creates a new balloon. Overridable by unit tests.  The caller is
+  // responsible for freeing the pointer returned.
+  virtual Balloon* MakeBalloon(const Notification& notification,
+                               Profile* profile);
+
+ private:
+  // The number of balloons being displayed.
+  int count() const { return balloons_.size(); }
+
+  // Adjusts the positions of the balloons (e.g., when one is closed).
+  void PositionBalloons(bool is_reposition);
+
+  // Calculates layout values for the balloons including
+  // the scaling, the max/min sizes, and the upper left corner of each.
+  class Layout {
+   public:
+    Layout();
+
+    // Refresh the work area and balloon placement.
+    void OnDisplaySettingsChanged();
+
+    // TODO(johnnyg): Scale the size to account for the system font factor.
+    int min_balloon_width() const { return kBalloonMinWidth; }
+    int max_balloon_width() const { return kBalloonMaxWidth; }
+    int min_balloon_height() const { return kBalloonMinHeight; }
+    int max_balloon_height() const { return kBalloonMaxHeight; }
+
+    // Returns both the total space available and the maximum
+    // allowed per balloon.
+    //
+    // The size may be a height or length depending on the way that
+    // balloons are laid out.
+    const void GetMaxLinearSize(int* max_balloon_size, int* total_size) const;
+
+    // Refresh the cached values for work area and drawing metrics.
+    // The application should call this method to re-acquire metrics after
+    // any resolution or settings change.
+    // Returns true if and only if a metric changed.
+    bool RefreshSystemMetrics();
+
+    // Returns the origin for the sequence of balloons depending on layout.
+    // Should not be used to place a balloon -- only to call NextPosition().
+    gfx::Point GetLayoutOrigin() const;
+
+    // Compute the position for the next balloon.
+    // Start with *position_iterator = GetLayoutOrigin() and call repeatedly
+    // to get a sequence of positions. Return value is the upper-left coordinate
+    // for each next balloon.
+    gfx::Point NextPosition(const gfx::Size& balloon_size,
+                            gfx::Point* position_iterator) const;
+
+   private:
+    enum Placement {
+      HORIZONTALLY_FROM_BOTTOM_LEFT,
+      HORIZONTALLY_FROM_BOTTOM_RIGHT,
+      VERTICALLY_FROM_TOP_RIGHT,
+      VERTICALLY_FROM_BOTTOM_RIGHT
+    };
+
+    // Minimum and maximum size of balloon
+    static const int kBalloonMinWidth = 300;
+    static const int kBalloonMaxWidth = 300;
+    static const int kBalloonMinHeight = 90;
+    static const int kBalloonMaxHeight = 120;
+
+    static Placement placement_;
+    gfx::Rect work_area_;
+    DISALLOW_COPY_AND_ASSIGN(Layout);
+  };
+
+  // Non-owned pointer to an object listening for space changes.
+  BalloonSpaceChangeListener* space_change_listener_;
+
+  // Queue of active balloons.
+  typedef std::deque<Balloon*> Balloons;
+  Balloons balloons_;
+
+  // The layout parameters for balloons in this collection.
+  Layout layout_;
+
+  DISALLOW_COPY_AND_ASSIGN(BalloonCollectionImpl);
+};
+
+#endif  // CHROME_BROWSER_NOTIFICATIONS_BALLOON_COLLECTION_H_
diff --git a/chrome/browser/notifications/balloon_collection_linux.cc b/chrome/browser/notifications/balloon_collection_linux.cc
new file mode 100644
index 0000000..6d29f97
--- /dev/null
+++ b/chrome/browser/notifications/balloon_collection_linux.cc
@@ -0,0 +1,21 @@
+// Copyright (c) 2009 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 "chrome/browser/notifications/balloon_collection.h"
+
+#include "base/gfx/size.h"
+#include "base/logging.h"
+
+Balloon* BalloonCollectionImpl::MakeBalloon(const Notification& notification,
+                                            Profile* profile) {
+  // TODO(johnnyg): http://crbug.com/23954.  Part of future Linux support.
+  NOTIMPLEMENTED();
+  return NULL;
+}
+
+bool BalloonCollectionImpl::Layout::RefreshSystemMetrics() {
+  // TODO(johnnyg): http://crbug.com/23954.  Part of future Linux support.
+  NOTIMPLEMENTED();
+  return false;
+}
diff --git a/chrome/browser/notifications/balloon_collection_mac.mm b/chrome/browser/notifications/balloon_collection_mac.mm
new file mode 100644
index 0000000..45728fb
--- /dev/null
+++ b/chrome/browser/notifications/balloon_collection_mac.mm
@@ -0,0 +1,22 @@
+// Copyright (c) 2009 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 "chrome/browser/notifications/balloon_collection.h"
+
+#include "base/gfx/size.h"
+#include "base/logging.h"
+
+Balloon* BalloonCollectionImpl::MakeBalloon(const Notification& notification,
+                                            Profile* profile) {
+  // TODO(johnnyg): http://crbug.com/23066.  Part of future Mac support.
+  NOTIMPLEMENTED();
+  return NULL;
+}
+
+bool BalloonCollectionImpl::Layout::RefreshSystemMetrics() {
+  // TODO(johnnyg): http://crbug.com/23066.  Part of future Mac support.
+  NOTIMPLEMENTED();
+  return false;
+}
+
diff --git a/chrome/browser/notifications/balloon_collection_win.cc b/chrome/browser/notifications/balloon_collection_win.cc
new file mode 100644
index 0000000..45f7921
--- /dev/null
+++ b/chrome/browser/notifications/balloon_collection_win.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 2009 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 "chrome/browser/notifications/balloon_collection.h"
+
+#include "base/gfx/rect.h"
+#include "base/logging.h"
+#include "base/stl_util-inl.h"
+#include "chrome/browser/notifications/balloon.h"
+#include "chrome/browser/views/notifications/balloon_view.h"
+
+namespace {
+
+void GetMainScreenWorkArea(gfx::Rect* bounds) {
+  DCHECK(bounds);
+  RECT work_area = {0};
+  if (::SystemParametersInfo(SPI_GETWORKAREA, 0, &work_area, 0)) {
+    bounds->SetRect(work_area.left, work_area.top,
+                    work_area.right, work_area.bottom);
+  } else {
+    // If call to ::SystemParametersInfo fails for some reason, we simply get
+    // the full screen size as an alternative.
+    bounds->SetRect(0, 0,
+                    ::GetSystemMetrics(SM_CXSCREEN) - 1,
+                    ::GetSystemMetrics(SM_CYSCREEN) - 1);
+  }
+}
+
+}  // namespace
+
+Balloon* BalloonCollectionImpl::MakeBalloon(const Notification& notification,
+                                            Profile* profile) {
+  Balloon* balloon = new Balloon(notification, profile, this);
+  balloon->set_view(new BalloonViewImpl());
+  gfx::Size size(layout_.min_balloon_width(), layout_.min_balloon_height());
+  balloon->set_size(size);
+  return balloon;
+}
+
+bool BalloonCollectionImpl::Layout::RefreshSystemMetrics() {
+  bool changed = false;
+
+  gfx::Rect new_work_area(work_area_.x(), work_area_.y(),
+                          work_area_.width(), work_area_.height());
+  GetMainScreenWorkArea(&new_work_area);
+  if (!work_area_.Equals(new_work_area)) {
+    work_area_.SetRect(new_work_area.x(), new_work_area.y(),
+                       new_work_area.width(), new_work_area.height());
+    changed = true;
+  }
+
+  return changed;
+}
diff --git a/chrome/browser/notifications/balloons.h b/chrome/browser/notifications/balloons.h
deleted file mode 100644
index 6191d53..0000000
--- a/chrome/browser/notifications/balloons.h
+++ /dev/null
@@ -1,200 +0,0 @@
-// Copyright (c) 2009 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.
-
-// Handles the visible notification (or balloons).
-
-#ifndef CHROME_BROWSER_NOTIFICATIONS_BALLOONS_H_
-#define CHROME_BROWSER_NOTIFICATIONS_BALLOONS_H_
-
-#include <deque>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/gfx/point.h"
-#include "base/gfx/rect.h"
-#include "base/gfx/size.h"
-#include "base/scoped_ptr.h"
-#include "chrome/browser/notifications/notification.h"
-
-class Balloon;
-class BalloonView;
-class Profile;
-class SiteInstance;
-
-class BalloonCloseListener {
- public:
-  virtual ~BalloonCloseListener() { }
-
-  // Called when a balloon is closed.
-  virtual void OnBalloonClosed(Balloon* source) = 0;
-};
-
-class BalloonSpaceChangeListener {
- public:
-  virtual ~BalloonSpaceChangeListener() { }
-
-  // Called when there is more or less space for balloons due to
-  // monitor size changes or balloons disappearing.
-  virtual void OnBalloonSpaceChanged() = 0;
-};
-
-class BalloonCollectionInterface {
- public:
-  virtual ~BalloonCollectionInterface() {}
-
-  // Adds a new balloon for the specified notification.
-  virtual void Add(const Notification& notification,
-                   Profile* profile,
-                   SiteInstance* site_instance) = 0;
-
-  // Is there room to add another notification?
-  virtual bool HasSpace() const = 0;
-};
-
-typedef std::deque<Balloon*> Balloons;
-
-// Represents a Notification on the screen.
-class Balloon {
- public:
-  Balloon(const Notification& notification,
-          Profile* profile,
-          SiteInstance* site_instance,
-          BalloonCloseListener* listener);
-  ~Balloon();
-
-  const Notification& notification() const {
-    return notification_;
-  }
-
-  Profile* profile() const {
-    return profile_;
-  }
-
-  SiteInstance* site_instance() const {
-    return site_instance_;
-  }
-
-  void SetPosition(const gfx::Point& upper_left, bool reposition);
-  void SetSize(const gfx::Size& size);
-  void Show();
-  void Close();
-
-  const gfx::Point& position() const;
-  const gfx::Size& size() const;
-
- private:
-  Profile* profile_;
-  SiteInstance* site_instance_;
-  Notification notification_;
-  BalloonCloseListener* close_listener_;
-  scoped_ptr<BalloonView> balloon_view_;
-  gfx::Point position_;
-  gfx::Size size_;
-  DISALLOW_COPY_AND_ASSIGN(Balloon);
-};
-
-class BalloonCollection : public BalloonCollectionInterface,
-                          public BalloonCloseListener {
- public:
-  explicit BalloonCollection();
-
-  BalloonSpaceChangeListener* space_change_listener() { return listener_; }
-  void set_space_change_listener(BalloonSpaceChangeListener* listener) {
-    listener_ = listener;
-  }
-
-  // BalloonCollectionInterface overrides
-  virtual void Add(const Notification& notification,
-                   Profile* profile,
-                   SiteInstance* site_instance);
-  virtual void ShowAll();
-  virtual void HideAll();
-  virtual bool HasSpace() const;
-
-  // BalloonCloseListener interface
-  virtual void OnBalloonClosed(Balloon* source);
-
- protected:
-  // Overridable by unit tests.
-  virtual Balloon* MakeBalloon(const Notification& notification,
-                               Profile* profile,
-                               SiteInstance* site_instance) {
-    return new Balloon(notification, profile, site_instance, this);
-  }
-
- private:
-  // The number of balloons being displayed.
-  int count() const { return balloons_.size(); }
-
-  // Calculates layout values for the balloons including
-  // the scaling, the max/min sizes, and the upper left corner of each.
-  class Layout {
-   public:
-    Layout();
-
-    // Refresh the work area and balloon placement.
-    void OnDisplaySettingsChanged();
-
-    int min_balloon_width() const;
-    int max_balloon_width() const;
-    int min_balloon_height() const;
-    int max_balloon_height() const;
-
-    // Returns both the total length available and the maximum
-    // allowed per balloon.
-    //
-    // The length may be a height or length depending on the way that
-    // balloons are laid out.
-    const void GetMaxLengths(int* max_balloon_length, int* total_length) const;
-
-    // Scale the size to count in the system font factor.
-    int ScaleSize(int size) const;
-
-    // Refresh the cached values for work area and drawing metrics.
-    // This is done automatically first time and the application should
-    // call this method to re-acquire metrics after any
-    // resolution or settings change.
-    //
-    // Return true if and only if a metric changed.
-    bool RefreshSystemMetrics();
-
-    // Returns the starting value for NextUpperLeftPosition.
-    gfx::Point GetStartPosition() const;
-
-    // Compute the position for the next balloon.
-    //   Modifies origin.
-    //   Returns the position of the upper left coordinate for the given
-    //   balloon.
-    gfx::Point NextPosition(const gfx::Size& balloon_size,
-                            gfx::Point* origin) const;
-
-   private:
-    enum Placement {
-      HORIZONTALLY_FROM_BOTTOM_LEFT,
-      HORIZONTALLY_FROM_BOTTOM_RIGHT,
-      VERTICALLY_FROM_TOP_RIGHT,
-      VERTICALLY_FROM_BOTTOM_RIGHT
-    };
-
-    // Minimum and maximum size of balloon
-    static const int kBalloonMinWidth = 300;
-    static const int kBalloonMaxWidth = 300;
-    static const int kBalloonMinHeight = 90;
-    static const int kBalloonMaxHeight = 120;
-
-    static Placement placement_;
-    gfx::Rect work_area_;
-    double font_scale_factor_;
-    DISALLOW_COPY_AND_ASSIGN(Layout);
-  };
-
-  // Non-owned pointer to an object listening for space changes.
-  BalloonSpaceChangeListener* listener_;
-
-  Balloons balloons_;
-  Layout layout_;
-  DISALLOW_COPY_AND_ASSIGN(BalloonCollection);
-};
-
-#endif  // CHROME_BROWSER_NOTIFICATIONS_BALLOONS_H_