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

1 files changed, 172 insertions, 0 deletions

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);
+}