Separate the logic of popup alignment and workarea handling as delegate.

ash/system/web_notification/popup_alignment_delegate.cc

+// Copyright 2014 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/system/web_notification/popup_alignment_delegate.h"
+
+#include "ash/display/display_controller.h"
+#include "ash/shelf/shelf_constants.h"
+#include "ash/shelf/shelf_layout_manager.h"
+#include "ash/shelf/shelf_types.h"
+#include "ash/shelf/shelf_widget.h"
+#include "ash/shell.h"
+#include "base/i18n/rtl.h"
+#include "ui/aura/window.h"
+#include "ui/gfx/display.h"
+#include "ui/gfx/geometry/rect.h"
+#include "ui/gfx/screen.h"
+#include "ui/message_center/message_center_style.h"
+#include "ui/message_center/views/message_popup_collection.h"
+
+namespace ash {
+
+namespace {
+
+const int kToastMarginX = 3;
+
+// If there should be no margin for the first item, this value needs to be
+// substracted to flush the message to the shelf (the width of the border +
+// shadow).
+const int kNoToastMarginBorderAndShadowOffset = 2;
+
+}
+
+PopupAlignmentDelegate::PopupAlignmentDelegate()
+    : display_id_(gfx::Display::kInvalidDisplayID),
+      screen_(NULL),

[stevenjb, 2014/07/02 21:59:23]

root_window_(NULL)

[Jun Mukai, 2014/07/07 18:12:35]

Done.

+      shelf_(NULL),
+      system_tray_height_(0) {
+}
+
+PopupAlignmentDelegate::~PopupAlignmentDelegate() {
+  if (screen_)
+    screen_->RemoveObserver(this);
+  Shell::GetInstance()->RemoveShellObserver(this);
+  if (shelf_)
+    shelf_->RemoveObserver(this);
+  shelf_ = NULL;

[stevenjb, 2014/07/02 21:59:23]

nit: unnecessary (and inconsistent with screen_)

[Jun Mukai, 2014/07/07 18:12:35]

Done.

+}
+
+void PopupAlignmentDelegate::StartObserving(
+    gfx::Screen* screen, const gfx::Display& display) {

[stevenjb, 2014/07/02 21:59:23]

one line per arg

[Jun Mukai, 2014/07/07 18:12:35]

Done.

+  screen_ = screen;
+  display_id_ = display.id();
+  UpdateShelf();
+  screen->AddObserver(this);
+  Shell::GetInstance()->AddShellObserver(this);
+  if (system_tray_height_ > 0)
+    OnAutoHideStateChanged(shelf_->auto_hide_state());
+}
+
+void PopupAlignmentDelegate::SetSystemTrayHeight(int height) {
+  system_tray_height_ = height;
+
+  // If the shelf is shown during auto-hide state, the distance from the edge
+  // should be reduced by the height of shelf's shown height.
+  if (shelf_ && shelf_->visibility_state() == SHELF_AUTO_HIDE &&
+      shelf_->auto_hide_state() == SHELF_AUTO_HIDE_SHOWN) {
+    system_tray_height_ -= kShelfSize - ShelfLayoutManager::kAutoHideSize;
+  }
+
+  if (system_tray_height_ > 0)
+    system_tray_height_ += message_center::kMarginBetweenItems;
+  else
+    system_tray_height_ = 0;
+
+  if (!shelf_)
+    return;
+
+  DoUpdateIfPossible();
+}
+
+int PopupAlignmentDelegate::GetToastOriginX(
+    const gfx::Rect& toast_bounds) const {
+  // In Ash, RTL UI language mirrors the whole ash layout, so the toast
+  // widgets should be at the bottom-left instead of bottom right.
+  if (base::i18n::IsRTL())
+    return work_area_.x() + kToastMarginX;
+
+  if (IsFromLeft())
+    return work_area_.x() + kToastMarginX;
+  return work_area_.right() - kToastMarginX - toast_bounds.width();
+}
+
+int PopupAlignmentDelegate::GetBaseLine() const {
+  return IsTopDown()
+      ? work_area_.y() + kNoToastMarginBorderAndShadowOffset +
+        system_tray_height_
+      : work_area_.bottom() - kNoToastMarginBorderAndShadowOffset -
+        system_tray_height_;
+}
+
+int PopupAlignmentDelegate::GetWorkAreaBottom() const {
+  return work_area_.bottom() - system_tray_height_;
+}
+
+bool PopupAlignmentDelegate::IsTopDown() const {
+  return GetAlignment() == SHELF_ALIGNMENT_TOP;
+}
+
+bool PopupAlignmentDelegate::IsFromLeft() const {
+  return GetAlignment() == SHELF_ALIGNMENT_LEFT;
+}
+
+ShelfAlignment PopupAlignmentDelegate::GetAlignment() const {
+  return shelf_ ? shelf_->GetAlignment() : SHELF_ALIGNMENT_BOTTOM;
+}
+
+void PopupAlignmentDelegate::UpdateShelf() {
+  if (shelf_)
+    return;
+
+  aura::Window* root_window = ash::Shell::GetInstance()->display_controller()->
+      GetRootWindowForDisplayId(display_id_);
+  shelf_ = ShelfLayoutManager::ForShelf(root_window);
+  if (shelf_)
+    shelf_->AddObserver(this);
+}
+
+void PopupAlignmentDelegate::OnDisplayWorkAreaInsetsChanged() {
+  UpdateShelf();
+
+  work_area_ = Shell::GetScreen()->GetDisplayNearestWindow(
+      shelf_->shelf_widget()->GetNativeView()).work_area();
+}
+
+void PopupAlignmentDelegate::OnAutoHideStateChanged(
+    ShelfAutoHideState new_state) {
+  work_area_ = Shell::GetScreen()->GetDisplayNearestWindow(
+      shelf_->shelf_widget()->GetNativeView()).work_area();
+  int width = 0;
+  if ((shelf_->visibility_state() == SHELF_AUTO_HIDE) &&
+      new_state == SHELF_AUTO_HIDE_SHOWN) {
+    // Since the work_area is already reduced by kAutoHideSize, the inset width
+    // should be just the difference.
+    width = kShelfSize - ShelfLayoutManager::kAutoHideSize;
+  }
+  work_area_.Inset(shelf_->SelectValueForShelfAlignment(
+      gfx::Insets(0, 0, width, 0),
+      gfx::Insets(0, width, 0, 0),
+      gfx::Insets(0, 0, 0, width),
+      gfx::Insets(width, 0, 0, 0)));
+
+  DoUpdateIfPossible();
+}
+
+void PopupAlignmentDelegate::OnDisplayAdded(
+    const gfx::Display& new_display) {
+}
+
+void PopupAlignmentDelegate::OnDisplayRemoved(
+    const gfx::Display& old_display) {
+}
+
+void PopupAlignmentDelegate::OnDisplayMetricsChanged(
+    const gfx::Display& display,
+    uint32_t metrics) {
+  if (display.id() == display_id_ && shelf_)
+    OnAutoHideStateChanged(shelf_->auto_hide_state());
+}
+
+}  // namespace ash