[Aura] Implement views-based applist.

Implement a views-based applist behind "aura-views-applist" flag.

BUG=98308,105913
TEST=Views-based app list should have no lag.


Review URL: http://codereview.chromium.org/8890049

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@115515 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 296 insertions, 0 deletions

diff --git a/ui/base/models/list_model.h b/ui/base/models/list_model.h
new file mode 100644
index 0000000..3634ed1
--- /dev/null
+++ b/ui/base/models/list_model.h
@@ -0,0 +1,116 @@
+// 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.
+
+#ifndef UI_BASE_MODELS_LIST_MODEL_H_
+#define UI_BASE_MODELS_LIST_MODEL_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/observer_list.h"
+#include "base/memory/scoped_vector.h"
+#include "ui/base/models/list_model_observer.h"
+
+namespace ui {
+
+// A list model that manages a list of ItemType pointers. Items added to the
+// model are owned by the model. An item can be taken out of the model by
+// RemoveAt.
+template <class ItemType>
+class ListModel {
+ public:
+  typedef std::vector<ItemType*> Items;
+
+  ListModel() {}
+  virtual ~ListModel() {}
+
+  // Adds |item| to the model at given |index|.
+  virtual void AddAt(int index, ItemType* item) {
+    DCHECK(index >= 0 && index <= item_count());
+    items_->insert(items_.begin() + index, item);
+    NotifyItemsAdded(index, 1);
+  }
+
+  // Removes an item at given |index| from the model. Note the removed item
+  // is NOT deleted and it's up to the caller to delete it.
+  virtual ItemType* RemoveAt(int index) {
+    DCHECK(index >= 0 && index < item_count());
+    ItemType* item = items_[index];
+    items_->erase(items_.begin() + index);
+    NotifyItemsRemoved(index, 1);
+    return item;
+  }
+
+  // Removes all items from the model. This does NOT delete the items.
+  virtual void RemoveAll() {
+    int count = item_count();
+    items_->clear();
+    NotifyItemsRemoved(0, count);
+  }
+
+  // Removes an item at given |index| from the model and deletes it.
+  virtual void DeleteAt(int index) {
+    delete RemoveAt(index);
+  }
+
+  // Removes and deletes all items from the model.
+  virtual void DeleteAll() {
+    int count = item_count();
+    items_.reset();
+    NotifyItemsRemoved(0, count);
+  }
+
+  // Convenience function to append an item to the model.
+  void Add(ItemType* item) {
+    AddAt(item_count(), item);
+  }
+
+  void AddObserver(ListModelObserver* observer) {
+    observers_.AddObserver(observer);
+  }
+
+  void RemoveObserver(ListModelObserver* observer) {
+    observers_.RemoveObserver(observer);
+  }
+
+  void NotifyItemsAdded(int start, int count) {
+    FOR_EACH_OBSERVER(ListModelObserver,
+                      observers_,
+                      ListItemsAdded(start, count));
+  }
+
+  void NotifyItemsRemoved(int start, int count) {
+    FOR_EACH_OBSERVER(ListModelObserver,
+                      observers_,
+                      ListItemsRemoved(start, count));
+  }
+
+  void NotifyItemsChanged(int start, int count) {
+    FOR_EACH_OBSERVER(ListModelObserver,
+                      observers_,
+                      ListItemsChanged(start, count));
+  }
+
+  int item_count() const { return static_cast<int>(items_.size()); }
+  const Items& items() const { return items_.get(); }
+
+  const ItemType* item_at(int index) const {
+    DCHECK(index >= 0 && index < item_count());
+    return items_[index];
+  }
+  ItemType* item_at(int index) {
+    return const_cast<ItemType*>(
+        const_cast<const ListModel<ItemType>*>(this)->item_at(index));
+  }
+
+ private:
+  ScopedVector<ItemType> items_;
+  ObserverList<ListModelObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ListModel<ItemType>);
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_MODELS_LIST_MODEL_H_
diff --git a/ui/base/models/list_model_observer.h b/ui/base/models/list_model_observer.h
new file mode 100644
index 0000000..65b22a8
--- /dev/null
+++ b/ui/base/models/list_model_observer.h
@@ -0,0 +1,31 @@
+// 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.
+
+#ifndef UI_BASE_MODELS_LIST_MODEL_OBSERVER_H_
+#define UI_BASE_MODELS_LIST_MODEL_OBSERVER_H_
+#pragma once
+
+#include "ui/base/ui_export.h"
+
+namespace ui {
+
+class UI_EXPORT ListModelObserver {
+ public:
+  // Invoked after items has been added to the model.
+  virtual void ListItemsAdded(int start, int count) = 0;
+
+  // Invoked after items has been removed. |start| is the index before the
+  // removal.
+  virtual void ListItemsRemoved(int start, int count) = 0;
+
+  // Invoked after items has been changed.
+  virtual void ListItemsChanged(int start, int count) = 0;
+
+ protected:
+  virtual ~ListModelObserver() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_MODELS_LIST_MODEL_OBSERVER_H_
diff --git a/ui/base/models/list_model_unittest.cc b/ui/base/models/list_model_unittest.cc
new file mode 100644
index 0000000..1718431
--- /dev/null
+++ b/ui/base/models/list_model_unittest.cc
@@ -0,0 +1,149 @@
+// 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 "ui/base/models/list_model.h"
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace ui {
+
+class FooItem {
+ public:
+  explicit FooItem(int id) : id_(id) {}
+
+  int id() const { return id_; }
+
+ private:
+  int id_;
+  DISALLOW_COPY_AND_ASSIGN(FooItem);
+};
+
+class ListModelTest : public testing::Test,
+                      public ListModelObserver {
+ public:
+  ListModelTest()
+      : added_count_(0),
+        removed_count_(0),
+        changed_count_(0) {
+  }
+
+  void ExpectCountsEqual(int added_count,
+                         int removed_count,
+                         int changed_count) {
+    EXPECT_EQ(added_count, added_count_);
+    EXPECT_EQ(removed_count, removed_count_);
+    EXPECT_EQ(changed_count, changed_count_);
+  }
+
+  void ClearCounts() {
+    added_count_ = removed_count_ = changed_count_ = 0;
+  }
+
+  // ListModelObserver implementation:
+  virtual void ListItemsAdded(int start, int count) OVERRIDE {
+    added_count_ += count;
+  }
+  virtual void ListItemsRemoved(int start, int count) OVERRIDE {
+    removed_count_ += count;
+  }
+  virtual void ListItemsChanged(int start, int count) OVERRIDE {
+    changed_count_ += count;
+  }
+
+ private:
+  int added_count_;
+  int removed_count_;
+  int changed_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(ListModelTest);
+};
+
+TEST_F(ListModelTest, Add) {
+  ListModel<FooItem> model;
+  model.AddObserver(this);
+
+  // Append FooItem(0)
+  model.Add(new FooItem(0));
+  ExpectCountsEqual(1, 0, 0);
+
+  // Append FooItem(1)
+  model.Add(new FooItem(1));
+  ExpectCountsEqual(2, 0, 0);
+
+  // Insert FooItem(2) at position 0
+  model.AddAt(0, new FooItem(2));
+  ExpectCountsEqual(3, 0, 0);
+
+  // Total 3 items in mode.
+  EXPECT_EQ(3, model.item_count());
+
+  // First one should be FooItem(2), followed by FooItem(0) and FooItem(1)
+  EXPECT_EQ(2, model.item_at(0)->id());
+  EXPECT_EQ(0, model.item_at(1)->id());
+  EXPECT_EQ(1, model.item_at(2)->id());
+}
+
+TEST_F(ListModelTest, Remove) {
+  ListModel<FooItem> model;
+  model.AddObserver(this);
+
+  model.Add(new FooItem(0));
+  model.Add(new FooItem(1));
+  model.Add(new FooItem(2));
+
+  ClearCounts();
+
+  // Remove item at index 1 from model and release memory.
+  model.DeleteAt(1);
+  ExpectCountsEqual(0, 1, 0);
+
+  EXPECT_EQ(2, model.item_count());
+  EXPECT_EQ(0, model.item_at(0)->id());
+  EXPECT_EQ(2, model.item_at(1)->id());
+
+  // Remove all items from model and delete them.
+  model.DeleteAll();
+  ExpectCountsEqual(0, 3, 0);
+}
+
+TEST_F(ListModelTest, RemoveAll) {
+  ListModel<FooItem> model;
+  model.AddObserver(this);
+
+  scoped_ptr<FooItem> foo0(new FooItem(0));
+  scoped_ptr<FooItem> foo1(new FooItem(1));
+  scoped_ptr<FooItem> foo2(new FooItem(2));
+
+  model.Add(foo0.get());
+  model.Add(foo1.get());
+  model.Add(foo2.get());
+
+  ClearCounts();
+
+  // Remove all items and scoped_ptr above would release memory.
+  model.RemoveAll();
+  ExpectCountsEqual(0, 3, 0);
+}
+
+TEST_F(ListModelTest, FakeUpdate) {
+  ListModel<FooItem> model;
+  model.AddObserver(this);
+
+  model.Add(new FooItem(0));
+  model.Add(new FooItem(1));
+  model.Add(new FooItem(2));
+
+  ClearCounts();
+
+  model.NotifyItemsChanged(0, 1);
+  ExpectCountsEqual(0, 0, 1);
+
+  model.NotifyItemsChanged(1, 2);
+  ExpectCountsEqual(0, 0, 3);
+}
+
+}  // namespace ui