chromeos: Sync animation.

ash/launcher/launcher_model.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/launcher_model.h"
 
 #include <algorithm>
 
 #include "ash/launcher/launcher_model_observer.h"
-#include "ui/aura/window.h"
 
 namespace ash {
 
 namespace {
 
+const int kMaxLoadingPlaceholder = 4;
+
 int LauncherItemTypeToWeight(LauncherItemType type) {
   switch (type) {
     case TYPE_BROWSER_SHORTCUT:
       return 0;
     case TYPE_APP_SHORTCUT:
       return 1;
+    case TYPE_APP_PLACEHOLDER:
+      return 2;
     case TYPE_TABBED:
     case TYPE_APP_PANEL:
     case TYPE_PLATFORM_APP:
-      return 2;
+      return 3;
     case TYPE_APP_LIST:
-      return 3;
+      return 4;
   }
 
   NOTREACHED() << "Invalid type " << type;
-  return 2;
+  return 3;
 }
 
 bool CompareByWeight(const LauncherItem& a, const LauncherItem& b) {
   return LauncherItemTypeToWeight(a.type) < LauncherItemTypeToWeight(b.type);
 }
 
 }  // namespace
 
-LauncherModel::LauncherModel() : next_id_(1) {
+LauncherModel::LauncherModel() : next_id_(1), ui_state_(NORMAL) {
   LauncherItem app_list;
   app_list.type = TYPE_APP_LIST;
   app_list.is_incognito = false;
 
   LauncherItem browser_shortcut;
   browser_shortcut.type = TYPE_BROWSER_SHORTCUT;
   browser_shortcut.is_incognito = false;
 
   AddAt(0, browser_shortcut);
   AddAt(1, app_list);
 }
 
 LauncherModel::~LauncherModel() {
 }
 
 int LauncherModel::Add(const LauncherItem& item) {
   return AddAt(items_.size(), item);
 }
 
 int LauncherModel::AddAt(int index, const LauncherItem& item) {
+  // Remove loading placeholders when adding app shortcuts in loading state.
+  if (ui_state_ == LOADING && item.type == TYPE_APP_SHORTCUT) {
+    int placeholders = GetDesiredNumOfPlaceholders();
+    if (placeholders > 0)
+      UpdatePlaceholders(placeholders - 1);
+  }
+
   index = ValidateInsertionIndex(item.type, index);
   items_.insert(items_.begin() + index, item);
   items_[index].id = next_id_++;
   FOR_EACH_OBSERVER(LauncherModelObserver, observers_,
                     LauncherItemAdded(index));
   return index;
 }
 
 void LauncherModel::RemoveItemAt(int index) {
   DCHECK(index >= 0 && index < item_count());
@@ skipping 48 matching lines @@
 }
 
 void LauncherModel::AddObserver(LauncherModelObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void LauncherModel::RemoveObserver(LauncherModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
+void LauncherModel::SetUIState(UIState ui_state) {
+  if (ui_state_ == ui_state)
+    return;
+
+  ui_state_ = ui_state;
+  UpdatePlaceholders(ui_state_ == LOADING ? GetDesiredNumOfPlaceholders() : 0);
+  FOR_EACH_OBSERVER(LauncherModelObserver, observers_,
+                    LauncherUIStateChanged());
+}
+
 int LauncherModel::ValidateInsertionIndex(LauncherItemType type,
                                           int index) const {
   DCHECK(index >= 0 && index <= item_count());
 
   // Clamp |index| to the allowed range for the type as determined by |weight|.
   LauncherItem weight_dummy;
   weight_dummy.type = type;
   index = std::max(std::lower_bound(items_.begin(), items_.end(), weight_dummy,
                                     CompareByWeight) - items_.begin(),
                    static_cast<LauncherItems::difference_type>(index));
   index = std::min(std::upper_bound(items_.begin(), items_.end(), weight_dummy,
                                     CompareByWeight) - items_.begin(),
                    static_cast<LauncherItems::difference_type>(index));
 
   return index;
 }
 
+int LauncherModel::GetDesiredNumOfPlaceholders() {
+  int desired_placholders = kMaxLoadingPlaceholder;
+
+  for (int i = 0; i < item_count() && desired_placholders; ++i) {
+    if (items_[i].type == TYPE_APP_SHORTCUT)
+      --desired_placholders;
+  }
+
+  return desired_placholders;
+}
+
+void LauncherModel::UpdatePlaceholders(int n) {
+  int count = 0;
+
+  for (int index = item_count() - 1; index >= 0; --index) {
+    if (items_[index].type == TYPE_APP_PLACEHOLDER) {

[sky, 2012/08/14 20:02:34]

Having to toggle the type like this feels hacky. What didn't you like about
STATUS_IS_PENDING? Or renaming it to STATUS_LOADING?

[xiyuan, 2012/08/14 23:11:32]

The problem with STATUS_IS_PENDING approach is that it is just a status and
needs to be bound with a TYPE_APP_SHORTCUT (or other types). But the pulse
animation could be started before we could create such items and needs to have
at least 4 of them running in loading state. And we need to create fake
TYPE_APP_SHORTCUT with STAUTS_IS_PENDING in this case. I feel using a new type
is simpler and cleaner than doing this.

+      if (count == n)
+        RemoveItemAt(index);
+      else
+        ++count;
+    }
+  }
+
+  while (count < n) {
+    LauncherItem placeholder;
+    placeholder.type = TYPE_APP_PLACEHOLDER;
+    placeholder.is_incognito = false;
+
+    Add(placeholder);
+    ++count;
+  }
+}
+
 }  // namespace ash