Implement ui for re-parenting an item from an app list folder to another position or folder in the …

ui/app_list/app_list_folder_item.cc

 // Copyright 2013 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/app_list/app_list_folder_item.h"
 
 #include "base/guid.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_item_list.h"
 #include "ui/gfx/canvas.h"
@@ skipping 88 matching lines @@
       new FolderImageSource(top_icons, icon_size),
       icon_size);
   SetIcon(icon, false);
 }
 
 const gfx::ImageSkia& AppListFolderItem::GetTopIcon(size_t item_index) {
   DCHECK(item_index <= top_items_.size());
   return top_items_[item_index]->icon();
 }
 
+gfx::Rect AppListFolderItem::GetTargetIconRectInFolderForItem(
+    AppListItem* item,
+    const gfx::Rect& folder_icon_bounds) {
+  for (size_t i = 0; i < top_items_.size(); ++i) {
+    if (item->id() == top_items_[i]->id()) {
+      Rects rects = AppListFolderItem::GetTopIconsBounds(folder_icon_bounds);
+      return rects[i];
+    }
+  }
+
+  gfx::Rect target_rect(folder_icon_bounds);
+  target_rect.ClampToCenteredSize(
+      gfx::Size(kItemIconDimension, kItemIconDimension));
+  return target_rect;
+}
+
 void AppListFolderItem::Activate(int event_flags) {
   // Folder handling is implemented by the View, so do nothing.
 }
 
 // static
 const char AppListFolderItem::kItemType[] = "FolderItem";
 
 // static
 Rects AppListFolderItem::GetTopIconsBounds(
     const gfx::Rect& folder_icon_bounds) {
@@ skipping 105 matching lines @@
   for (size_t i = 0;
        i < kNumFolderTopItems && i < item_list_->item_count(); ++i) {
     AppListItem* item = item_list_->item_at(i);
     item->AddObserver(this);
     top_items_.push_back(item);
   }
   UpdateIcon();
 }
 
 }  // namespace app_list