Split app list drop target into reorder and folder drop targets.

ui/app_list/views/apps_grid_view.h

 // 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.
 
 #ifndef UI_APP_LIST_VIEWS_APPS_GRID_VIEW_H_
 #define UI_APP_LIST_VIEWS_APPS_GRID_VIEW_H_
 
 #include <set>
 #include <string>
 
@@ skipping 273 matching lines @@
                             bool animate_target,
                             const gfx::Rect& target);
 
   // Extracts drag location info from |event| into |drag_point|.
   void ExtractDragLocation(const ui::LocatedEvent& event,
                            gfx::Point* drag_point);
 
   // Calculates |drop_target_| based on |drag_point|. |drag_point| is in the
   // grid view's coordinates. When |use_page_button_hovering| is true and
   // |drag_point| is hovering on a page button, use the last slot on that page
   // as drop target.

[Matt Giuca, 2014/09/12 01:13:28]

Rewrite this comment now that |drop_target_| has been split up, and also note
that this method will set |drop_attempt_| as well.

[calamity, 2014/09/12 08:26:06]

Done.

   void CalculateDropTarget(const gfx::Point& drag_point,
                            bool use_page_button_hovering);
 
   // Same as CalculateDropTarget, but with folder UI enabled. The |drop_target_|
   // can be either a target for re-ordering, or a target folder to move the
   // dragged item into if |drag_view_| enters its re-ordering or folder
   // dropping circle.

[Matt Giuca, 2014/09/12 01:13:28]

Ditto (and see my comments in this method's implementation).

[calamity, 2014/09/12 08:26:06]

Done.

   void CalculateDropTargetWithFolderEnabled(const gfx::Point& drag_point,
                                             bool use_page_button_hovering);
 
   // Prepares |drag_and_drop_host_| for dragging. |grid_location| contains
   // the drag point in this grid view's coordinates.
   void StartDragAndDropHostDrag(const gfx::Point& grid_location);
 
   // Dispatch the drag and drop update event to the dnd host (if needed).
   void DispatchDragEventToDragAndDropHost(
       const gfx::Point& location_in_screen_coordinates);
@@ skipping 71 matching lines @@
   // If |hide| is set the view will get hidden, otherwise it gets shown.
   void SetViewHidden(views::View* view, bool hide, bool immediate);
 
   // Whether the folder drag-and-drop UI should be enabled.
   bool EnableFolderDragDropUI();
 
   // Whether target specified by |drap_target| can accept more items to be
   // dropped into it.
   bool CanDropIntoTarget(const Index& drop_target);
 
-  // Returns the visual index of the nearest tile in which |drag_view_| enters
-  // either its re-ordering or folder dropping circle.
-  Index GetNearestTileForDragView();
+  // Calculates the visual index of the nearest tile for which |drag_view_|
+  // enters either its re-ordering or folder dropping circle.
+  void CalculateNearestTileForDragView();
 
   // Calculates |nearest_tile| in which |vertex| of the |drag_view| is
   // enclosed.
   // *|nearest_tile| and *|d_min| will be updated based on the calculation.
   // *|d_min| is the distance between |nearest_tile| and |drag_view_|.
   void CalculateNearestTileForVertex(
       const gfx::Point& vertex, Index* nearest_tile, int* d_min);
 
   // Returns the bounds of the tile in which |point| is enclosed if there
   // is a valid item sits on the tile.
@@ skipping 100 matching lines @@
 #if defined(OS_WIN)
   // Created when a drag is started (ie: drag exceeds the drag threshold), but
   // not Run() until supplied with a shortcut path.
   scoped_refptr<SynchronousDrag> synchronous_drag_;
 
   // Whether to use SynchronousDrag to support dropping to task bar etc.
   bool use_synchronous_drag_;
 #endif
 
   Pointer drag_pointer_;
-  Index drop_target_;
+
+  // The most recent reorder drop target.
+  Index reorder_drop_target_;
+
+  // The most recent folder drop target.
+  Index folder_drop_target_;
+
+  // The current action that ending a drag will perform.
   DropAttempt drop_attempt_;
 
   // Timer for re-ordering the |drop_target_| and |drag_view_|.
   base::OneShotTimer<AppsGridView> reorder_timer_;
 
   // Timer for dropping |drag_view_| into the folder containing
   // the |drop_target_|.
   base::OneShotTimer<AppsGridView> folder_dropping_timer_;
 
   // Timer for dragging a folder item out of folder container ink bubble.
@@ skipping 30 matching lines @@
 
   // True if the drag_view_ item is a folder item being dragged for reparenting.
   bool dragging_for_reparent_item_;
 
   DISALLOW_COPY_AND_ASSIGN(AppsGridView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_APPS_GRID_VIEW_H_