Add an option to tree_view for whether to show lines from the root node...

views/controls/tree/tree_view.cc

 // Copyright (c) 2006-2008 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 "views/controls/tree/tree_view.h"
 
 #include <vector>
 
 #include "app/gfx/canvas.h"
 #include "app/gfx/canvas_paint.h"
 #include "app/gfx/favicon_size.h"
 #include "app/gfx/icon_util.h"
 #include "app/l10n_util.h"
 #include "app/l10n_util_win.h"
 #include "app/resource_bundle.h"
 #include "base/gfx/point.h"
 #include "base/keyboard_codes.h"
 #include "base/stl_util-inl.h"
 #include "base/win_util.h"
 #include "grit/app_resources.h"
 #include "views/focus/focus_manager.h"
 #include "views/widget/widget.h"
 
 namespace views {
 
 TreeView::TreeView()
     : tree_view_(NULL),
       model_(NULL),
+      auto_expand_children_(false),
       editable_(true),
       next_id_(0),
       controller_(NULL),
       editing_node_(NULL),
       root_shown_(true),
+      lines_at_root_(false),
       process_enter_(false),
       show_context_menu_only_when_node_selected_(true),
       select_on_right_mouse_down_(true),
       ALLOW_THIS_IN_INITIALIZER_LIST(wrapper_(this)),
       original_handler_(NULL),
       drag_enabled_(false),
       has_custom_icons_(false),
       image_list_(NULL) {
 }
 
@@ skipping 300 matching lines @@
   ConvertPointToScreen(this, &screen_loc);
   return screen_loc;
 }
 
 HWND TreeView::CreateNativeControl(HWND parent_container) {
   int style = WS_CHILD | TVS_HASBUTTONS | TVS_HASLINES | TVS_SHOWSELALWAYS;
   if (!drag_enabled_)
     style |= TVS_DISABLEDRAGDROP;
   if (editable_)
     style |= TVS_EDITLABELS;
+  if (lines_at_root_)
+    style |= TVS_LINESATROOT;
   tree_view_ = ::CreateWindowEx(WS_EX_CLIENTEDGE | GetAdditionalExStyle(),
                                 WC_TREEVIEW,
                                 L"",
                                 style,
                                 0, 0, width(), height(),
                                 parent_container, NULL, NULL, NULL);
   SetWindowLongPtr(tree_view_, GWLP_USERDATA,
                    reinterpret_cast<LONG_PTR>(&wrapper_));
   original_handler_ = win_util::SetWindowProc(tree_view_,
                                               &TreeWndProc);
@@ skipping 44 matching lines @@
 
     case TVN_ITEMEXPANDING: {
       // Notification that a node is expanding. If we haven't populated the
       // tree view with the contents of the model, we do it here.
       DCHECK(model_);
       NMTREEVIEW* info = reinterpret_cast<NMTREEVIEW*>(l_param);
       NodeDetails* details =
           GetNodeDetailsByID(static_cast<int>(info->itemNew.lParam));
       if (!details->loaded_children) {
         details->loaded_children = true;
-        for (int i = 0; i < model_->GetChildCount(details->node); ++i)
+        for (int i = 0; i < model_->GetChildCount(details->node); ++i) {
           CreateItem(details->tree_item, TVI_LAST,
                        model_->GetChild(details->node, i));
+          if (auto_expand_children_)
+            Expand(model_->GetChild(details->node, i));
+        }
       }
       // Return FALSE to allow the item to be expanded.
       return FALSE;
     }
 
     case TVN_SELCHANGED:
       if (controller_)
         controller_->OnTreeViewSelectionChanged(this);
       break;
 
@@ skipping 334 matching lines @@
       }
       // Fall through and let the default handler process as well.
       break;
   }
   WNDPROC handler = tree->original_handler_;
   DCHECK(handler);
   return CallWindowProc(handler, window, message, w_param, l_param);
 }
 
 }  // namespace views