Move bookmark's folder menu upwards only when its parent button is moved

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #import "chrome/browser/bookmarks/bookmark_model_factory.h"
@@ skipping 1919 matching lines @@
     NSRect buttonFrame = [button frame];
     buttonFrame.origin.y -= bookmarks::kBookmarkFolderButtonHeight;
     [button setFrame:buttonFrame];
   }
   // Search for and adjust submenus, if necessary.
   NSInteger buttonCount = [buttons_ count];
   if (buttonCount) {
     BookmarkButton* subButton = [folderController_ parentButton];
     for (NSButton* aButton in buttons_.get()) {
       // If this button is showing its menu then we need to move the menu, too.
-      if (aButton == subButton)
-        [folderController_
-            offsetFolderMenuWindow:NSMakeSize(0.0, chrome::kBookmarkBarHeight)];
+      if (aButton == subButton) {
+        NSInteger targetIndex = [buttons_ indexOfObject:aButton];

[Alexei Svitkine (slow), 2014/10/06 15:37:30]

This results in O(n^2) behavior, since -indexOfObject: will find the index from
the array again.

Can you avoid this? Either add an index variable and increment it in the loop or
alternatively change it to a for (int i = 0; ... loop.

[Gaja, 2014/10/07 04:39:12]

Done. Making use of an index variable by incrementing it in loop.

+        if ((targetIndex + 1) > buttonIndex) {

[Alexei Svitkine (slow), 2014/10/06 15:37:30]

Can you add a comment explaining this?

Maybe if you combine with the above if statement once index is being tracked,
just add to the existing comment above.

[Gaja, 2014/10/07 04:39:12]

Done. I have added it to existing comment above.

+          [folderController_ offsetFolderMenuWindow:NSMakeSize(0.0,
+                                 bookmarks::kBookmarkFolderButtonHeight)];
+        }
+      }
     }
   } else if (parentButton_ != [barController_ otherBookmarksButton]) {
     // If all nodes have been removed from this folder then add in the
     // 'empty' placeholder button except for "Other bookmarks" folder
     // as we are going to hide it.
     NSRect buttonFrame =
         GetFirstButtonFrameForHeight([self menuHeightForButtonCount:1]);
     BookmarkButton* button = [self makeButtonForNode:nil
                                                frame:buttonFrame];
     [buttons_ addObject:button];
@@ skipping 50 matching lines @@
 
 - (void)setIgnoreAnimations:(BOOL)ignore {
   ignoreAnimations_ = ignore;
 }
 
 - (BookmarkButton*)buttonThatMouseIsIn {
   return buttonThatMouseIsIn_;
 }
 
 @end  // BookmarkBarFolderController