Adjust bookmark folder menu window if its parent button is partly off-screen to the left.

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 540 matching lines @@
     newWindowTopLeft.x = [self childFolderWindowLeftForWidth:windowWidth];
     NSPoint topOfWindow = NSMakePoint(0,
                                       NSMaxY([parentButton_ frame]) -
                                           bookmarks::kBookmarkVerticalPadding);
     topOfWindow = [[parentButton_ window]
                    convertBaseToScreen:[[parentButton_ superview]
                                         convertPoint:topOfWindow toView:nil]];
     newWindowTopLeft.y = topOfWindow.y +
                          2 * bookmarks::kBookmarkVerticalPadding;
   }
+
+  // If parent button was partially off screen to the left, offset it's folder
+  // menu window horizontally, so that complete menu is seen from the left.
+  if (newWindowTopLeft.x < 0.0)

[Alexei Svitkine (slow), 2014/10/06 17:55:28]

Are you sure this is correct?

What if the user has two monitors and the main monitor (with the menu bar) is to
right of the secondary monitor? And the user's Chrome window is on the second
screen (on the left).

I suspect that this will result in the coordinates being negative but not
needing adjustment.

Can you verify that case?

[Gaja, 2014/10/07 07:41:10]

Oh, I did not think of it. But I have a doubt here.

If the button is partially off screen on the right, its menu is shown completely
i.e it is adjusted such that its full width is seen.
If user has two monitors and secondary monitor is on to the right of main
monitor, in this case the menu shares both the screens?

I do not have multi monitor setup to verify :(

I will use the logic written to handle on the right side, and upload the changes
in patch set 2.

+    newWindowTopLeft.x = 0.0;
+
   return newWindowTopLeft;
 }
 
 // Set our window level to the right spot so we're above the menubar, dock, etc.
 // Factored out so we can override/noop in a unit test.
 - (void)configureWindowLevel {
   [[self window] setLevel:NSPopUpMenuWindowLevel];
 }
 
 - (int)menuHeightForButtonCount:(int)buttonCount {
@@ skipping 1432 matching lines @@
 
 - (void)setIgnoreAnimations:(BOOL)ignore {
   ignoreAnimations_ = ignore;
 }
 
 - (BookmarkButton*)buttonThatMouseIsIn {
   return buttonThatMouseIsIn_;
 }
 
 @end  // BookmarkBarFolderController