Ensure the previously active browser window gets the focus after a browser window is closed on OSX.

chrome/browser/ui/cocoa/browser_window_utils.mm

 // Copyright (c) 2011 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/browser_window_utils.h"
 
 #include <Carbon/Carbon.h>
 
 #include "base/logging.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/global_keyboard_shortcuts_mac.h"
 #include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_window.h"
 #import "chrome/browser/ui/cocoa/chrome_event_processing_window.h"
 #import "chrome/browser/ui/cocoa/nsmenuitem_additions.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 
 @interface MenuWalker : NSObject
 + (NSMenuItem*)itemForKeyEquivalent:(NSEvent*)key
                                menu:(NSMenu*)menu;
 @end
 
@@ skipping 156 matching lines @@
 
 + (void)activateWindowForController:(NSWindowController*)controller {
   // Per http://crbug.com/73779 and http://crbug.com/75223, we need this to
   // properly activate windows if Chrome is not the active application.
   [[controller window] makeKeyAndOrderFront:controller];
   ProcessSerialNumber psn;
   GetCurrentProcess(&psn);
   SetFrontProcessWithOptions(&psn, kSetFrontProcessFrontWindowOnly);
 }
 
++ (void)selectPreviousActiveBrowserWindow:(Browser*)closedBrowser {
+  if (![NSApp isActive] || closedBrowser != BrowserList::GetLastActive())
+    return;

[Scott Hess - ex-Googler, 2012/02/09 22:51:54]

Are you sure about the -isActive test?  You would presumably want the right
window to be key if a page closes itself using close() while the app is not
active.  What you don't want is for the app to force the window to the front,
which is what Activate() will do.  Will -becomeKeyWindow to the native window
handle work, instead of Activate()?

[jennb, 2012/02/09 23:25:24]

My thinking is that if Chrome is not active, then we'll let the system do it's
usual thing.

+
+  // Select previous active window if this is the current active window.
+  // Otherwise, OSX will always give focus to a Panel window after this one
+  // is closed because Panels have a higher priority NSWindowLevel.
+  BrowserList::const_reverse_iterator iter = BrowserList::begin_last_active();
+  BrowserList::const_reverse_iterator end = BrowserList::end_last_active();
+  for (; iter != end; ++iter) {
+    Browser* browser = *iter;
+    if (browser != closedBrowser &&
+        [browser->window()->GetNativeHandle() canBecomeKeyWindow]) {
+      browser->window()->Activate();
+      return;
+    }
+  }
+}

[Scott Hess - ex-Googler, 2012/02/09 22:51:54]

This will subvert the ordering logic if there are any non-browser windows on the
stack (like Task Manager - yes, I checked, this changed).  I think it would be
more reasonable to iterate the app's window list, and pick the first one which
-canBecomeKeyWindow && isNotPanel.  You could PROBABLY do this by doing
something like setting a global flag for your panels to return from
-canBecomeKeyWindow, then calling something like:

  [[NSApp makeWindowsPerform:@selector(canBecomeKeyWindow) inOrder:YES]
makeKeyWindow];

though you might have to order the outbound window out before calling that.

By having a "global" above I really mean something like a method on
BrowserCrApplication to let your panels return NO to -canBecomeKeyWindow during
this, though I don't know how your panels are implemented.

I was going to suggest having your panels return NO to -canBecomeKeyWindow
scoped to the close, but I don't think that'll work if this is the last browser
window open (in which case one of your panels should get key, I guess?).

[jennb, 2012/02/09 23:25:24]

Thanks for pointing out the non-browser window case. I wasn't aware of such
windows. I want the last active Chrome window to become key, whether it's a
browser or non-browser window. If a Panel was last active, it is allowed to
become key so I can't rule out all Panels.

Perhaps I can use a combination of iterating the app's window list and comparing
against browserlist's last active list to find an alternate solution. Will work
on it more.

 @end