[Mac] Restore focus to the tab contents when dismissing the find bar....

chrome/browser/cocoa/focus_tracker.mm

+// Copyright (c) 2009 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/cocoa/focus_tracker.h"

[Avi (use Gerrit), 2009/09/14 21:55:27]

Interesting approach, and it makes sense to use a special class if it's that
tricky to get right.

In terms of usability, it seems kinda like a stack object (snapshot on
construction, restore on destruction). Do we want to try to make it C++ey for
that?

[rohitrao (ping after 24h), 2009/09/14 22:22:00]

The code is also non-trivial and used in at least two different places, so I'd
rather consolidate it.
I can play around with this some more.  The real trouble with
restore-on-destruct is that I need to know the current window before I can
restore (hence the restoreFocusInWindow: selector).  There are also some cases
where I explicitly don't want to restore focus, so we'll need a good way to
handle that as well.

+
+#include "base/logging.h"
+
+@implementation FocusTracker
+
+- (id)initWithWindow:(NSWindow*)window {
+  if ((self = [super init])) {
+    NSResponder* current_focus = [window firstResponder];
+
+    // Special case NSTextViews, because they are removed from the
+    // view hierarchy when their text field does not have focus.  If
+    // an NSTextView is the current first responder, save a pointer to
+    // its NSTextField delegate instead.
+    if ([current_focus isKindOfClass:[NSTextView class]]) {
+      id delegate = [(NSTextView*)current_focus delegate];
+      if ([delegate isKindOfClass:[NSTextField class]])
+        current_focus = delegate;
+      else
+        current_focus = nil;
+    }
+
+    if ([current_focus isKindOfClass:[NSView class]]) {
+      NSView* current_focus_view = (NSView*)current_focus;
+      focusedView_.reset([current_focus_view retain]);
+    }
+  }
+
+  return self;
+}
+
+- (BOOL)restoreFocusInWindow:(NSWindow*)window {
+  if (!focusedView_.get())
+    return NO;
+
+  if ([focusedView_ window] && [focusedView_ window] == window)
+    return [window makeFirstResponder:focusedView_.get()];
+
+  return NO;
+}
+
+@end