ui/base/cocoa/nib_loading.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 "ui/base/cocoa/nib_loading.h"

#include "base/mac/bundle_locations.h"
#include "base/memory/scoped_nsobject.h"

namespace ui {

NSView* GetViewFromNib(NSString* name) {
  scoped_nsobject<NSNib> nib(
      [[NSNib alloc] initWithNibNamed:name
                               bundle:base::mac::FrameworkBundle()]);
  if (!nib)
    return nil;

  NSArray* objects;
  BOOL success = [nib instantiateNibWithOwner:nil
                              topLevelObjects:&objects];
  if (!success)
    return nil;

  // When loading a nib manually (as opposed to using an NSWindowController or
  // NSViewController), all the top-level objects need to be explicitly
  // released. See
  // http://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/LoadingResources/CocoaNibs/CocoaNibs.html#//apple_ref/doc/uid/10000051i-CH4-SW10
  // for more information.
  [objects makeObjectsPerformSelector:@selector(release)];

  // For some strange reason, even nibs that appear to have but one top-level
  // object often have more (an NSApplication, etc.). Filter out what isn't
  // desired.
  for (NSView* view in objects) {
    if (![view isKindOfClass:[NSView class]])
      continue;

    return [[view retain] autorelease];
  }

  return nil;
}

}  // namespace ui