Cache GTMTheme across windows to avoid re-creating it every time we create a ...

chrome/browser/cocoa/browser_window_controller.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.
 
 #include <Carbon/Carbon.h>
 
 #include "base/mac_util.h"
 #include "base/scoped_nsdisable_screen_updates.h"
 #import "base/scoped_nsobject.h"
 #include "base/sys_string_conversions.h"
@@ skipping 1184 matching lines @@
   // Position the find bar relative to the infobar container.
   [findBarCocoaController_
     positionFindBarView:[infoBarContainerController_ view]];
 }
 
 @end
 
 @implementation GTMTheme (BrowserThemeProviderInitialization)
 + (GTMTheme *)themeWithBrowserThemeProvider:(BrowserThemeProvider*)provider
                              isOffTheRecord:(BOOL)isOffTheRecord {
-  GTMTheme *theme = [[[GTMTheme alloc] init] autorelease];
+  // First check if it's in the cache.
+  typedef std::pair<std::string, BOOL> ThemeKey;
+  static std::map<ThemeKey, GTMTheme*> cache;

[Mark Mentovai, 2009/08/26 01:25:49]

I think that every place we have a static that leaks its garbage we should put a
comment like "this might be a candidate for a Singleton or a LazyInstance" so
that if we ever decide we want to make things singletons or lazy instances, we
can go through and do them easily.

[pink (ping after 24hrs), 2009/08/26 14:55:56]

Done.

+  ThemeKey key(provider->GetThemeID(), isOffTheRecord);
+  GTMTheme* theme = cache[key];
+  if (theme)
+    return theme;
+
+  theme = [[GTMTheme alloc] init];  // "Leak" it in the cache.
+  cache[key] = theme;
   if (isOffTheRecord) {
     NSColor* incognitoColor = [NSColor colorWithCalibratedRed:83/255.0
                                                         green:108.0/255.0
                                                          blue:140/255.0
                                                         alpha:1.0];
     [theme setBackgroundColor:incognitoColor];
     return theme;
   }
 
   NSImage* frameImage = provider->GetNSImageNamed(IDR_THEME_FRAME);
@@ skipping 69 matching lines @@
   NSColor* toolbarButtonBorderColor = toolbarButtonIconColor;
   [theme setValue:toolbarButtonBorderColor
      forAttribute:@"borderColor"
             style:GTMThemeStyleToolBar
             state:YES];
 
   return theme;
 }
 @end