Fixed UINavigationController swizzling

If PSStackedViewController was created more than once, the swizzling was reverted every two creations.
steipete · Apr 2, 2013 · 43407af · 43407af
1 parent fb9bf4f
commit 43407af
Showing 1 changed file with 8 additions and 4 deletions.
diff --git a/PSStackedView/PSStackedViewController.m b/PSStackedView/PSStackedViewController.m
@@ -120,10 +120,14 @@ - (void)sharedInitialization {
     cornerRadius_ = 6.0f;
 
 #ifdef ALLOW_SWIZZLING_NAVIGATIONCONTROLLER
-    PSSVLog("Swizzling UIViewController.navigationController");
-    Method origMethod = class_getInstanceMethod([UIViewController class], @selector(navigationController));
-    Method overrideMethod = class_getInstanceMethod([UIViewController class], @selector(navigationControllerSwizzled));
-    method_exchangeImplementations(origMethod, overrideMethod);
+    static dispatch_once_t token;
+
+    dispatch_once(&token, ^{
+        PSSVLog("Swizzling UIViewController.navigationController");
+        Method origMethod = class_getInstanceMethod([UIViewController class], @selector(navigationController));
+        Method overrideMethod = class_getInstanceMethod([UIViewController class], @selector(navigationControllerSwizzled));
+        method_exchangeImplementations(origMethod, overrideMethod);
+    });
 #endif
 
 }