From 20c898677d17172c2879b1335e11ba8851ced80f Mon Sep 17 00:00:00 2001
From: Scott Talbert <swt@techie.net>
Date: Mon, 22 Dec 2014 23:44:44 -0500
Subject: [PATCH] Avoid calling viewWillAppear twice on OSX 10.10

---
 MASPreferencesWindowController.m | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/MASPreferencesWindowController.m b/MASPreferencesWindowController.m
index 8d74eb8..052c691 100644
--- a/MASPreferencesWindowController.m
+++ b/MASPreferencesWindowController.m
@@ -303,8 +303,12 @@ - (void)setSelectedViewController:(NSViewController <MASPreferencesViewControlle
 #else
     _selectedViewController = [controller retain];
 #endif
-    if ([controller respondsToSelector:@selector(viewWillAppear)])
-        [controller viewWillAppear];
+    // In OSX 10.10, setContentView below calls viewWillAppear.  We still want to call viewWillAppear on < 10.10,
+    // so the check below avoids calling viewWillAppear twice on 10.10.
+    // See https://github.com/shpakovski/MASPreferences/issues/32 for more info.
+    if (![NSViewController instancesRespondToSelector:@selector(viewWillAppear)])
+        if ([controller respondsToSelector:@selector(viewWillAppear)])
+            [controller viewWillAppear];
     
     [self.window setContentView:controllerView];
     [self.window recalculateKeyViewLoop];