All Questions
13,537
questions
1408
votes
39
answers
514k
views
How can I check for an active Internet connection on iOS or macOS?
I would like to check to see if I have an Internet connection on iOS using the Cocoa Touch libraries or on macOS using the Cocoa libraries.
I came up with a way to do this using an NSURL. The way I ...
- 47.1k
1323
votes
82
answers
1.0m
views
Xcode - How to fix 'NSUnknownKeyException', Reason: "… this class is not key value coding-compliant for the key X" error?
I'm trying to link a UILabel with an IBOutlet created in my class.
My application is crashing with the following error"
***
Terminating app due to uncaught exception
'NSUnknownKeyException', ...
338
votes
89
answers
241k
views
Hidden Features of Xcode
With a huge influx of newbies to Xcode, I'm sure there are lots of Xcode tips and tricks to be shared.
What are yours?
317
votes
4
answers
95k
views
Core Data vs SQLite 3 [closed]
I am already quite familiar with relational databases and have used SQLite (and other databases) in the past. However, Core Data has a certain allure, so I am considering spending some time to learn ...
- 5,418
212
votes
29
answers
536k
views
Xcode build failure "Undefined symbols for architecture x86_64"
An Xcode beginner's question:
It is my first experience with Xcode 4.6.3.
I am trying to write a very simple console program, that searches for paired BT devices and prints them to an NSLog.
It ...
- 2,447
211
votes
12
answers
136k
views
Execute a terminal command from a Cocoa app
How can I execute a terminal command (like grep) from my Objective-C Cocoa application?
- 70.8k
178
votes
13
answers
43k
views
What is the best way to solve an Objective-C namespace collision?
Objective-C has no namespaces; it's much like C, everything is within one global namespace. Common practice is to prefix classes with initials, e.g. if you are working at IBM, you could prefix them ...
- 131k
176
votes
6
answers
90k
views
How to create a Menubar application for Mac
EDIT: This is a nice ready-made menubar application here (github source) by this answer.
I was wondering how to make a menubar application, what are the requirements for that to do so?
I saw a ...
- 34.9k
170
votes
7
answers
107k
views
What's the difference between "bundle display name" and "bundle name" in cocoa application's info plist
Here is a good question:
Bundle Name, Executable Name, Product Name...anything else?
but I just wonder about the difference between "bundle display name" and "bundle name" in cocoa application's ...
- 6,217
150
votes
7
answers
87k
views
How do you set the text in an NSTextField?
I'm trying to set the text in an NSTextField, but the -setStringValue: and -setTitleWithMnemonic: methods are not working. Any ideas?
- 16k
143
votes
18
answers
127k
views
How to manually create icns files using iconutil?
When I'm validating my app I get this error:
the application bundle does not contain an icon in ICNS format, containing both a 512x512 and a 512x512@2x image.
I use to make the icns icons with ...
- 2,350
128
votes
3
answers
80k
views
How to get Core Data object from specific Object ID?
I can easily get an object's ID in Core Data using the following code:
NSManagedObjectID *moID = [managedObject objectID];
However, is there a way to get an object out of the core data store by ...
- 14.6k
124
votes
2
answers
60k
views
Remove autolayout (constraints) in Interface Builder
I'm trying to make my project compatible with Snow Leopard and I am not able to remove the autolayout in the nibs using Interface builder (XCode 4.3 on Lion).
Is it possible to remove the constraints ...
- 5,338
108
votes
23
answers
45k
views
Hidden Features of Xcode 4
Now that Xcode 4 is officially released it's time for a follow up to my previous question: Hidden Features of Xcode
So what are they? What are those hidden little Xcode 4 hints & tips that you ...
106
votes
4
answers
49k
views
Get value from NSTextField
I have an NSTextField and I need to get the field's value into a variable. What's the appropriate method?
- 1,189
102
votes
9
answers
35k
views
Xcode linker error: file too small for architecture x86_64
I'm developing an application in Xcode.
When I try to build, this error comes up:
ld: in /Users/theodore/Library/Developer/Xcode/DerivedData/Tower-bkpdifuqssebjdgurzmtirbxejnn/Build/Intermediates/...
- 16.9k
102
votes
20
answers
130k
views
Input from the keyboard in command line application
I am attempting to get the keyboard input for a command line app for the new Apple programming language Swift.
I've scanned the docs to no avail.
import Foundation
println("What is your name?")
???
...
- 1,953
92
votes
10
answers
41k
views
View-based NSTableView with rows that have dynamic heights
I have an application with a view-based NSTableView in it. Inside this table view, I have rows that have cells that have content consisting of a multi-row NSTextField with word-wrap enabled. ...
- 1,338
92
votes
4
answers
96k
views
Are "EXC_BREAKPOINT (SIGTRAP)" exceptions caused by debugging breakpoints?
I have a multithreaded app that is very stable on all my test machines and seems to be stable for almost every one of my users (based on no complaints of crashes). The app crashes frequently for one ...
- 1,235
91
votes
7
answers
77k
views
How can I set the icon for a Mac Application in Xcode?
I have been learning a lot about writing Objective-C code and designing in Interface Builder and I wanted to set icons for my simple programs.
I added the same JPG to all the size fields in Icon ...
- 5,002
90
votes
7
answers
48k
views
How to hide the Dock icon
I want to make a preference for hiding the Dock icon and showing an NSStatusItem.
I can create the StatusItem but I don't know how to remove the icon from Dock. :-/
Any ideas?
- 4,767
84
votes
5
answers
40k
views
Where is a Mac Application's NSUserDefaults Data Stored?
I am using NSUserDefaults to store some data in my application.
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setObject:@"dummy string" forKey:@"lastValue"];
[prefs ...
- 1,086
82
votes
9
answers
59k
views
How to save a NSImage as a new file
How can I save a NSImage as a new file (png, jpg, ...) in a certain directory?
- 2,986
80
votes
3
answers
37k
views
What is the strong property attribute
I am using the Xcode beta for developers, and am noticing some subtle differences. Among them is a new attribute for declared properties.
@property(strong)IBOutlet NSArrayController *arrayControl;
...
- 2,859
79
votes
11
answers
56k
views
NSArray Equivalent of Map
Given an NSArray of NSDictionary objects (containing similar objects and keys) is it possible to write perform a map to an array of specified key? For example, in Ruby it can be done with:
array.map(&...
- 3,405
79
votes
16
answers
65k
views
How do I determine the OS version at runtime in OS X or iOS (without using Gestalt)?
The Gestalt() function located in CarbonCore/OSUtils.h has been deprecated as of OS X 10.8 Mountain Lion.
I often use this function to test the version of the OS X operating system at runtime (see ...
- 11.3k
77
votes
19
answers
48k
views
How do you convert an iPhone OSStatus code to something useful?
I am getting more than a little sick of this iPhone SDK and its documentation...
I am calling AudioConverterNew
in the documentation under Returns: it says "returns a status code"
...
really...
so ...
- 4,164
76
votes
11
answers
103k
views
Rounding numbers in Objective-C
I'm trying to do some number rounding and conversion to a string to enhance the output in an Objective-C program.
I have a float value that I'd like to round to the nearest .5 and then use it to set ...
- 2,330
73
votes
1
answer
11k
views
Do you need to create an NSAutoreleasePool within a block in GCD?
Normally, if you spawn a background thread or run an NSOperation on an NSOperationQueue you need to create an NSAutoreleasePool for that thread or operation because none exists by default.
Does the ...
- 170k
69
votes
10
answers
68k
views
How to get the file size given a path?
I have a path to file contained in an NSString. Is there a method to get its file size?
- 23.4k
68
votes
5
answers
109k
views
List of all users and groups
I'm trying to get a list of all users and all groups on Mac OS X 10.5+. How can I do this?
For example, the list of all users on my machine should return:
_amavisd, _appowner, _appserver, _ard, ...
- 243k
67
votes
12
answers
28k
views
How to detect if OS X is in dark mode?
My cocoa app has to change its behaviour when run in the new OS X "dark mode".
Is there a way to detect if OS X style is set to this mode?
- 705
67
votes
1
answer
2k
views
Separate cookie jar per WebView in OS X
I've been trying to achieve the goal of having a unique (not shared) cookie jar per WebView in macOS (cookies management works different for iOS).
After reading a lot of StackOverflow questions and ...
- 29.6k
65
votes
6
answers
58k
views
Class Foo is implemented in both MyApp and MyAppTestCase. One of the two will be used. Which one is undefined
Recently I started Unit testing my application. This project (in Xcode4) was created without a unit test bundle so I had to set it up.
I have followed the steps from here: http://cocoawithlove.com/...
- 44.7k
60
votes
6
answers
39k
views
Sample code for creating a NSTextField "label"?
In my desktop Mac OS X app, I'd like to programatically create a NSTextField "label" which has the same behavior and properties as a typical label created in Interface Builder.
I usually use (and ...
- 11.3k
58
votes
2
answers
23k
views
Send notification to Mountain lion notification center
Can someone give an example of sending a test notification from a Cocoa app to Notifications Center? eg. when I click on an NSButton
- 837
57
votes
9
answers
51k
views
How to convert an NSData into an NSString Hex string?
When I call -description on an NSData object, I see a pretty Hex string of the NSData object's bytes like:
<f6e7cd28 0fc5b5d4 88f8394b af216506 bc1bba86 4d5b483d>
I'd like to get this ...
- 11.3k
57
votes
1
answer
1k
views
Layer-backed NSView rotation and skewed siblings
I have a strange issue with layer-backed NSView and it's siblings, some of them are not rendered correctly when added into the existing view hierarchy attached to the rotated superview. Below are the ...
- 4,261
56
votes
6
answers
12k
views
Can I receive a callback whenever an NSPasteboard is written to?
I've read Apple's Pasteboard Programming Guide, but it doesn't answer a particular question I have.
I'm trying to write a Cocoa application (for OS X, not iOS) that will keep track of everything that ...
- 17.6k
55
votes
15
answers
61k
views
How do you fix "code object is not signed at all In subcomponent:" in Xcode 6, Mac OS X Yosemite or Mavericks?
When compiling my application I'm getting the following error:
CodeSign /Users/pupeno/Library/Developer/Xcode/DerivedData/ProjectX-cynmgyozflnwbpamwnpsnhgshuyq/Build/Products/Debug/Project\ X.app
...
- 285k
55
votes
7
answers
17k
views
How to listen to global hotkeys with Swift in a macOS app?
I'm trying to have a handler in my Mac OS X app written in Swift for a global (system-wide) hotkey combo but I just cannot find proper documentation for it. I've read that I'd have to mess around in ...
- 723
54
votes
5
answers
32k
views
OS X - How can a NSViewController find its window?
I have a Document based core data app. The main document window has a number of views, each controlled by its own custom NSViewController which are switched in as necessary. I want each of these view ...
- 1,256
52
votes
3
answers
14k
views
Why are umbrella frameworks discouraged? [closed]
I want to distribute Framework A. Framework A depends on Framework B. I want a user of my framework to only need to include Framework A, but still have programmatic access to Framework B.
Apple does ...
- 3,175
51
votes
7
answers
27k
views
Get my Mac's computer name
How can I get the computer's name on a Mac? I'm talking about the same name as the one you can find in System Profiler under "Software".
- 55.2k
50
votes
5
answers
22k
views
How do I quit a mac application programmatically?
I need to add a quit-button to my application that runs from the menubar in mac.
How do I programmatically quit an application in mac?
- 3,960
50
votes
8
answers
30k
views
How to Write OS X Finder plugin
I'm looking for a guide or sample code for writing Mac OS X Finder plugins? It would like to know how to do some simple actions:
adding image overlayers to icons
adding context menu items
listen to ...
- 59.1k
49
votes
6
answers
18k
views
Fast enumeration on an NSIndexSet
Can you fast enumerate a NSIndexSet? if not, what's the best way to enumerate the items in the set?
- 24.7k
49
votes
8
answers
16k
views
NSTextField transparent background
I create transparent NSTextField
self.myTextField = [[NSTextField alloc] initWithFrame:CGRectMake(backgroundView.frame.origin.x + backgroundView.frame.size.width + 20, self.projectTitle.frame.origin....
- 1,429
48
votes
6
answers
16k
views
Callbacks When an NSScrollView is Scrolled?
I'm making a Mac app which needs to know when the user is scrolling the NSScrollView, however, I can't find any methods like UIScrollView, which has the following delegate methods:
– ...
- 6,510
48
votes
4
answers
27k
views
What is the File's Owner (in Interface builder)?
I am new to Cocoa and I don't understand the concept of File's Owner of a .nib file.
Here is the way I would see things :
Consider a file myNibFile.nib file that describes how a window looks.
Now, I ...
- 3,553