All The Quickies, Chronologically

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All The Quickies, Chronologically

Increasing the length of the "Open Recent" menu (NSDocument->General) (29 November , 2008) [permalink]
10-15 items not enough for your "Open Recent" menu of a favorite app? Set the app's NSRecentDocumentsLimit default to something more to your liking:
```
defaults write com.flyingmeat.acorn NSRecentDocumentsLimit 137
```
(thanks to Gus Mueller for this one)
emacs registers (emacs->General) (21 November , 2008) [permalink]
Stick something into a register:
```
(select stuff)
C-x r x 1
```
where "1" is the register identifier.
Getting stuff out of a register:
```
C-x r g 1
```

gdb'ing specific architectures (gdb->Debugging) (31 October , 2008) [permalink]
With a fat binary (32/64bit), gdb picks the 64 bit version. If you're trying to debug a 32-bit unit test on the command-line though, the 64-bitness of /Developer/Tools/otest gets in the way:

% gdb /Developer/Tools/otest
2008-10-31 19:29:50.834 otest[711:813] Error loading
/blah/blah/blah/build/Debug/Tests.octest/Contents/MacOS/Tests:
dlopen(/blah/blah/blah/build/Debug/Tests.octest/Contents/MacOS/Tests,
265): no suitable image found.  Did find:
        /blah/blah/blah/build/Debug/Tests.octest/Contents/MacOS/Tests:
        mach-o, but wrong architecture
2008-10-31 19:29:50.887 otest[711:813] The test bundle at
build/Debug/Tests.octest could not be loaded because it is built for a
different architecture than the currently-running test rig (which is
running as unknown).
2008-10-31 19:29:50.904 otest[714:203] *** NSTask: Task create for
path '/blah/blah/blah/build/Debug/Tests.octest/Contents/MacOS/Tests'
failed: 8, "Exec format error".  Terminating temporary process.

You can supply a -arch flag to pick what you want:

% gdb -arch i386 /Developer/Tools/otest

And then debug your 32-bit unit test.

Balance a tag in SGML mode (emacs->Random) (11 October , 2008) [permalink]
```
C-/
```
Making "edit all in scope" work (Xcode->Hacks) (23 August , 2008) [permalink]
Xcode's "Edit All in Scope" feature is inexplicably tied to visible syntax colorization (actually, only Edit All in Scope for object pointers is tied to this, scalar variables and pointers work fine otherwise). So if you're not getting the Edit All in Scope menu item to enable, make sure "Color indexed Symbols" is turned on in the Xcode "Fonts and Colors" preferences.
This advice brought to you by a DTS incident.

Seeing extended attributes with 'ls' (Unix->General) (25 July , 2008) [permalink]
Sometimes you see an @ after the directory permissions in an ls -l:

% ls -l ~/junk/SnapshotRepository.sparseimage
-rw-r--r--@ 1 markd  markd  135270400 Jul 24 20:38 /Users/markd/junk/SnapshotRepository.sparseimage

That means there's some extended attributes. use ls -l@ to see them:

% ls -l@ ~/junk/SnapshotRepository.sparseimage
-rw-r--r--@ 1 markd  markd  135270400 Jul 24 20:38 /Users/markd/junk/SnapshotRepository.sparseimage
	com.apple.diskimages.fsck	       20

Changing __MyCompanyName__ (Xcode->Hacks) (25 July , 2008) [permalink]
You've probably noticed that source files generated from within XCode include a comment block header:
```
//
//  TapDance.h
//  Groovilicous
//
//  Created by markd on 7/25/08.
//  Copyright 2008 __MyCompanyName__. All rights reserved.
//
```
With the __MyCompanyName__ placeholder. There is no UI to change this, for obvious reasons. (Why would anyone want to easily and conveniently change something they'll otherwise need to edit in each and every source file they create. That's unpossible). The obvious solution is to drop to the terminal and run the straightforward command:
```
% defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions '{"ORGANIZATIONNAME" = "Borkware";}'
```
Seemple, no? Zee trick, she is doone.
Turning off Xcode's "Undo past save" warning (Xcode->General) (14 July , 2008) [permalink]
For some reason, Xcode thinks that an undo past the last save is something horrible that you need to be warned about. After living with unstable software, cmd-S is a habit, and undoing past it is No Big Deal. Really. Here's how to turn it off:
```
% defaults write com.apple.Xcode XCShowUndoPastSaveWarning NO
```

Making naked memory autoreleased (General->General) (03 June , 2008) [permalink]
(courtesy of Mike Ash, who fixed some errors in the previous version of this quickie)

void *tempCopyOf(void *data, NSUInteger size)
{
   return data ? [[NSData dataWithBytes:data length:size] mutableBytes] : NULL;
}

OBTW, these techniques will fail under GC. Here's how you'd write a working one under GC:

void *tempCopyOf(void *data, NSUInteger size)
{
   void *buffer = NULL;
   if( data ) {
       buffer = NSAllocateCollectable(size, 0);
       memcpy(buffer, data, size);
   }
   return buffer;
}

Unfortunately I'm not aware of a nice way that works in dual-mode code.

Toggle 'screen's visible bell on and off (Unix->General) (27 May , 2008) [permalink]
Assuming ^t is the hotkey, doing ^t ^g will toggle the visible bell on and off.
Multiple Objects in one document (Photoshop->General) (10 May , 2008) [permalink]
Say you have two Smart Objects from ACR or something, and now you want them into one document so you can do some layer mask nonsense. To get them into one file do this:
- Open up both files
- Bring the source file up, shift-drag the layer from the palette
- Drag into the image area of the target document

Opening webview links in the user's default browser. (WebKit->General) (09 May , 2008) [permalink]

...
  [someWebView setPolicyDelegate: self];
...

- (void) webView:(WebView *)webView
decidePolicyForNavigationAction:(NSDictionary *)actionInformation
         request:(NSURLRequest *)request
           frame:(WebFrame *)frame
decisionListener:(id)listener {
    NSURL *url = [request URL];
    if (url != nil) {
        [[NSWorkspace sharedWorkspace] openURL:url];
    }

}  // decidePolicyForNavigationAction

Reverting opened, but unedited files (Perforce->General) (29 April , 2008) [permalink]
```
 p4 revert -a
```
will revert all files that haven't actually be edited, leaving the edited opened.
(Thanks to TVL for this one)
Turning off the executable bit in Perforce (Perforce->General) (29 April , 2008) [permalink]
```
p4 edit -t text [file_list] 
p4 submit
```
(Thanks to TVL for this one)
Printing network traffic (Unix->Hacks) (13 March , 2008) [permalink]
```
% sudo tcpdump -Atq -s 0 -i en1
```
-i en1 will display traffic on your airport card. Use en0 (or nothing, for most systems) for built-in ethernettage.
You can add a host line to limit output to a particular host
```
% sudo tcpdump -Atq -s 0 -i en1 host zombo.com
```
(thanks to Dan Jalkut for this one)
Eating Brains (Debugging->gdb) (11 March , 2008) [permalink]
You can turn on Zombies to catch uses of objects after they have been released. Here's an easy way to do it in the gdb console:
```
  % gdb build/Debug/Snorkfizzle.app/Contents/MacOS/Snorkfizzle
  (gdb) set env NSZombieEnabled=YES
  (gdb) fb -[_NSZombie methodSignatureForSelector:]
  (gdb) run
```
Then exercise your app and trip the error.

Running a window modally (NSWindow->General) (02 March , 2008) [permalink]

  // I am the very modal of a modern major general.
  int blah = [NSApp runModalForWindow:[self window]];

and then elsewhere, like in your OK or cancel button

  [NSApp stopModalWithCode:NSOKButton];

Getting OS version from the command line (Unix->Random) (11 February , 2008) [permalink]
```
% sw_vers -productVersion
10.5.1
```

Varargs in Objective-C (General->Random) (27 January , 2008) [permalink]
This processes a nil-terminated sequence of strings:

- (void) snorgWaffle: (NSString *) start, ... {

    va_list argList;
    va_start (argList, start);

    NSString *string = start;

    while (string != nil) {
        NSLog (@"Done did saw string '%@'", string);

        string = va_arg (argList, NSString *);
    }

    va_end (argList);

} // snorgWaffle

and can be called like

[self snorgWaffle:@"red", @"planet", @"zeitgeist", nil];

Launch Services admin tool (Random->Random) (20 December , 2007) [permalink]
If you need to poke around ~~Lunch~~ Launch Services, use the lsregister tool that lives in /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support
Today's date as a string (NSString->General) (04 December , 2007) [permalink]
The general solution for converting a date to a string is NSDateFormatter. Sometimes you need to generate a date string in a particular format easily. For instance if you need "December 4, 2007", you can use:
```
[[NSDate date] descriptionWithCalendarFormat: @"%B %e, %Y" timeZone: nil locale: nil]
```
(Thanks to Mike Morton for this one)

Binary Searching in a sorted NSArray (NSArray->General) (23 November , 2007) [permalink]
How do you binary search a sorted NSArray? Use toll free bridging to CFArray which actually has a binary search function:

    NSMutableArray *sortedArray = [NSMutableArray arrayWithObjects: @"Alice", @"Beth", @"Carol",@"Ellen",nil];
    
    //Where is "Beth"?
    unsigned index = (unsigned)CFArrayBSearchValues((CFArrayRef)sortedArray,
                                                    CFRangeMake(0, CFArrayGetCount((CFArrayRef)sortedArray)),
                                                    (CFStringRef)@"Beth",
                                                    (CFComparatorFunction)CFStringCompare,
                                                    NULL);
    if (index < [sortedArray count])
    {
        NSLog(@"Beth was found at index %u", index);
    } else {
        NSLog(@"Beth was not found (index is beyond the bounds of sortedArray)");
    }
    
    //Where should we insert "Debra"?
    unsigned insertIndex = (unsigned)CFArrayBSearchValues((CFArrayRef)sortedArray,
                                                          CFRangeMake(0, CFArrayGetCount((CFArrayRef)sortedArray)),
                                                          (CFStringRef)@"Debra",
                                                          (CFComparatorFunction)CFStringCompare,
                                                          NULL);
    [sortedArray insertObject:@"Debra" atIndex:insertIndex];
    NSLog([sortedArray description]);

    //note: NSArray indices and counts were typed as unsigned.  With the move to 64-bit, they are NSUInteger.
    //CFArray indices and counts are CFIndex, which was SInt32 but also will move to 64-bit?
    //Why was it ever signed and will it remain so?

Muchos Thankos to James Hober for this one.

Gus Mueller chimed in saying that if you use CFArrayBSearchValues, be sure to sort with CFArraySortValues rather than using the Cocoa sorting routines (or at least the comparison) - they treat diacritic marks differently, leading to strange errors. From Gus, a quick objc addition to NSMutableArray:

- (void) cfStringSort {
   CFArraySortValues((CFMutableArrayRef)self, CFRangeMake(0, [self count]), (CFComparatorFunction)CFStringCompare, NULL);
}

Making a Cocoa moby file (General->Random) (29 September, 2007) [permalink]

% cat /System/Library/Frameworks/Foundation.framework/Headers/*.h > ~/moby
% cat /System/Library/Frameworks/AppKit.framework/Headers/*.h >> ~/moby
% chmod 444 ~/moby

Sorting with Selectors (NSObject->General) (02 September, 2007) [permalink]
You can sort mutable arrays by providing a selector that is invoked on each of the elements of the array. I always get confused about NSOrderedAscending / NSOrderedDescending (I think they're actually backwards, but that's just me). Here it is in a nutcase: Given this sort command:
```
    [themStitches sortUsingSelector: @selector(compareByRowLocation:)];
```
And this selector on the BWCrossStitch class:
```
  - (NSComparisonResult) compareByRowLocation: (BWCrossStitch *) thing2;
```
Figure out which is lesser or greater, and return one of these. Note that self is the object's logical value, not the actual value of the self pointer.
- NSOrderedAsending if self < thing2
- NSOrderedDescending if self > thing2
- NSOrderedSame if self == thing2

Cad Macro (ClanLord->Random) (12 August , 2007) [permalink]
From Seilk. I can never find it when I want it.

shift-click
{ 
   $any_click 
   if @click.simple_name == "" 
      if @my.right_item == "caduceus" 
         "\use /off\r" 
      end if 
   else if @click.simple_name == @my.simple_name 
      if @my.right_item != "moonstone" 
         "\equip \"moonstone\"\r" 
      end if 
      "\use 3\r" 
   else 
      if @my.right_item != "caduceus" 
         "\equip \"caduceus\"\r" 
      end if 
      "\use " @click.simple_name "\r" 
      message "* Now healing" @click.name 
   end if 
}

Sending email with .mac when port 25 is blocked (Random->Random) (11 August , 2007) [permalink]
Say you're at a conference, away from your usual ISP, and you're trying to send email, but all port 25 traffic is blocked. Say also you have .mac, for which you keep paying and paying and paying to have a reliable external email address, and sending email is also blocked. .mac (and perhaps other places) use an alternate port (port 587 in .mac's case) which can be use to work around this. Now I can send email, and life is happy.
Runing a unit test in ppc mode (Xcode->General) (07 August , 2007) [permalink]
Say your xcode project happily runs unit tests in i386 mode. You're about to land something that does byte-swapping, and you want to make sure it's sane in PPC mode, and you haven't turned on your G5 in months. You can do this command-line styles on your ICBM (assuming your project doesn't already do ppc and i386 unit tests). Build your test, and use translate to run the powerPC side of the world:
```
% xcodebuild -configuration Release -target "Test All" -project Tests.xcodeproj NATIVE_ARCH="i386 ppc"

% /usr/libexec/oah/translate /Developer/Tools/otest build/Release/Tests.octest
```
Running shell command pasting result back into the buffer (emacs->General) (19 July , 2007) [permalink]
So to run uuidgen, for instance:
C-U M-! ret uuidgen ret
Don't show file names with a multi-file grep (Unix->General) (23 May , 2007) [permalink]
use the -h flag:
```
% grep -h chicken ~/Documents/ircLogs/FreeNode/2007*/#macsb*
```

Put a string on the pasteboard (NSString->Random) (22 May , 2007) [permalink]
Here's a category for easily putting a string on the paste|clipboard:

@implementation NSString (PasteboardGoodies)

- (void) sendToPasteboard
{
        [[NSPasteboard generalPasteboard] 
            declareTypes: [NSArray arrayWithObject: NSStringPboardType]
            owner:nil];
        [[NSPasteboard generalPasteboard]
            setString: self
            forType: NSStringPboardType];
} // sendToPasteboard

@end // PasteboardGoodies

Thanks to Dan Jalkut for this tip.

Reverting all files (Perforce->General) (22 May , 2007) [permalink]
```
% p4 revert -c default ...
```
Breaking on exceptions (gdb->General) (05 May , 2007) [permalink]
It can be annoying tracking down the cause of thrown exceptions in Cocoa. you get a notice like 2007-05-05 17:18:00.702 QueenStitcher[2804:117] *** Assertion failure in -[NSColorWell setColor:], NSColorWell.m:497, u suk l0s3r, and then the runloop happily runs again, giving you no clue where the problem is. I tell gdb to always break on Cocoa exceptions:
```
fb -[NSException raise]
fb objc_exception_throw()
```
For maximal enjoyment, add these two lines to your ~/.gdbinit file, so they'll get set no matter how you invoke gdb (no need to add these to every single project, for instance).
I've been told VoiceOver uses exceptions heavily, so if you're doing VoiceOver development, these breaks may cause you pain.

'join' an array of strings into a single string (NSString->General) (05 May , 2007) [permalink]

NSArray *chunks  = ... get an array, say by splitting it;
string = [chunks componentsJoinedByString: @" :-) "];

would produce something like

oop :-) ack :-) bork :-) greeble :-) ponies

Stripping out newlines from a string (NSString->General) (05 May , 2007) [permalink]
So you have an NSString and want to yank out the newlines. You can do a splitand join, like in scripting languages, or you can make a mutable copy and manipulate that:
```
    NSMutableString *mstring = [NSMutableString stringWithString:string];
    NSRange wholeShebang = NSMakeRange(0, [string length]);

    [mstring replaceOccurrencesOfString: @"\n"
             withString: @""
             options: 0
             range: wholeShebang];

    return [NSString stringWithString: mstring];
```
(this can also be used for generic string manipulations, not just stripping out newlines).
This technique takes half the time (at least) of split/join. But probably not enough to make an impact. In a simple test, split/join took 0.124 seconds to strip 36909 newlines in a 1.5 meg textfile, and 0.071 seconds to do the same.
printf'ing / NSLogging strings without a terminating zero byte (General->Random) (04 May , 2007) [permalink]
```
  printf ("hello %.*s\n", 5, "there is no good going on");
  NSLog (@"hello %.*s\n", 5, "there is no good going on");
```
results in
```
hello there
2007-05-04 09:14:15.575 printf[4914] hello there
```
Similarly, something like printf ("hello %*.*s\n", 10, 5, "florgsnorgle"); will right-justify 'florg' in a field of 10 characters.
(Thanks to TVL for this goodie)

'split' a string into an array (NSString->General) (09 April , 2007) [permalink]

  NSString *string = @"oop:ack:bork:greeble:ponies";
  NSArray *chunks = [string componentsSeparatedByString: @":"];

Sanity checking an XML file (Unix->General) (20 March , 2007) [permalink]
% xmllint -noout kipple.xml Handy for a quick check after hand-editing a file.
Changing a file's modification date (Unix->Random) (16 March , 2007) [permalink]
Sometimes you're doing work which uses a file's modification time to decide whether you want to do something (like don't process today's log file, or remove a really old file). You could use a time machine to test this, or use touch. You can specify a specific date or time using the format [[CC]YY]MMDDhhmm[.SS]]. Here's an example with alternating bolds to make it easier to read:
```
% touch -t 200703141536 snork.waffle

% ls -l snork.waffle
-rw-r--r--   1 markd  markd  298 Mar 14 15:36 snork.waffle
```
Making the VPN survive fast user switching. (Hacks->Hacks) (12 March , 2007) [permalink]
Testing admin vs non admin user scenarios while connected to the mothership VPN is a pain. Heres a way to modify the system configuration plist to make the VPN connection survive fast user switching.
Open up Internet Connect, select your VPN icon in the toolbar, and choose options from the Connect menu. Uncheck "Disconnect when switching user accounts".
Setting compiler flags on a per-file basis (Xcode->General) (09 March , 2007) [permalink]
Sometimes you need to set compiler flags on a per-file basis, like you need to suppress a warning in one place or set a one-off #define, but not for the entire project. You can set these flags in the build tab of the Get Info window of the source file in the target's compile sources build phase. If you get info on the source file in other places in Xcode, there's no build tab, and you're left with that "Am I crazy? I know I've seen that setting somewhere before, but where is it? I better go back to listening to Finnish polkas 24/7 and give up this software thing" kind of feeling.
Seeing the files in a zip archive (Unix->General) (08 March , 2007) [permalink]
% unzip -l snorgle.zip
Making naked memory autoreleased (Hacks->General) (28 February , 2007) [permalink]
From the devious mind of Rainer Brockerhoff : given a pointer + length, dynamically allocate a copy and make it autoreleased, without (directly) involving cocoa objects. One handy usage: giving a plugin a copy of some struct, but be protected against the plugin messing it up.
```
static void *tempCopyOf(void *data,UInt32 size) {
    void *buffer = NULL;
    if (data) {
        buffer = malloc(size);
        if (buffer) {
            bcopy(data,buffer,size);
            [NSData dataWithBytesNoCopy: buffer  length: size  freeWhenDone: YES];
        }
    }
    return (buffer);
}
```
You can get really fancy and assign buffer to calloc(1, size) if you want to give it "pass NULL to get a zero-filled buffer back" semantics.
Also note this doesn't play well with garbage collection - caveat nerdor. (Thanks to Ken Ferry for that note)

Converting from a path to an FSRef (General->Random) (27 February , 2007) [permalink]

  NSString *pathString = ... whatever ...;

  FSRef ref;
  status = FSPathMakeRef ((const UInt8 *)[pathString fileSystemRepresentation],
                          &ref, NULL);

  if (status != noErr) {
      NSLog (@"bummer.  couldn't make FSREf from path '%@'",
             pathString);
  }

Derezzing resource files (General->Random) (21 February , 2007) [permalink]
I needed to derez a resource file, with the data living in the resource fork, and get editable STR and STR# entities. Here's one way to do it, with the moving pieces in bold.
```
% /Developer/Tools/DeRez -useDF  ./blarg.rsrc  /Developer/SDKs/MacOSX10.4u.sdk/Developer/Headers/FlatCarbon/MacTypes.r  > oopack2
```
And the reverse process is like:
```
% /Developer/Tools/Rez -o blah.rsrc -useDF  /Developer/SDKs/MacOSX10.4u.sdk/Developer/Headers/FlatCarbon/MacTypes.r oopack2
```
Extracting PDF text on the cheap (Random->Hacks) (19 February , 2007) [permalink]
Sometimes you need the text from a PDF, and copy-pasting from Preview isn't terribly reliable. If you really just need text and no formatting, Spotlight can help you out:
```
% /usr/bin/mdimport -d2  ../Book.pdf >& oopack.txt
```
And edit out the little bit of extra metadata output.
Changing a working tree's repository location (Subversion->Hacks) (19 February , 2007) [permalink]
Sometimes your subversion repository moves (like if you're using a private one and the machine changes addresses). Here's how to repoint a working tree to the new location (handy if there's outstanding changes that are a pain to move over to a fresh checkout)
```
% svn switch --relocate http://from-address.flongswozzle.net http://to-address.borkware.com
```
Muchos thankos to Lucas Eckels for the tip.

Defaults-writing an array (General->General) (08 February , 2007) [permalink]

% defaults write com.borkware.snongflozzle ookook -array thing1 thing2 thing3

Reducing verbiage on web pages to make them readable. (Random->General) (29 January , 2007) [permalink]
In #macsb IRC one day I was complaining about a rumor site blog posting that was hugely long and nearly incomprehensible. I was pointed to the summarization service as a way of reducing the brainpower needed to figure out what was going on:
- Select all the text
- Go to the services menu and select summarization service
- You'll get a window with a slider at the bottom. Move that down all the way to the left
- Amazingly, with 9/10 of blog posts it works REALLY well.
(thanks to Chris Forsythe for this one)
Using NSInvocation (General->General) (17 January , 2007) [permalink]
When you have a target and a selector, it's pretty easy to invoke the selector on the target if you're passing one or two parameters, with performSelector:, performSelector:withObject:, and so on. If you need to pass three arguments, or things that aren't objects, then you need to use NSInvocation.
In this case, the selector being called takes two arguments, one of which is an object, the other is an NSTimeInterval. The atIndex: jazz starts with 2 so that the self parameter and the selector can be passed to the method.
```
  NSMethodSignature *signature = [target_ methodSignatureForSelector:selector_];

  NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
  [invocation setSelector:selector_];
  [invocation setTarget:target_];
  [invocation setArgument:&self
              atIndex:2];
  [invocation setArgument:&lastWait_
              atIndex:3];

  [invocation invoke];
```
Non-chunky high-DPI image drawing (NSImage->General) (15 January , 2007) [permalink]
If you load NSImages from random files and draw them larger than they say they are, sometimes you get a really chunky, pixellated display for images that have a high DPI rather than a smooth interpolation (or even using all those extra pixels due to the high DPI). This is because (I think) that the image says that it's 100x100, even though you have 1000x1000 pixels available, and Cocoa decides to scale up only 100x100 pixels.
One way to hack around it is to tell the image to use the pixel size of the underlying image representation:
```
    NSImage *image;
    image = [[NSImage alloc] initWithContentsOfFile: path];

    NSBitmapImageRep *rep = [[image representations] objectAtIndex: 0];
    // If you think you might get something other than a bitmap image representation,
    // check for it here.

    NSSize size = NSMakeSize ([rep pixelsWide], [rep pixelsHigh]);
    [image setSize: size];
```
Running a specific unit test from the command line (Xcode->General) (12 January , 2007) [permalink]
```
% /Developer/Tools/otest -SenTest  ClassName ./build/Debug/TheUnitTest.octest
```
Truncating text in the middle of a string (NSTextView->General) (04 January , 2007) [permalink]
Sometimes you see text that is of the form "Some Gro...eral Fish", with the middle truncated but the ends still readable. You can get this effect yourself with:
```
[[textfield cell] setLineBreakMode: NSLineBreakByTruncatingMiddle]
```
(Thanks to Daniel Jalkut for this one)
Making a moby file out of a hierarchy (General->General) (27 November , 2006) [permalink]
```
% find . -name "*.h" -print -exec cat {} \; > ~/moby-file.h
```

Easy command-line argument handling (General->General) (21 November , 2006) [permalink]
You can use NSUserDefaults to sniff your command line. So using something like this:

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    gridType = [defaults objectForKey: @"gridType"];

Will have the value of "flarn" whether you do something like

% defaults write com.borkware.BorkStitch gridType flarn

% ./build/Debug/BorkStitch.app/Contents/MacOS/BorkStitch -gridType flarn

Easier Development of Screen Savers (Screen Savers->General) (14 October , 2006) [permalink]
When you're writing a screen saver, do you find yourself often copying the basted thing to your ~/Library/Screen Savers folder? If so, you can make a symbolic link that points to your screen saver bundle, and that will automatically get used whenever you engage the screen saver engine. e.g.
```
% cd ~/Library/Screen Savers
% ln -s ~/Projects/MonkeySaver/build/Debug/MonkeySaver.saver .
```
tar + xargs for huge numbers of files (Unix->General) (09 October , 2006) [permalink]
If you have too many files to add to a tarball, you can run into the shell's command limitation. If you use xargs + tar cf, you'll not get all of your files added to the tarball. Use tar's rf command to append to an archive rather than creating one:
```
% find . -name "*.yuck" -print | xargs tar rvf oop.tar
```
Turning off font-lock mode everywhere (emacs->General) (30 September, 2006) [permalink]
(global-font-lock-mode -1)
Turning off scroll-to-end in shell-mode (emacs->General) (30 September, 2006) [permalink]
(setq comint-scroll-show-maximum-output nil)

Putting an NSXMLDocument into a text view (NSXML->General) (25 August , 2006) [permalink]

    NSData *blah = [xmldocument XMLDataWithOptions: NSXMLNodePrettyPrint];
    NSString *snork = [[NSString alloc] initWithData: blah
                                        encoding: NSUTF8StringEncoding];
    NSAttributedString *arrrgh;
    arrrgh = [[NSAttributedString alloc] initWithString: snork];

    [[xmlTextView textStorage]
        setAttributedString: [arrrgh autorelease]];

Subversion over ssh (Subversion->General) (12 August , 2006) [permalink]
To access a repository that lives over ssh (vs http or file), use the svn+ssh protocol thingie in the commands, like
% svn mkdir -m "initial revision" svn+ssh://borkware.com/path/to/svnroot/thingie
Turning off Spotlight (Random->General) (11 August , 2006) [permalink]
% sudo mdutil -i off /
Enabling buttons based on tableview selection (Bindings->NSTableView) (04 August , 2006) [permalink]
Bind to your array controller selection, using @count.

CGShading (Graphics->General) (22 July , 2006) [permalink]
CGShading lets you do color ramps. Setting one up is a little complicated, juggling a couple of CG data structures and writing the ramping function.

    float domain[2] = { 0.0, 1.0 };     // 1-in function
    float range[8] = { 0.0, 1.0,        // N-out, RGBA
                       0.0, 1.0,
                       0.0, 1.0,
                       0.0, 1.0 };
    CGFunctionCallbacks callbacks = { 0, evaluate, NULL };

    CGFunctionRef shaderFunction;
    shaderFunction = CGFunctionCreate (self,    // info / rock / context
                                       1,       // # of inputs for domain
                                       domain,  // domain
                                       4,       // # of inputs for range
                                       range,   // range
                                       &callbacks);

    CGColorSpaceRef deviceRGB;
    deviceRGB = CGColorSpaceCreateDeviceRGB ();

    CGShadingRef shader;
    shader = CGShadingCreateAxial (deviceRGB,       // colorspace
                                   cgpoint(start),  // start of axis
                                   cgpoint(end),    // end of axis
                                   shaderFunction,  // shader, 1-n, n-out
                                   NO,              // extend start
                                   NO);             // extend end

    CGContextSaveGState (context); {
        NSRect bounds = [self bounds];
        CGContextClipToRect (context, cgrect(bounds));
        CGContextDrawShading (context, shader);
    } CGContextRestoreGState (context);

    [self drawSpotAt: start  size: 4];
    [self drawSpotAt: end  size: 4];

    CGFunctionRelease (shaderFunction);
    CGColorSpaceRelease (deviceRGB);
    CGShadingRelease (shader);

And the evaluator function is given an array of inputs and outputs. Use the in value(s) (which run from your domain's start-to-finish values) to generate the out values (which should be in the range's start-to-finish values):

static void evaluate (void *info, const float *in, float *out)
{
    float thing;
    thing = in[0];

    out[0] = thing;
    out[1] = thing;
    out[2] = thing;
    out[3] = 1.0;

} // evaluate

Getting a CGContext from Cocoaland (Graphics->General) (22 July , 2006) [permalink]
You can use CG (CoreGraphics) functions inside of a Cocoa view - pass the graphics port of the current context to the CG functions, like this:

#define cgrect(nsrect) (*(CGRect *)&(nsrect))

- (void) drawRect: (NSRect) rect
{
    NSRect bounds = [self bounds];

    NSGraphicsContext *cocoaContext = [NSGraphicsContext currentContext];
    CGContextRef context = (CGContextRef)[cocoaContext graphicsPort];

    CGContextSetLineWidth (context, 5.0);

    CGContextBeginPath(context); {
        CGContextAddRect (context, cgrect(bounds));
        CGContextSetRGBFillColor (context, 1.0, 0.9, 0.8, 1.0);
    } CGContextFillPath(context);

} // drawRect

Using CGLayers (Graphics->General) (22 July , 2006) [permalink]
CGLayer is a Tiger (and beyond) feature that will cache Quartz operations. Kind of like a PICT for CG. Make a new layer based on the context you're going to be drawing it in, then get a context from the layer, and draw into that. So something like this:

- (void) makeLayerInContext: (CGContextRef) enclosingContext
{
    layer = CGLayerCreateWithContext (enclosingContext, CGSizeMake(100, 100),
                                      NULL); // options - unused in Tiger
    CGContextRef context;
    context = CGLayerGetContext (layer);

    // .. and do your drawing

} // makeLayer

And then to draw the layer at a particular point (like replicating it a bunch of different points as done here):

    for (i = 0; i < pointCount; i++) {
        CGContextDrawLayerAtPoint (context, locations[i], layer);
    }

Macro recording (emacs->General) (11 July , 2006) [permalink]
C-x ( : start recording keyboard macro
C-x ) : stop recording keyboard macro
C-x e : replay current keyboard macro
Perl breaks in weird and wonderful(?) ways (Unix->General) (03 July , 2006) [permalink]
Perl 5.8 uses unicode internally by default, which apparently causes trouble for some big perl packages (like SpamAssassin's makefile getting totally trashed when you create it). Set the LANG environment variable to be en_US to make it happier.
Deatching another screen session. (Unix->General) (30 June , 2006) [permalink]
Sometimes if you have an unclean disconnect, screen can still be attached and you get the smackdown:
```
% screen -r
There is a screen on:
        8395.pts-0.vikki    (Multi, attached)
```
You can boot off that other loser by using:
```
% screen -d 8395.pts-0.vikki
```
and then doing screen-r again
Changing the 'screen' hotkey (Unix->Tools) (28 June , 2006) [permalink]
Running emacs inside of screen is made difficult because both want to use C-A for something important. C-O (AFAIK so far) isn't too useful for my use of emacs, so I use that for screen now:
```
screen -e^Oo emacs
```
Rejoining a disconnected screen session (Unix->Tools) (28 June , 2006) [permalink]
```
screen -r
```
Fixing emacs backspace in screen (emacs->General) (28 June , 2006) [permalink]
When running emacs insde of screen, screen helpfully turns the backspace/delete key into "^[[3~", which gets turned into a forward-delete. Unfortunately, just bashing deletechar into backward-delete-char-untabify causes backspace in incremental search to cancel the search, which is annoying.
One option is to set the TERM env var to rxvt:
```
% setenv TERM rxvt
```
Before cranking up screen.

Next value from a sequence (Postgresql->General) (20 June , 2006) [permalink]

insert into blah (id, stuff) 
       values (nextval('sequence_name'), 'stuff');

Printing wide character strings (gdb->General) (19 June , 2006) [permalink]
gdb won't by default let you print wide character strings. Here is a little bit of gdb code that'll let you print them. In case that page moves, here is the relevant stuff. Paste this into your .gdbinit and then you can use wchar_print:

define wchar_print
        echo "

        set $i = 0
        while (1 == 1)
                set $c = (char)(($arg0)[$i++])
                if ($c == '\0')
                        loop_break
                end
                printf "%c", $c
        end

        echo "

end

document wchar_print
wchar_print <wstr>
Print ASCII part of <wstr>, which is a wide character string of type wchar_t*.
end

Daemontools controls (Unix->General) (16 June , 2006) [permalink]
# svc -d /service/whatever - Bring the server down
# svc -u /service/whatever - Start the server up and leave it in keepalive mode.
# svc -o /service/whatever - Start the server up once. Do not restart it if it stops.
# svc -t /service/whatever - Stop and immediately restart the server.
# svc -k /service/whatever - Sends the server a KILL signal. This is like KILL -9. If svc -t fails to fully kill the process, use this option.
(Thanks to the OpenACS documentation)
Unladen Swallows? (VoodooPad->AppleScript) (08 June , 2006) [permalink]
```
tell application "VoodooPad"
	taunt
end tell
```
Break on szone_error not working (gdb->General) (06 June , 2006) [permalink]
Sometimes when you have memory corruption issues, the malloc library happily informs you:
```
Borkdoku(11062,0xcec0600) malloc: *** error for object 0xd109010: 
   incorrect checksum for freed object - object was probably modified 
   after being freed, break at szone_error to debug
```
Which is fine and dandy, but it lies. I've never gotten szone_error to actually do anything. Try breaking on malloc_printf instead.
Weak Linking in a Plugin (Tools->General) (05 June , 2006) [permalink]
I've got some useful utilities in a .c file that I use for some debugging things. And I'm also writing a plugin that will go into an app I don't control. I also have a test harness that I can load the plugin and do effective debugging. This debugging file has some static variables that it uses to control things, like whether to emit log messages, or do other diagnoses.
The problem is, if I include the usefulStuff.c in my plugin and my test harness, there are two copies of the static variables, and the test harness can't control the plugin. If I don't include usefulStuff.c in the plugin I get link errors. If I don't declare as weak linked the functions I use, I'll get errors when the final program loads the plugin. Sucks to be me.
Here's one way of doing it (which is kinda hacky, but after spending a day inside of the ld man page, and other pain, the fact it works is good enough for me for right now).
In the source file for the plugin that uses stuff from usefulStuff:
Declare the function to be weak:
```
extern void BWDebugLog (int blah, char *blah) __attribute__((weak_import));
```
(you can also do this in your header files. In this case, I didn't want to touch the header)
Before you use the function, make sure it's not NULL. Note there's no trailing () after the function name.
```
if (BWDebugLog != NULL) {
    BWDebugLog (23, "stuff");
}
```
In the Xcode project for the plugin
Add the flags -flat_namespace and -undefined dynamic_lookup to the "Other Linker Flags" (a.k.a. OTHER_LDFLAGS). The flat namespace lets the symbols be found in the test harness when the plugin is loaded. The undefined dynamic_lookup means to suppress warnings about undefined symbols. This could conceivably mask errors, but it's no worse than ZeroLink.
In the Xcode project for the test harness
Add usefulStuff.c, and turn on the "Preserve Private External Symbols" checkbox (a.k.a -keep_private_externs). That turns the symbol BWDebugLog (and others) into exported symbols that'll be visible to the plugin. Otherwise the plugin will never get past that != NULL check earlier.
Once all that's done, my plugin loads into the test harness and can get controlled. It can be loaded into the Real App without undefined symbol errors.
Setting variables when loading a file (emacs->General) (02 June , 2006) [permalink]
So say you're working on a project with two-space indents, but most of your other work happens with four-space indents. If the two-space crowd is amenable, add this to the bottom of the file:
```
/* For the emacs weenies in the crowd.
Local Variables:
   c-basic-offset: 2
End:
*/
```
Debugging unit tests from the command-line (Xcode->General) (29 May , 2006) [permalink]
First, find the .octest file of interest:
```
% find . -name "*.octest" -print
./build/Debug/Tests.octest
```
Then gdb Tools/otest:
```
% gdb /Developer/Tools/otest
```
Then run it with the name of the bundle:
```
(gdb) run ./build/Debug/Tests.octest
```
Format of new pages (VoodooPad->General) (28 May , 2006) [permalink]
Make a page called NewPageTemplate. Use $title$ for the page term.
Giving the event loop some love (General->General) (24 May , 2006) [permalink]
Say you're in a callback environment in the main thread, but need to update the UI, like to update a progress meter. You can give the runloop a chance to do one flip by doing:
```
void giveSomeLove ()
{
    // give the app some love so it'll update the window
    [[NSRunLoop currentRunLoop] runUntilDate: [NSDate distantPast]];
} // giveSomeLove
```

Using an NSOpenPanel (General->General) (24 May , 2006) [permalink]

    NSOpenPanel *panel = [NSOpenPanel openPanel];

    [panel setPrompt: @"Stuff for the Choose Button"];

    [panel beginSheetForDirectory: nil
           file: nil
           types: [NSArray arrayWithObject: @"buf"] // or other file types
           modalForWindow: window
           modalDelegate: self
           didEndSelector: @selector(openPanelDidEnd:returnCode:contextInfo:)
           contextInfo: nil];

and the didEndSelector implementation looks kinda like this:

- (void) openPanelDidEnd: (NSOpenPanel *) sheet
              returnCode: (int) returnCode
             contextInfo: (void *) context
{
    if (returnCode == NSOKButton) {
        NSArray *fileNames = [sheet filenames];

        NSLog (@"wooOOooot! %@", [fileNames objectAtIndex: 0]);
    }

} // openPanelDidEnd

show predefined preprocessor macros (General->General) (17 May , 2006) [permalink]
% gcc -E -dM - </dev/null
Using libgmalloc in gdb (gdb->General) (01 May , 2006) [permalink]
libgmalloc puts guard pages at the end of malloc'd blocks of memory, letting you catch buffer overruns. (This will hugely inflate your program's working set, and may lead to swapping) To turn on libgmalloc in gdb, do this:
```
(gdb) set env DYLD_INSERT_LIBRARIES /usr/lib/libgmalloc.dylib
```
Converting a Fixed to a float (Random->General) (01 May , 2006) [permalink]
```
float blah = FixedToFloat(someFixedvalue);
```
other goodies in FixMath.h
Grepping for flags (Unix->General) (23 April , 2006) [permalink]
Sometimes you want to grep for something like "-H", but don't want it to be interpreted as a grep flag. The -e option to the rescue:
```
% grep -e -H filename
```

Running a pre-canned applescript (AppleScript->General) (21 April , 2006) [permalink]
Here's a way to run a 'fire and forget' Applescript that lives in your application bundle.

#define runScriptName @"checknewnow"
#define runScriptType @"scpt"


- (IBAction)runScript:(id)sender
{
    /* Locate that darn thing*/
    NSString *scriptPath = [[NSBundle mainBundle]
                               pathForResource: runScriptName
                               ofType: runScriptType];
    NSURL *scriptURL = [NSURL fileURLWithPath: scriptPath];

    NSAppleScript *as = [[NSAppleScript alloc]
                            initWithContentsOfURL: scriptURL
                            error: nil];
    [as executeAndReturnError: NULL];
    [as release];
}

(Thanks to of Chris "The_Tick" Forsythe)

Finding 'self' on Intel (gdb->General) (18 April , 2006) [permalink]
(gdb) po *(int*)($ebp+8)
Displaying four-character ints (gdb->General) (17 April , 2006) [permalink]
Old-school Mac programming (and Quicktime, and other places) use four-character ints, things like 'bork'. You can have gdb print them out if you need to look at one or two of them:
```
(gdb) print/T 1936746868
$4 = 'spit'
```
(thanks to Daniel Jalkut for the print/T trick)
Using awk to extract the n'th column (Unix->General) (21 March , 2006) [permalink]
nm outputs a three-column format. I needed to get the set of defined symbols (in particular those that start with __, in tracking down a C++ linking problem), which is the third column. awk is good for that. Use $N to get the nth column (zero-index). This pipeline did the trick:
```
 nm ./oopack.o | awk '{print $2}' | sort | grep __
```
(Thanks to DougEDoug for the pointer)
Mysterious duplicated symbols (Xcode->General) (21 March , 2006) [permalink]
This killed a big chunk of time, so I figured I better record it here. While building a C++ shared library, I was getting errors like:
ld: multiple definitions of symbol __ZN13CaptureWidgetD2Ev /Users/blah/blah/build/./capture.build/Debug/capture.build/Objects-normal/ppc/capturewidget-F17F43C0.o definition of __ZN13CaptureWidgetD2Ev in section (__TEXT,__text) /Users/blah/blah/build/./capture.build/Debug/capture.build/Objects-normal/ppc/capturewidget-F17F43C0.o definition of __ZN13CaptureWidgetD2Ev in section (__TEXT,__text)
This is especially annoying, because the same object file is listed as having a duplicated symbol. If you take out the file from being compiled, you get undefined symbols for that particular source file, and if you put it back in, you get duplicated symbols.
Turn out the problem is that Xcode (somehow) added the C++ file to the "Build Sources" phase of the target. It happily generated two identical object files, and proceded to link them (hence the error), but doesn't get the reporting information correct (hence saying that both symbols come from the same file)
Running a unit-test from the command line (Xcode->General) (21 February , 2006) [permalink]
```
% /Developer/Tools/otest path/to/build/Unittest/TheUnit Test.octest
```
Recursively adding directories (CVS->General) (17 February , 2006) [permalink]
To recursively add stuff in CVS:
```
% find . -type d -print | grep -v CVS | xargs cvs add
% find . -type f -print | grep -v CVS | xargs cvs add
```
The first adds the directories, the second adds the files. Filenames with spaces in them won't be added, and it won't do the Right Thing with -kb for binary files.
Changing a dylib's install name (Tools->General) (16 February , 2006) [permalink]
A dynamic library has an 'install name', which is where the library will assume it will be installed. For things like frameworks that will be stored in an application bundle, the install name has something like @executable_path/../blah. Sometimes you get a library from someone else (or something generated by a gigantic configure script) and need to change the install name. The install_name_tool will do that for you. Say I had a library, libbork.dylib, that will end up being placed side-by-side with the executable of a cocoa app, this is how I would fix it:
```
% install_name_tool -id @executable_path/libbork.dylib ./libbork.dylib
```
Caveman debugging in both Safari and Dashboard (Dashboard->General) (13 February , 2006) [permalink]
It'd be too convenient to have a uniform mechanism to perform caveman debugging of widgets in both Safari-preview mode (where you can use window.console.log) and Dashboard mode (where you can't). Luckily (?), window.alert in Dashboard will log to the console in Dashboard, but shows an alert in safari.
So, combine the two for maximal pleasure:
```
function cavemanLog(message) {
  
  if (window.widget) {
    // Won't display an error box, but will show in the console log.
    window.alert(message);

  } else {
    // Send output to the javascript console.
    window.console.log(message);
  }

} // cavemanLog
```
Adding a column to a table (Postgresql->General) (03 January , 2006) [permalink]
alter table pfo_survey_response_2006 add column section text
console logging in Safari (Safari->General) (16 December , 2005) [permalink]
```
  if (window.console) {
    window.console.log ("ook1");
  }
```
(window.console exists in Safari, but not in Dashboard)

Watching all notifications (Notifications->General) (12 December , 2005) [permalink]
There's three notification centers - one for the app, one for the workspace, and the distributed notification center. Here's how to watch everything:

#import <Cocoa/Cocoa.h>
#import <stdio.h> // for printf()

@interface NotificationSpy
{
}

+ (void) startSpying;
+ (void) stopSpying;

@end // NotificationSpy


// prevent us from adding ourselves multiple times

static BOOL g_spying;


@implementation NotificationSpy

// turn on listening for all notifications.

+ (void) startSpying
{
    if (!g_spying) {
        NSNotificationCenter *center;

        // first the default notification center, which is all
        // notifications that just happen inside of our program

        center = [NSNotificationCenter defaultCenter];
        
        [center addObserver: self
                selector: @selector(observeDefaultCenterStuff:)
                name: nil
                object: nil];

        // then the NSWorkspace notification center, which tells us things
        // like other applications launching, and the machine sleeping
        // and waking

        center = [[NSWorkspace sharedWorkspace]
                     notificationCenter]; 

        [center addObserver: self
                selector: @selector(observeWorkspaceStuff:)
                name: nil
                object: nil];

        // and lastly the distributed notification center.  This is a
        // global (to the computer) notification center.  You can find
        // out when a different program gets focus, or the sound or
        // screen brightness changes.

        center = [NSDistributedNotificationCenter 
                     notificationCenterForType: NSLocalNotificationCenterType];

        [center addObserver: self
                selector: @selector(observeDistributedStuff:)
                name: nil
                object: nil];

        g_spying = YES;
    }

} // startSpying 


// remove us as observers

+ (void) stopSpying
{
    if (!g_spying) {
        NSNotificationCenter *center;

        // take us off the default center for our app
        center = [NSNotificationCenter defaultCenter];
        [center removeObserver: self];

        // and for the workspace
        center = [[NSWorkspace sharedWorkspace] 
                     notificationCenter];
        [center removeObserver: self];

        // and finally off of the machine-wide center
        center = [NSDistributedNotificationCenter 
                     notificationCenterForType: NSLocalNotificationCenterType];
        [center removeObserver: self];

        g_spying = NO;
    }

} // stopSpying



+ (void) observeDefaultCenterStuff: (NSNotification *) notification
{
    // QuietLog can also be found in the quickies
    QuietLog (@"default: %@", [notification name]);
} // observeDefaultCenterStuff



+ (void) observeDistributedStuff: (NSNotification *) notification
{
    QuietLog (@"distributed: %@", [notification name]);
} // observeDistributedStuff



+ (void) observeWorkspaceStuff: (NSNotification *) notification
{
    QuietLog (@"workspace: %@", [notification name]);
} // observeWorkspaceStuff


@end // NotificationSpy

Preventing Safari from displaying PDFs (WebKit->General) (10 December , 2005) [permalink]
I loathe using Safari to read PDFs. To tell Safari to stop it, try doing
```
% defaults write com.apple.Safari WebKitOmitPDFSupport -bool YES
```
if you have the misfortune of having the Acrobat Reader plug-in, you can nuke /Library/Internet Plug-Ins/AdobePDFViewer.plugin
Runing a widget without installing it (Dashboard->General) (08 December , 2005) [permalink]
When you double-click a widget or open it from the terminal, you get asked if you want to install it (which will move your widget to ~/Library/Widgets, which is really annoying when it drags it out of your development area. When faced with the dialog, hold down command and option to get a "Run" button. That'll run the widget in-pace. If you tun on the devmode:
```
% defaults write com.apple.dashboard devmode YES
```
You can drag widgets out of the dashboard area and have them on-screen. Cmd-R will reload the widget.

Displaying archived web data in a WebView (WebKit->General) (05 December , 2005) [permalink]

WebArchive *archive = ... get from somewhere...;

WebFrame *frame = [webView mainFrame];
[frame loadArchive: webarchive];

KVO Array controller gotcha (Bindings->General) (30 November , 2005) [permalink]
If you're doing KVO and don't override observeValueForKeyPath:ofObject:change:context:, (or you do override it but don't handle your callbacks) you'll generally get an exception. This trains you to do it right and never call super for the callbacks you're handling, or you'll get an exception.
Except if you've added KVO to a subclass of NSArrayController (and possibly all controller types), and don't call super's observeValueForKeyPath:ofObject:change:context:, bindings won't work at all, with no warning/notice/nothing. (Courtesy of Duncan Wilcox)
Stopping a chirping G5 (Hacks->Random) (29 November , 2005) [permalink]
Some (many? all?) G5s make a quiet chirping sound at one-second intervals, like a quiet cricket. It might also chirp when dragging windows or doing something with expose. If that bothers you (like it bothered me), go download CHUD (which you should have already), go to the Processor system preference panel, and turn off "allow nap". That may shorten the life of your machine. But what that means, I have no idea.
Enabling the Safari debug menu (Safari->General) (27 November , 2005) [permalink]
defaults write com.apple.Safari IncludeDebugMenu 1
NSTimers and NSTerminateLater (NSTimer->General) (21 November , 2005) [permalink]
If your application has an open TCP connection to a server and you receive an applicationShouldTerminate: message, you're likely to want to returnNSTerminateLater so that you can first gracefully shut down the connection before quitting.
There is a gotcha: returning NSTerminateLater stops the main runloop, so your NSTimers will stop working from that point on. Thus, if you were depending on a timer firing to finish up your shut-down process, you'll never see it, and you'll hang. The solution is to return NSTerminateCancel, then do whatever you need to do and then terminate yourself manually. (Thanks to Larry Gerndt for this one!)

Tracing message sends using gdb (Debugging->gdb) (31 October , 2005) [permalink]

b objc_msgSend
comm
silent
printf "%c[%s %s]\n", $r3&&((id)$r3)->isa->info&2?'+':'-', $r3?((id)$r3)->isa->name:"nil", $r4
cont
end
b objc_msgSend_rtp
comm
silent
printf "%c[%s %s]\n", $r3&&((id)$r3)->isa->info&2?'+':'-', $r3?((id)$r3)->isa->name:"nil", $r4
cont
end

And you'll get some output like this:

-[NSTableColumn _bindingAdaptor]
+[NSBinder binderClassesForObject:]
+[NSBinder _allBinderClasses]
+[NSDisplayPatternTitleBinder isUsableWithObject:]
+[NSBox self]

(courtesy of Rob Mayoff)

Archiving a document using keyed archiving (NSCoder->General) (13 October , 2005) [permalink]
This uses the new Tiger NSDocument load/store. For real code you'll want to handle errors and create an appropriate NSError object. This also saves the document in an XML format.

- (NSData *) dataOfType: (NSString *) typeName
                  error: (NSError **) error
{
    *error = nil;

    NSMutableData *data = [[NSMutableData alloc] init];

    NSKeyedArchiver *archiver;
    archiver = [[NSKeyedArchiver alloc]
                   initForWritingWithMutableData: data];
    [archiver setOutputFormat: NSPropertyListXMLFormat_v1_0];

    [archiver encodeObject: stitches  forKey: @"stitches"];
    // and archive other stuff you want

    [archiver finishEncoding];

    return ([data autorelease]);

} // dataOfType


- (BOOL) readFromData: (NSData *) data
              ofType: (NSString *) typeName
               error: (NSError **) error
{
    *error = nil;

    NSKeyedUnarchiver *archiver;
    archiver = [[NSKeyedUnarchiver alloc]
                   initForReadingWithData: data];

    [stitches release];

    stitches = [archiver decodeObjectForKey: @"stitches"];
    // decode other stuff of interest

    [stitches retain];

    return (YES);

} // readFromData

Supporting NSKeyedArchiving in your objects (NSCoder->General) (13 October , 2005) [permalink]
They should conform to the NSCoding protocol.

- (void) encodeWithCoder: (NSCoder *) coder
{
    [coder encodeInt: x  forKey: @"x"];
    [coder encodeInt: y  forKey: @"y"];
    [coder encodeObject: color1  forKey: @"color1"];
    [coder encodeObject: color2  forKey: @"color2"];
    [coder encodeInt: direction  forKey: @"direction"];

} // encodeWithCoder


- (id) initWithCoder: (NSCoder *) coder
{
    if (self = [super init]) {
        x = [coder decodeIntForKey: @"x"];
        y = [coder decodeIntForKey: @"y"];
        color1 = [coder decodeObjectForKey: @"color1"];
        color2 = [coder decodeObjectForKey: @"color2"];
        direction = [coder decodeIntForKey: @"direction"];
    }

    return (self);

} // initWithCoder

Iterating through an NSIndexSet (General->General) (12 October , 2005) [permalink]

unsigned index;
for (index = [indexSet firstIndex];
      index != NSNotFound; index = [indexSet indexGreaterThanIndex: index])  {
   ...
}

(courtesy of mikeash)

Putting an image into an attributed string (NSString->General) (29 September, 2005) [permalink]
You'll need to use a text attachment.

- (NSAttributedString *) prettyName
{
    NSTextAttachment *attachment;
    attachment = [[[NSTextAttachment alloc] init] autorelease];
    NSCell *cell = [attachment attachmentCell];

    NSImage *icon = [self icon]; // or wherever you are getting your image
    [cell setImage: icon];

    NSString *name = [self name];
    NSAttributedString *attrname;
    attrname = [[NSAttributedString alloc] initWithString: name];

    NSMutableAttributedString *prettyName;
    prettyName = (id)[NSMutableAttributedString attributedStringWithAttachment:
                                                attachment]; // cast to quiet compiler warning
    [prettyName appendAttributedString: attrname];

    return (prettyName);

} // prettyName

This puts the image at the front of the string. To put the image in the middle of the string, you'll need to create an attributedstring with attachment, and then append that to your final attributed string.

Doing Sheets (NSWindow->General) (19 September, 2005) [permalink]
To show a sheet in a window, use NSApplication to kick it off:

    [NSApp beginSheet: saveSheet
           modalForWindow: window
           modalDelegate: self
           didEndSelector: @selector(saveSheetDidEnd:returnCode:contextInfo:)
           contextInfo: NULL];

In the controls in the sheet, use something like

    [NSApp endSheet: saveSheet  returnCode: NSOKButton];

To invoke the didEndSelector. Inside of that method, you can check the return code and decide what to do:

- (void) saveSheetDidEnd: (NSWindow *) sheet
              returnCode: (int) returnCode
             contextInfo: (void *) contextInfo
{
    if (returnCode == NSOKButton) {
        // ...
    } else if (returnCode == NSCancelButton) {
        // ...
    } else {
        // ...
    }

    [sheet close];

} // saveSheetDidEnd

Getting the contents of a TextView as an NSString (NSTextView->NSString) (15 September, 2005) [permalink]
```
NSString *commitMessage;
commitMessage = [[commitTextView textStorage] string];
```
Show NSTextField text in gray if the field is disabled (NSTextView->General) (14 September, 2005) [permalink]
NSTextField doesn't change its text color if the field is enabled or disabled (?) Even more bizarre, using NSColor's disabledControlTextColor won't draw the text in the disabled color. You need to use the secondarySelectedControlColor, which supposedly is for active controls that don't have focus. Go figure.
To do it yourself, subclass NSTextField and override setEnabled: to change the color:
```
- (void) setEnabled: (BOOL) flag
{
    [super setEnabled: flag];

    if (flag == NO) {
        [self setTextColor: [NSColor secondarySelectedControlColor]];
    } else {
        [self setTextColor: [NSColor controlTextColor]];
    }

} // setEnabled
```
This actually kind of a gross workaround for a Cocoa bug - the disabled color is getting made darker rather than lighter. The secondarySelectedControlColor ends up looking disabled by a happy coincidence that it starts out lighter before being darkened. (or something like this. UberDude Dave MacLachlan has done the legwork to figure out the underlying problem.)
Monitoring one array from two controllers (Bindings->General) (14 September, 2005) [permalink]
If you're wanting to use two NSArrayControllers to monitor one NSMutableArray, you'll need to use each of the controller's contentArray binding. Just using the content outlet (or setContent: call), you'll only get arrangedObjects updates from one controller. (thanks to Duncan Wilcox for this one)
Replacing NSTextView's contents with an attributed string (NSTextView->General) (12 September, 2005) [permalink]
```
        [[textView textStorage] setAttributedString: theNewString];
```
Unslecting all segments with radio-mode tracking (NSSegmentedControl->Hacks) (12 September, 2005) [permalink]
NSSegmentedControl won't let you unselect all segments if there is currently one segment selected (it's perfectly happy with having everything unselected so long as nothing else is selected). This is annoying, so you have to go into the Momentary tracking mode, unselect each of the cells, then go back to the original mode.
In my NSSegmentedControl category, I have a method to solve this problem:
```
@interface NSSegmentedControl (BorkwareAdditions)
- (void) unselectAllSegments;
// ... other goodies
@end // NSSegmentedControl

- (void) unselectAllSegments
{
    NSSegmentSwitchTracking current;
    current = [self trackingMode];

    [self setTrackingMode: NSSegmentSwitchTrackingMomentary];

    int i;
    for (i = 0; i < [self segmentCount]; i++) {
        [self setSelected: NO  forSegment: i];
    }

    [self setTrackingMode: current];

} // unselectAllSegments
```
Handling KVO with arrays (Bindings->General) (11 September, 2005) [permalink]
When you insert or remove objects in a KVO compliant manner, your observer is informed of the specifics of the change via the change dictionary:
```
- (void) observeValueForKeyPath: (NSString *) keyPath
                       ofObject: (id) object
                         change: (NSDictionary *) change
                        context: (void *) context
```
The NSKeyValueChangeKindKey key in the dictionary tells you if the change was an insertion (NSKeyValueMinusSetMutation) or a deletion (NSKeyValueIntersectSetMutation)
If it is an insertion, the NSKeyValueChangeIndexesKey is an index set that contains the index of the inserted object. You can query the collection for the object at that index to get the new object.
if it a deletion, the NSKeyValueChangeIndexesKey tells you the index where the object was deleted from, and the NSKeyValueChangeOldKey contains an NSArray of objects which were removed, in case you want to hang on to it, or use it to clean out some of your data structures.

Force an NSWindowController's nib to be loaded (NSWindow->General) (10 September, 2005) [permalink]
The window controller nib doesn't get loaded until the window is manipulated. This can cause confusion if you do any kind of setup before the window is shown. If you call the window method, that will force the nib file to be loaded. Something like this:

+ (BWInspector *) sharedInspector
{
    static BWInspector *s_inspector;

    if (s_inspector == nil) {
        s_inspector = [[BWInspector alloc]
                          initWithWindowNibName: @"BWInspector"];
        assert (s_inspector != nil);

        // force loading of nib
        (void) [s_inspector window];
    }

    return (s_inspector);

} // sharedInspector

Making a panel not eat the key (NSWindow->General) (10 September, 2005) [permalink]
The default settings for an NSPanel in IB cause the panel to take the main window out of the responder chain, and so commands (like undo) don't propagate to the window the inspector is editing. In IB, make sure the settings "Utility window" and "Non Activating Panel" are selected.
Finding the height of the title bar (NSWindow->General) (04 September, 2005) [permalink]
When you setFrame: for a window, you have to account for the height of the title bar. In the Classic days it was 16 pixels. In Aqua-land, it's currently 22 pixels. But that's not safe to use, so try this instead:
```
- (float) titleBarHeight
{
    NSRect frame = NSMakeRect (0, 0, 100, 100);

    NSRect contentRect;
    contentRect = [NSWindow contentRectForFrameRect: frame
                            styleMask: NSTitledWindowMask];

    return (frame.size.height - contentRect.size.height);

} // titleBarHeight
```
Rainer Brockerhoff points out that this might miss any system-suppled window decorations at the bottom of the window. There aren't any now, but Mac OS X 10.37 Sabertooth might, so you may want to take into account the y positions of the original rectangle and the newly calculated content rect.
Resizing a window with animation (NSWindow->General) (04 September, 2005) [permalink]
Use setFrame:display:animate: to resize a window, and have the window animate between the two sizes. Remember that Cocoa uses a bottom-left origin, which is a pain when dealing with windows. You want the window's top left to be the same between the old and new sizes, so you have to dink with the origin as well as the size:
```
    float delta = ... how much to make the window bigger or smaller ...;
    NSRect frame = [window frame];

    frame.origin.y -= delta;
    frame.size.height += delta;

    [window setFrame: frame
             display: YES
             animate: YES];
```

Resizing a window with animation and cool cross-fade effect with views (NSWindow->General) (04 September, 2005) [permalink]
NSViewAnimation lets you resize a window and cross-fade some views in one operation. (note I've had problems with the window size getting a couple of pixels off using this. Hopefully either I'm doing something dumb, or Apple fixes a bug). This code resizes the window, and changes the view that lives inside of a box. This is like how the Pages inspector works (except Pages doesn't do the gratuitous animation effect)

    NSRect newWindowFrame = ... the new window size;

    NSDictionary *windowResize;
    windowResize = [NSDictionary dictionaryWithObjectsAndKeys:
                                 window, NSViewAnimationTargetKey,
                                 [NSValue valueWithRect: newWindowFrame],
                                 NSViewAnimationEndFrameKey,
                                 nil];

    NSDictionary *oldFadeOut = nil;
    if (oldView != nil) {
        oldFadeOut = [NSDictionary dictionaryWithObjectsAndKeys:
                                   oldView, NSViewAnimationTargetKey,
                                   NSViewAnimationFadeOutEffect,
                                   NSViewAnimationEffectKey, nil];
    }

    NSDictionary *newFadeIn;
    newFadeIn = [NSDictionary dictionaryWithObjectsAndKeys:
                                  newView, NSViewAnimationTargetKey,
                              NSViewAnimationFadeInEffect,
                              NSViewAnimationEffectKey, nil];

    NSArray *animations;
    animations = [NSArray arrayWithObjects:
                              windowResize, newFadeIn, oldFadeOut, nil];

    NSViewAnimation *animation;
    animation = [[NSViewAnimation alloc]
                    initWithViewAnimations: animations];

    [animation setAnimationBlockingMode: NSAnimationBlocking];
    [animation setDuration: 0.5]; // or however long you want it for

    [animation startAnimation]; // because it's blocking, once it returns, we're done

    [animation release];

Bizarro Error message (Tools->General) (02 September, 2005) [permalink]
gcc gave me this error:
cc1obj: error: type '<built-in>' does not have a known size
without any line number to give a clue what was going on. The error turned out to be having an objective-C method with an argument type of (void), a typo that should have been (void *).

Draw a string centered in a rectangle (Graphics->General) (02 September, 2005) [permalink]

    NSString *blah = @"Placeholder Pane";
    NSSize size = [blah sizeWithAttributes: nil];

    NSPoint startPoint;
    startPoint.x = bounds.origin.x + bounds.size.width / 2 - size.width / 2;
    startPoint.y = bounds.origin.y + bounds.size.height / 2 - size.height / 2;

    [blah drawAtPoint: startPoint
          withAttributes: nil];

Registering default user defaults (Bindings->General) (02 September, 2005) [permalink]
Here is one way to register the "factory settings" for your user defaults (preferences / configurations). You will pick up these values automagically via bindings to the Shared Defaults.

- (void) setDefaultPrefs
{
    NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];

    [dictionary setObject: NSLocalizedString(@"BorkDown", nil)
                forKey: @"menuTitle"];

    [dictionary setObject: NSLocalizedString(@"Time has run out.", nil)
                forKey: @"alertWindowText"];

    // and any other preferences you might have

    [[NSUserDefaults standardUserDefaults]
        registerDefaults: dictionary];

} // setDefaultPrefs

Posing as a class (Hacks->General) (01 September, 2005) [permalink]
Say you wanted to take a peek at how NSSpellChecker does its thing. You can make a subclass, override methods, log interesting stuff, and then send super. Use poseAsClass: to hook yourself into the matrix during the +load method:

@interface BorkSpellChecker : NSSpellChecker
{
}
@end // BorkSpellChecker


@implementation BorkSpellChecker

+ (void) load
{
    NSLog (@"posing");
    [self poseAsClass: [NSSpellChecker class]];

} // load


- (void) ignoreWord: (NSString *) word  inSpellDocumentWithTag: (int) tag
{
    NSLog (@"ignore word: %@  intag: %d",
           word, tag);
    [super ignoreWord: word
           inSpellDocumentWithTag: tag];

} // ignoreWord

Determining the paragraph style at a particular point (NSTextView->General) (29 August , 2005) [permalink]

- (NSParagraphStyle *) paragraphStyleInTextView: (NSTextView *) textView
                                        atIndex: (int) index
{
    NSTextStorage *storage = [textView textStorage];

    NSDictionary *attributes;
    NSRange effectiveRange;
    attributes = [storage attributesAtIndex: index
                          effectiveRange: &effectiveRange];

    NSParagraphStyle *style;
    style = [attributes valueForKey: NSParagraphStyleAttributeName];

    return (style);

} // paragraphStyleInTextView

Finding the span of a paragraph (NSTextView->General) (29 August , 2005) [permalink]
The NSString paragraphRangeForRange: method gives you the span of a paragraph. If you're using the text architecture, you need to get the string from the text storage. This chunklet shows the paragraph span for the current selection:
```
    NSRange selectedRange = [textview selectedRange];
    NSTextStorage *storage = [textview textStorage];
    effectiveRange = [[storage string] paragraphRangeForRange: selectedRange];
```
Adding Growl Notifications (Random->General) (25 August , 2005) [permalink]
It's pretty easy adding growl notifications to your app. Download the SDK from growl.info. Set up your Xcode project to copy the Growl.framework into your application bundle.
Pick a class to be the contact point with Growl. Your AppController class is a good place. Import <Growl/Growl.h>
Set the delegate to the GrowlApplicationBridge:
```
    [GrowlApplicationBridge setGrowlDelegate: self];
```
Doing this will eventually have the registrationDictionaryForGrowl delegate message called. Return a dictionary with two arrays (Which can be the same). These are the names of the alerts you will be posting. These are human-readable, so you'll want to use a localized string (which I've already set in the global variable here:
```
- (NSDictionary *) registrationDictionaryForGrowl
{
    NSArray *notifications;
    notifications = [NSArray arrayWithObject: g_timesUpString];

    NSDictionary *dict;

    dict = [NSDictionary dictionaryWithObjectsAndKeys:
                             notifications, GROWL_NOTIFICATIONS_ALL,
                         notifications, GROWL_NOTIFICATIONS_DEFAULT, nil];

    return (dict);

} // registrationDictionaryForGrowl
```
And use this to post a notification:
```
[GrowlApplicationBridge notifyWithTitle: @"Woop!  Time has expired!"
                        description: @"You have been waiting for 37 minutes"
                        notificationName: g_timesUpString
                        iconData: nil
                        priority: 0
                        isSticky: NO
                        clickContext: nil];
```
Consult the SDK documentation for more explanations of the features, but they are pretty self-explanitory.
Adding credits to your about box (Xcode->General) (23 August , 2005) [permalink]
If you have a file called "Credits.html" or "Credits.rtf", the contents of that file will be added to your about box. If your project doesn't have one already, you can use Xcode to add an empty file and put it in your English.lproj folder. Make sure you add it to your project.

A Quieter NSLog (General->Hacks) (22 August , 2005) [permalink]

// NSLog() writes out entirely too much stuff.  Most of the time I'm
// not interested in the program name, process ID, and current time
// down to the subsecond level.
// This takes an NSString with printf-style format, and outputs it.
// regular old printf can't be used instead because it doesn't
// support the '%@' format option.

void QuietLog (NSString *format, ...) {
    va_list argList;
    va_start (argList, format);
    printf ("%s\n", [[NSString stringWithFormat: format, argList] UTF8String]);
    va_end  (argList);
} // QuietLog

(Thanks to Quinn Taylor for a shorter version)

Using an NSWIndowController to load a window (NSWindow->General) (22 August , 2005) [permalink]
Here's how I like doing things. First make a subclass of NSWindowController:

@interface BWInspector : NSWindowController
{
    // ivars, IBOutlets, etc
}

// IBActions, etc

+ (BWInspector *) sharedInspector;
@end // BWInspector

Then make a nib file with the window, the controls, and other fun stuff you want. This one lives in English.lproj/BWInspector.nib

Then in that class method load the window:

+ (BWInspector *) sharedInspector
{
    static BWInspector *g_inspector;

    if (g_inspector == nil) {
        g_inspector = [[BWInspector alloc]
                          initWithWindowNibName: @"BWInspector"];

        assert (g_inspector != nil); // or other error handling

        [g_inspector showWindow: self];
    }

    return (g_inspector);

} // sharedInspector

That will load the nib file, set up the connections and then open the window for display

Making localizable strings (NSString->General) (22 August , 2005) [permalink]
You will need a file named Localizable.strings that lives in your English.lproj directory (or whatever localization directory is appropriate). It has this syntax:
```
"BorkDown" = "BorkDown";
"Start Timer" = "Start Timer";
"Stop Timer" = "Stop Timer";
```
That is, a key followed by a localized value.
In your code, you can then use NSLocalizedString() or one of its variants:
```
        [statusItem setTitle: NSLocalizedString(@"BorkDown", nil)];
```
The second argument is ignored by the function. Obstensively it is a /* comment */ in the strings file so that you can match the key back to what it is supposed to actually be.
Ignoring files (Subversion->General) (19 August , 2005) [permalink]
I don't want subversion to mess with some files, or to tell me about them when doing an svn status. Add this to your ~/.subversion/config file.
```
[miscellany]
global-ignores = build *.mode* *.pbxuser *~.nib .DS_Store *~
```
Now it won't bug me about the build directory the -per-user Xcode files, nib backup files, the #$&!! .DS_Store file that the Finder litters everywhere, and also don't bug me about emacs backup files.
You can search for global-ignores in that file to see some info about the setting. You might want to check out Spring Cleaning with Subversion too.
Turning off ZeroLink in all of the project templates (Xcode->General) (18 August , 2005) [permalink]
I loathe ZeroLink. It causes more problems than it fixes. The Xcode guys must love it dearly. The new .xcconfig files in Xcode 2.1 won't let you turn it off, rendering those files useless to me. The Official Apple suggestion is to edit all of your project templates (?). Here is a quick script that'll churn through all of the project templates (and also your own projects) and turn off ZeroLink.
```
% cd '/Library/Application Support/Apple/Developer Tools/Project Templates'
% find . -name "*.pbxproj" -exec perl -pi -e "s/ZERO_LINK = YES/ZERO_LINK = NO/g" {} \; -print
```

Iterating attributes in an attributed string (NSString->General) (27 July , 2005) [permalink]
This prints out each of the attribute runs from an attributed string:

- (void) iterateAttributesForString: (NSAttributedString *) string
{
    NSDictionary *attributeDict;
    NSRange effectiveRange = { 0, 0 };

    do {
        NSRange range;
        range = NSMakeRange (NSMaxRange(effectiveRange),
                             [string length] - NSMaxRange(effectiveRange));

        attributeDict = [string attributesAtIndex: range.location
                                longestEffectiveRange: &effectiveRange
                                inRange: range];

        NSLog (@"Range: %@  Attributes: %@",
               NSStringFromRange(effectiveRange), attributeDict);

    } while (NSMaxRange(effectiveRange) < [string length]);

} // iterateAttributesForString

Resizing Windows in IB (Tools->General) (14 July , 2005) [permalink]
Resizing complex windows in IB can be a pain because the contents don't reflow when you change the window size.
In Interface Builder 2: If you hold down the control key while resizing, though, the contents obey their spring configurations and will resize accordingly. Makes the process a whole lot easier.
In Interface Builder 3: If you hold down command while resizing, the contents obey their spring configurations and will resize accordingly. (This avoids the annoying process of resizing each widget within the windows afterwards.) Holding option while resizing will display the pixel values of the padding. Holding command-option while dragging displays both.
(muchos thankos to Quinn Taylor at the BYU CocoaHeads for the IB3 update)

View with bindings (Bindings->General) (13 July , 2005) [permalink]
ThumbBorker has a custom view class that updates a selection rectangle when the user finished dragging the mouse. It uses setValue:forKeyPath: to stick the value back into the bound object.

The bindings and path are ivars:

     id selectionRectBinding;
     NSString *selectionRectKeyPath;

In bind:toObject:withKeyPath:options: hang on to the binding object and the key path and set up observing:

         // hold on to the binding info
         selectionRectBinding = observableObject;
         selectionRectKeyPath = [observableKeyPath copy];

         // connect KVO
         [valuePathBinding addObserver: self
                           forKeyPath: selectionRectKeyPath
                           options: nil
                           context: NULL];

         // new binding, needs to redraw
         [self setNeedsDisplay: YES];

And in the mouseUp: handler, set the value back into the bound object:

     // figure out the selection rectangle
     NSRect selectionRect = [self normalizedSelectionRect];

     // wrap in a value and tell the bound object the new value

     NSValue *value;
     value = [NSValue valueWithRect: selectionRect];

     [selectionRectBinding setValue: value
                           forKeyPath: selectionRectKeyPath];

Setting computed default value for a managed object (Core Data->General) (13 July , 2005) [permalink]
Make a subclass of NSManagedObject and override awakeFromInsert:
```
- (void) awakeFromInsert
{
    [super awakeFromInsert];

    NSDate *date = [NSDate date];

    [self setValue: date  forKey: @"when"];

} // awakeFromInsert
```
Changing the "Not Applicable" text in tableviews (Bindings->General) (11 July , 2005) [permalink]
Sometimes you want to bind a tableview column to objects that might not support that particular binding (like having an uber-overview tableview for core data entities that don't all share the same attributes). If your column has a numeric formatter, IB won't let you specify a string for the "not applicable" value, so you end up with a really ugly tableview covered in "Not Applicable"s
Put this in a convenient place:
```
+ (void) initialize
{
    [NSTextFieldCell setDefaultPlaceholder: @""
                               forMarker: NSNotApplicableMarker
                             withBinding: NSValueBinding];

} // initialize
```
NSSearchField filtering for an NSArrayController (Bindings->General) (10 July , 2005) [permalink]
In Tigger, NSSearchField can now automagically filter an array via IB magic.
In Interface Builder, drag over the NSSearchField, and bind the predicate like this:
- Bind To: your array controller
- Controller Key: filterPredicate
- Predicate Format: what contains[c] $value (assuming the attribute you're filtering is called what)
If you're wanting to be able to filter on multiple attributes, make additional predicate bindings. Doing the CoreData option-drag of an entity into IB is really handy - take a peek at how it configures the search field for filtering multiple columns.

Making a tag / branch (Subversion->General) (10 July , 2005) [permalink]
This will make a tag called "stable-1" of the current trunk revision:

% svn copy file:///usr/local/svnroot/HackDie/trunk 
            file:///usr/local/svnroot/HackDie/tags/stable-1 
            -m "tag for HackDie internal stable release #1"

Custom Accessor Methods (scalar) (Core Data->General) (09 July , 2005) [permalink]
Say there's a float ivar called radius

- (float) radius
{
    [self willAccessValueForKey: @"radius"];
    float f = radius;
    [self didAccessvalueForKey: @"radius"];

   return (f);

} // radius


- (void) setRadius: (float) newRadius
{
    [self willChangeValueForKey: @"radius"];
    radius = newRadius;
    [self didChangeValueForKey: @"radius"];

} // setRadius

Custom accessor methods (objects) (Core Data->General) (09 July , 2005) [permalink]
Wrap the methods with will/did Access/Change ValueForKey:, and also use KVC to set primitive values:

- (NSString *) name
{
    [self willAccessValueForKey: @"name"];
    NSString *string = [self primitiveValueForKey: @"name"];
    [self didAccessValueForKey: @"name"];
} // name

- (void) setName: (NSString *) x
{
    [self willChangeValueForKey: @"name"];
    [self setPrimitiveValue: x  forKey: @"name"];
    [self didChangeValueForKey: @"name"];
} // setName

Inserting an object (Core Data->General) (09 July , 2005) [permalink]
Inserting a new object into a managed object context is a multi-stage process. This assumes that self has methods to get the managed object context and managed object model (Apple's CoreData Application template does)

Thanks to Evan Moseman who pointed me at the new easy way to do it:

        NSManagedObjectContext *moc = [self managedObjectContext];
	NSManagedObject *obj = [NSEntityDescription 
		insertNewObjectForEntityForName :@"Condition" 
		inManagedObjectContext: context];

And the older, more manual way if you need some more control over the process:

    NSManagedObjectContext *moc = [self managedObjectContext];
    NSManagedObjectModel *mom = [self managedObjectModel];

    NSEntityDescription *entity;
    entity = [[mom entitiesByName] objectForKey: @"Condition"];

    NSString *className;
    className = [entity managedObjectClassName];

    NSManagedObject *obj;
    obj = [[NSClassFromString(className) alloc]
              initWithEntity: entity
              insertIntoManagedObjectContext: moc];

    [obj autorelease];

    [obj setValue: @"nook"  forKey: @"name"];
    [obj setValue: [NSNumber numberWithInt: 23]  forKey: @"ranking"];

Manipulating a to-many relationship (Core Data->General) (09 July , 2005) [permalink]
Use mutableSetValueForKey: This returns a proxy that mutates the relationship and does KVO notifications. Think of the name as "[NS]MutableSet" "valueForKey" rather than "mutableSetValue" "forKey", because it returns a mutable set that you manipulate
```
NSMutableSet *employees;
employees = [department mutableSetValueForKey: @"employees"];
[employees addObject: newEmployee];
[employees removeObject: sackedEmployee];
```

Manually sorting results in a fetch request (Core Data->General) (09 July , 2005) [permalink]
I haven't figured out how to get the Xcode fetched query editor to sort. In the mean time, here's how to do it in code:

    NSSortDescriptor *sorter;
    sorter = [[NSSortDescriptor alloc]
                 initWithKey: @"when"
                 ascending: YES];

    [fetchRequest setSortDescriptors:
               [NSArray arrayWithObject: sortDescriptor]];

Sorting results (Core Data->General) (09 July , 2005) [permalink]
Want data to be sorted in tableviews and whatnot? You can set the "sortDescriptors" binding on an array controller. Write a method that returns the sort descriptors you want:
```
- (void) setWhenSortDescriptors: (NSArray *) descriptors
{
} // setWhenSortDescriptors


- (NSArray *) whenSortDescriptors
{
    NSSortDescriptor *sorter;
    sorter = [[[NSSortDescriptor alloc]
                  initWithKey: @"when"
                  ascending: NO] autorelease];

    return ([NSArray arrayWithObject: sorter]);

} // whenSortDescriptors
```
This is for a 'permanent' sorting, not allowing the user to change the sorting. Also, new/changed objects added to the collection don't appear to be placed in sorted order.
Storing Images into the data store (Core Data->General) (09 July , 2005) [permalink]
So ya want to store an image into the data store. mmalc says
Don't use the XML store, but instead use the SQLite store
If an entity has a large data blob as an attribute, you should make a separate entity for that attribute.
e.g. a Person has a 'photo' attribute. Create a Photo entity with a single attribute (the data) and a relationship back to the person (if it makes sense, usually it does), and a relationship from the Person to the Photo entity.
This means that the photo data will only be loaded from the persistent store if you actually use it.
(markd: this also has the nice side effect of letting the db put all the blob data elsewhere, rather than in with the other data, giving you better locality of reference to your Person data without slogging through all the Photo jazz if you don't need it)
Blanket Disabling of ZeroLink (Xcode->Hacks) (29 June , 2005) [permalink]
(see also ZeroLink Must Die.
This find will grovel around project files and turn off ZeroLink. You can start at the path here to turn it off in all of your Xcode templates, and you can also point the find at your own XCode projects. Make backups first if you're feeling squeamish or your stuff isn't under version control.
```
% cd '/Library/Application Support/Apple/Developer Tools/Project Templates'
% find . -name "*.pbxproj" -exec perl -pi -e "s/ZERO_LINK = YES/ZERO_LINK = NO/g" {} \; -print
```

Showing all files that changed at a particular revision (Subversion->General) (23 June , 2005) [permalink]
If you're inside of a working copy, you can do:

% svn log -v -r 373
------------------------------------------------------------------------
r373 | markd | 2005-06-22 16:05:38 -0400 (Wed, 22 Jun 2005) | 1 line
Changed paths:
   A /xyz/trunk/docs/bugreports/4158233-nsbrowser
   A /xyz/trunk/docs/bugreports/4158233-nsbrowser/browser-rows.png
   A /xyz/trunk/docs/bugreports/4158233-nsbrowser/browserdraw.tar.gz
   A /xyz/trunk/docs/bugreports/4158233-nsbrowser/bug.txt

initial revision
------------------------------------------------------------------------

and you can look repository-wide too: % svn log -v -r 373 file:///usr/local/svnroot/

Access environment variables from Cocoa (Random->General) (13 June , 2005) [permalink]
Check out NSProcessInfo's environment method
Setting environment variables for the gui login session (Random->General) (13 June , 2005) [permalink]
For environment variables you want set for the user's GUI login session, make a plist called ~/.MacOSX/environment.plist. Make the root a Dictionary, and add the key/value pairs (all strings) to it. Don't forget to logout and back in.
Apple-Generic Versioning (Xcode->General) (11 April , 2005) [permalink]
You can use agvtool do to apple-style generic versioning, which has two version numbers - one's a float that's monotonically increasing, and the other is a "marketing" version, that can be things like "1.0.4b34". Courtesy of Chris Hanson from a mailing list posting:
Set your Versioning System (VERSIONING_SYSTEM) to "apple-generic".
Set your Current Project Version (CURRENT_PROJECT_VERSION) to some floating point value that you'll increment every build. You could just start at 1, unless you already have builds out there with other numbers.
This will generate and build a source file automatically that defines two globals whenever you build your project. One is a double corresponding to CURRENT_PROJECT_VERSION, the other is a string. The file is a derived source file; it won't be added to your project, but it will be built with it.
If you're building a framework, there are other build settings you'll probably want to set as well, such as Current Version (DYLIB_CURRENT_VERSION), Compatibility Version (DYLIB_COMPATIBILITY_VERSION), and VERSION_INFO_PREFIX.
To update the version number, you can use agvtool next-version or agvtool new-version.
Make Mail.app display plain text messages (Random->Random) (07 April , 2005) [permalink]
Many HTML emails I receive get rendered in Mail.app in tiny, tiny point sizes. To have Mail.app prefer to display plain text instead, quit Mail.app and run this:
% defaults write com.apple.mail PreferPlainText -bool TRUE
Using tar to copy across the network (Unix->General) (03 April , 2005) [permalink]
% tar cf - ./stuff | ssh theOtherMachine "tar xf -"
Restrict editing to the region (emacs->General) (31 March , 2005) [permalink]
M-x narrow-to-region
Hides everything not in the current region.
Unnarrowing the region (emacs->General) (31 March , 2005) [permalink]
M-x widen
Open path sheet in the Finder (General->General) (28 March , 2005) [permalink]
Open a Finder window, then type command-shift-g. Works in standard file dialogs too.
Add new directory directly to repository (Subversion->General) (18 March , 2005) [permalink]
% svn mkdir -m "initial revision" file:///usr/local/svnroot/MilleBorks

Adding new project to repository (1 project : 1 repository) (Subversion->General) (18 March , 2005) [permalink]
The Subversion folks recommend that project have a branches, tag, and trunk directory, to make doing things like branches and tags easier. Importing this way will mean your repository will only have this one project.

% mkdir DungeonBorkventure
% cd DungeonBorkventure
% mkdir branches tags trunk
# put source files into trunk
% svn import . file:///usr/local/svnroot -m "initial checkin"
% cd ..
% rm -rf DungeonBorkventure  # or move it aside
% svn checkout file:///usr/local/svnroot/trunk DungeonBorkventure
% cd DungeonBorkventure
# and get to work

Adding new project to repository (multiple projects : 1 repository) (Subversion->General) (18 March , 2005) [permalink]
To have multiple projects in one repository, you have to create directories in the repository first to hold the project, then import the code. Here is importing two projects, MilleBorks and DungeonBorkventure

First, make the directories in the repository:

% svn mkdir -m "initial revision" file:///usr/local/svnroot/DungeonBorkventure
% svn mkdir -m "initial revision" file:///usr/local/svnroot/MilleBorks

Then import the different code bases:

% cd /path/to/DungeonBorkventure
% svn import -m "initial revision" . file:///usr/local/svnroot/DungeonBorkventure
% cd /path/to/MilleBorks
% svn import -m "initial revision" . file:///usr/local/svnroot/MilleBorks

Then checkout working copies of the projects:

% cd /work/and/play/area
% svn checkout file:///usr/local/svnroot/MilleBorks/trunk MilleBorks
% svn checkout file:///usr/local/svnroot/DungeonBorkventure/trunk DungeonBorkventure

Making a new FSFS repository (Subversion->General) (18 March , 2005) [permalink]
% svnadmin create --fs-type fsfs /usr/local/svnroot/
Seeing what files will come down in the next update (Subversion->General) (18 March , 2005) [permalink]
To see if folks have committed changes that'll get brought down in the next update.
% svn status --show-updates
You can specify files and directories of interest.
Merging a Branch with new directories in CVS (CVS->General) (16 March , 2005) [permalink]
When merging a branch back into the trunk (using the update command) be sure to use the -d option. Otherwise CVS will just ignore any directories added in the branch.
```
% cvs update -Ad  #switch to the trunk (if you haven't already)
% cvs update -d -j branch_name
[resolve conflicts]
% cvs commit -m "whatever"
```
(Courtesy of Jeremy Stein)
Using awk to print fields (Unix->General) (14 March , 2005) [permalink]
Here's a way to have awk print all fields (separated by spaces) from each line, except for fields number 1 and 9 (starting with a count of 1):
```
% awk '{ for (f=1; f <= NF; f++) { if (f != 1 && f != 9) printf("%s ", $f);} printf("
");}' < ook.txt
```
Or you can put this at the end of a pipeline instead of directing a text file into the command. (courtesy of DougEDoug)
Loading a bundle into a running program (gdb->Hacks) (28 February , 2005) [permalink]
Sometimes it's handy to load a bundle into a running app to do some poseAsClass: for doing some debugging or reverse engineering. Make a Cocoa bundle which has the code you want to load, then do:
```
(gdb) call (id) objc_getClass("NSBundle")
$1 = (struct objc_object *) 0xa0a051d8

gdb) call (id)[$1 bundleWithPath:@"/blah/blah/PoseAsClassBundle.bundle"]
$2 = (struct objc_object *) 0x51467e0

(gdb) call (BOOL)[$2 load]
Reading symbols for shared libraries . done
```
Enabling "control reaches end of non-void function" (Xcode->General) (28 February , 2005) [permalink]
One nice gcc warning that's not enabled by default is one that complains if you exit from a function (by falling off the end) without returning anything. This is an easy error to make, and can be hard to track down (especially if you do it in an objective-C init method). To enable this warning, add "-Wreturn-type" to the "Other C Flags" setting in your favorite build style.
Getting the current user's name (Random->General) (26 February , 2005) [permalink]
NSUserName() or NSFullUserName().
Thanks to Peter Hosey for letting us know about a better API for getting these.
Responding to modifier keys only (NSView->General) (24 February , 2005) [permalink]
NSView's keyDown: and keyUp: don't fire when just a modifier key goes down. If you do want to react to this, you'll need to override flagsChanged: (NSEvent *) event and look at the event there. (flagsChanged: comes from NSResponder, so any responder in the responder chain can react to it)

Observing using KVO (Bindings->General) (24 February , 2005) [permalink]
Register an observer with something like:

    [searchArrayController addObserver: self
                           forKeyPath: @"selectionIndexes"
                           options: NSKeyValueObservingOptionNew
                           context: NULL];

This makes self an observer of the searchArrayController. We'll get notified when the selectionIndexes value changes, and we'll be notified with the new value.

When the notification happens, this method (invoked against the self used earlier) is invoked:

- (void) observeValueForKeyPath: (NSString *) keyPath
                       ofObject: (id) object
                         change: (NSDictionary *) change
                        context: (void *) context
{
} // observeValueForKeyPath

and you can poke around the arguments to see wha'happened.

Fixing Bindings-related memory leak (Bindings->Hacks) (24 February , 2005) [permalink]
If you have bindings hooked up to File's Owner in some circumstances (like with an NSWindowController-based nib file), a retain cycle is created, and so the window controller will never get released (having an extra retain for each binding to File's Owner). An easy way to work around this is to;
- Add an NSObjectController (I call it "Fake FIle's Owner") to the nib file and the window controller class.
- Point the bindings to the controller rather than file's owner
- Hook up the window controller's outlet to point to the object controller
- [fakeFileOwner setContent: self]
Then again, this all might be Wrong. jkp_ in #macdev points out that the setContent:self will retain self twice more, with no release in sight. The only wayd that would really work is if you provided a subclass of NSObjectController that released after it setContent: and also in _startObservingObject: That might be the cleanest solution - provide a custom proxy object that doesnt retain the filesOwner and bind to that....same thing, only you have to do the overrides. So this one's in limbo(e) for now. wheeee! He's come up with a hack to work around things:
```
- (oneway void) release;
{
    // special case when count is 3, we are being retained twice by the object controller...
    if ( [self retainCount] == 3 )
    {
        [super release];
        [filesOwnerProxy setContent:nil];
        return;
    }
    
    [super release];
}
```
Reacting to TableView selection changes when using bindings (Bindings->NSTableView) (24 February , 2005) [permalink]
You're using bindings to handle the tableview, but now you have some code that needs to do something when the selection changes (in my case I was disabling a sheet's OK button if the selection in two tableviews was the same). The way to track that change is to add yourself as an observer of the array controller that's driving the tableview, and then do the work in the observeValueForKeyPath: method. Register your observer like this:
```
    [searchArrayController addObserver: self
                           forKeyPath: @"selectionIndexes"
                           options: NSKeyValueObservingOptionNew
                           context: NULL];
```
So now self's observeValue method will get invoked when selectionIndexes changes in the array controller.

Performing relative (grab-hand) scrolling (NSView->General) (23 February , 2005) [permalink]
Grab-hand scrolling is a handy feature in several apps. It's nice being able to scroll around a large document diagonally, fer instance. Here's one way to do it (assuming you have a standard NSScrollView -> NSClipView -> YourView setup)

@interface Blah : NSView
{
    NSPoint grabOrigin;
    NSPoint scrollOrigin;
}
@end // Blah

...

@implementation Blah

...

- (void) mouseDown: (NSEvent *) event
{
    // deal in window coordinates.  there is a scrolling problem
    // if using view coordinates because view coordinates
    // can get transformed
    grabOrigin = [event locationInWindow];

    NSClipView *contentView;
    contentView = (NSClipView*)[layerView superview];

    scrollOrigin = [contentView bounds].origin;

} // mouseDown


- (void) mouseDragged: (NSEvent *) event
{
    NSPoint mousePoint;
    mousePoint = [event locationInWindow];

    float deltaX, deltaY;
    deltaX = grabOrigin.x - mousePoint.x;
    deltaY = mousePoint.y - grabOrigin.y;

    NSPoint newOrigin;
    newOrigin = NSMakePoint (scrollOrigin.x + deltaX,
                             scrollOrigin.y + deltaY);

    [layerView scrollPoint: newOrigin];

} // mouseDragged
...

@end // Blah

You can be fancy and check for the option key by look at [event modifierFlags] and looking for NSAlternateKeyMask, and also use the NSCursor open/closedHandCursor.

Reacting to the Escape key (NSView->General) (21 February , 2005) [permalink]
There's no predefined constant for the Escape key. Luckily the escape key predates every personal computer, and so it has a pretty reliable character value that's generated: 27:
```
- (void) keyDown: (NSEvent *) event
{
    NSString *chars = [event characters];
    unichar character = [chars characterAtIndex: 0];

    if (character == 27) {
        NSLog (@"ESCAPE!");
    }
} // keyDown
```

Reacting to the delete key (NSView->General) (21 February , 2005) [permalink]
Look for NSDeleteCharacter in the event's character string:

- (void) keyDown: (NSEvent *) event
{
    NSString *chars = [event characters];
    unichar character = [chars characterAtIndex: 0];

    if (character == NSDeleteCharacter) {
        NSLog (@"Delete!");
    }
} // keyDown

Minimal KVC accessors for arrays (Bindings->General) (21 February , 2005) [permalink]
For an attribute named "layers", here are the KVC accessors to write to let observers react to object addition and removal:

- (NSArray *) layers
{
    return (layers);
} // layers


- (void) insertObject: (id) obj
      inLayersAtIndex: (unsigned) index
{
    [layers insertObject: obj  atIndex: index];
} // insertObjectInLayers


- (void) removeObjectFromLayersAtIndex: (unsigned) index
{
    [layers removeObjectAtIndex: index];
} // removeObjectFromLayersAtIndex

Discovering when exiting a sub event loop (General->General) (18 February , 2005) [permalink]
[self performSelector: @selector(whatever) withObject: nil afterDelay: 0];
The selector gets posted after a sub event loop finishes. You can use this for finding out when a live slider is done being manipulated, for instance
Using KVO for whole-object observation (Bindings->General) (18 February , 2005) [permalink]
I've got an object that has a bunch of individual attributes that are controlled by an inspector, and another object (a view that holds that object) which needs to redraw when something changes in the object, but it doesn't care which individual attribute it is. Rather than having the view observe each of the individual attributes, KVO provides a way to automatically trigger another observation when any dependent attribute changes.
First, in the +initialize for the class that's going to be observed:
```
+ (void) initialize
{
    NSArray *keys;
    keys = [NSArray arrayWithObjects: @"showMajorLines", @"minorWeight",
                    @"minorColor", @"minorWeightIndex", @"minorColorIndex",
                    @"majorWeightIndex", @"majorColorIndex", nil];

    [BWGridAttributes
        setKeys: keys
        triggerChangeNotificationsForDependentKey: @"gridAttributeChange"];

} // initialize
```
So now when "showMajorLines" changes, "gridAttributeChange" will also be observed. KVO requires there actually must exist a gridAttributeChange method (or ivar I presume) before it'll do the notification to observing objects, so there needs to be a do-nothing method:
```
- (BOOL) gridAttributeChange
{
    return (YES);
} // gridAttributeChange
```
So now the view can do this:
```
- (void) setGridAttributes: (BWGridAttributes *) a
{
    [attributes removeObserver: self
                forKeyPath: @"gridAttributeChange"];

    [a retain];
    [attributes release];
    attributes = a;

    [a addObserver: self
       forKeyPath: @"gridAttributeChange"
        options: NSKeyValueObservingOptionNew
        context: NULL];

} // setGridAttributes
```
And will get updated whenever an individual attribute changes.

Adding your own objects to the responder chain (NSObject->General) (09 February , 2005) [permalink]
For I project I was working on, I needed the editing tools (for a graphical editor) to be in the responder chain so they could react to menu items. Doing this was surprisingly easy.

First step was to make the tools inherit from NSResponder:

@interface BWTool : NSResponder
{
    // blah
}
// ... more blah
@end // BWTool

Then, in the view class where the tool gets set, put the tool in the responder chain by setting its next responder to be the view's current next responder. If a different tool gets set, take the current tool's next responder and give it to the new tool. Otherwise the view gets its original next responder back:

- (void) setTool: (BWTool *) newTool
{
    NSResponder *nextResponder;

    // this is the next element in the chain

    if (currentTool != nil) {
        nextResponder = [currentTool nextResponder];
    } else {
        nextResponder = [self nextResponder];
    }

    // decide who gets to point to the next responder

    if (newTool != nil) {
        // stick the tool into the chain
        [self setNextResponder: newTool];
        [newTool setNextResponder: nextResponder];

    } else {
        // cut the tool out of the chain (if there was one)
        [self setNextResponder: nextResponder];
    }

    [newTool retain];
    [currentTool release];

    currentTool = newTool;

} // setDrawTool

And now tools can have action methods, and menu items that enable and disable appropriately.

Disabling "Return moves editing to next cell" in TableView (NSTableView->General) (04 February , 2005) [permalink]
When you edit cells in a tableview, pressing return, tab, or shift-tab will end the current editing (which is good), and starts editing the next cell. But of times you don't want that to happen - the user wants to edit an attribute of a given row, but it doesn't ever want to do batch changes to everything.

To make editing end, you need to subclass NSTableView and add code to catch the textDidEndEditing delegate notification, massage the text movement value to be something other than the return and tab text movement, and then let NSTableView handle things.

// make return and tab only end editing, and not cause other cells to edit

- (void) textDidEndEditing: (NSNotification *) notification
{
    NSDictionary *userInfo = [notification userInfo];

    int textMovement = [[userInfo valueForKey:@"NSTextMovement"] intValue];

    if (textMovement == NSReturnTextMovement
        || textMovement == NSTabTextMovement
        || textMovement == NSBacktabTextMovement) {

        NSMutableDictionary *newInfo;
        newInfo = [NSMutableDictionary dictionaryWithDictionary: userInfo];

        [newInfo setObject: [NSNumber numberWithInt: NSIllegalTextMovement]
                 forKey: @"NSTextMovement"];

        notification =
            [NSNotification notificationWithName: [notification name]
                                       object: [notification object]
                                       userInfo: newInfo];

    }

    [super textDidEndEditing: notification];
    [[self window] makeFirstResponder:self];

} // textDidEndEditing

(Thanks to Steven Jacowski for a tweak that ends editing on clicks on different cells)

Making a table view a drag source (NSTableView->General) (30 January , 2005) [permalink]
If you want to make your NSTableView a source for a drag and drop operation, you need to implement
```
- (BOOL) tableView: (NSTableView *) view
         writeRows: (NSArray *) rows
      toPasteboard: (NSPasteboard *) pboard
```
in your table view data source (and don't forget to hook up the datasource if you use bindings to populate the tableview)
Table View drag destination on or between rows (NSTableView->General) (30 January , 2005) [permalink]
When your NSTableView is a drag destination, you may want to support both dragging onto existing objects (to replace them, or augment them with some new attribute the user is dragging over) and support dragging between existing objects (to insert a new one in between. To get this behavior, you need to use NSTableView's -setDropRow:dropOperation:, like so:
```
- (NSDragOperation) tableView: (NSTableView *) view
                 validateDrop: (id ) info
                  proposedRow: (int) row
        proposedDropOperation: (NSTableViewDropOperation) op
{
    // have the table highlight on-row / between-row correctly
    [view setDropRow: row
          dropOperation: op];

    // or use whateve
```