Completed Project

Recently I was working on a project where I wanted a certain effect. This was that I wanted the user to be able to delete items out of a table by clicking on the item and not having to add some button somewhere else to do it. So the answer was to put a button on the table to delete it. That was simple enough, just make a table with button cells, but it didn’t look very nice, it showed all the button when you could only delete one at a time. So thus, I decided to make the buttons only appear on the selected table items. Its simple, functional, and you can do it too if you just follow this short guide.

To tackle this problem, there are two “hacks” that we need to do.  First, we have to somehow make the NSButtonCell hide itself.  Next, we have to keep track of which row is selected, and tie that information back to our buttons. To accomplish the first task, will tie the button being hidden to it’s enabled value, since this way is easier then creating a new binding, and it doesn’t matter is the button is disabled if it’s hidden anyway.  Subclass NSButtonCell and override this method with this code.

- (void) drawWithFrame: (NSRect)cellFrame inView: (NSView*)controlView
{
	if([self isEnabled])
		[super drawWithFrame:cellFrame inView:controlView];
}

In interface builder, drag a NSButtonCell to one of the columns of your NSTableView. (Apple hides it as a ‘Check Box Cell’, see below, you have to change the type to ‘Momentary Push In’).

Check Box Cell (NSButtonCell)

Setting the Class to HidingButtonCell

Change the class to your custom subclass. Next we need to somehow get the data in a form we can bind to the button’s enabled key.  There are potentially a couple ways to do this, but I decided to subclass NSTableView, and override this method.

- (void)selectRowIndexes:(NSIndexSet *)indexes byExtendingSelection:(BOOL)extend
{
	[super selectRowIndexes:indexes byExtendingSelection:extend];
	[controller setSelectionIndex:[indexes firstIndex]];
 
	int i;
	for(i = 0; i < [[controller arrangedObjects] count]; i++)
	{
		[[[controller arrangedObjects] objectAtIndex:i] setObject:
			[NSNumber numberWithInt:[indexes firstIndex] == i] forKey:@"enabled"];
	}
 
}

Of, course this way of doing this assumes you’re binding to an NSArray of NSMutableDictionaries.  Next, back in Interface Builder we can bind the column to the new data that’s going to be generated with that method. And thats it enjoy you’re disappearing buttons.  If you want the button to delete the row, like mine, just connect the NSButtonCell’s action to the NSArrayController’s remove: method. If I made any mistakes, or made anything unclear, please leave a comment.  For a closer look, Download the Xcode Project

Sorry it took me so long to put it up.  Some things to note: It interfaces with Remi’s Chat Program in everything except that iOS doesn’t support the rich text.  You may notice if you download the project that I created a file called NSPatches, this was to allow for the iOS to properly unarchive some classes that it doesn’t have, most notably NSFont.  Other then that, from what I can tell ThoMoNetworking works flawlessly on iOS.  The only thing I couldn’t test was from iOS to iOS, since I lacked two iOS devices, but from iOS to OS X worked great, so I would assume it would work fine.  So here is the bulk of the code for you to peruse, and you can download the project underneath, enjoy!

P.S. Let me know if anybody runs into any issues with the code, I may be able to resolve them easily, since some crashes might just be due to iOS not having certain clases that OS X has, which a simple appending to the NSPatches file should fix.

//
//  Remi_s_Chat_AppViewController.m
//  Remi's Chat App
//
//  Created by Remi Bernotavicius on 7/18/10.
//  Copyright __MyCompanyName__ 2010. All rights reserved.
//
 
#import "Remi_s_Chat_AppViewController.h"
 
@implementation Remi_s_Chat_AppViewController
 
/*
// The designated initializer. Override to perform setup that is required before the view is loaded.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        // Custom initialization
    }
    return self;
}
*/
 
/*
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView {
}
*/
 
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    [super viewDidLoad];
 
	myServer = [[ThoMoServerStub alloc] initWithProtocolIdentifier:@"remischat"];
	[myServer setDelegate:self];
	[myServer start];
 
	myClient = [[ThoMoClientStub alloc] initWithProtocolIdentifier:@"remischat"];
	[myClient setDelegate:self];
	[myClient start];
 
	[[UIApplication sharedApplication] setDelegate:self];
}
 
- (void)applicationWillTerminate:(UIApplication *)application
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithString:[NSFullUserName() stringByAppendingString:@" disconnected"]] autorelease];
	[temp appendAttributedString:[[[NSAttributedString alloc] initWithString:@"\n"] autorelease]];
	[myServer sendToAllClients:temp];
}
 
- (void)server:(ThoMoServerStub *)theServer acceptedConnectionFromClient:(NSString *)aClientIdString;
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithString:[NSFullUserName() stringByAppendingString:@" connected"]] autorelease];
	[temp appendAttributedString:[[[NSAttributedString alloc] initWithString:@"\n"] autorelease]];
	[myServer send:temp toClient:aClientIdString];
}
 
/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/
 
- (void)didReceiveMemoryWarning {
	// Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
 
	// Release any cached data, images, etc that aren't in use.
}
 
- (void)viewDidUnload {
	// Release any retained subviews of the main view.
	// e.g. self.myOutlet = nil;
}
 
- (void)textFieldDidBeginEditing:(UITextField *)textField
{
	CGRect newFrame = self.view.frame;
	if ([[UIApplication sharedApplication] statusBarOrientation]== UIInterfaceOrientationPortrait
		|| [[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationPortraitUpsideDown)
		newFrame.size.height -= 216;
	else
		newFrame.size.height -= 162;
 
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [UIView setAnimationDuration:0.3];
 
    [self.view setFrame:newFrame];
 
    [UIView commitAnimations];
}
 
-(IBAction)sendMessage:(id)sender
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithString:[NSFullUserName() stringByAppendingString:@": "]] autorelease];
	[temp appendAttributedString:[[[NSMutableAttributedString alloc] initWithString:toSend.text] autorelease]];
	[temp appendAttributedString:[[[NSMutableAttributedString alloc] initWithString:@"\n"] autorelease]];
 
	[myServer sendToAllClients:temp];
	toSend.text = @"";
}
 
- (void)textFieldDidEndEditing:(UITextField *)textField
{
	CGRect newFrame = self.view.frame;
	if ([[UIApplication sharedApplication] statusBarOrientation]== UIInterfaceOrientationPortrait
		|| [[UIApplication sharedApplication] statusBarOrientation] == UIInterfaceOrientationPortraitUpsideDown)
		newFrame.size.height += 216;
	else
		newFrame.size.height += 162;
 
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [UIView setAnimationDuration:0.3];
 
    [self.view setFrame:newFrame];
 
    [UIView commitAnimations];
}
 
-(void)server:(ThoMoServerStub *)theServer didReceiveData:(id)theData fromClient:(NSString *)aClientIdString {}
 
-(void)client:(ThoMoClientStub *)theClient didReceiveData:(id)theData fromServer:(NSString *)aServerIdString;
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithAttributedString:theData] autorelease];
	history.text = [history.text stringByAppendingString:[temp string]];
 
	[history scrollRangeToVisible:NSMakeRange([history.text length]-2, 1)];
}
 
- (void)dealloc {
    [super dealloc];
}
 
@end

Download the Xcode Project

With such a powerful framework at my disposal, I decided to test it out.  I wanted to see just how easy it would be to create my own ad-hoc chatting program.  I’ve included the source as well so you can test out the framework for yourselves.

I give you, Remi’s Chat Program

Since ThoMoNetworking lets you send any object, I was able to send NSAttributedString objects, so the text’s color and font are preserved.  I was also able to include recalling previously sent messages with the arrow keys (like in the terminal) and growl support as a superfluous features.  This seemingly complicated program is actually very little code.

//
//  Remi_s_Chat_ProgramAppDelegate.m
//  Remi's Chat Program
//
//  Created by Remi Bernotavicius on 6/1/10.
//  Copyright 2010 __MyCompanyName__. All rights reserved.
//
 
#import "Remi_s_Chat_ProgramAppDelegate.h"
 
@implementation Remi_s_Chat_ProgramAppDelegate
 
- (NSDictionary *) registrationDictionaryForGrowl {
	NSArray *array = [NSArray arrayWithObjects:@"new message", nil];
    NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
                          [NSNumber numberWithInt:1],
                          @"TicketVersion",
                          array,
                          @"AllNotifications",
                          array,
                          @"DefaultNotifications",
                          nil];
    return dict;
}
 
-(void) growlAlert:(NSString *)message title:(NSString *)title{
    [GrowlApplicationBridge notifyWithTitle:title
								description:message
						   notificationName:@"new message"
								   iconData:[[[NSApplication sharedApplication] applicationIconImage] TIFFRepresentation]
								   priority:0
								   isSticky:NO
							   clickContext:@"bringFrontContext"];
}
 
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
	[GrowlApplicationBridge setGrowlDelegate:self];
 
	myServer = [[ThoMoServerStub alloc] initWithProtocolIdentifier:@"remischat"];
	[myServer setDelegate:self];
	[myServer start];
 
	myClient = [[ThoMoClientStub alloc] initWithProtocolIdentifier:@"remischat"];
	[myClient setDelegate:self];
	[myClient start];
 
	[[NSApplication sharedApplication] setDelegate:self];
	previousChats = [[NSMutableArray alloc] init];
	current = 0;
}
 
- (void)server:(ThoMoServerStub *)theServer acceptedConnectionFromClient:(NSString *)aClientIdString;
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithString:[NSFullUserName() stringByAppendingString:@" connected"]] autorelease];
	[temp addAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[NSFont boldSystemFontOfSize:12], NSFontAttributeName, nil] range:NSMakeRange(0, [temp length])];
	[temp appendAttributedString:[[[NSAttributedString alloc] initWithString:@"\n"] autorelease]];
	[myServer send:temp toClient:aClientIdString];
}
 
-(void)dealloc
{
	[previousChats release];
	[super dealloc];
}
 
-(void)retreat
{
	if(current < [previousChats count]) 	{ 		current++; 		[[toSend textStorage] setAttributedString:[previousChats objectAtIndex:current]]; 		if(current == [previousChats count]-1) 			[previousChats removeLastObject]; 	} } -(void)advance { 	 	if(current > 0 && [previousChats count] > 0)
	{
		if(current > [previousChats count]-1)
			[previousChats addObject:[[toSend attributedString] copy]];
		current--;
		[[toSend textStorage] setAttributedString:[previousChats objectAtIndex:current]];
	}
}
 
- (void)windowDidBecomeKey:(NSNotification *)notification
{
	[mainWindow makeFirstResponder:[toSend superview]];
}
 
-(IBAction)sendMessage:(id)sender
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithString:[NSFullUserName() stringByAppendingString:@": "]] autorelease];
	[temp appendAttributedString:[toSend attributedString]];
 
	[previousChats addObject:[toSend attributedString]];
 
	if ([previousChats count] <= 10)
		current = [previousChats count];
	else
		[previousChats removeObjectAtIndex:0];
 
	NSString* t = [temp string];
	if(![[t substringWithRange:NSMakeRange([t length]-1, 1)] isEqual:@"\n"])
		[temp appendAttributedString:[[[NSAttributedString alloc] initWithString:@"\n"] autorelease]];
	[myServer sendToAllClients:temp];
	[[toSend textStorage] setAttributedString:[[[NSAttributedString alloc] initWithString:@""] autorelease]];
}
 
- (void) growlNotificationWasClicked:(id)clickContext{
	[[NSApplication sharedApplication] activateIgnoringOtherApps:YES];
 
}
 
-(void)server:(ThoMoServerStub *)theServer didReceiveData:(id)theData fromClient:(NSString *)aClientIdString {}
 
-(void)client:(ThoMoClientStub *)theClient didReceiveData:(id)theData fromServer:(NSString *)aServerIdString;
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithAttributedString:[history attributedString]] autorelease];
	[temp appendAttributedString:theData];
	[[history textStorage] setAttributedString:temp];
 
	[history scrollRangeToVisible:NSMakeRange([[history textStorage] length], 0)];
 
	if(![mainWindow isKeyWindow])
	{
		[[NSApplication sharedApplication] requestUserAttention:NSCriticalRequest];
		[self growlAlert:[(NSAttributedString*)theData string] title:@"New Message"];
	}
}
 
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
{
	NSMutableAttributedString* temp = [[[NSMutableAttributedString alloc] initWithString:[NSFullUserName() stringByAppendingString:@" disconnected"]] autorelease];
	[temp appendAttributedString:[[[NSAttributedString alloc] initWithString:@"\n"] autorelease]];
	[temp addAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[NSFont boldSystemFontOfSize:12], NSFontAttributeName, nil] range:NSMakeRange(0, [temp length])];
	[myServer sendToAllClients:temp];
 
	return NSTerminateNow;
}
 
@end

Download the Xcode Project

Let me know if there are any issues with the source, or if you would like to see more, like an iPhone OS example, just post a comment.

WikiTyper in Action

If you have any comments on the game please post them below. Some things I know are not working and I might fix in the future if people ask about them.  The words per minute is actual words per minute not the correct wpm, (if anyone knows the formula?)  Also occasionally it will display characters that you cannot type, but I couldn’t find a way to remedy that efficiently.  Finally, for those of you Linux and Windows users, a Java port is being made by someone else.  I will post a link if/when it is finished.

-(void)_setDisplayName:(NSString*)name
{
	//Hack Display Name to make KVO Compliant
	[self willChangeValueForKey:@"displayName"];
	[(YourClassNameHere*)super _setDisplayName:name];
	[self didChangeValueForKey:@"displayName"];
}

And that should be it. Note: I changed the method’s return type to void because otherwise it will create an error in the console about KVO compliant methods not being able to return anything other then void.

Also note that this is for read-only binding, to do a binding where you can change the value you have to implement and expose a new binding programmatically.

Apple’s Documentation on KVO

After researching the error, I came to the conclusion that it has to do with snow leopard upgrading CUPS. The newest version of CUPS, I read, requires that all the drivers’ files be owned by root. After investigating I found that Xerox’s PPD’s and plugins were NOT owned by root and thus causing the problem. To remedy this problem just type this command into the terminal:

sudo chown -R root:admin /Library/Printers

(The command might take a while to run.) This owns the /Library/Printers folder and everything in it to root, this could potentially fix many different printer software to work with snow leopard since it can effect pretty much any printer driver. So if you’re having problems try giving this a shot. Good luck.

First enable Gmail Contacts sync in Address Book by clicking Address Book > Preferences… > Accounts. Then click “On My Mac”, and then check the box next to synchronize with Google. After enabling it you will be prompted for your Gmail username and password. Then you should see a sync icon in your status bar. This lets you manually force a sync with google by clicking “sync now.” When it syncs you will probably have to resolve some ‘sync issues’ (basically deciding which contact is correct, the Gmail or Address Book version.)

If this icon annoys you, just hold down the apple key and drag it out of the bar to remove it, to put it back you can enable it in iSync.app’s preferences.

Now to tweak it. Your computer syncs your contacts in a job in that runs through a process called launchd (For those of you that don’t know, in Tiger and newer, launchd takes the job of cron on normal unix systems.) By default this process runs only once every hour, we are going to try and tweak this. To easily edit your loaded jobs, download Lingon from here http://sourceforge.net/projects/lingon/files/. Open up Lingon, on the left under ‘My Agents’ you should see ‘com.google.GoogleContactSyncAgent.’ Click this, and you here you are able to change it from running every hour to as little time as every second (although I don’t recommend this AT ALL.) Just adjust this setting to a shorter time period to speed it up. The real trick here though is that you can set something called a watch file/directory. This lets the process run when that file/directory has been modified. To make the sync run whenever you change one of your contacts you should just fill in under “Run when this file is modified” this file /Users/remi/Library/Application Support/AddressBook/AddressBook-v22.abcddb This file is your address book database, so hence it runs when you update the database. Remember that this makes your contacts instantly updated from your computer to google, but no the other way around. The frequency that the contacts come into your computer from google is determined by the “run it every” setting. I do not know why apple did not have the file set to watch the address book database to begin with, so I’m not sure if there are any adverse effects, but there has been none that I have experienced so far. Once you are finished editing the job, hit save, then log out and back in or restart for it to take effect. To try it out just edit one of your contacts in Address Book.app and see the update automatically appear on Gmail, and if you iPhone is synced to Gmail, then right to your iPhone.

Please post a comment if you have problems with this method, good luck everyone!

The first thing you must do is specify a doctype, here it is for transitional

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Next comes the hmtl tag, but what you have to do in it is define the XML name space and the language as english

<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en:gb">

Now add the head tag, specify the page encoding, and add a title which is required in valid XHTML

<head profile="http://gmpg.org/xfn/11">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Hello World!</title>

For the most part all of your XHTML Transitional pages should start that way. The next thing to do is just to take care of some pretty simple formatting rules. First off, all of your tags must be in lowercase, and this goes for your tag’s properties too, for example onClick is bad, it has to be onclick, and <P> has to be <p>. Next all your tags have to be closed, if you’re use to using single <p>  tags, you’ll have to do them in the self-closing style: <p />.  Script and style tags must contain a type, so like the following,

<script type="text/javascript"></script>, <style type="text/css"></style>

Also JavaScript not in an external file has to be escaped properly from the XHTML interpreter like follows:

<script type="javascript">
//<![CDATA[
alert("Hello");
//]]>
</script>

Image tags also, have to be closed but also they have to include the alt attribute, even if its just blank.

<img src="http://kunugiken.com/DRF/refresh.png" alt="" />

Another interesting thing to note is that when you declare your page as XHTML, is can break some of your CSS if it is not done correctly, one example would be the left property, for example the following will work in most browsers, but will not work on XHTML pages

position: absolute;
left: 40;

In actuality the left, top, right or bottom properties take a numerical value with a unit of measurement, so it has to be the following

position: absolute;
left: 40px;

Remember that this is also true if you’re setting the CSS from inside JavaScript.

I hope that you found this helpful, these are just some of the things that caught me up while converting my site to XHTML. Although it wasn’t so hard to make my blog part of the site proper XHTML because wordpress does a nice job of making XHTML compliant code anyway. (Although I had to mess with some of the plugins to get them to do it right). Check out W3School’s page on XHTML, and try taking their quiz! I hope you found XHTML at least interesting, and will consider converting your pages. Good Luck Everyone.

On the Ubuntu computer open the terminal, found in Applications > Accessories > Terminal.  First we’re going to create a folder to keep this growl stuff in.

mkdir ~/growl
cd ~/growl

of course you don’t have to keep it in your home directory
Next, lets download pygNotify

wget http://pygnotify.googlecode.com/files/pygNotify-0.1.tgz
tar xvfz pygNotify-0.1.tgz
mv pygNotify-0.1/pygNotify.py .
rm -r pygNotify-0.1

The next thing you need is get the python libraries from the growl SDK, that you can download from their website here http://growl.info/source.php Unfortunately the SDK is in a dmg so you’ll have to use a mac to extract it then copy it to the Ubuntu machine. You’ll need the folder Bindings/Python and also the script Bindings/Network/netgrowl.py. I will write the rest assuming you copied them into a folder called dmg in your home directory. Now we need to install the libraries. Cd into the directory you copied over from the dmg.

cd ~/dmg/Python
sudo python setup.py install

Now you need to move the netgrowl.py also from the dmg to the growl folder we created earlier

mv ~/dmg/netgrowl.py ~/growl

Then we should be done with the stuff from the dmg so we can clean up

rm -r ~/dmg

It should be all installed at this point. Now we need to enable receiving network notifications on the mac computers you want to receive the notifications from your ubuntu machine.

If you haven’t already, download and install growl from its website http://growl.info/ Once installed, go to System Preferences in the apple menu and click on Growl. Then click the network tab, then check “Listen for incoming notifications” and also check “Allow remote application registration” and set a password. Even if you don’t want a password, as far as I can tell you have to set one for it to work. Next you’ll need your computer’s ip address. Open Terminal.app found in /Applications/Utilities and type

ifconfig | grep "inet " | grep -v 127.0.0.1 | cut -d\ -f2

The output should be your ip, write it down because we’ll use it in this next step.  Repeat for each mac.  Now back on your ubuntu machine we need to register your server as an application that can send notifications on your mac.

cd ~/growl
python pygNotify.py -n "Ubuntu Server" -p "password" -H your.macs.ip.address -r -m "register"

Please note that the second command is one line.  Replace password with the password you set earlier, and replace the part after -H with your mac ip address.  You’ll have to do this for every mac you setup to receive network notifications.

Note that the option after -n is the title of the application as it will appear to growl, and you can register multiple times with your mac if you use different names. By using different names for different sets of notifications it becomes possible to set customized settings for both on your mac. ie you could register “System Monitor” and maybe “Email Server” and have them have different message styles on the mac

Once the command runs, it should be registered on the mac and show up in the application list. A keychain confirmation may come up on the mac asking you if you want growlHelper to access the keychain. You should hit always allow, so this notification doesn’t come up every time.

Note: If when you run the command you get a “IndentationError: expected an indented block” when you try to run the script, my best guess is that its due to the formatting being messed up when you copied it to the server. If you find yourself unable to fix this just copy and paste the file from here: http://the.taoofmac.com/space/Projects/netgrowl and finally that worked for me.

Now to send a message

python pygNotify.py -n "Ubuntu Server" -t "test message" -p "password" -H your.macs.ip.address -m "hello world"

Again note that the command is one line.  The part after the -t option is the title of the alert, and the part after -m is the message. Also note if you want the alert to be sticky, meaning it stays on the screen, you can use the -s option.

And that’s, it hopefully. If you have problems with it registering or sending messages, be sure to check your firewall settings, to make sure growlHelper.app can access the internet, or that udp port 9887 is open I believe. Also you can try deleting the password set by growl in the keychain, and resetting it in the System Preferences Growl pane again. This can reset growl’s privileges to access the keychain, which may or may not be set to deny it access. The whole setup can be a finicky system at times, so good luck!

Click here to view the embedded video.