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  • How do I use an indeterminate status indicator as the image for an NSStatusItem?

    - by abrahamvegh
    I have an application that is an NSStatusItem. It has a few different modes, each of which require an external process to be launched, during which the icon is simply highlighted, and appears to be frozen. I want to use the -setImage method (or reasonable facsimile) to display something along the lines of a "spinner" commonly seen in web applications and all over OS X. Is there any native method for accomplishing this (e.g. some instance of NSProgressIndicator?) or must I manually display an animation by cycling through a set of images? In either case, how would I implement?

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  • how to make a explorer like logic in Obj C for iphone

    - by Ekra
    Hi friends, To make the query simple first we can take example:- If we open the explorer in our Windows desktop how it shows us the tree. As we keep on clicking the tree it get expanded and shows the file in it. The same way I want to show a explorer which gets expanded as the user clicks on it(I want to get the business logic the UI is simple). The information of the explorer i.e. which folder has what files come in a XML format to me. I have 2 options of getting the XML either I can get the whole XML at one query(but I guess this might slow the application if the XML is quite big). OR I can get the XML for every list like first only the root structure then if user clicks on any folder in root I can get the list(the files or folders inside that folder) of that particular folder. Now the question is What would be the approach to implement both the method and which would be the best. Should I need to create some dictionary to maintain the link of the files like which file is inside what. I am not able to get as how I would be able to link all the files. Any hint or direction would be highly appreciated. Thanks in advance

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  • Texture2D problem

    - by Anders Karlsson
    I have a problem that is driving me crazy, I want to write a number of texts on the screen using Texture2D however I only seem to be able to write the first one. If I individually write one of the labels it works but not if I write all of them, only the first label is displayed. Let me show some code: -(void)drawText:(NSString*)theString AtX:(float)X Y:(float)Y withFont:(UIFont*)aFont { // set color glColor4f(1, 0, 0, 1.0); // Enable modes needed for drawing glEnableClientState(GL_TEXTURE_COORD_ARRAY); Texture2D* textTexture = [[Texture2D alloc] initWithString:theString dimensions:viewSize // 320x480 alignment:UITextAlignmentLeft font:aFont]; glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); [textTexture drawInRect:CGRectMake(X,Y,1,1)]; glDisableClientState(GL_TEXTURE_COORD_ARRAY); [textTexture release]; } When I call this drawText once it seems to display the text properly, but if I call it a second time nothing seems to be displayed. Somebody has an idea what it could be? The states like GL_BLEND and GL_TEXTURE_2D have been enabled in the view setup function. In the Texture2D the dimensions are 512x512 as I pass the whole screen to function. If I don't pass that the text gets enlarged and fuzzy. I am a bit uncertain about that parameter. TIA for any help.

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  • Justifying UIVIews on the iPhone: Algorithm Help

    - by coneybeare
    I have been messing around with a way to justify align a collection of UIView subclasses within a containing view. I am having a little bit of trouble with the algorithm and was hoping someone could help spot my errors. Here is pseudocode of where I am now: // 1 see how many items there are int count = [items count]; // 2 figure out how much white space is left in the containing view float whitespace = [containingView width] - [items totalWidth]; // 3 Figure out the extra left margin to be applied to items[1] through items[count-1] float margin = whitespace/(count-1); // 4 Figure out the size of every subcontainer if it was evenly split float subcontainerWidth = [containingView width]/count; // 5 Apply the margin, starting at the second item for (int i = 1; i < [items count]; i++) { UIView *item = [items objectAtIndex:i]; [item setLeftMargin:(margin + i*subcontainerWidth)]; } The items do not appear to be evenly spaced here. Not even close. Where am I going wrong? Here is a shot of this algorithm in action: EDIT: The code above is pseudocode. I added the actual code here but it might not make sense if you are not familiar with the three20 project. @implementation TTTabStrip (JustifiedBarCategory) - (CGSize)layoutTabs { CGSize size = [super layoutTabs]; CGPoint contentOffset = _scrollView.contentOffset; _scrollView.frame = self.bounds; _scrollView.contentSize = CGSizeMake(size.width + kTabMargin, self.height); CGFloat contentWidth = size.width + kTabMargin; if (contentWidth < _scrollView.size.width) { // do the justify logic // see how many items there are int count = [_tabViews count]; // 2 figure out how much white space is left float whitespace = _scrollView.size.width - contentWidth; // 3 increase the margin on those items somehow to reflect. it should be (whitespace) / count-1 float margin = whitespace/(count-1); // 4 figure out starting point float itemWidth = (_scrollView.size.width-kTabMargin)/count; // apply the margin for (int i = 1; i < [_tabViews count]; i++) { TTTab *tab = [_tabViews objectAtIndex:i]; [tab setLeft:(margin + i*itemWidth)]; } } else { // do the normal, scrollbar logic _scrollView.contentOffset = contentOffset; } return size; } @end

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  • Allowing user to select a UIPickerView row by tapping.

    - by camilo
    Hi. I'm trying to use a UIPicker View with a behavior somehow different of what's usually seen in iPhone code examples. What I want to do is to allow users to scroll through the picker contents, but not to select a picker's row automatically (using the "didSelectRow" method from picker's delegate). Instead, I want to allow the user to touch the center row of the picker, which gets highlighted, and becomes the selection. Is there any way to achieve this? Thanks in advance.

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  • How to get the same UITableViewCell layout as in the Address Book app?

    - by Romain
    Hi, I currently have a custom UITableViewCell which contains a few labels, and an image. The "main" label is used to display people's names. Currently, I'm styling it in bold text. What I'd like to do (to gain some space and readability), is to mimic the Address Book app cell style, that is: first name in light text, and family name in bold text. Is there a way to do this using the same UILabel? Or, should I use 2 different UILabels? How should I layout them, without knowing their sizes? Thanks in advance for your assistance!

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  • Delay in playing a beep sound

    - by iSharreth
    -(IBAction)playSound{ AVAudioPlayer *myExampleSound; NSString *myExamplePath = [[NSBundle mainBundle] pathForResource:@"myaudiofile" ofType:@"caf"]; myExampleSound =[[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:myExamplePath] error:NULL]; myExampleSound.delegate = self; [myExampleSound play]; } I want to play a beep sound when a button is clicked. I had used the above code. But it is taking some delay in playing the sound. Anyone please help.

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  • Implementing a horizontal compass on the iPhone - algorithm?

    - by Andrew Johnson
    A horizontal compass looks something like this if you are facing due East (90 degrees). 85----90---95 If you were facing due 355 degrees northwest, it would look like this: 350----355---0 As you turn the compass, the number should cycle from 0 - 360 - 0 So, my question is, how would you implement a view like this on the iPhone? I had a couple of ideas: Make one long image with all numbers and tick marks, and shift it left/right when the compass heading changes Create pieces of the view as tiles and append them when the compass heading changes. Create a line of tick marks that shifts with the compass heading, and just write numbers on it as needed. How would you attack this problem? Im mainly looking for algorithmic advice, but if you ave code or pseudo-code to demonstrate, that would be helpful too.

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  • handleOpenURL not called using a custom url schema in iPhone OS

    - by favo
    Hi, I have successfuly added my own url schemes to my App. The App correctly launches using the schemes. Now I want to handle the incoming data but the delegate is not called. It is an universal app and I have added the following function to both AppDelegates: - (BOOL)application:(UIApplication *)application handleOpenURL:(NSURL *)url { if (!url) { return NO; } NSString *URLString = [url absoluteString]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"test message", nil) message:URLString delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil]; [alert show]; [alert release]; return YES; } I am testing with a schema like: myapp://appalarm.com …and would expect to be appalarm.com in the URLString What is wrong with it? Thanks for your responses!

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  • Setting UIImage dimensions on UITableViewCell image

    - by bbrown
    I've got a standard UITableViewCell where I'm using the text and image properties to display a favicon.ico and a label. For the most part, this works really well since UIImage supports the ICO format. However, some sites (like Amazon.com say) have favicon.icos that make use of the ICO format's ability to store multiple sizes in the same file. Amazon stores four different sizes, all the way up to 48x48. This results in most images being 16x16 except for a few that come in at 32x32 or 48x48 and make everything look terrible. I have searched here, the official forum, the documentation, and elsewhere without success. I have tried everything that I could think of to constrain the image size. The only thing that worked was an undocumented method, which I'm not about to use. This is my first app and my first experience with Cocoa (came from C#). In case I wasn't clear in what I'm looking for, ideally the advice would center around setting the dimensions of the UIImage so that the 48x48 version would scale down to 16x16 or a method to tell UIImage to use the 16x16 version present in the ICO file. I don't necessarily need code: just a suggestion of an approach would do me fine. Does anyone have any suggestions? (I asked in the official forum as well because I've sunk more than a day into this already. If a solution is posted there, I'll put it here as well.)

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  • CALayer drawInContext vs addSublayer

    - by Michael
    How can I use both of these in the same UIView correctly? I have one custom subclassed CALayer in which I draw a pattern within drawInContext I have a another in which I set an overlay PNG image as the contents. I have a third which is just a background. How do I overlay all 3 of these items? [self.layer addSublayer:bottomLayer]; // this line is the problem [squaresLayer drawInContext:viewContext]; [self.layer addSublayer:imgLayer]; The other 2 by themselves draw correctly if I do them in that order. No matter where I try and put bottomLayer, it always prevents squaresLayer from drawing. The reason I need 3 layers is I intend to animate the colors in the background and custom layers. The top layer is just a graphical overlay.

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  • NSCalendar: Problem getting weeks in a month...

    - by AngrySpade
    I am creating a calendar control of sorts... One thing I need to know is how many weeks are there in a Month... So NSCalendar rangeOfUnit:inUnit:forDate Seems to be exactly what I need... Except I am noticing something that seems off and I can't quite figure out why this is happening... The following code... NSCalendar *calendar = [NSCalendar currentCalendar]; NSDateComponents *dateComponents = [[NSDateComponents alloc] init]; [dateComponents setYear: 2010]; [dateComponents setDay: 1]; for (int x=1; x<=12; x++) { [dateComponents setMonth: x]; NSDate *date = [calendar dateFromComponents:dateComponents]; NSLog(@"Date: %@", date); NSRange range = [calendar rangeOfUnit: NSWeekCalendarUnit inUnit: NSMonthCalendarUnit forDate:date]; NSLog(@"%d Weeks in Month %d", range.length, [dateComponents month]); } Is returning the following debug messages... 2010-03-14 13:08:10.350 Scrap[4256:207] Date: 2010-01-01 00:00:00 -0500 2010-03-14 13:08:10.351 Scrap[4256:207] 5 Weeks in Month 1 2010-03-14 13:08:10.352 Scrap[4256:207] Date: 2010-02-01 00:00:00 -0500 2010-03-14 13:08:10.352 Scrap[4256:207] 4 Weeks in Month 2 2010-03-14 13:08:10.353 Scrap[4256:207] Date: 2010-03-01 00:00:00 -0500 2010-03-14 13:08:10.353 Scrap[4256:207] 5 Weeks in Month 3 2010-03-14 13:08:10.354 Scrap[4256:207] Date: 2010-04-01 00:00:00 -0400 2010-03-14 13:08:10.355 Scrap[4256:207] 5 Weeks in Month 4 2010-03-14 13:08:10.356 Scrap[4256:207] Date: 2010-05-01 00:00:00 -0400 2010-03-14 13:08:10.357 Scrap[4256:207] 5 Weeks in Month 5 2010-03-14 13:08:10.358 Scrap[4256:207] Date: 2010-06-01 00:00:00 -0400 2010-03-14 13:08:10.358 Scrap[4256:207] 5 Weeks in Month 6 2010-03-14 13:08:10.359 Scrap[4256:207] Date: 2010-07-01 00:00:00 -0400 2010-03-14 13:08:10.360 Scrap[4256:207] 5 Weeks in Month 7 2010-03-14 13:08:10.361 Scrap[4256:207] Date: 2010-08-01 00:00:00 -0400 2010-03-14 13:08:10.364 Scrap[4256:207] 5 Weeks in Month 8 2010-03-14 13:08:10.364 Scrap[4256:207] Date: 2010-09-01 00:00:00 -0400 2010-03-14 13:08:10.365 Scrap[4256:207] 5 Weeks in Month 9 2010-03-14 13:08:10.366 Scrap[4256:207] Date: 2010-10-01 00:00:00 -0400 2010-03-14 13:08:10.366 Scrap[4256:207] 5 Weeks in Month 10 2010-03-14 13:08:10.367 Scrap[4256:207] Date: 2010-11-01 00:00:00 -0400 2010-03-14 13:08:10.367 Scrap[4256:207] 5 Weeks in Month 11 2010-03-14 13:08:10.369 Scrap[4256:207] Date: 2010-12-01 00:00:00 -0500 2010-03-14 13:08:10.369 Scrap[4256:207] 52 Weeks in Month 12 I cant quite figure out why I get 52 weeks in month 12. Any clues?

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  • How to solve a deallocated connection in iPhone SDK 3.1.3? - Streams - CFSockets

    - by Christian
    Hi everyone, Debugging my implementation I found a memory leak issue. I know where is the issue, I tried to solve it but sadly without success. I will try to explain you, maybe someone of you can help with this. First I have two classes involved in the issue, the publish class (where publishing the service and socket configuration is done) and the connection (where the socket binding and the streams configuration is done). The main issue is in the connection via native socket. In the 'publish' class the "server" accepts a connection with a callback. The callback has the native-socket information. Then, a connection with native-socket information is created. Next, the socket binding and the streams configuration is done. When those actions are successful the instance of the connection is saved in a mutable array. Thus, the connection is established. static void AcceptCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) { Publish *rePoint = (Publish *)info; if ( type != kCFSocketAcceptCallBack) { return; } CFSocketNativeHandle nativeSocketHandle = *((CFSocketNativeHandle *)data); NSLog(@"The AcceptCallback was called, a connection request arrived to the server"); [rePoint handleNewNativeSocket:nativeSocketHandle]; } - (void)handleNewNativeSocket:(CFSocketNativeHandle)nativeSocketHandle{ Connection *connection = [[[Connection alloc] initWithNativeSocketHandle:nativeSocketHandle] autorelease]; // Create the connection if (connection == nil) { close(nativeSocketHandle); return; } NSLog(@"The connection from the server was created now try to connect"); if ( ! [connection connect]) { [connection close]; return; } [clients addObject:connection]; //save the connection trying to avoid the deallocation } The next step is receive the information from the client, thus a read-stream callback is triggered with the information of the established connection. But when the callback-handler tries to use this connection the error occurs, it says that such connection is deallocated. The issue here is that I don't know where/when the connection is deallocated and how to know it. I am using the debugger, but after some trials, I don't see more info. void myReadStreamCallBack (CFReadStreamRef stream, CFStreamEventType eventType, void *info) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; Connection *handlerEv = [[(Connection *)info retain] autorelease]; // The error -[Connection retain]: message sent to deallocated instance 0x1f5ef0 (Where 0x1f5ef0 is the reference to the established connection) [handlerEv readStreamHandleEvent:stream andEvent:eventType]; [pool drain]; } void myWriteStreamCallBack (CFWriteStreamRef stream, CFStreamEventType eventType, void *info){ NSAutoreleasePool *p = [[NSAutoreleasePool alloc] init]; Connection *handlerEv = [[(Connection *)info retain] autorelease]; //Sometimes the error also happens here, I tried without the pool, but it doesn't help neither. [handlerEv writeStreamHandleEvent:eventType]; [p drain]; } Something strange is that when I run the debugger(with breakpoints) everything goes well, the connection is not deallocated and the callbacks work fine and the server is able to receive the message. I will appreciate any hint!

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  • UILabel not updating

    - by iFloh
    Sorry the basic question, but this bugs me for a while now. I create a details view from a UITable and try to dynamically set its labels, but they are not updating: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { myObject *tmpObj = [[myObject objectAtIndex:indexPath.section] objectAtIndex:indexPath.row]; myViewController *tmpVC = [[myViewController alloc] initWithNibName:@"NIBfile" bundle:nil]; [tmpVC.myLabel setText:tmpObj.myTitle]; // The debugger shows the text: myTitle = "myText" NSLog(@"%@", tmpVC.myLabel); // NSLog SHOWS NULL [self.navigationController pushViewController:tmpVC animated:YES]; [tmpObj release]; } any ideas why the value is not coming through?

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  • Custom view with nib as subview doesn't seem to be loading

    - by Ben Collins
    I've created a custom view that loads its content from a nib, like this: /* PricingDataView.h */ #import <UIKit/UIKIt.h> @interface PricingDataView : UIView { UIView *contentView; } @property (nonatomic, retain) IBOutlet UIView *contentView; @end /* PricingDataView.m */ #import "PricingDataView.h" @implementation PricingDataView @synthesize contentView; - (id)initWithFrame:(CGRect)frame { if ((self = [super initWithFrame:frame])) { [[NSBundle mainBundle] loadNibNamed:@"PricingDataView" owner:self options:nil]; [contentView setFrame:frame]; [self addSubview:contentView]; } return self; } /* ... */ In the nib file I set PricingDataView as the type of the File's Owner, and connected the contentView outlet in IB. I placed a regular UIView from the Interface Library onto the full-sized view shown to the user, and then changed it's class name to PricingDataView. It all builds, but at runtime, nothing is rendered where my custom view is supposed to be. I put breakpoints in PricingDataView.initWithFrame, but they don't hit, so I know I'm missing something that would cause the view to be initialized. What I'm curious about is that int the process of loading my other views from nibs, all the initialization happens for me, but not with this one. Why?

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  • Variable Scope Problem, iPhone

    - by Stumf
    Hello all, I need some help here so I will do my best to explain. I have worked on this all day and had no success (just learning!) I have: NSArray *getValue(NSString *iosearch) { ................................. ................................... \\ More code here } - (NSString *) serialnumber { NSArray *results = getValue(@"serial-number"); if (results) return [results objectAtIndex:0]; return nil; } - (NSString *) backlightlevel { NSArray *results = getValue(@"backlight-level"); if (results) return [results objectAtIndex:0]; return nil; } I have a tableView set up and want to display my array in it so I then have: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {............. ......................................................... cell.text = [results objectAtIndex:indexPath.row]; // error results undeclared here return cell; } The problem is I get results undeclared as indicated above. I also can't figure how I could get serialnumber and backlightlevel to display on the click of a button or even at load. My attempts have thrown back errors like error: 'serialnumber' undeclared (first use in this function) and warnings like warning: 'return' with a value, in function returning void. Sorry for the long question! Many thanks, Stuart

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  • iPhone UI addSubview causing concurrency exception

    - by Eli
    This is really odd... I run my app, and while it is opening and the views are constructing I get: Collection <CALayerArray: 0x124650> was mutated while being enumerated. The code trace goes through the following: main UIApplicationMain -[UIApplication _run] CFRunLoopRunInMode CFRunLoopRunSpecific _UIApplicationHandleEvent -[UIApplication sendEvent:] -[UIApplication handleEvent:withNewEvent:] -[UIApplication _runWithURL:sourceBundleID:] -[UIApplication _performInitilizationWithURL:sourceBundleID:] -[AppDelegate applicationDidFinishLaunching:] +[Controller initializeController] //This is my own function [window addSubview: pauseMenuController.view] //This is the last point of my code it goes through -[UIView(Hierarchy) addSubview:] -[UIView(Internal) _addSubview:positioned:relativeTo:] -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:] -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:] -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:] _NSFastEnumerationMutationHandler objc_exception_throw I've run the game lots and lots and lots of times and I've never seen this, then suddenly it popped up. The weird thing is that I'm not creating any other threads (that I know of) until after this code all gets called. It'll be easier for me to debug this if someone can give me some explanation of what might be getting modified while it's being accessed in a UIView. Does it have something to do with adding something to the view while it's already adding something, maybe? Any ideas?

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  • Special Characters from SQLite DB

    - by Matthias
    Hi, I read from a sqlite db to my iphone app. Within the texts sometimes there are special characters like 'xf2' or 'xe0' as I can see in the debugger in the char* data type. When I try to transform the chars to an NSString Object by using initWithUTF8String, I get a nil back. How can I transform such special characters? Thanks for your help. Bye Matthias

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  • Approaches to create a nested tree structure of NSDictionaries?

    - by d11wtq
    I'm parsing some input which produces a tree structure containing NSDictionary instances on the branches and NSString instance at the nodes. After parsing, the whole structure should be immutable. I feel like I'm jumping through hoops to create the structure and then make sure it's immutable when it's returned from my method. We can probably all relate to the input I'm parsing, since it's a query string from a URL. In a string like this: a=foo&b=bar&a=zip We expect a structure like this: NSDictionary { "a" => NSDictionary { 0 => "foo", 1 => "zip" }, "b" => "bar" } I'm keeping it just two-dimensional in this example for brevity, though in the real-world we sometimes see var[key1][key2]=value&var[key1][key3]=value2 type structures. The code hasn't evolved that far just yet. Currently I do this: - (NSDictionary *)parseQuery:(NSString *)queryString { NSMutableDictionary *params = [NSMutableDictionary dictionary]; NSArray *pairs = [queryString componentsSeparatedByString:@"&"]; for (NSString *pair in pairs) { NSRange eqRange = [pair rangeOfString:@"="]; NSString *key; id value; // If the parameter is a key without a specified value if (eqRange.location == NSNotFound) { key = [pair stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding]; value = @""; } else { // Else determine both key and value key = [[pair substringToIndex:eqRange.location] stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding]; if ([pair length] > eqRange.location + 1) { value = [[pair substringFromIndex:eqRange.location + 1] stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding]; } else { value = @""; } } // Parameter already exists, it must be a dictionary if (nil != [params objectForKey:key]) { id existingValue = [params objectForKey:key]; if (![existingValue isKindOfClass:[NSDictionary class]]) { value = [NSDictionary dictionaryWithObjectsAndKeys:existingValue, [NSNumber numberWithInt:0], value, [NSNumber numberWithInt:1], nil]; } else { // FIXME: There must be a more elegant way to build a nested dictionary where the end result is immutable? NSMutableDictionary *newValue = [NSMutableDictionary dictionaryWithDictionary:existingValue]; [newValue setObject:value forKey:[NSNumber numberWithInt:[newValue count]]]; value = [NSDictionary dictionaryWithDictionary:newValue]; } } [params setObject:value forKey:key]; } return [NSDictionary dictionaryWithDictionary:params]; } If you look at the bit where I've added FIXME it feels awfully clumsy, pulling out the existing dictionary, creating an immutable version of it, adding the new value, then creating an immutable dictionary from that to set back in place. Expensive and unnecessary? I'm not sure if there are any Cocoa-specific design patterns I can follow here?

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  • ConnectionKit & iPhone SDK

    - by Wilco
    I'm still getting my feet wet with the iPhone SDK, but I'm wondering if it would be possible to get the ConnectionKit framework working for an iPhone app. I know it was developed for the desktop OS, so I'm not sure what sort of dependencies it has and whether or not it could be shoehorned into the iPhone OS. In my case, I would like to use its FTP functionality, though having access to this entire framework could prove useful for future projects as well. Any ideas or experience trying this? In case it helps, here's the official ConnectionKit site: http://opensource.utr-software.com/connection/

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  • NSOperation and UIKit problem

    - by Infinity
    Hello guys! I am doing my download with an object which was inherited from NSOperation. I have read the documentation and when my operation finished I must call the [self.delegate performSelectorOnMainThread:@selector(operationDidFinish:) withObject:self waitUntilDone:YES]; method. It needs to be called on the main thread, because the UIKit is not thread safe and the documentation says this in these non thread safe frameworks cases. In the delegate method I am drawing a pdf or an image, but because it is drawn on the main thread the User Interface is very laggy until the drawing is finished. Maybe can you suggest me a good way to avoid this problem?

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  • I just don't get AudioFileReadPackets

    - by Eric Christensen
    I've tried to write the smallest chunk of code to narrow down a problem. It's now just a few lines and it doesn't work, which makes it pretty clear that I have a fundamental misunderstanding of how to use AudioFileReadPackets. I've read the docs and other examples online, and apparently I'm just not getting. Could you explain it to me? Here's what this block should do: I've previously opened a file. I want to read just one packet - the first one of the file - and then print it. But it crashes on the AudioFileReadPackets line: AudioFileID mAudioFile2; AudioFileOpenURL (audioFileURL, 0x01, 0, &mAudioFile2); UInt32 *audioData2 = (UInt32 *)malloc(sizeof(UInt32) * 1); AudioFileReadPackets(mAudioFile2, false, NULL, NULL, 0, (UInt32*)1, audioData2); NSLog(@"first packet:%i",audioData2[0]); (For clarity, I've stripped out all error handling.) It's the AFRP line that crashes out. (I understand that the third and fourth argument are useful, and in my "real" code, I use them, but they're not required, right? So NULL in this case should work, right?) So then what's going on? Any guidance would be much appreciated. Thanks.

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