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  • How Can I Compress Texture in OpenGL on iPhone/iPad?

    - by nonamelive
    Hi, I'm making an iPad app which needs OpenGL to do a flip animation. I have a front image texture and a back image texture. Both the two textures are screenshots. // Capture an image of the screen UIGraphicsBeginImageContext(view.bounds.size); [view.layer renderInContext:UIGraphicsGetCurrentContext()]; image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); // Allocate some memory for the texture GLubyte *textureData = (GLubyte*)calloc(maxTextureSize*4, maxTextureSize); // Create a drawing context to draw image into texture memory CGContextRef textureContext = CGBitmapContextCreate(textureData, maxTextureSize, maxTextureSize, 8, maxTextureSize*4, CGImageGetColorSpace(image.CGImage), kCGImageAlphaPremultipliedLast); CGContextDrawImage(textureContext, CGRectMake(0, maxTextureSize-size.height, size.width, size.height), image.CGImage); CGContextRelease(textureContext); // ...done creating the texture data [EAGLContext setCurrentContext:context]; glGenTextures(1, &textureToView); glBindTexture(GL_TEXTURE_2D, textureToView); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, maxTextureSize, maxTextureSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureData); // free texture data which is by now copied into the GL context free(textureData); Each of the texture takes up about 8MB memory, which is unacceptable for an iPhone/iPad app. Could anyone tell me how can I compress the texture to reduce the memory. I'm a complete newbie to OpenGL. Any help would be appreciated!

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  • What's the correct way to stop a background process on Mac OS X?

    - by mcsheffrey
    I have an application with 2 components: a desktop application that users interact with, and a background process that can be enabled from the desktop application. Once the background process is enabled, it will run as a user launch agent independently of the desktop app. However, what I'm wondering is what to do when the user disables the background process. At this point I want to stop the background process but I'm not sure what the best approach is. The 3 options that I see are: Use the 'kill' command. Direct, but not reliable and just seems somewhat "wrong". Use an NSMachPort to send an exit request from the desktop app to the background process. This is the best approach I've thought of but I've run into an implementation problem (I'll be posting this in a separate query) and I'd like to be sure that the approach is right before going much further. Something else??? Thank you in advance for any help/insight that you can offer.

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  • Attributed strings in UITableViewCells without WebView?

    - by arnekolja
    Hello, does anyone know if there's a way in with 3.0+ to display attributed strings within a UITableViewCell without using a UIWebView for that? I need to display a string with linked, tappable substrings as the typical detailTextLabel. I wouldn't mind exchanging this UILabel against another type of view, but I think a UIWebView could be just too slow when rendering a table with hundrets of cells. Or does someone have opposite experiences here? So my question is: what's the best way to achieve mixed strings in a very large table without a great performance hit? I searched for this almost a whole day now, but I can only find old posts mentioning that there's no attributed string on the iPhone (outdated, as this was pre-3.0) and/or saying that they use a UIWebView for that. But really, I don't think this would perform very well on large tables, would it? Many, many thanks in advance Arne

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  • Release an object without a pointer?

    - by Kai Friis
    I’ve just started developing for iPhone and am trying to get my head around memory management. I made a small program that shows a map and an annotation on the map. For the annotation I made a simple class that implements the MKAnnotation protocol. To create and add the annotation I wrote this: [self.myMapView addAnnotation:[[MyAnnotation alloc] init]]; It worked fine until I tried to release the object. Nothing to release. This is what I would have done in C#, I guess it doesn’t work without garbage collection? So is this the only way to do it? MyAnnotation *myAnnotation = [[MyAnnotation alloc] init]; [self.myMapView addAnnotation: myAnnotation]; [myAnnotation release];

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  • Cocoa Touch best practice for capturing/logging/diagnosing crashes

    - by Dylan
    As I get closer to releasing my first public iPhone app I'm concerned about catching crashes in the field. I'm curious to hear how others have gone about this. I'm not sure what's possible outside of the debugger. Is all lost with an EXC_BAD_ACCESS or can I still catch it and get something useful into a log? Is the program main() the spot to put a @try/@catch?

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  • iPhone - How do I find the MAC address of the connected WiFi access point?

    - by Ciaran
    Without using the private APIs, is it possible to programatically determine the MAC address of the access point that the iPhone is connected to? I understand that this should be doable using the core BSD libraries, but we are new to this, so it would be great if someone can point us to some starter code. Note: we're trying to determine the MAC address of the remote device - not the MAC address of the iPhone.

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  • How to use NSObject subclass?

    - by Jon
    So I've created a subclass of NSObject called Query @interface Query : NSObject @property (nonatomic, assign) NSNumber *weight; @property (nonatomic, assign) NSNumber *bodyFat; @property (nonatomic, assign) NSNumber *activityLevel; @end Is this correct for setting the object's property? In VC1: BodyFatViewController *aViewController = [[BodyFatViewController alloc]init]; aViewController.query = self.query; [self.navigationController pushViewController:aViewController animated:YES]; In VC2: - (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { Query *anQuery = [[Query alloc]init]; anQuery.bodyFat = [self.bodyFatArray objectAtIndex:row]; anQuery.weight = self.query.weight; self.query = anQuery; }

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  • Populate tableView with more than one array

    - by Ewoods
    The short version: Is there a way to populate one specific row in a tableView with one value from one array, then populate another row in that same tableView with one value from a different array? For example, cell 1 would have the first value from Array A, cell 2 would have the first value from Array B, cell 3 would have the first value from Array C, etc. The long version: I hope this isn't too confusing. I've got an array of names, and then three more arrays with actions associated with those people. For example, the names array has Jim, Bob, and Sue, and then there's an array for eating, reading, and sleeping that records every time each person does one of these things (all of these arrays are populated from a MySQL database). The names array is used to populate a root tableView. Tapping on one of the names brings up a detail view controller that has another tableView that only has three rows. This part is all working fine. What I want to happen is when I tap on a name, it moves to the detail view and the three cells would then show the last event for that person for each of the three activities. Tapping on one of those three events then moves to a new view controller with a tableView that shows every event for that category. For example, if I tapped on Bob, the second page would show the last time Bob ate, read, and slept. Tapping on the first row would bring up a table that showed every time Bob has eaten. So far I've only been able to populate the second tableView with all of the rows from one of the arrays. I need it the other way around (one row from all of the arrays).

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  • Problem with a NSString that equals to (null)

    - by Guy Dor
    Hi, I have an UIViewController named MainViewController I have another UIViewController named LeftSharingViewController; I would like to get and use the NSString from MainViewController in my LeftSharingViewController I have a problem, I always get (null) instead of the NSString wanted value. Here's my code and how does the NSString get it's value MainViewController: - (void)webViewDidFinishLoad:(UIWebView *)webView { leftWebViewString = [NSString stringWithString:leftWebView.request.URL.absoluteString]; } LeftSharingViewController.h: #import <UIKit/UIKit.h> #import "MainViewController.h" #import <MessageUI/MessageUI.h> #import <MessageUI/MFMailComposeViewController.h> @class MainViewController; @interface LeftSharingViewController : UIViewController <MFMailComposeViewControllerDelegate> { MainViewController *mainViewController; NSString *leftWebViewUrl; } @property (nonatomic, retain) MainViewController *mainViewController; @property (nonatomic, retain) NSString *leftWebViewUrl; @end LeftSharingViewController.m: #import "LeftSharingViewController.h" #import "MainViewController.h" @implementation LeftSharingViewController @synthesize mainViewController; @synthesize leftWebViewUrl; - (void)viewWillAppear:(BOOL)animated { self.leftWebViewUrl = self.mainViewController.leftWebViewString; } #pragma mark - #pragma mark Compose Mail -(void)displayComposerSheet { MFMailComposeViewController *mailPicker = [[MFMailComposeViewController alloc] init]; mailPicker.mailComposeDelegate = self; [mailPicker setSubject:@"Check Out This Website!"]; [mailPicker setMessageBody:[NSString stringWithFormat:@"Take a look at this site:%@", leftWebViewUrl] isHTML:YES]; mailPicker.modalPresentationStyle = UIModalPresentationFormSheet; [self presentModalViewController:mailPicker animated:YES]; [mailPicker release]; } Thanks!

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  • Accepting drag operations in an NSCollectionView subclass

    - by andyvn22
    I've subclassed NSCollectionView and I'm trying to receive dragged files from the Finder. I'm receiving draggingEntered: and returning an appropriate value, but I'm never receiving prepareForDragOperation: (nor any of the methods after that in the process). Is there something obvious I'm missing here? Code: - (void)awakeFromNib { [self registerForDraggedTypes:[NSArray arrayWithObjects:NSFilenamesPboardType, nil]]; } - (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender { NSLog(@"entered"); //Happens NSPasteboard *pboard; NSDragOperation sourceDragMask; sourceDragMask = [sender draggingSourceOperationMask]; pboard = [sender draggingPasteboard]; if ([[pboard types] containsObject:NSFilenamesPboardType]) { NSLog(@"copy"); //Happens return NSDragOperationCopy; } return NSDragOperationNone; } - (BOOL)prepareForDragOperation:(id <NSDraggingInfo>)sender { NSLog(@"prepare"); //Never happens return YES; }

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  • sigleton EXC_BAD_ACCESS

    - by lclaud
    Hi, so I have a class that I decleare as a singleton and in that class I have a NSMutableArray that contains some NSDictionaries with some key/value pairs in them. The trouble is it doesn't work and I dont't know why... I mean it crashes with EXC_BAD_ACCESS but i don't know where. I followed the code and it did create a new array on first add, made it to the end of the funtion ..and crashed ... @interface dataBase : NSObject { NSMutableArray *inregistrari; } @property (nonatomic,retain) NSMutableArray *inregistrari; -(void)adaugaInregistrareCuData:(NSDate *)data siValoare:(NSNumber *)suma caVenit:(BOOL)venit cuDetaliu:(NSString *)detaliu; -(NSDictionary *)raportIntreData:(NSDate *)dataInitiala siData:(NSDate *)dataFinala; -(NSArray *)luniDisponibileIntreData:(NSDate *)dataInitiala siData:(NSDate *)dataFinala; -(NSArray *)aniDisponibiliIntreData:(NSDate *)dataInitiala siData:(NSDate *)dataFinala; -(NSArray *)vectorDateIntreData:(NSDate *)dataI siData:(NSDate *)dataF; -(void)salveazaInFisier; -(void)incarcaDinFisier; + (dataBase *)shareddataBase; @end And here is the .m file #import "dataBase.h" #import "SynthesizeSingleton.h" @implementation dataBase @synthesize inregistrari; SYNTHESIZE_SINGLETON_FOR_CLASS(dataBase); -(void)adaugaInregistrareCuData:(NSDate *)data siValoare:(NSNumber *)suma caVenit:(BOOL)venit cuDetaliu:(NSString *)detaliu{ NSNumber *v=[NSNumber numberWithBool:venit]; NSArray *input=[NSArray arrayWithObjects:data,suma,v,detaliu,nil]; NSArray *keys=[NSArray arrayWithObjects:@"data",@"suma",@"venit",@"detaliu",nil]; NSDictionary *inreg=[NSDictionary dictionaryWithObjects:input forKeys:keys]; if(inregistrari == nil) { inregistrari=[[NSMutableArray alloc ] initWithObjects:inreg,nil]; }else { [inregistrari addObject:inreg]; } [inreg release]; [input release]; [keys release]; } It made it to the end of that adaugaInregistrareCuData ... ok . said the array had one object ... and then crashed

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  • Recursively find files/directories within a directory

    - by enchilada
    I want to use enumeratorAtURL:includingPropertiesForKeys:options:errorHandler: to do this, as I'm coding under Snow Leopard. I know how to use this method. However, as for my purposes it's not adequate to load the contents lazily, I have the following question: How can I create an object hierarchy (of, say, the custom FileOrDirectory class with the standard children,count,isLeaf attributes) from the information I load from the enumeratorAtURL: method? I need to load this data beforehand, and show it in an outline view, for my purposes.

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  • Avaudioplayer problem

    - by Arun Sharma
    Hi All, Actually i am using avaudioplayer. my player is working very fine (forward,revind,play,pause,volume,progress bar). Only problem is that i am not able to stop the song. so all songs are overlapped please any body tell me where i put [self.player stop] to stop my player when i play new song.

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  • After I apply custom logic, next UI action crashes my app.

    - by DanF
    I've got an team (eveningRoster) that I'm making a button add employees to. The team is really a relationship to that night's event, but it's represented with an AC. I wanted to make sure an employee did not belong to the team before it adds, so I added a method to MyDocument to check first. It seems to work, the error logs complete, but after I've added a member, the next time I click anything, the program crashes. Any guesses why? Here's the code: -(IBAction)playsTonight:(id)sender { NSArray *selection = [fullRoster selectedObjects]; NSArray *existing = [eveningRoster arrangedObjects]; //Result will be within each loop. BOOL result; //noDuplicates will stay YES until a duplicate is found. BOOL noDuplicates = YES; //For the loop: int count; for (count = 0; count < [selection count]; count++){ result = [existing containsObject:[selection objectAtIndex:count]]; if (result == YES){ NSLog(@"Duplicate found!"); noDuplicates = NO; } } if (noDuplicates == YES){ [eveningRoster addObjects:[fullRoster selectedObjects]]; NSLog(@"selected objects added."); [eveningTable reloadData]; NSLog(@"Table reloaded."); } [selection release]; [existing release]; return; }

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  • Getting text position while parsing pdf with Quartz 2D

    - by Koteg
    Hi guys, another question regarding pdf parsing... Just read PDF Reference version 1.7 "5.3.1 Text-Positioning Operators" and I am a little bit confused. I wrote some code to get transformation matrix and initial text position. CGPDFOperatorTableSetCallback (table, "MP", &op_MP);//Define marked-content point CGPDFOperatorTableSetCallback (table, "DP", &op_DP);//Define marked-content point with property list CGPDFOperatorTableSetCallback (table, "BMC", &op_BMC);//Begin marked-content sequence CGPDFOperatorTableSetCallback (table, "BDC", &op_BDC);//Begin marked-content sequence with property list CGPDFOperatorTableSetCallback (table, "EMC", &op_EMC);//End marked-content sequence //Text State operators CGPDFOperatorTableSetCallback(table, "Tc", &op_Tc); CGPDFOperatorTableSetCallback(table, "Tw", &op_Tw); CGPDFOperatorTableSetCallback(table, "Tz", &op_Tz); CGPDFOperatorTableSetCallback(table, "TL", &op_TL); CGPDFOperatorTableSetCallback(table, "Tf", &op_Tf); CGPDFOperatorTableSetCallback(table, "Tr", &op_Tr); CGPDFOperatorTableSetCallback(table, "Ts", &op_Ts); //text showing operators CGPDFOperatorTableSetCallback(table, "TJ", &op_TJ); CGPDFOperatorTableSetCallback(table, "Tj", &op_Tj); CGPDFOperatorTableSetCallback(table, "'", &op_apostrof); CGPDFOperatorTableSetCallback(table, "\"", &op_double_apostrof); //text positioning operators CGPDFOperatorTableSetCallback(table, "Td", &op_Td); CGPDFOperatorTableSetCallback(table, "TD", &op_TD); CGPDFOperatorTableSetCallback(table, "Tm", &op_Tm); CGPDFOperatorTableSetCallback(table, "T*", &op_T); //text object operators CGPDFOperatorTableSetCallback(table, "BT", &op_BT);//Begin text object CGPDFOperatorTableSetCallback(table, "ET", &op_ET);//End text object So this is the output after application lunch: 2010-09-02 15:09:23.041 testSearch[8251:207] op_BT begin Integer value: 0 2010-09-02 15:09:23.043 testSearch[8251:207] op_BT end 2010-09-02 15:09:23.043 testSearch[8251:207] op_Tf begin Integer value: 1 2010-09-02 15:09:23.044 testSearch[8251:207] op_Tf end 2010-09-02 15:09:23.044 testSearch[8251:207] op_Tm begin Float value: 557.364197 2010-09-02 15:09:23.045 testSearch[8251:207] op_Tm end 2010-09-02 15:09:23.045 testSearch[8251:207] op_TJ begin 2010-09-02 15:09:23.046 testSearch[8251:207] Array string value [0]: F 2010-09-02 15:09:23.046 testSearch[8251:207] Array integer value [1]: 94985208 2010-09-02 15:09:23.047 testSearch[8251:207] Array string value [2]: r 2010-09-02 15:09:23.047 testSearch[8251:207] Array integer value [3]: 94985208 2010-09-02 15:09:23.048 testSearch[8251:207] Array string value [4]: o 2010-09-02 15:09:23.048 testSearch[8251:207] Array integer value [5]: 94985208 2010-09-02 15:09:23.049 testSearch[8251:207] Array string value [6]: m s 2010-09-02 15:09:23.049 testSearch[8251:207] Array integer value [7]: 94985208 2010-09-02 15:09:23.049 testSearch[8251:207] Array string value [8]: a 2010-09-02 15:09:23.050 testSearch[8251:207] Array integer value [9]: 94985208 2010-09-02 15:09:23.050 testSearch[8251:207] Array string value [10]: m 2010-09-02 15:09:23.051 testSearch[8251:207] Array integer value [11]: 94985208 2010-09-02 15:09:23.051 testSearch[8251:207] Array string value [12]: p 2010-09-02 15:09:23.052 testSearch[8251:207] Array integer value [13]: 94985208 2010-09-02 15:09:23.053 testSearch[8251:207] Array string value [14]: l 2010-09-02 15:09:23.054 testSearch[8251:207] Array integer value [15]: 94985208 2010-09-02 15:09:23.055 testSearch[8251:207] Array string value [16]: e t 2010-09-02 15:09:23.055 testSearch[8251:207] Array integer value [17]: 94985208 2010-09-02 15:09:23.057 testSearch[8251:207] Array string value [18]: o r 2010-09-02 15:09:23.057 testSearch[8251:207] Array integer value [19]: 94985208 2010-09-02 15:09:23.058 testSearch[8251:207] Array string value [20]: e 2010-09-02 15:09:23.058 testSearch[8251:207] Array integer value [21]: 94985208 2010-09-02 15:09:23.059 testSearch[8251:207] Array string value [22]: s 2010-09-02 15:09:23.059 testSearch[8251:207] Array integer value [23]: 94985208 2010-09-02 15:09:23.060 testSearch[8251:207] Array string value [24]: u 2010-09-02 15:09:23.061 testSearch[8251:207] Array integer value [25]: 94985208 2010-09-02 15:09:23.061 testSearch[8251:207] Array string value [26]: l 2010-09-02 15:09:23.062 testSearch[8251:207] Array integer value [27]: 94985208 2010-09-02 15:09:23.062 testSearch[8251:207] Array string value [28]: t 2010-09-02 15:09:23.063 testSearch[8251:207] op_TJ end If someone is familiar with text matrix and text positioning operators it would be nice to explain how all those thing work. How to calculate text position (or glyph?) using Tm (transformation matrix and other data)?

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  • NSNotification postNotificationName in AppDelegate but NSNotificationCenter in ViewController?

    - by James Testa
    I can't get the selector method, receiveChatText, in the NSNotificationCenter to execute and I am wondering if the problem is because the NSNotification postNotificationName is in AppDelegate.m but NSNotificationCenter is in ViewController.m? I.E. can the postNotificationName know that the NSNotificationCenter is in another viewController file or is that something I need to tell it? In a viewController.m I have -(id)init { self = [super init]; if(self){ [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(receiveChatText:) name:ChatMessageReceived object:nil]; return self; } - (void)receiveChatText:(NSNotification *)note { NSLog(@"received chat text"); } and in the top level AppDelegate.m file I have the following: -(void) didReceiveMessage { [[NSNotificationCenter defaultCenter] postNotificationName:ChatMessageReceived object:nil userInfo:nil]; } Any ideas what could stop receiveChatText from being executed when didReceiveMessage is called?

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  • Cocoa window position anomaly

    - by Marius
    Hello everyone, I have a weird problem with positioning a window on screen. I want to center the window on the screen, but i don't know how to do that. Here's what i've got. The window is created from nib by the main controller: IdentFormController *ftf = [[IdentFormController alloc] initWithWindowNibName:@"IdentForm"]; [[ftf window] makeKeyAndOrderFront:self]; Now the IdentFormController has awakeFromNib() method in which it tries to position the window. For the sake of simplicity i've just tried to do setFrameOrigin(NSMakePoint(0, 0)). What happens is as follows: The first time i create this window, everything works as expected. But if i create it again after releasing the previous, it starts appearing at random positions. Why does it do that?

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  • error writing to plist

    - by Najeebullah Shah
    [array writeToFile:[documentsDirectory stringByAppendingPathComponent:@"data.plist" atomically:YES]; this line gives error that method -stringByAppendingPathComponent not found. whats the issue NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSArray *array = [[NSArray alloc]initWithObjects:@"First", @"Second", @"Third", nil]; [array writeToFile:[documentsDirectory stringByAppendingPathComponent:@"data.plist" atomically:YES]];

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  • UITableView: Mixing static and dynamic cells

    - by AlexR
    I am trying to mix dynamic and static cells in a grouped table view: I would like to get two sections with static cells at the top followed by a section of dynamic cells (please refer to the screenshot below). I have set the table view contents to static cells. I designed the static cells in Interface Builder and gave them identifiers related to their section and row: "section0static0", "section0static1", "section1static0" and "section1static1". I named the dynamic cell "section2dynamic". My delegate methods, in which I am trying to return the correct cell identifier (static or dynamic) are as follows: - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { switch (section) { case 0: return 2; break; case 1: return 2; break; case 2: return 0; break; default: break; } return 0; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @""; if (indexPath.section <= 1) CellIdentifier = [NSString stringWithFormat:@"section%istatic%i",indexPath.section,indexPath.row]; else CellIdentifier = [NSString stringWithFormat:@"section%idynamic",indexPath.section]; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; return cell; } Edit Based on AppleFreak's advice I have changed my code as follows: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell; if (indexPath.section <= 1) { // section <= 1 indicates static cells cell = [super tableView:tableView cellForRowAtIndexPath:indexPath]; } else { // section > 1 indicates dynamic cells CellIdentifier = [NSString stringWithFormat:@"section%idynamic",indexPath.section]; cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath]; } return cell; } However, my app crashes with error message Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UITableView dataSource must return a cell from tableView:cellForRowAtIndexPath:' for section 0 and row 0. The cell returned from cell = [super tableView:tableView cellForRowAtIndexPath:indexPath] for section 0 and row 0 is nil. What is wrong with my code? Could there be any problems with my outlets? I haven't set any outlets because I am subclassing UITableViewController and supposedly do not any outlets for tableview to be set (?). Any suggestions on how to better do it?

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  • Convert NSData into Hex NSString

    - by Dawson
    With reference to the following question: Convert NSData into HEX NSSString I have solved the problem using the solution provided by Erik Aigner which is: NSData *data = ...; NSUInteger capacity = [data length] * 2; NSMutableString *stringBuffer = [NSMutableString stringWithCapacity:capacity]; const unsigned char *dataBuffer = [data bytes]; NSInteger i; for (i=0; i<[data length]; ++i) { [stringBuffer appendFormat:@"%02X", (NSUInteger)dataBuffer[i]]; } However, there is one small problem in that if there are extra zeros at the back, the string value would be different. For eg. if the hexa data is of a string @"3700000000000000", when converted using a scanner to integer: unsigned result = 0; NSScanner *scanner = [NSScanner scannerWithString:stringBuffer]; [scanner scanHexInt:&result]; NSLog(@"INTEGER: %u",result); The result would be 4294967295, which is incorrect. Shouldn't it be 55 as only the hexa 37 is taken? So how do I get rid of the zeros? EDIT: (In response to CRD) Hi, thanks for clarifying my doubts. So what you're doing is to actually read the 64-bit integer directly from a byte pointer right? However I have another question. How do you actually cast NSData to a byte pointer? To make it easier for you to understand, I'll explain what I did originally. Firstly, what I did was to display the data of the file which I have (data is in hexadecimal) NSData *file = [NSData dataWithContentsOfFile:@"file path here"]; NSLog(@"Patch File: %@",file); Output: Next, what I did was to read and offset the first 8 bytes of the file and convert them into a string. // 0-8 bytes [file seekToFileOffset:0]; NSData *b = [file readDataOfLength:8]; NSUInteger capacity = [b length] * 2; NSMutableString *stringBuffer = [NSMutableString stringWithCapacity:capacity]; const unsigned char *dataBuffer = [b bytes]; NSInteger i; for (i=0; i<[b length]; ++i) { [stringBuffer appendFormat:@"%02X", (NSUInteger)dataBuffer[i]]; } NSLog(@"0-8 bytes HEXADECIMAL: %@",stringBuffer); As you can see, 0x3700000000000000 is the next 8 bytes. The only changes I would have to make to access the next 8 bytes would be to change the value of SeekFileToOffset to 8, so as to access the next 8 bytes of data. All in all, the solution you gave me is useful, however it would not be practical to enter the hexadecimal values manually. If formatting the bytes as a string and then parsing them is not the way to do it, then how do I access the first 8 bytes of the data directly and cast them into a byte pointer?

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  • Data sources and NSTableView

    - by lampShade
    I know that table sources need a data source to hold the data that the tableview will display. Lets' say that I'm going to make my AppController be the data source of my tableview and that I make the connection in interface builder. My question is since my actual data is going to be stored in an array,let's call it myArray, when I set the data source in code should I do this [tableView setDataSource:myArray]; or this [tableView setDataSource:self]; I'm confused about this. setting the data source with the keyword "self" would set it to the AppController if I'm not mistaken.

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  • ObjectiveC - Releasing objects added as parameters

    - by NobleK
    Ok, here goes. Being a Java developer I'm still struggling with the memory management in ObjectiveC. I have all the basics covered, but once in a while I encounter a challenge. What I want to do is something which in Java would look like this: MyObject myObject = new MyObject(new MyParameterObject()); The constructor of MyObject class takes a parameter of type MyParameterObject which I initiate on-the-fly. In ObjectiveC I tried to do this using following code: MyObject *myObject = [[MyObject alloc] init:[[MyParameterObject alloc] init]]; However, running the Build and Analyze tool this gives me a "Potential leak of an object" warning for the MyParameter object which indeed occurs when I test it using Instruments. I do understand why this happens since I am taking ownership of the object with the alloc method and not relinquishing it, I just don't know the correct way of doing it. I tried using MyObject *myObject = [[MyObject alloc] init:[[[MyParameterObject alloc] init] autorelease]]; but then the Analyze tool told me that "Object sent -autorelease too many times". I could solve the issue by modifying the init method of MyParameterObject to say return [self autorelease]; in stead of just return self;. Analyze still warnes about a potential leak, but it doesn't actually occur. However I believe that this approach violates the convention for managing memory in ObjectiveC and I really want to do it the right way. Thanx in advance.

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