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  • How to assign a value to an pointer-pointer passed in call by reference?

    - by mystify
    I want to achieve something similar to what these guys do here: - (NSUInteger)countForFetchRequest:(NSFetchRequest *)request error:(NSError **)error like you can see, you pass an NSError pointer and that nice method will assign a real NSError object to your pointer in case there is an error. So the cool thing about this is, that the method returns an NSUInteger but can ALSO return an NSError, without having to mess around with ugly and fat arrays or dictionaries. So how could I assign an object to the passed-in error pointer?

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  • unrecognized selector sent to instance while trying to add an object to a mutable array

    - by madpoet
    I'm following the "Your Second iOS App" and I decided to play with the code to understand Objective C well... What I'm trying to do is simply adding an object to a mutable array in a class. Here are the classes: BirdSighting.h #import <Foundation/Foundation.h> @interface BirdSighting : NSObject @property (nonatomic, copy) NSString *name; @property (nonatomic, copy) NSString *location; @property (nonatomic, copy) NSDate *date; -(id) initWithName: (NSString *) name location:(NSString *) location date:(NSDate *) date; @end BirdSighting.m #import "BirdSighting.h" @implementation BirdSighting -(id) initWithName:(NSString *)name location:(NSString *)location date:(NSDate *)date { self = [super init]; if(self) { _name = name; _location = location; _date = date; return self; } return nil; } @end BirdSightingDataController.h #import <Foundation/Foundation.h> @class BirdSighting; @interface BirdSightingDataController : NSObject @property (nonatomic, copy) NSMutableArray *masterBirdSightingList; - (NSUInteger) countOfList; - (BirdSighting *) objectInListAtIndex: (NSUInteger) theIndex; - (void) addBirdSightingWithSighting: (BirdSighting *) sighting; @end BirdSightingDataController.m #import "BirdSightingDataController.h" @implementation BirdSightingDataController - (id) init { if(self = [super init]) { NSMutableArray *sightingList = [[NSMutableArray alloc] init]; self.masterBirdSightingList = sightingList; return self; } return nil; } -(NSUInteger) countOfList { return [self.masterBirdSightingList count]; } - (BirdSighting *) objectInListAtIndex: (NSUInteger) theIndex { return [self.masterBirdSightingList objectAtIndex:theIndex]; } - (void) addBirdSightingWithSighting: (BirdSighting *) sighting { [self.masterBirdSightingList addObject:sighting]; } @end And this is where I'm trying to add a BirdSighting instance to the mutable array: #import "BirdsMasterViewController.h" #import "BirdsDetailViewController.h" #import "BirdSightingDataController.h" #import "BirdSighting.h" @implementation BirdsMasterViewController - (void)awakeFromNib { [super awakeFromNib]; BirdSightingDataController *dataController = [[BirdSightingDataController alloc] init]; NSDate *date = [NSDate date]; BirdSighting *sighting = [[[BirdSighting alloc] init] initWithName:@"Ebabil" location:@"Ankara" date: date]; [dataController addBirdSightingWithSighting: sighting]; NSLog(@"dataController: %@", dataController.masterBirdSightingList); self.dataController = dataController; } .......... @end It throws NSInvalidArgumentException in BirdSightingDataController addBirdSightingWithSighting method... What am I doing wrong?

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  • how to load multiple images in iCarousel using this code?

    - by Dany
    i'm loading bunch of images in coverflow using i carousel but i'm not getting it?..initially i got Signal sigabart issue..after i edited some of the code the view gets displayed...Am i missing something?... #import "CollectionViewController.h" @interface CollectionViewController () @property (nonatomic, retain) NSMutableArray *items; @end @implementation CollectionViewController @synthesize carousel; @synthesize items; - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization } return self; } - (void)dealloc { carousel.delegate = nil; carousel.dataSource = nil; [items release]; [carousel release]; [super dealloc]; } - (void)viewDidLoad { [super viewDidLoad]; carousel.type = iCarouselTypeCoverFlow2; } - (void)viewDidUnload { [super viewDidUnload]; self.carousel = nil; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { return (interfaceOrientation == UIInterfaceOrientationPortrait); } #pragma mark - #pragma mark iCarousel methods - (NSUInteger)numberOfItemsInCarousel:(iCarousel *)carousel { return [items count]; } - (NSUInteger)numberOfVisibleItemsInCarousel:(iCarousel *)carousel { return 29; } - (UIView *)carousel:(iCarousel *)carousel viewForItemAtIndex:(NSUInteger)index reusingView:(UIView *)view { //create new view if no view is available for recycling if (view == nil) { view = [NSArray arrayWithObjects:[UIImage imageNamed:@"gal1.jpg"], [UIImage imageNamed:@"gal2.jpg"], [UIImage imageNamed:@"gal3.jpg"], [UIImage imageNamed:@"gal5.jpg"], [UIImage imageNamed:@"gal6.jpg"], [UIImage imageNamed:@"gal7.jpg"], [UIImage imageNamed:@"gal8.jpg"], [UIImage imageNamed:@"gal9.jpg"], [UIImage imageNamed:@"gal10.jpg"], [UIImage imageNamed:@"gal11.jpg"], [UIImage imageNamed:@"gal12.jpg"], [UIImage imageNamed:@"gal13.jpg"], [UIImage imageNamed:@"gal14.jpg"], [UIImage imageNamed:@"gal15.jpg"], [UIImage imageNamed:@"gal16.jpg"], [UIImage imageNamed:@"gal17.jpg"], [UIImage imageNamed:@"gal18.jpg"], [UIImage imageNamed:@"gal19.jpg"], [UIImage imageNamed:@"gal20.jpg"], [UIImage imageNamed:@"gal21.jpg"], [UIImage imageNamed:@"gal22.jpg"], [UIImage imageNamed:@"gal23.jpg"], [UIImage imageNamed:@"gal24.jpg"], [UIImage imageNamed:@"gal25.jpg"], [UIImage imageNamed:@"gal26.jpg"], [UIImage imageNamed:@"gal27.jpg"], [UIImage imageNamed:@"gal28.jpg"], } else { } return view; } @end while running on simulator i just get the screen not images?...i got stuck here....

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  • Shuffle Two NSMutableArray independently

    - by Superman
    I'm creating two NSMutableArray in my viewDidLoad, I add it in a NSMutableDictionary. When I tried shuffling it with one array, It is okay. But the problem is when Im shuffling two arrays independently its not working,somehow the indexes got mixed up. Here is my code for my array (I have two of these): self.items1 = [NSMutableArray new]; for(int i = 0; i <= 100; i++) { NSArray *paths = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0]; NSString *savedImagePath = [documentsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"[Images%d.png", i]]; if([[NSFileManager defaultManager] fileExistsAtPath:savedImagePath]){ self.container = [[NSMutableDictionary alloc] init]; [container setObject:[UIImage imageWithContentsOfFile:savedImagePath] forKey:@"items1"]; [container setObject:[NSNumber numberWithInt:i] forKey:@"index1"]; [items1 addObject:container]; } } NSLog(@"Count : %d", [items1 count]); [items1 enumerateObjectsUsingBlock:^(id object, NSUInteger index, BOOL *stop) { NSLog(@"%@ images at index %d", object, index); }]; then my shuffle code(Which I tried duplicating for the other array,but not working also): srandom(time(NULL)); NSUInteger count = [items1 count]; for (NSUInteger i = 0; i < count; ++i) { int nElements = count - i; int n = (random() % nElements) + i; [items1 exchangeObjectAtIndex:i withObjectAtIndex:n]; } How am I going to shuffle it using above code (or if you have other suggestions) with two arrays? Thanks My other problem is when I tries subclassing the class for the shuffle method or either use the above code, their index mixed. For example: Object: apple, ball, carrots, dog Indexes: 1 2 3 4 but in my View when shuffled: Object: carrots, apple, dog, balle Indexes: 2 4 1 3

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  • Serialize struct with pointers to NSData

    - by leolobato
    Hey guys, I need to add some kind of archiving functionality to a Objective-C Trie implementation (NDTrie on github), but I have very little experience with C and it's data structures. struct trieNode { NSUInteger key; NSUInteger count, size; id object; __strong struct trieNode ** children; __strong struct trieNode * parent; }; @interface NDTrie (Private) - (struct trieNode*)root; @end What I need is to create an NSData with the tree structure from that root - or serialize/deserialize the whole tree some other way (conforming to NSCoding?), but I have no clue how to work with NSData and a C struct containing pointers. Performance on deserializing the resulting object would be crucial, as this is an iPhone project and I will need to load it in the background every time the app starts. What would be the best way to achieve this? Thanks!

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  • URL filtering for UIWebView on the iPhone

    - by Zac Altman
    Can someone please shed some light on how I would get this to work: http://www.icab.de/blog/2009/08/18/url-filtering-with-uiwebview-on-the-iphone/ I tried making the "FilteredWebCache.h" and "FilteredWebCache.m" files in my project, but it said that "FilterManager.h" did not exist. What am I meant to do with those files? This I put in viewDidLoad: NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *docDir = [paths objectAtIndex:0]; NSString *path = docDir; // the path to the cache file NSUInteger discCapacity = 10*1024*1024; NSUInteger memoryCapacity = 512*1024; FilteredWebCache *cache = [[FilteredWebCache alloc] initWithMemoryCapacity:memoryCapacity diskCapacity:discCapacity diskPath:path]; [NSURLCache setSharedURLCache:cache]; [cache release];

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  • How to dynamically compose a bitmask?

    - by mystify
    Lets say I have to provide an value as bitmask. NSUInteger options = kFoo | kBar | kFooBar; and lets say that bitmask is really huge and may have 100 options. But which options I have, depends on a lot of situations. How could I dynamically compose such a bitmask? Is this valid? NSUInteger options; if (foo) { options = options | kFoo; } if (bar) { options = options | kBar; } if (fooBar) { options = options | kFooBar; } (despite the fact that this would probably crash when doing that | bitmask operator thing to "nothing".

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  • Objective C block gives link error

    - by ennuikiller
    I'm trying to use objective-c blocks for some iPhone programming and am getting the following link time error: The relevant code is: - (NSDictionary *) getDistances { CLLocationCoordinate2D parkingSpace; NSMutableDictionary *dict; NSIndexSet *indexForUser; BOOL (^test)(id obj, NSUInteger idx, BOOL *stop); test = ^ (id obj, NSUInteger idx, BOOL *stop) { NSString *user = (NSString *)[(NSDictionary *)obj valueForKey:@"userid"]; if ([user isEqualToString:self->sharedUser.userName]) { return YES; } return NO; }; [self->sharedUser.availableParking indexesOfObjectsPassingTest:test]; } Any help would be very much appreciated!!

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  • Using core plot for iPhone, drawing date on x axis

    - by xmax
    I have available an array of dictionary that contains NSDate and NSNumber values. I wanted to plot date on X axis. for plotting I need to supply xRanges to plot with some decimal values.I don't understand how can i supply NSdate values to xRange (low and length). And what should be there in this method: -(NSNumber *)numberForPlot:(CPPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index I mean how my date value will be returned as NSNumber..? I think i should use some interval over there.but what should be the exact conversion..? can any one explain me what are the exact requirement to plot the date on xAxis..? I am plotting my plot in half of the view.

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  • Problem dispatching with google mobile analytics for iphone

    - by Eamonn
    I have integrated Google mobile analytics into my iphone app, but for some reason the page views and events are not dispatching. I put this into my app delegate applicationDidFinishLaunching method (i've x'd out the UA string): [[GANTracker sharedTracker] startTrackerWithAccountID:@"UA-xxxxxx-x" dispatchPeriod:10 delegate:self]; NSError *error; [[GANTracker sharedTracker] trackPageview:@"/home" withError:&error]; This is the delegate method: - (void)trackerDispatchDidComplete:(GANTracker *)tracker eventsDispatched:(NSUInteger)eventsDispatched eventsFailedDispatch:(NSUInteger)eventsFailedDispatch { NSLog(@"Google Analytics Dispatch: succeeded:%i, failed:%i",eventsDispatched,eventsFailedDispatch); } which prints out the message: Google Analytics Dispatch: succeeded:0, failed:190 Did anyone else run into this problem?

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  • NSArraycontroller selectionIndexes bindings

    - by Michael Scherbaum
    Hi all, I have the following set-up: A Window that has a splitView in which I display I NSCollectionView in the left view and a detailView in the right view. Both views are set-up in separate xibs. Furthermore I have a Datacontroller (of class NSArrayController) that manages a mutable Array of NSMutableDictionaries (moviesForChoice). The dataController is set-up as application delegate. The movie objects in the array have properties like (name, plot, genre etc.) so far so good... In the xib for the NScollectionview I bound a NSArraycontroller content property to my datacontroller via Application.delegate.moviesForChoice The collectionView accesses the arraycontroller.arrrangedObjects and arraycontroller.selectionIndexes. This works fine the contents are displayed and the selection works fine in the collectionview (my collectionviewItem renders a selection color) In the xib for the detailView I want to display information for the selected object in the collectionview. Therefore I also added an arraycontroller to the xib, bound the content aray to Application.delegate.moviesForChoice and bound the NSTextfields in the view to e.g. arraycontroller.selection.name Here comes my issue: everytime I open the window with the two xibs, my collectionview displays all movies that are for choice correctly, and the detailview displays the information for the 1st object in my collectionview. Whenever I click on a different movie in the collectionView the res. item renders a selection color, but the detailView doesn't update. My understanding of it would be that the DataController is not informed about updates in the selectionIndexes and can therefore not trigger an update in the detailView. Correct me if I'm wrong... To remedy this I tried to bind the selectionIndexes property of the arraycontroller in the collectionView xib to Application.delegate.moviesForChoice.selecionIndexes but this failed with: addObserver:forKeyPath:options:context:] is not supported. Key path: selectionIndexes I could imagine that this means that the datacontroller is not KVO compliant for my Array moviesForChoice, but I implemented the following methods for it: -(void)insertObject:(NSDictionary *)dict inMoviesForChoiceAtIndex:(NSUInteger)index { [moviesForChoice insertObject:dict atIndex:index]; } -(void)removeObjectFromMoviesForChoiceAtIndex:(NSUInteger)index { [moviesForChoice removeObjectAtIndex:index]; } -(void)setMoviesForChoice:(NSMutableArray *)a { moviesForChoice = a; } -(NSArray*)moviesForChoice { return moviesForChoice; } -(NSUInteger)countOfMoviesForChoice { return [moviesForChoice count]; } - (void)addMovieForChoiceObject:(Movie *)anObject { [moviesForChoice addObject:anObject]; } So where am I wrong? How do I correctly bind to the selectionIndexes? You help is much appreciated! M

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  • How to remove NSDate objects from a NSMutableArray

    - by Ryan
    I have been working with NSArrays and NSMutableArrays that store NSDate objects for a few days now. I noticed that calling [listOfDates removeObject:date1] removes all the NSDate objects from the array. I have instead been doing this to remove objects: NSMutableArray *dateList; // Has Dates in it NSDate *dateToRemove; // Date Object to Remove __block NSUInteger indexToRemove; __block BOOL foundMatch = NO; [dateList enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) { if ([obj isEqualToDate:dateToRemove]) { indexToRemove = idx; foundMatch = YES; *stop = YES; } }]; if (foundMatch) { [dateList removeObjectAtIndex:indexToRemove]; } Is there a better way to be doing this? Perhaps another data structure? Or a simpler function?

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  • how to get IndexPath

    - by user145883
    in iphone application. I'm trying to get indexPath.row value to do something on the basis of row selected in programmatically created tableview. Can someone please tell me why is the indexPath.row value is not coming correct. It's some thing like 21487...3? NSUInteger nSections = [myTableView numberOfSections]; NSUInteger nRows = [myTableView numberOfRowsInSection:nSections]; NSIndexPath *indexPath = [NSIndexPath indexPathForRow: nRows inSection:nSections]; NSLog(@"No of sections in my table view %d",nSections); NSLog(@"No of rows in my table view %d",nRows); NSLog(@"Value of selected indexPath Row %d", indexPath.row); Thanks, Aaryan

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  • in iOS7 how do you stop the First viewcontroller autorotating?

    - by uaka
    I have an app that just needs one screen to autorotate, the first and last screens should be portrait. I can get the last screen to stop rotating using: -(NSUInteger)supportedInterfaceOrientations { return UIInterfaceOrientationMaskPortrait; } But this does not work on the first screen, I am using a storyboard with a UINavigationController (I'm thinking that may have something to do with it?) Any help would be gratefully received. Thanks

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  • iPhone keyboard's return key will move curser to next textfield

    - by iAm
    Hello Fellow Koder ••• I have a TableViewController that is using a grouped Style and has two(2) sections. The first section has 4 rows and the second section has 3 rows. I have placed a UILabel and a UITextField in each cell, and have a custom method(textFieldDone:) to handle the cursor movement to the next text field when the return key is press. This works fine and dandy if there is only one section, but I have two :( and yes I need two:) so I started koden' up an answer, but got results that just don't work, I did notice during my debugging that cell Identifier (I use Two) is only showing the one (in the debug consol) and it's the first one only (Generic Cell). - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { UITableViewCell *cell = nil; switch (indexPath.section) { case AUTO_DETAILS: { static NSString *cellID = @"GenericCell"; cell = [tableView dequeueReusableCellWithIdentifier:cellID]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:cellID] autorelease]; UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 75, 25)]; label.tag = kLabelTag; label.font = [UIFont boldSystemFontOfSize:14]; label.textAlignment = UITextAlignmentRight; [cell.contentView addSubview:label]; [label release]; UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(90, 12, 200, 25)]; textField.clearsOnBeginEditing = NO; [textField setDelegate:self]; [textField addTarget:self action:@selector(topTextFieldDone:) forControlEvents:UIControlEventEditingDidEndOnExit]; [cell.contentView addSubview:textField]; } NSInteger row = [indexPath row]; UILabel *label = (UILabel *)[cell viewWithTag:kLabelTag]; UITextField *textField = nil; for (UIView *oneView in cell.contentView.subviews) { if ([oneView isMemberOfClass:[UITextField class]]) textField = (UITextField *)oneView; } label.text = [topCellLabels objectAtIndex:row]; NSNumber *rowAsNum = [[NSNumber alloc] initWithInt:row]; switch (row) { case kMakeRowIndex: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.make; break; case kModelRowIndex: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.model; break; case kYearRowIndex: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.year; break; case kNotesRowIndex: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.notes; break; default: break; } if (textFieldBeingEdited == textField) { textFieldBeingEdited = nil; } textField.tag = row; [rowAsNum release]; break; } case AUTO_REGISTRATION: { static NSString *AutoEditCellID = @"AutoEditCellID"; cell = [tableView dequeueReusableCellWithIdentifier:AutoEditCellID]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue2 reuseIdentifier:AutoEditCellID] autorelease]; UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 75, 25)]; label.tag = kLabelTag; label.font = [UIFont boldSystemFontOfSize:14]; label.textAlignment = UITextAlignmentRight; [cell.contentView addSubview:label]; [label release]; UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(90, 12, 200, 25)]; textField.clearsOnBeginEditing = NO; [textField setDelegate:self]; [textField addTarget:self action:@selector(bottomTextFieldDone:) forControlEvents:UIControlEventEditingDidEndOnExit]; [cell.contentView addSubview:textField]; } NSInteger row = [indexPath row]; UILabel *label = (UILabel *)[cell viewWithTag:kLabelTag]; UITextField *textField = nil; for (UIView *oneView in cell.contentView.subviews) { if ([oneView isMemberOfClass:[UITextField class]]) textField = (UITextField *)oneView; } label.text = [bottomCellLabels objectAtIndex:row]; NSNumber *rowAsNum = [[NSNumber alloc] initWithInt:row]; switch (row) { case 0: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.vinNumber; break; case 1: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.policyNumber; break; case 2: if ([[tempValues allKeys] containsObject:rowAsNum]) textField.text = [tempValues objectForKey:rowAsNum]; else textField.text = automobile.licensePlate; break; default: break; } if (textFieldBeingEdited == textField) { textFieldBeingEdited = nil; } textField.tag = row; [rowAsNum release]; break; } default: break; } return cell; } Now remember that the first section is working fine and the kode for that method is this: -(IBAction)topTextFieldDone:(id)sender { UITableViewCell *cell = (UITableViewCell *)[[sender superview] superview]; UITableView *table = (UITableView *)[cell superview]; NSIndexPath *textFieldIndexPath = [table indexPathForCell:cell]; NSUInteger row = [textFieldIndexPath row]; row++; if (row > kNumOfEditableRows) row = 0; NSUInteger newIndex[] = {0, row}; NSIndexPath *newPath = [[NSIndexPath alloc] initWithIndexes:newIndex length:2]; UITableViewCell *nextCell = [self.tableView cellForRowAtIndexPath:newPath]; UITextField *nextField = nil; for (UIView *oneView in nextCell.contentView.subviews) { if ([oneView isMemberOfClass:[UITextField class]]) nextField = (UITextField *)oneView; } [nextField becomeFirstResponder]; } It was my idea to just create a second method (secondSectionTextFieldDone:) like this -(IBAction)bottomTextFieldDone:(id)sender { UITableViewCell *cell = (UITableViewCell *)[[sender superview] superview]; UITableView *table = (UITableView *)[cell superview]; NSIndexPath *textFieldIndexPath = [table indexPathForCell:cell]; NSUInteger row = [textFieldIndexPath row]; row++; if (row > 3) row = 0; NSUInteger newIndex[] = {0, row}; NSIndexPath *newPath = [[NSIndexPath alloc] initWithIndexes:newIndex length:2]; UITableViewCell *nextCell = [self.tableView cellForRowAtIndexPath:newPath]; UITextField *nextField = nil; NSString *string = [NSString stringWithFormat:@"AutoEditCellID"]; for (UIView *oneView in nextCell.contentView.subviews) { NSLog(@"%@", nextCell.reuseIdentifier); /* DEBUG LOG */ if ([oneView isMemberOfClass:[UITextField class]] && (nextCell.reuseIdentifier == string)) nextField = (UITextField *)oneView; } [nextField becomeFirstResponder]; } but the result does not solve the issue. so my question is, how can i get the cursor to jump to the next textfield in the section that it is in, If there is one, and if not, then send a message "resignFirstResponder" so that, the keyboard goes away.

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  • Can't get Jacobi algorithm to work in Objective-C

    - by Chris Long
    Hi, For some reason, I can't get this program to work. I've had other CS majors look at it and they can't figure it out either. This program performs the Jacobi algorithm (you can see step-by-step instructions and a MATLAB implementation here). BTW, it's different from the Wikipedia article of the same name. Since NSArray is one-dimensional, I added a method that makes it act like a two-dimensional C array. After running the Jacobi algorithm many times, the diagonal entries in the NSArray (i[0][0], i[1][1], etc.) are supposed to get bigger and the others approach 0. For some reason though, they all increase exponentially. For instance, i[2][4] should equal 0.0000009, not 9999999, while i[2][2] should be big. Thanks in advance, Chris NSArray+Matrix.m @implementation NSArray (Matrix) @dynamic offValue, transposed; - (double)offValue { double sum = 0.0; for ( MatrixItem *item in self ) if ( item.nonDiagonal ) sum += pow( item.value, 2.0 ); return sum; } - (NSMutableArray *)transposed { NSMutableArray *transpose = [[[NSMutableArray alloc] init] autorelease]; int i, j; for ( i = 0; i < 5; i++ ) { for ( j = 0; j < 5; j++ ) { [transpose addObject:[self objectAtRow:j andColumn:i]]; } } return transpose; } - (id)objectAtRow:(NSUInteger)row andColumn:(NSUInteger)column { NSUInteger index = 5 * row + column; return [self objectAtIndex:index]; } - (NSMutableArray *)multiplyWithMatrix:(NSArray *)array { NSMutableArray *result = [[NSMutableArray alloc] init]; int i = 0, j = 0, k = 0; double value; for ( i = 0; i < 5; i++ ) { value = 0.0; for ( j = 0; j < 5; j++ ) { for ( k = 0; k < 5; k++ ) { MatrixItem *firstItem = [self objectAtRow:i andColumn:k]; MatrixItem *secondItem = [array objectAtRow:k andColumn:j]; value += firstItem.value * secondItem.value; } MatrixItem *item = [[MatrixItem alloc] initWithValue:value]; item.row = i; item.column = j; [result addObject:item]; } } return result; } @end Jacobi_AlgorithmAppDelegate.m // ... - (void)jacobiAlgorithmWithEntry:(MatrixItem *)entry { MatrixItem *b11 = [matrix objectAtRow:entry.row andColumn:entry.row]; MatrixItem *b22 = [matrix objectAtRow:entry.column andColumn:entry.column]; double muPlus = ( b22.value + b11.value ) / 2.0; muPlus += sqrt( pow((b22.value - b11.value), 2.0) + 4.0 * pow(entry.value, 2.0) ); Vector *u1 = [[[Vector alloc] initWithX:(-1.0 * entry.value) andY:(b11.value - muPlus)] autorelease]; [u1 normalize]; Vector *u2 = [[[Vector alloc] initWithX:-u1.y andY:u1.x] autorelease]; NSMutableArray *g = [[[NSMutableArray alloc] init] autorelease]; for ( int i = 0; i <= 24; i++ ) { MatrixItem *item = [[[MatrixItem alloc] init] autorelease]; if ( i == 6*entry.row ) item.value = u1.x; else if ( i == 6*entry.column ) item.value = u2.y; else if ( i == ( 5*entry.row + entry.column ) || i == ( 5*entry.column + entry.row ) ) item.value = u1.y; else if ( i % 6 == 0 ) item.value = 1.0; else item.value = 0.0; [g addObject:item]; } NSMutableArray *firstResult = [[g.transposed multiplyWithMatrix:matrix] autorelease]; matrix = [firstResult multiplyWithMatrix:g]; } // ...

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  • iPod/iPhone OpenGL ES UIView flashes when updating

    - by Dave Viner
    I have a simple iPhone application which uses OpenGL ES (v1) to draw a line based on the touches of the user. In the XCode Simulator, the code works perfectly. However, when I install the app onto an iPod or iPhone, the OpenGL ES view "flashes" when drawing the line. If I disable the line drawing, the flash disappears. By "flash", I mean that the background image (which is an OpenGL texture) disappears momentarily, and then reappears. It appears as if the entire scene is completely erased and redrawn. The code which handles the line drawing is the following: renderLineFromPoint:(CGPoint)start toPoint:(CGPoint)end { static GLfloat* vertexBuffer = NULL; static NSUInteger vertexMax = 64; NSUInteger vertexCount = 0, count, i; //Allocate vertex array buffer if(vertexBuffer == NULL) vertexBuffer = malloc(vertexMax * 2 * sizeof(GLfloat)); //Add points to the buffer so there are drawing points every X pixels count = MAX(ceilf(sqrtf((end.x - start.x) * (end.x - start.x) + (end.y - start.y) * (end.y - start.y)) / kBrushPixelStep), 1); for(i = 0; i < count; ++i) { if(vertexCount == vertexMax) { vertexMax = 2 * vertexMax; vertexBuffer = realloc(vertexBuffer, vertexMax * 2 * sizeof(GLfloat)); } vertexBuffer[2 * vertexCount + 0] = start.x + (end.x - start.x) * ((GLfloat)i / (GLfloat)count); vertexBuffer[2 * vertexCount + 1] = start.y + (end.y - start.y) * ((GLfloat)i / (GLfloat)count); vertexCount += 1; } //Render the vertex array glVertexPointer(2, GL_FLOAT, 0, vertexBuffer); glDrawArrays(GL_POINTS, 0, vertexCount); //Display the buffer [context presentRenderbuffer:GL_RENDERBUFFER_OES]; } (This function is based on the function of the same name from the GLPaint sample application.) For the life of me, I can not figure out why this causes the screen to flash. The line is drawn properly (both in the Simulator and in the iPod). But, the flash makes it unusable. Anyone have ideas on how to prevent the "flash"?

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  • OCUnit & NSBundle

    - by kpower
    I created OCUnit test in concordance with "iPhone Development Guide". Here is the class I want to test: // myClass.h #import <Foundation/Foundation.h> #import <UIKit/UIKit.h> @interface myClass : NSObject { UIImage *image; } @property (readonly) UIImage *image; - (id)initWithIndex:(NSUInteger)aIndex; @end // myClass.m #import "myClass.m" @implementation myClass @synthesize image; - (id)init { return [self initWithIndex:0]; } - (id)initWithIndex:(NSUInteger)aIndex { if ((self = [super init])) { NSString *name = [[NSString alloc] initWithFormat:@"image_%i", aIndex]; NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:@"png"]; image = [[UIImage alloc] initWithContentsOfFile:path]; if (nil == image) { @throw [NSException exceptionWithName:@"imageNotFound" reason:[NSString stringWithFormat:@"Image (%@) with path \"%@\" for current index (%i) wasn't found.", [name autorelease], path, aIndex] userInfo:nil]; } [path release]; } return self; } - (void)dealloc { [image release]; [super dealloc]; } @end And my unit-test (LogicTests target): // myLogic.m #import <SenTestingKit/SenTestingKit.h> #import <UIKit/UIKit.h> #import "myClass.h" @interface myLogic : SenTestCase { } - (void)testTemp; @end @implementation myLogic - (void)testTemp { STAssertNoThrow([[myClass alloc] initWithIndex:0], "myClass initialization error"); } @end All necessary frameworks, "myClass.m" and images added to target. But on build I have an error: [[myClass alloc] initWithIndex:0] raised Image (image_0) with path \"(null)\" for current index (0) wasn't found.. myClass initialization error This code (initialization) works fine in application itself (main target) and later displays correct image. I've also checked my project folder (build/Debug-iphonesimulator/LogicTests.octest/) - there are LogicTests, Info.plist and necessary image files (image_0.png is one of them). What's wrong?

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  • trying to delete a song from a list UITableView sigbart error - addMusic Example

    - by Pavan
    hi im trying to implement a delete feature into the addmusic example this is the code ive added it doesnt work, i cant get my head around whats wrong. can someone please tell me whats wrong and what i need to do to make sure it works. - (void)tableView:(UITableView*)tableView willBeginEditingRowAtIndexPath:(NSIndexPath *)indexPath { } - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { // If row is deleted, remove it from the list. if (editingStyle == UITableViewCellEditingStyleDelete) { MainViewController *mainViewController = (MainViewController *) self.delegate; NSUInteger index = [indexPath row]; MPMediaItem *itemToDelete = [mainViewController.userMediaItemCollection mediaItemAtIndex:index]; if ([itemToDelete isEqual:mainViewController.musicPlayer.nowPlayingItem]) { [mainViewController.musicPlayer skipToNextItem]; } MPMediaItemCollection *newCollection = [mainViewController.userMediaItemCollection collectionByDeletingMediaItemAtIndex:index]; mainViewController.userMediaItemCollection = newCollection; NSUInteger indices[] = {0, index}; NSIndexPath *deletePath = [NSIndexPath indexPathWithIndexes:indices length:2]; [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:deletePath] withRowAnimation:UITableViewRowAnimationFade]; I also get these warnings when i compile the program and run it: heres the image: http://www.freeimagehosting.net/uploads/6e42f166b9.png Any ideas and help appreciated.

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  • iphone encryption not working

    - by Futur
    I have this encryption/decryption implemented and executes with no error, but i am unable to decrypt the data and im not sure whether the data is encrypted, kindly help. - (NSData *)AES256EncryptWithKey:(NSString *)key { char keyPtr[kCCKeySizeAES256+1]; bzero(keyPtr, sizeof(keyPtr)); [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [strData length]; data = [[NSData alloc] init]; data = [strData dataUsingEncoding:NSUTF8StringEncoding]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void *pribuffer = malloc(bufferSize); size_t numBytesEncrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL /* initialization vector (optional) */, [data bytes], dataLength, /* input */ [data bytes], bufferSize, /* output */ &numBytesEncrypted); if (cryptStatus == kCCSuccess) { return [NSData dataWithBytesNoCopy:data length:numBytesEncrypted]; }} The decryption is : -(NSData *)AES256DecryptWithKey:(NSString *)key andForData:(NSData *)objDataObject { char keyPtr[kCCKeySizeAES256+1]; bzero(keyPtr, sizeof(keyPtr)); [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; NSUInteger dataLength = [objDataObject length]; size_t bufferSize = dataLength + kCCBlockSizeAES128; void *buffer = malloc(bufferSize); size_t numBytesDecrypted = 0; CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, keyPtr, kCCKeySizeAES256, NULL, [objDataObject bytes], dataLength, [objDataObject bytes], bufferSize, &numBytesDecrypted); if (cryptStatus == kCCSuccess) { return [NSData dataWithBytesNoCopy:objDataObject length:numBytesDecrypted]; } } i call the above methods like this: CryptoClass *obj = [CryptoClass new]; NSData *objData = [obj AES256EncryptWithKey:@"hell"]; NSData *val = [obj AES256DecryptWithKey:@"hell" andForData:objData ]; NSLog(@"decrypted string is : %@ AND LENGTH IS %d",[val description],[val length]); Decryption doesnt seem to happen at all and the encryption - i am not sure about it, kindly help me here.

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  • Location of the object after scrolling in UIScrollView

    - by ludo
    Hi, I have a scrollView (width:320px height:100px) on my UIView, inside it I add 10 images with width:106.5px each. After that I use this function to have 3 different parts inside my scrollView, so everytime I scroll, an image will automatically be center. -(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate { [self returnToPosition:self.scrollView]; } -(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView { [self returnToPosition:self.scrollView]; } -(void)returnToPosition:(UIScrollView *)scrollView { CGFloat itemWidth = 106.5f; CGFloat position = [self.scrollView contentOffset].x; CGFloat newPosition = 0.0f; CGFloat offSet = position / itemWidth; NSUInteger target = (NSUInteger)(offSet + 0.5f); newPosition = target * itemWidth; [self.scrollView setContentOffset:CGPointMake(newPosition, 0.0f) animated:YES]; } Here is my question, I want to be able to know which image will be in the middle position after the user scroll the View, because I want to display on my UIView a text, specific to that image. But I don't know how to do that. Some Ideas?

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  • core-plot barchart does not work!!

    - by user355068
    Hello~ I try to draw bar chart!! numberForPlot is not good work, only CPBarPlotFieldBarLength set. -(NSNumber *)numberForPlot: (CPPlot *)plot field:(NSUInteger)fieldEnum recordIndex:(NSUInteger)index { NSDecimalNumber *num = nil; NSString *key = (fieldEnum == CPScatterPlotFieldX) ? @"x" : @"y"; if ( [plot isKindOfClass:[CPBarPlot class]] ) { switch ( fieldEnum ) { NSLog(@"fieldEnum = %d",fieldEnum); case CPBarPlotFieldBarLocation: num = (NSDecimalNumber *)[NSDecimalNumber numberWithUnsignedInteger:index]; NSLog(@"CPBarPlotFieldBarLocation return num = %@",num); break; case CPBarPlotFieldBarLength: num = (NSDecimalNumber *)[NSDecimalNumber numberWithUnsignedInteger: (index+1)*(index+1)]; if ( [plot.identifier isEqual:Plot3Identity] ) num = [[self.ExForPlot objectAtIndex:index] valueForKey:key]; NSLog(@"CPBarPlotFieldBarLength return num = %@",num); break; } } else { NSLog(@"...??.."); } return num; } # LOG 2010-06-01 02:43:19.424 myHealth[5071:207] CPBarPlotFieldBarLength return num = 0 2010-06-01 02:43:19.425 myHealth[5071:207] CPBarPlotFieldBarLength return num = 0 2010-06-01 02:43:19.425 myHealth[5071:207] CPBarPlotFieldBarLength return num = 30 # EXPlot set // Add some initial data NSMutableArray *contentArray = [NSMutableArray arrayWithCapacity:100]; int prevWeight = 0; int prevBmi = 0 ; if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL) == SQLITE_OK) { while (sqlite3_step(statement)==SQLITE_ROW) { id x = [NSNumber numberWithInt:graphTimeStamp]; id y = [NSNumber numberWithInt:sqlite3_column_int(statement, 2)]; [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:x, @"x", y, @"y", nil]]; } self.ExForPlot = contentArray;

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  • Subclassing NSArrayController in order to limit size of arrangedObjects

    - by Simone Manganelli
    I'm trying to limit the number of objects in an array controller, but I still want to be able to access the full array, if necessary. A simple solution I came up with was to subclass NSArrayController, and define a new method named "limitedArrangedObjects", that returns a limited number of objects from the real set of arranged objects. (I've seen http://stackoverflow.com/questions/694493/limiting-the-number-of-objects-in-nsarraycontroller , but that doesn't address my problem.) I want this property to be observable via bindings, so I set a dependency to arrangedObjects on it. Problem is, when arrangedObjects is updated, limitedArrangedObjects seems not to be observing the value change in arrangedObjects. I've hooked up an NSCollectionView to limitedArrangedObjects, and zero objects are being displayed. (If I bind it to arrangedObjects instead, all the objects show up as expected.) What's the problem? Here's the relevant code: @property (readonly) NSArray *limitedArrangedObjects; - (NSArray *)limitedArrangedObjects; { NSArray *arrangedObjects = [super arrangedObjects]; NSUInteger upperLimit = 10000; NSUInteger count = [arrangedObjects count]; if (count > upperLimit) count = upperLimit; arrayToReturn = [arrangedObjects subarrayWithRange:NSMakeRange(0, count)]; return arrayToReturn; } + (NSSet *)keyPathsForValuesAffectingValueForKey:(NSString *)key; { NSSet *keyPaths = [super keyPathsForValuesAffectingValueForKey:key]; if ([key isEqualToString:@"limitedArrangedObjects"]) { NSSet *affectingKeys = [NSSet setWithObjects:@"arrangedObjects",nil]; keyPaths = [keyPaths setByAddingObjectsFromSet:affectingKeys]; } return keyPaths; }

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  • Displaying Plist data into UItableview

    - by Christien
    I have a plist with Dictionary and numbers of strings per dictionary.show into the url below.and this list of items is in thousands in the plist. I need to display these plist data into the UItableview . How to do this? My Code: - (void)viewWillAppear:(BOOL)animated { // get paths from root direcory NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [documentPaths objectAtIndex:0]; NSString *documentPlistPath = [documentsDirectory stringByAppendingPathComponent:@"p.plist"]; NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:documentPlistPath]; valueArray = [dict objectForKey:@"title"]; self.mySections=[valueArray copy]; NSLog(@"value array %@",self.mySections); } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return [self.mySections count]; } -(NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { NSString *key = [[self.mySections objectAtIndex:section]objectForKey:@"pass"]; return [NSString stringWithFormat:@"%@", key]; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 5; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleValue1 reuseIdentifier:CellIdentifier]; } // Configure the cell... NSUInteger section = [indexPath section]; NSUInteger row = [indexPath row]; cell.textLabel.text = [[self.mySections objectAtIndex:row] objectForKey:@"title"]; cell.detailTextLabel.text=[[self.mySections objectAtIndex:section] objectForKey:[allKeys objectAtIndex:1]]; return cell; } Error is 2012-12-17 16:21:07.372 Project[2076:11603] * Terminating app due to uncaught exception 'NSRangeException', reason: '-[__NSCFArray objectAtIndex:]: index (4) beyond bounds (4)' * First throw call stack: (0x1703052 0x1523d0a 0x16aba78 0x16ab9e9 0x16fcc60 0x1d03a 0x391e0f 0x392589 0x37ddfd 0x38c851 0x337301 0x1704e72 0x277592d 0x277f827 0x2705fa7 0x2707ea6 0x2707580 0x16d79ce 0x166e670 0x163a4f6 0x1639db4 0x1639ccb 0x1505879 0x150593e 0x2f8a9b 0x2158 0x20b5) terminate called throwing an exceptionkill

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  • Is this a safe/valid hash method implementation?

    - by Sean
    I have a set of classes to represent some objects loaded from a database. There are a couple variations of these objects, so I have a common base class and two subclasses to represent the differences. One of the key fields they have in common is an id field. Unfortunately, the id of an object is not unique across all variations, but within a single variation. What I mean is, a single object of type A could have an id between, say, 0 and 1,000,000. An object of type B could have an id between, 25,000 and 1,025,000. This means there's some overlap of id numbers. The objects are just variations of the same kind of thing, though, so I want to think of them as such in my code. (They were assigned ids from different sets for legacy reasons.) So I have classes like this: @class BaseClass @class TypeAClass : BaseClass @class TypeBClass : BaseClass BaseClass has a method (NSNumber *)objectId. However instances of TypeA and TypeB could have overlapping ids as discussed above, so when it comes to equality and putting these into sets, I cannot just use the id alone to check it. The unique key of these instances is, essentially, (class + objectId). So I figured that I could do this by making the following hash function on the BaseClass: -(NSUInteger)hash { return (NSUInteger)[self class] ^ [self.objectId hash]; } I also implemented isEqual like so: - (BOOL)isEqual:(id)object { return (self == object) || ([object class] == [self class] && [self.objectId isEqual:[object objectId]]); } This seems to be working, but I guess I'm just asking here to make sure I'm not overlooking something - especially with the generation of the hash by using the class pointer in that way. Is this safe or is there a better way to do this?

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