objective-c

NSManagedObjectContext returns YES for hasChanges when there are none

I created a separate NSManagedObjectContext on a separate thread to perform some store maintenance. However, I have noticed that the context returns YES for hasChanges as soon as a managed object in it is even referenced e.g. NSString *name = managedObject.name; This context is created and used exclusively in 1 method. Why is it retur...

DTGridView losing content while scrolling

I am using DTGridView from the DTKit by Daniel Tull. I implemented it in a very simple ViewController and the test I am doing is to place a button in the last row of the grid, which should add another row to the grid (and therefor moving the button to a row beneath it). The problem is, when I click the button a couple of times and then ...

Selecting random numbers iphone sdk

Hey, I want to select 10 random numbers from 1 to 35. I am trying to do the following, but I get some repeated numbers int totalNumberCnt = 1; while (totalNumberCnt < 11) { int randomNumber1 = 1 + arc4random() % 35; NSString *numberString = [NSString stringWithFormat: @"%d",randomNumber1]; NSLog(numberString); [first...

UIWebView is ignoring cookies?!

Hello everybody, I am creating an app for the iPhone that fetches a specific page from a website, but to be able to view this site you need to log in with a username and a password. I've created this code: NSString *urlAddress = @"http://www.wdg-hamburg.de"; NSURL *url = [NSURL URLWithString:urlAddress]; NSString *post = @"name=login...

Objective-C - Unloading loaded view when it is swapped

Hi, What is the best way to do view management in a multiview application? Right now I have this ViewSwitcher method/function that comes from a custom delegate I created. The code is a whole bunch of if else like this MyViewController *c = [[MyViewController alloc] initWithNibName:@"MyViewController" bundle:nil]; c.delegate...

Objective-C - check if a method exist

Hi, is there anyway I can test if a method exist in Objective-C? I'm trying to add a guard to see if my object has the method before calling it. Thanks, Tee ...

Objective C unable to update UILabel more than once.

I have a method which I created that appends some new text to a UILabel. I've tried two ways of doing this (one is commented out) but both of them only update the label the first time. Any more calls to this method do not update the label. - (void) updateLog: (NSString*) text { /* NSMutableString *newText = [logLabel.text muta...

Detecting Acceleration in a car (iPhone Accelerometer)

Hello, I am working on an iPhone app where we are trying to calculate the acceleration of a moving car. Similar apps have accomplished this (Dynolicious), but the difference is that this app is designed to be used during general city driving, not on a drag strip. This leads us to one big concern that Dynolicious was luckily able to avo...

How do I call an Obj-C method from Javascript?

Hi all, I'm developing a native iPhone app using Phonegap, so everything is done in HTML and JS. I am using the Flurry SDK for analytics and want to use the [FlurryAPI logEvent:@"EVENT_NAME"]; method to track events. Is there a way to do this in Javascript? So when tracking a link I would imagine using something like <a onClick="fl...

Modifying all HTTP requests on iPhoneOS with MobileSubstrate?

I want to write a MobileSubstrate (http://www.iphonedevwiki.net/index.php/MobileSubstrate) addon that takes every HTTP request and modifies the URL. (The reason is very complicated and would take a while to explain, so just trust me that there's not an alternative). Basically, I need to know what's the best Objective-C message or C funct...

How to format float to 2 decimals in objective C

I have a string that I'm converting to a float that I want to check for values in an if statement. The original float value is the iPhone's trueHeading that is returned from the didUpdateHeading method. When I convert the original float to a string using @"%.2f" it works perfectly, but what I'm trying to do is convert the original float...

Changing UIView on orientation change

Hey all. I have a fairly simple question. I am developing a "rich" iPad app, and I have two background images specifically designed for landscape and portrait. I'd like this ImageView to automatically change depending on the devices orientation. (like pretty much all of Apples iPad apps). Can anyone point me in the right direction? I'm...

iPhone Dev: Animating PNG Sequences

What is the best or recommended technique for animating PNG Sequences. Heres what I've learned: Do it Manually Using MutableArrays containing Strings, you can animate a UIImageView with a timer which increments an index number UIImage - animation methods This works, the only problem is to find if an image has completed its animation, y...

Wandering CGAffineTransformMakeRotation

Okay this is about to make me insane -- any help would be appreciated. I have two images which are part of a timer application. One is the needle/hand and the other is a little hub which is styled to look like the needle base. I'm using a CGAffineTransformMakeRotation to rotate the needle and the base stays stationary. The problem: there...

Assign TableView column binding to a specific core-data object in to-many related entity based on separate attribute

How would I assign a column of a TableView to be a specific entry in a Core Data entity that is linked to the NSArrayController via a to-many relationship? For example Entity: MovieEntity Attributes: title(NSString), releaseDate(NSDate) Relationship: posters<-->> PosterEntity Entity:PosterEntity Attributes: imageLocation(NSURL), defau...

How can I easily save the Window size and position state using Obj-C?

What is the best way to remember the Windows position between application loads using Obj-C? I am using Interface Builder for the interface, is it possible to do this with bindings. What is the recommended method? Thank you. ...

Accessing 2D array and passing string to label.text

Hi. I'm trying to create 2D array and initialize it with NSStrings. When I try to copy content of a cell from the array to a label.text, the application crashes. NSMutableArray *array = [NSMutableArray arrayWithCapacity:0]; [array addObject:[NSMutableArray arrayWithObjects: [NSArray arrayWithObjects: @"0-0", @"0-1",...

NSTextFieldCell or just NSCell with vertical text (and colored tinting)

I'm struggling with trying to find an elegant way of displaying the column headers for a table view in a vertical fashion (rotated 90 deg counter clockwise from traditional). I'm not married to doing this as an actual NSTableHeaderCell, I figured it might be easier to do it by overriding NSTextFieldCell or NSCell. The cells only contai...

objective-c determine if parameter is an object

in Objective-c I have this function prototype: -(NSString*)formatSQL:(NSString*) sql, ... I may pass to this function any type of parameters: NSString, NSNumber, integer, float How can I determine in the function if a parameter is an object (NSString..) or a primitive (integer...)? thanks BrochPirate ...

[iPhone] Objective-C : Endless UIScrollView without pagingEnabled

Hi folks! In my iPhone app there is a scrollview (pagingEnabled=NO) which can contain up to 200 subviews (150 x 150) and the challenge is to do lazy loading and simulate endless scrolling (without bouncing) in horizontal directions. Is there a solution or an alternative for this request? Thanks a lot, Daniel ...