objective-c

Bind enabled of NSButton to selection in NSTextView

I have a button that does something to the selected text in NSTextView. If nothing is selected then nothing happens when the button is pressed... so can the enabled property of a button be bound to whether or not some text is selected? ...

Does NSKeyedUnarchiver autorelease?

I'm doing some archiving to a property list and when I unarchive my data using NSKeyedUnarchiver I find that my app crashes if I release the object afterward. I was wondering if the finishDecoding message also autoreleases the object. Seems weird that it crashes when I release it. ...

NSScanner scanFloat returning unexpected results

I'm trying to build a UIColor from a comma-delimited list of values for RGB, which is "0.45,0.53,0.65", represented here by the colorConfig object... NSScanner *scanner = [NSScanner scannerWithString:colorConfig]; [scanner setCharactersToBeSkipped:[NSCharacterSet characterSetWithCharactersInString:@"\n, "]]; float red, green, blue; retu...

UISlider to control AVAudioPlayer

hi everyone, I'm trying to implement a little function in my app. I am currently playing sounds as AVAudioPlayers and that works fine. What I would like to add is to control the sound's position (currentTime) with an UISlider: is there a simple way to do it ? I looked at an Apple project but it was quite messy....have you got samples o...

Can a function return an object? Objective-C and NSMutableArray

I have an NSMutableArray. It's members eventually become members of an array instance in a class. I want to put the instantiantion of NSMutable into a function and to return an array object. If I can do this, I can make some of my code easier to read. Is this possible? Here is what I am trying to figure out. //Definition: function Obje...

NSString stringWithFormat: with C array?

Hi, I'm writing a program that calculates the Jacobi algorithm. It's written in Objective-C since it runs on a Mac, but the majority is written in standard C. I'm using a two-dimensional C array and an NSArray containing 5 NSTextField labels. The following code yields an EXC_BAD_ACCESS error: for ( int i = 0; i < 5; i++ ) { NSStr...

Tiling solution for the iPhone that can handle infinite # of tiles

I have been looking at ways to implement a tiling solution on the iPhone/iPad similar to something like Google Maps. I have looked at examples of how to implement a CATiledLayer into a view that is inside a UIScrollView. Then when you scroll the view, the tiles request the new data to be shown. However, this seems to work when you hav...

iPhone OS: Rotate just the button images, not the views

Hi, I am developing an iPad application which is basically a big drawing canvas with a couple of button at the side. (Doesn't sound very original, does it? :P) No matter how the user holds the device, the canvas should remain in place and should not be rotated. The simplest way to achieve this would be to support just one orientation. ...

Which object called another object's method in Obj-C

Hi, I am looking to write a plugin controller in Cocoa that loads bundles, and exposes a specific set of methods for the plugins to call. My question is this: is it possible to know (any) info about the object that called a method in the controller. When an instantiated plugin calls a method in my plugin controller, I would like to kno...

[Obj-C/Cocoa] NSURLConnection leak issues

As a disclaimer I'd like to state that I'm fairly new to Objective-C and Cocoa. Currently I'm trying to write a basic application that can POST XML data to a particular endpoint. To achieve this, I've created a ServiceRouter class which uses NSURLConnection to post XML data to a particular URL. The ServiceRouter class is intended as a ...

how to detect touch on UIView with UIimage ontop of it?

hello all, i want to use a UIview and a UIImage ontop of it with a text box and button i want the user to drag it when the UIview or anything in the view is touched, what would be the best way to implement this method? the UIView is on a single View Controller and using Interface Builder to make my UIviews and UIimages. ...

How can I pass a UIEvent to a UIScrollView

I am subclassing UIWindow and creating an implementation of sendEvent: as follows: - (void)sendEvent:(UIEvent *)event { [super sendEvent:event]; // Send event to UIScrollView here } How can I send the event to a UIScrollView. I tried calling the touchesBegan:, etc. messages, but that did not do anything. ...

Why does my UIScrollView change it's original content offset when I scroll?

Before I scroll, my UIScrollView is laid out perfectly. See here However if I scroll up, the view bounces as I go out of bounds and then resets too high. See here I am going to guess this has to do with a hack that I did earlier to get the view to originally show like in the first screen shot. For some reason, to get my view to look ...

Why do my raytraced spheres have dark lines when lit with multiple light sources?

I have a simple raytracer that only works back up to the first intersection. The scene looks OK with two different light sources, but when both lights are in the scene, there are dark shadows where the lit area from one ends, even if in the middle of a lit area from the other light source (particularly noticeable on the green ball). Th...

Single specific string replace method Objective C

Hi guys, I wanted to know if theres a single method or way that will help me replace strings for specific characters. like MALE - M FEMALE - F CHILD - P The longer way out is this.. [str stringByreplacingOccurencesOfString:@"MALE" withString:@"M"]; [str stringByreplacingOccurencesOfString:@"FEMALE" withString:@"F"]; [str stringByre...

Clear Background color on UIImageView?

hello i have a UIimageView with a PNG image that has round corners, image sits fine the only problem it has is that i can see the UIImage Corners with a white background, how can I make the background clear and transparent. ...

How do you implement syntax highlighting?

I am embarking on some learning and I want to write my own syntax highlighting for files in C++. Can anyone give me ideas on how to go about doing this? To me it seems that when a file is opened: It would need to be parsed and decided what type of source file it is. Trusting the extension might not be fool-proof A way to know what ...

Two UITabBarControllers and Autorotation

I have two UITabBarControllers in my mainwnidow.nib wired to my appdelegate. In my app delegate, I can load either one: - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { //either [window addSubview:tabBarController.view]; //or [window addSubview:tabBar2Controll...

Line smoothing in Cocoa Touch

How would I smooth a line (UIBeizerPath) or a set of points? Right now it draws it jagged. I read about spline interpolation, could anyone point me to an implementation of this in cocoa or C or give me an alternate line smoothing algorithm. ...

Can NSDictionary be used with TableView on iPhone?

In a UITableViewController subclass, there are some methods that need to be implemented in order to load the data and handle the row selection event: - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; //there is only one section needed for my table view } - (NSInteger)tableView:(UITableView *)tableView nu...