cocoa-touch

iphone: the quickest easiest way to detect first launch

What's the quickest, easiest way to check if an application is being launched for the first time? ...

Interface Builder can't display 160dpi images correctly ??

Hi ! I'm developing an iPhone app. A simple image is the background of the main view. I've set an UIImageView in the background and set an image in, using IB. the image is a 160dpi PNG image. It appears like CRAP in IB. When running in the simulator it is ok, crisp. How am I supposed to work and place my controls precisely on a such p...

Responsibilities of Delegates and Controllers in Cocoa Touch?

I'm new to development on the iPhone. Just about every sample project (as well as the default project templates) have one or more delegates and controllers. Can someone give me a breakdown of what the delegates are responsible for vs. what the controllers are supposed to do? ...

What is the void* returned from CGBitmapContextGetData?

I'm trying to get the pixel information from an image and have got to the point where I have my void* data object which is a pointer to the image data. What exactly is this object? I've tried iterating over it hoping that it's an array of pixel info but it doesn't seem to work. I want to get the rgb values for each pixel. ...

Algorithm: array of arrays in Cocoa Touch (perhaps using NSCountedSet)

This one is a bit tedious in as far as explaining, so here goes. I'm essentially populating a tableView on the iPhone with multiple sections, and potentially multiple rows per section. To my understanding, it's best to have an array of arrays so that you can simply determine how many sections one has by sending a message to the top level...

UIPickerView Row Color

Hi All, Does anyone know how to change the color of a row (or row background) in the UIPickerView control from the iPhone SDK? Similiar to the below title for row, however I would also like to change the color of the row: - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component; ...

How can I send mail from an iPhone application

Hi All, Good morning, Can anybody help me out in following problem: I want to send an Email from my iPhone application. I have heard about the fact that iPhone SDK doesn't have any mailing API to send mail. In this case, what are the different ways to achieve this facility. But i don't want to use the following code because it will ex...

Bonjour Networking Help on iPhone WiTap sample

I can follow most of Apple's WiTap sample, but am sort of stumped on this bit in the send method: - (void) send:(const uint8_t)message { if (_outStream && [_outStream hasSpaceAvailable]) if([_outStream write:(const uint8_t *)&message maxLength:sizeof(const uint8_t)] == -1) [self _showAlert:@"Failed sending data to peer"]; } - (voi...

Exit Edit Mode

I have an array of objects which populate a UITableView. When a user removes the last object from the array, I automatically create a new "default" object. However, in the TableView, when the user gets there, the list is still in "Edit" mode. Is there a way for me to programatically set the TableView back to "normal" mode again? ...

Rotating two UIImageViews 360 degrees

Hi! I've been trying to have two fixed sized UIImageviews with images on the them (that cover all the view), But I've been trying really hard (I give up!) to rotate each of them in a circular manner. So if I have one UIView, and the other right next to it, I would like to be able to rotate the first one (and the other inmediately, no ga...

How accurate is the triangulated GPS of the non-3G iPhone?

Does anyone have any experience with the triangulated GPS used by the non-3G iPhone? How does it compare with 3G positioning? Does the iPhone 3G use triangulation in the event that there is no GPS signal available? Is there anyway to determine the accuracy of the non 3G coordinates? Thanks. ...

How to integrate NSURLConnection with UIProgressView?

I'm trying to integrate a NSURLConnection object with UIProgressView, so I can update the user while a file download is happening in the background. I created a separate object to download the file in the background, and I'm having problems figuring out how to update the progress property in the UIProgressView object with the correct va...

Who's responsible for creating the MainViewController instance in the iPhone NavBar example

I'm exploring the NavBar example from the iPhone dev center. More specifically, I'm trying to understand where the MainViewController object is instantiated and I simply can't find where this is happening. The only references to the MainViewController class is in AppDelegate, where there is a forward declaration and #import. However, ...

How do I draw a point using Core Graphics?

I see APIs in Quartz for drawing lines and circles. But all I want to do is to specify the (x,y) cartesian coordinate to color a pixel a particular value. How do I do that? ...

Using one delegate to manage two UIActionSheets

Hi everyone. I have two UIActionSheets and I am thinking that I will control them with one delegate (the UIViewController that instantiates them). The delegate will capture an actionSheet call and try to figure out which of the two threw the event. I tried to get the modalView's title to differentiate, but it seems to be invalid... S...

How to force a screen orientation in specific view controllers?

My application is pretty simple: it starts up with a view controller that holds a table view (in grouped view layout) with a few options. When the user taps on one of the options, I push another view controller onto my navigation controller. This second view controller simply displays a UIImageView, and the user can change the screen or...

[UIImage imageNamed...] vs [UIImage imageWithData...]

I want to load some images into my application from the file system. There's 2 easy ways to do this: [UIImage imageNamed:fullFileName] or: NSString *fileLocation = [[NSBundle mainBundle] pathForResource:fileName ofType:extension]; NSData *imageData = [NSData dataWithContentsOfFile:fileLocation]; [UIImage imageWithData:imageData]; ...

How to load viewController from a nib file

I have a Tab bar bases project (along with navigation control), inside a particular tab there is a tableViewLoaded , when i click on the table rows it shoud open another view , ie it pushes another controller , i have a view controller in the MainWindow.nib for this view also with some items like buttons labels , but whn i click it doesn...

Can the iPhone only use an SQLite database?

Can the iPhone use other databases besides SQLite, like MySQL? ...

Optimizing iPhone Application Launch Time

As anyone with an iPhone knows, some applications launch quickly, while others take several seconds. What are the best techniques for ensuring an iPhone app launches and becomes usable in a snappy manner? ...