cocoa

How to view existing data in Core Data?

Well, may be this question is silly, but I couldn't find a way (except programmatically). I built a project (for iPhone OS 3.0) which uses Core Data. The xcdatamodel file shows the schema description, but I want to see the data in tabular form (like the management studio for mssql server or phpmyadmin for mysql). Is there any way (excep...

My program is spending most of its time in objc_msgSend. Does that mean that Objective-C has bad performance?

Hello Stackoverflow. I have written an application that has a number of custom views and generally draws a lot of lines and bitmaps. Since performance is somewhat critical for the application, I spent a good amount of time optimizing draw performance. Now, activity monitor tells me that my application is usually using about 12% CPU and...

NSArrayController not working with NSMutableDictionary for NSTableView

Hi all, I am trying to display content in NSTableView using NSMutableArrayController of NSMutableDictionary records. I followed steps written below: In application delegate class, I created an NSMutableArray object with name 'geniuses' and stored some NSMutableDictionary objects with keys: 'geniusName' and 'domain'. I took an NSArray...

Binding a text field to Shared User defaults controller doesn't use null value

I set the text field to bind with a values controller key, a keypath of spacesPerTab, and setting 4 as the placeholder values. But when executing it, the text field displays nothing. This works for checkboxes. ...

Ok to implement backend/shared functionality for iPhone in JavaScript?

Is it ok to use the Webkit Javascript engine to implement cross-platform, non-GUI backend functionality on the iPhone, iPad? In my case, I was interested in re-using Javascript code that I have that works on top of SQLite. I thought I would need to re-implement the logic in Obj-C but perhaps I could just share it and expose some hooks ...

How can I save an NSDocument concurrently?

I have a document based application. Saving the document can take a few seconds, so I want to enable the user to continue using the program while it saves the document in the background. Due to the document architecture, my application is asked to save to a temporary location and that temporary file is then copied over the old file. How...

Do properties need to be deallocated?

I subclassed NSObject: #import <Foundation/Foundation.h> @interface STObject : NSObject { NSString *message_type; NSString *twitter_in_reply_to_screen_name; } @property(nonatomic, copy) NSString *message_type; @property(nonatomic, copy) NSString *twitter_in_reply_to_screen_name; @end My implementation looks like: #import ...

(Cocoa) Can I Subclass and Delegate at the same time?

@interface ClassB <ClassADelegate> : ClassA id <ClassBDelegate> delegate; @end As the code says, ClassB subclasses from ClassA and handles the formation protocol of Class A. However, the variable "delegate" will be duplicated. (ClassA also has "delegate") In fact, it can be done without subclassing, but it seems the code is cumberso...

iphone calls both if and else at the same time?

Hi, I need to determine what file type a file is and then perform a certain action for it. this seems to work fine for some types, however all media types such as videos and sound files get mixed up. I determine the file type by doing this: BOOL matchedMP3 = ([[rowValue pathExtension] isEqualToString:@"mp3"]); if (matchedMP3 == ...

Cast an NSDictionary value while applying an NSPredicate?

Hi I have an Array of NSDictionary objects. These Dictionaries are parsed from a JSON file. All value objects in the NSDictionary are of type NSString, one key is called "distanceInMeters". I had planned on filtering these arrays using an NSPredicate, so I started out like this: NSPredicate *predicate = [NSPredicate predicateWithForm...

Why does [NSOutlineView clickedRow] always return -1?

I have a fairly pedestrian non-editable NSOutlineView setup. In the bindings for the outline view, I have set the Double Click Target binding to my file's owner (MyDocument FWIW) with a selector of outlineViewWasDoubleClicked The method exists and is called, but when I call -clickedRow it consistently returns -1 rather than the row numb...

How to paint background of specific range of text in NSTextView

Hi, This is not a specific bug, its more about not knowing how to do something. I've an NSTextView and I need to paint the background of specific ranges of text when the user clicks on a specific part of the text view. I've tried this but I just get erratic behaviour in the sense that sometimes text loses the foreground color or the ba...

There's @interface in my @implementation — why is that?

This is a pretty noobish question – I'm looking at some Cocoa sample code and there's @interface blocks in the .m files as well as the headers. For instance, in the AppDelegate class header, a UIWindow and UI navigation are defined as instance variables, but the @property declarations are actually made in the implementation file. Is ther...

Add an objective @property attribute in objective-c

Does anyone know of a way to add additional attribute types to the @property keyword without modifying the compiler? Or can anyone think of another way to genericize getter/setter creation? Basically, I have a lot of cases in a recent project where it's handy for objects to lazily instantiate their array properties. This is because we...

SQLitePersistent objects only loading NSNumber fields, everything else left null

I've used SQLitePersistentObjects for a lot of different iPhone projects and haven't yet encountered this issue. I'm not sure if it's a bug or merely an issue on my part. I have a model with quite a few fields in it. Here are the fields enumerated as they exist in the sqlite database: SELECT pk,sender_i_d,read,target,web_u_r_l,sender_t...

Perform selector on parent NSOperation

I extend NSOperation (call it A) which contains NSOperationQueue for other NSOperations (which is another extended class different from A, call these operations B). When operation A is running (executing B operations) how do i call a specific function/method on operation A when certain event takes place on B operations? For example every...

Debugging unexpected error message - possible memory management problem?

I am trying to debug an application that is throwing up strange (to my untutored eyed) errors. When I try to simply log the count of an array... NSLog(@"Array has %i items", [[self startingPlayers] count]); ...I sometimes get an error: -[NSCFString count]: unrecognized selector sent to instance 0x1002af600 or other times -[NSConc...

Detecting network adapter changes on the iPhone

Say that there are no WIFI networks currently available and my network-enabled app is connected over 3G. How can I detect if a user has roamed into a WIFI network? I would also like to detect the case when the user is connected over WIFI and suddenly received 3G signal. In other words, I would like to be asynchronously notified of netw...

Automatic screenshot uploading on Mac like Cloud App

Cloud App has this neat feature wherein it automatically uploads new screenshots as they are added to the Desktop. Any ideas how this is done? ...

Cocoa framework development: sharing between projects

I am currently developing a handful of similar Cocoa desktop apps. In an effort to share code between them, I have identified a set of core classes and functions that can be common across all of these applications. I would like to bundle this common code into a framework which all of my current applications (and any future ones) can link...