Search Results

Search found 236 results on 10 pages for 'mystify'.

Page 8/10 | < Previous Page | 4 5 6 7 8 9 10  | Next Page >

  • What does that +0100 value mean in NSDate?

    - by mystify
    When I look at an NSDate value in the debugger, I get something like this: 1.4.2010 22:01:47 +0100 I don't get it what this +0100 is good for. Sometimes it is +0200. Is that supposed to be the time zone or something like that? What's it exactly? How does it affect the "since reference date" value?

    Read the article

  • Does Core Data automatically validate new values when they are set?

    - by mystify
    In this question, someone asked how to write a validation method for Core Data. I did that, and it looks cool. But one thing doesn't happen: The validation. I can easily set any "bad" value and this method doesn't get called automatically. What's the concept behind this? Must I always first call the validation method before setting any value? So would I write setter methods which call the appropriate validation method first? And if yes, what's the point of following a strict convention in how to write the validation method signature? I guess there's also some automatic way of validation, then. How to activate this?

    Read the article

  • Does it make any sense to develop for iPhone OS 3.0 instead of 3.2?

    - by mystify
    When it comes to backwards-compatibility, I want to stick to iPhone OS 3.0 so also some of the poor iPod Touch users who aren't rich enough for iPhones use my apps. But iPhone OS 3.2 has some pretty cool features that would be nice to have. Problematic thing: Since it's just a minor upgrade, I can imagine most iPod Touch users who decided to upgrade to 3.0 probably never upgraded to 3.2. I'm not sure if Apple actually asked them to pay like 10 bucks for going from 3.0 to 3.2. However, if Apple did ask them for money, I'm sure like 90% of all iPod Touch users didn't upgrade. So the big question is: IF you decide to go with iPhone OS 3.0, is it a stupid idea to stick to 3.2 just because of a few more features? Will this effectively kill half of your iPod Touch userbase?

    Read the article

  • Is there an autorelease pool in class methods?

    - by mystify
    I have an class method which generates an UIView, like this: + (UIImage*)imageWithFileName:(NSString*)imgFile { UIImage *img = nil; NSBundle *appBundle = [NSBundle mainBundle]; NSString *resourcePath = [appBundle pathForResource:imgFile ofType:nil]; if (resourcePath != nil) { NSURL *imageURL = [NSURL fileURLWithPath:resourcePath]; NSData *data = [[NSData alloc] initWithContentsOfURL:imageURL]; img = [UIImage imageWithData:data]; // should be autoreleased!! [data release]; } return img; } However, when I use this, the image data is NEVER freed. There is definitely a memory bug with this, although I didn't break any memory management rule I am aware of. My guess is that because this is a class method which gets called from instance methods, There is no active autorelease pool in place or it's one that only gets drained when I quit the app. Could that be right?

    Read the article

  • How to animate the change of image in an UIImageView?

    - by mystify
    I have an UIImageView with an image. Now I have a completely new image (graphic file), and want to display that in this UIImageView. If I just set myImageView.image = newImage; the new image is visible immediately. Not animatable. I want it to nicely fade into the new image. I thought maybe there's a better solution than just creating a new UIImageView on top of that and blending with animation?

    Read the article

  • Should I really use a UITableView in this situation?

    - by mystify
    Imagine you have a view like this: At the top, there is an UISegmentedControl with two segments. It functions like a tab. Pressing one segment will activate this particular content below that UISegmentedControl. Below the UISegmentedControl are some switches. These modify the way how the content should be rendered. And finally, below those switches, there's a table. Imagine a table not in sense of UITableView, but just what it really is: A table. It shows little messages like twitter messages or chat messages for example, one below the other. Like you know it from skype and other chats. Basically they're just rows with some formatting. A label, some image views, some lines, a background. Pretty basic. The data comes from an array. No core data. The whole thing including the segmented control and setup switches must be scrollable. So what I did is: I put all this stuff in an UIScrollView. Now I have to make the decision if I would use a UITableView inside there for that table part, or if I would just print a lot of rows on to the scroll view (with -drawRect:). But some problems stick in my head: Can I put a UITableView inside a UIScrollView? I assume this makes a lot of problems. I don't want that the table part is separately scrollable. Again imagine that view: First there are some basic choice things (segmented control, switches). Then there comes the table. When you scroll, the whole thing scrolls. That's mainly because this first part with the settings can be pretty big, so you would want to scroll it away. The next thing is: Can I customize UITableView in such a way, that it consists of two parts? One for that settings part, and one for the actual data to display?

    Read the article

  • What does <![CDATA[]]> in XML mean?

    - by mystify
    I often find this strange CDATA tag in XML files: <![CDATA[]]> I have observed that this CDATA tag always comes at the beginning, and then followed by some stuff. But sometimes it is used, sometimes it is not. I assume it is to mark that some "data" will be inserted after that. But what kind of "data"? Isn't anything I write in XML tags some sort of "data"?

    Read the article

  • Are there concurrency problems when using -performSelector:withObject:afterDelay: ?

    - by mystify
    For example, I often use this: [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:someDelay]; Now, lets say I call this 10 times to perform at the exact same delay, like: [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; - (void)doSomethingAfterDelay:(id)someObject { /* access an array, read stuff, write stuff, do different things that would suffer in multithreaded environments .... all operations are nonatomic! */ } I have observed pretty strange behavior when doing things like this. For my understanding, this method schedules a timer to fire on the current thread, so in this case the main thread. But since it doesn't create new threads, it actually should not be possible to run into concurrency problems, right?

    Read the article

  • Are there concurrency problems when using -performSelector:withObject:afterDelay: ?

    - by mystify
    For example, I often use this: [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:someDelay]; Now, lets say I call this 10 times to perform at the exact same delay, like: [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; [self performSelector:@selector(doSomethingAfterDelay:) withObject:someObject afterDelay:2.0]; - (void)doSomethingAfterDelay:(id)someObject { /* access an array, read stuff, write stuff, do different things that would suffer in multithreaded environments .... all operations are nonatomic! */ } I have observed pretty strange behavior when doing things like this. For my understanding, this method schedules a timer to fire on the current thread, so in this case the main thread. But since it doesn't create new threads, it actually should not be possible to run into concurrency problems, right?

    Read the article

  • How to make an mutable C array for this data type?

    - by mystify
    There's this instance variable in my objective-c class: ALuint source; I need to have an mutable array of OpenAL Sources, so in this case probably I need a mutable C-array. But how would I create one? There are many questions regarding that: 1) How to create an mutable C-array? 2) How to add something to that mutable C-array? 3) How to remove something from that mutable C-array? 4) What memory management pitfalls must I be aware of? Must i free() it in my -dealloc method? And yes, I think this is something for the nice community wiki...

    Read the article

  • How to make an tiled background like on the web?

    - by mystify
    On the iPhone, how could I achieve the same tiled background effect? For example, I have an pattern image which I want to repeat only horizontally. Would I have to go the route in -drawRect: by myself and loop over to draw the pattern, or is there a convenient method to do that?

    Read the article

  • How are files (especially audio files) organized internally?

    - by mystify
    I try to grok that: Apple is talking about "packets" in audio files, and there is a fancy function called AudioFileReadPackets which takes a lot of arguments. One of them specifies the "start packet", and another one the number of packets which you want to read. So I imagine an audio file to look like this, internally: It's made up of a lot of packets. If it's an audio file which has an variable bit rate format, then every packet may have a different size. If the file has an constant bit rate format, then every packet is the same size. So an audio file is like a truck full of boxes, and every box contains some interesting stuff. Is that correct? Does it apply to any kind of file? Is this how files actually look like?

    Read the article

< Previous Page | 4 5 6 7 8 9 10  | Next Page >