Iphone – How to create a custom locale with a custom NSDecimalSeparator value

cocoa-touchiphoneuikit

I'm having trouble with

+ (NSDecimalNumber *)decimalNumberWithString:(NSString *)numericString locale:(NSDictionary *)locale

Because I want to provide very high precision values programmatically to have no floating-point errors initially, apple gives me the only option to rely on a wonky locale.

So the documentation says pretty encrypted:

Parameters: …
locale
A dictionary
that defines the locale (specifically
the NSDecimalSeparator) to use to
interpret the number in numericString.

Discussion
The locale parameter determines whether the NSDecimalSeparator is a
period (as is used, for example, in
the United States) or a comma (as is
used, for example, in France).

well, after searching for NSDecimalSeparator in the docs, nothing found. Searching on the net, found that this thing is "deprecated". So currently I do something dangerous like this:

NSLocale *usLoc = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];
NSDecimalNumber *num = [NSDecimalNumber decimalNumberWithString:str locale:usLoc];

So I wonder: If they really need this wonky locale for something crucial like this (I add strings programmatically, no user input), couldn't I somehow create an own locale? That parameter wants an NSDictionary, so the idea:

Could I create an NSMutableDictionary out of that locale Dictionary that comes for -initWithLocaleIdentifier:@"en_US", and then just edit this %?&§! NSDecimalSeparator field?

And another thing that raises my headaches: Why does the parameter ask for an NSDictionary, where I have to pass an NSLocale object? Or is my code wrong? (not tested, since my app is currently totally screwed up 😉 )

Best Answer

There doesn't appear to be a way to add/modify the values in an instance of NSLocale; you can only get the logical locale for the user (currentLocale and autoupdatingCurrentLocale), the system locale without any changes made by the user in their system preferences (systemLocale), or any other named locale that the system knows about (initWithLocaleIdentifier).

NSLocale responds to the objectForKey: message, which is the same message that NSDictionary uses; that's why you can use an NSLocale even though the method calls for an NSDictionary. Since NSDecimalNumber is likely only going to look at one value, NSDecimalSeparator, I have a feeling you could get away with creating an NSDictionary object with that key and pass it as the locale parameter, but this might break in the future, since NSDecimalNumber expects a full-blown NSLocale instance and might be changed to check for other keys.

You are creating these strings programmatically, right? So you can control what decimal separator you use. My recommendation would be to use ., and get the en_US locale:

NSLocale *us = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];

The decimal separator is sure to be . every time.

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Ios – How to develop for iPhone using a Windows development machine

It's certainly possible to develop on a Windows machine, in fact, my first application was exclusively developed on the old Dell Precision I had at the time :)

There are three routes;

Install OSx86 (aka iATKOS / Kalyway) on a second partition/disk and dual boot.
Run Mac OS X Server under VMWare (Mac OS X 10.7 (Lion) onwards, read the update below).
Use Delphi XE4 and the macincloud service. This is a commercial toolset, but the component and lib support is growing.

The first route requires modifying (or using a pre-modified) image of Leopard that can be installed on a regular PC. This is not as hard as you would think, although your success/effort ratio will depend upon how closely the hardware in your PC matches that in Mac hardware - e.g. if you're running a Core 2 Duo on an Intel Motherboard, with an NVidia graphics card you are laughing. If you're running an AMD machine or something without SSE3 it gets a little more involved.

If you purchase (or already own) a version of Leopard then this is a gray area since the Leopard EULA states you may only run it on an "Apple Labeled" machine. As many point out if you stick an Apple sticker on your PC you're probably covered.

The second option is more costly. The EULA for the workstation version of Leopard prevents it from being run under emulation and as a result, there's no support in VMWare for this. Leopard server, however, CAN be run under emulation and can be used for desktop purposes. Leopard server and VMWare are expensive, however.

If you're interested in option 1) I would suggest starting at Insanelymac and reading the OSx86 sections.

I do think you should consider whether the time you will invest is going to be worth the money you will save though. It was for me because I enjoy tinkering with this type of stuff and I started during the early iPhone betas, months before their App Store became available.

Alternatively, you could pick up a low-spec Mac Mini from eBay. You don't need much horsepower to run the SDK and you can always sell it on later if you decide to stop development or buy a better Mac.

Update: You cannot create a Mac OS X Client virtual machine for OS X 10.6 and earlier. Apple does not allow these Client OSes to be virtualized. With Mac OS X 10.7 (Lion) onwards, Apple has changed its licensing agreement in regards to virtualization. Source: VMWare KnowledgeBase

Ios – How to size a UITextView to its content

This works for both iOS 6.1 and iOS 7:

- (void)textViewDidChange:(UITextView *)textView
{
    CGFloat fixedWidth = textView.frame.size.width;
    CGSize newSize = [textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)];
    CGRect newFrame = textView.frame;
    newFrame.size = CGSizeMake(fmaxf(newSize.width, fixedWidth), newSize.height);
    textView.frame = newFrame;
}

Or in Swift (Works with Swift 4.1 in iOS 11)

let fixedWidth = textView.frame.size.width
let newSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat.greatestFiniteMagnitude))
textView.frame.size = CGSize(width: max(newSize.width, fixedWidth), height: newSize.height)

If you want support for iOS 6.1 then you should also:

textview.scrollEnabled = NO;

Best Answer

Related Solutions

Ios – How to develop for iPhone using a Windows development machine

Ios – How to size a UITextView to its content

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