let timeFont = [NSFontAttributeName:UIFont(name: "Voyage", size: 20.0)]
var attrString3 = NSAttributedString("(Time)", attributes : timeFont); // <--- compiler error "Extra argument in call"
This code worked in xcode 6.0, but now that I've upgraded to xcode 6.1 it doesn't work anymore and I can't figure out what I need to get it back working. It says that there is an extra argument, but that's not correct. I believe that it has something to do with the new failable initializers, but everything that I've tried doesn't' work.
There are two reasons your code is failing to compile:
The initializer for NSAttributedString that you want to use now requires the explicit labeling of the string parameter
The UIFont initializer that you are using now returns an optional (i.e., UIFont?), which needs to be unwrapped before you pass it in the attributes dictionary.
Try this instead:
let font = UIFont(name: "Voyage", size: 20.0) ?? UIFont.systemFontOfSize(20.0)
let attrs = [NSFontAttributeName : font]
var attrString3 = NSAttributedString(string: "(Time)", attributes: attrs)
Note the use of the new coalescing operator ??. This unwraps the optional Voyage font, but falls back to the System Font if Voyage is unavailable (which seems to be the case in the Playground). This way, you get your attributed string regardless, even if your preferred font can't be loaded.
Xcode 6.1 comes with Swift 1.1 that supports constructors that can fail. UIFont initialisation can fail and return nil. Also use string: when creating NSAttributedString:
if let font = UIFont(name: "Voyage", size: 20.0) {
let timeFont = [NSFontAttributeName:font]
var attrString3 = NSAttributedString(string: "(Time)", attributes : timeFont)
}
Related
I am trying to grab data from a text field labeled 'temperatureTextField' and assigning it to 't' which is a Double. Ideally the user is meant to add a number value to the temperatureTextField.
Here is my method:
#IBOutlet weak var temperatureTextField: UITextField!
#IBAction func convert(sender: AnyObject) {
let t = Double(temperatureTextField.text!)
let tempM = TemperatureModel(temp: t!)
temperatureTextField.text = String(tempM.toCelsius())
}
The red exclamation is coming from the line "let t = Double(temperatureTex...)"
You're probably using Xcode 6, so Swift 1.2, but the String initializer for Double is only available in Swift 2 (Xcode 7).
You can always use NSString's doubleValue property:
let t = (temperatureTextField.text! as NSString).doubleValue
but I'd recommend using Xcode 7 and Swift 2 as soon as possible.
As Eric suggested, I ran into this issue because I was running an outdated version of xcode.
Here is what my code looked liked after, in case anyone runs into trouble and is unable to update:
let t = (inputText.text! as NSString).doubleValue
let tempModel = TemperatureModel(temp: t)
inputText.text = "\(tempModel.toCelsius())"
Since I am fairly new to Swift programming on OSX, this question may contain several points that needs clarification.
I have a method which iterates over all subviews of a given NSView instance. For this, I get the array of subviews which is of type [AnyObject] and process one element at a time.
At some point I would like to access the identifier property of each instance. This property is implemented from a protocol in NSView named NSUserInterfaceItemIdentification, which type is given in the documentation as (optional) String?. In order to get that identifier I would have written
var view : NSView = subview as NSView;
var viewIdent : String = view.identifier!;
The second line is marked by the compiler with an error stating that identifier is not of an optional type, but instead of type String, and hence the post-fix operator ! cannot be applied.
Removing this operator compiles fine, but leads to a runtime error EXC_BAD_ACCESS (code=1, address=0x0) because identifier seems to be nil for some NSButton instance.
I cannot even test for this property, because the compiler gives me a String is not convertible to UInt8 while I try
if (view.identifier != nil) {viewIdent = view.identifier;}
My questions are
Is the documentation wrong? I.g. the property identifier is not optional?
How can I ship around this problem and get code that runs robust?
If the documentation states that view.identifier is an Optional, it means it can be nil. So it's not a surprise that for some button instances it is indeed nil for you.
Force unwrapping this element that can be nil will lead your app to crash, you can use safe unwrapping instead:
if let viewIdent = view.identifier {
// do something with viewIdent
} else {
// view.identifier was nil
}
You can easily check the type of an element in Xcode: click on the element while holding the ALT key. It will reveal a popup with informations, including the type. You can verify there that your element is an Optional or not.
Tip: you can safe unwrap several items on one line, it's rather convenient:
if let view = subview as? NSView, viewIdent = view.identifier {
// you can do something here with `viewIdent` because `view` and `view.identifier` were both not nil
} else {
// `view` or `view.identifier` was nil, handle the error here
}
EDIT:
You have to remove this line of yours before using my example:
var viewIdent : String = view.identifier!
Because if you keep this line before my examples, it won't work because you transform what was an Optional in a non-Optional by adding this exclamation mark.
Also it forces casting to a String, but maybe your identifier is an Int instead, so you shouldn't use this kind of declaration but prefer if let ... to safe unwrap and cast the value.
EDIT2:
You say my example doesn't compile... I test every answer I make on SO. I tested this one in a Playground before answering, here's a screenshot:
Also, after checking it, I confirm that the identifier is an Optional String, that's the type given by Xcode when using ALT+CLICK on the property. The documentation is right.
So if it's different for you, it means you have a different problem unrelated to this one; but my answer for this precise question remains the same.
How do you invoke HIDictionaryWindowShow in Swift? I try this:
import Carbon
if let text = _dictionaryText, let range = _dictionaryRange
{
let font = CTFontCreateWithName("Baskerville", 16, nil);
let point = CGPoint(x: 0.0, y: 0.0);
var trns = CGAffineTransform();
HIDictionaryWindowShow(nil, text, range, font, point, false, &trns);
}
But getting error
Cannot invoke 'HIDictionaryWindowShow' with an argument list of type
'(nil, String, CFRange, CTFont!, CGPoint, Bool, CGAffineTransform)'
Not seeing the wrong argument here. First and last argument should be allowed to be nil but docs say that NULL is Ok as the first argument which is nil in Swift or is it? As there is no NULL in Swift what do I need to specify instead of it?
Sorry I don't have the Swift code, but you can probably work from the following untested objective-c code. Note that showDefinitionForAttributedString was added to replace HIDictionaryWindowShow which is, as you know, a carbon function and won't be supported forever.
[self.view showDefinitionForAttributedString:[[NSAttributedString alloc] initWithString:text] atPoint:NSMakePoint(0.0, 0.0)];
EDIT:
In looking further the second argument is not correct in your example. Carbon lib does not understand String, it wants CFTypeRef.
My code, that draws an CFAttributedString into a graphic context, used to work fine before the update to Xcode 6.3.
Now, after the upgrade, I get the following errors:
'_' is not convertible to 'CFString!'
and
'[String : AnyObject]' is not convertible to '[String : AnyObject]'
for the lines of code that define the attributes for the string:
let attributes : [String:AnyObject] = [
kCTForegroundColorAttributeName:UIColor.darkGrayColor().CGColor,
kCTFontAttributeName:font
]
This is how I draw the text:
var attrString = CFAttributedStringCreate(nil,myString,attributes)
var line = CTLineCreateWithAttributedString(attrString)
var lineWidth = CTLineGetBoundsWithOptions(line, CTLineBoundsOptions.UseGlyphPathBounds).width
var lineHeight = CTLineGetBoundsWithOptions(line, CTLineBoundsOptions.UseGlyphPathBounds).height
CGContextSetTextMatrix(context, transformScale)
CGContextSetTextPosition(context, (rect.width - lineWidth)/2, rect.height - lineHeight*1.5)
CTLineDraw(line, context)
I tried to cast kCTForegroundColorAttributeName and kCTFontAttributeName with adding "as String" after them. This removed the errors but the strings didn't seem to get the attributes.
I solved the problem by changing the formatting and by replacing kCTForegroundColorAttributeName with NSForegroundColorAttributeName
Here is the fixed line:
let attributes: [String: AnyObject] = [
NSForegroundColorAttributeName : UIColor.darkGrayColor().CGColor,
NSFontAttributeName : font
]
i'm just in playground trying to get this thing to work, but it doesn't want to work for me..
var total = 1234.1234
var formatter = NSNumberFormatter()
formatter.numberStyle = .CurrencyStyle
println("\(formatter.stringFromNumber(total))")
// Returns: "Optional("$1,234.12")" instead of just "$1,234.12"
I want to show just the formatted number to the user but the extra Optional bit keeps showing up.
Since you're just in playgrounds and are sure that the optional contains a value,
you can use forced unwrappping by adding an exclamation mark:
print("\(formatter.stringFromNumber(total)!)")