I've got a cocoa application that reads in a text file. I'd like to display that text in a multi-line label, but I for the life of me can't figure it out. I opened up my .nib file and poped a multi-line label down but after that I'm stuck.
I don't have any experience working with Xcode or Cocoa, mostly Eclipse, Visual Studio, and pretty much every other IDE except Xcode which seems very foreign.
If you have the text in an NSString, you can easily put it in the label.
First, in the .h file (or header) of your controller class, create a new IBOutlet so you can refer to the label:
IBOutlet NSTextField *myLabel;
Go into the .xib file where the label is. Control-drag from the controller object to the label, and select the "myLabel" option to apply it to that specific label.
Then, in the method where you want to put the text in the label, type the following:
[myLabel setStringValue:myString]; (where "myString" is your NSString)
Note: This is all assuming you know how to do basic things like controller classes- if not, I'd definitely check out Cocoa Dev Central (http://www.cocoadevcentral.com/.)
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I have working program with Wrapping Text Fields, and I would like to add vertical scrolling. I have found that there is Text View object in xcode library and it has NSTextView in NSScrollView. The problems came when I simply tried to substitute Text Fields with Text View. First, when I made outlet, this outlet belongs to NSScrollView (no NSTextView), and NSScrollView doesn't have String type, which I need for working code. Second, when I deleted NSScrollView (I don't know if it was right to do this) and typed instead NSTextView in outlet, I could use type string, but code didn't work. What I did wrong, what should I do ?
Add an UITextView
Drag an outlet from it to your class
Make this class implement UITextViewDelegate
In code, set this text views delegate to this class
It is really simple, I'm confused by steps you took to try to get it working.
I am learning Stanford CS193p course with Xcode 4.3.3. I think the screenshot below is pretty much self-explaining. But i will describe the problem with words anyway.
I control-drag a UILabel from storyboard to corresponding implementation file to make the IBOutlet #property. Then I see two connections displayed when clicking the filled circle in the left side of the editor where shows line numbers. I don't know how to delete it.
Moreover, I see only ONE connection in storyboard's connections inspector of the UIlabel.
More weird, when I try to set the UILabel's text inside the setter of a public preperty, it fails to update the label's text:
-(void) setQuestion:(NSString *)question
{
_question = question;
self.questionLabel.text = question;
NSLog(#"The quesion is %#",question);
NSLog(#"The quesion label text is %#",self.questionLabel.text);
}
I use two NSLog to debug and get the following. It shows the NSString *question is #"What do you want your label to say?", yet the self.questionLabel.text is null. The value assign fails. I suspect this relate to the duplicated connections thing mentioned above.
2012-07-29 04:03:53.817 Kitchen Sink[18628:f803] The quesion is What
do you want your label to say?
2012-07-29 04:03:53.820 Kitchen
Sink[18628:f803] The quesion label text is (null)
The following is the screenshot showing the duplicated connections. I am probably missing something obvious, please help.
I would stalk this up to Xcode storyboard wonkiness.
First, try a clean of the project and a re-build.
Should you still have that problem, manually define the #property without dragging from the AskerViewController view to the AskerViewController implementation (.m) file by doing the following.
Cut that IBOutlet #property line in the interface section of the implementation (.m) file for AskerViewController. Click the label in storyboard. Disconnect any binding that label to the AskerViewController. Clean the project. Then, paste back in the property, and control-drag from the label to the view controller orb at the bottom of the AskerViewController view in your storyboard file.
So I'm just trying to create a very simple app for demo purposes here:
Created a Single View Application, using storyboards
Added a UIView to the storyboard
Added the following code to my controller's header file:
#property (weak, nonatomic) IBOutlet UIView *myView;
Now, I understand that I can link the UIView to the controller by:
arranging my code such that the header file is next to the storyboard
holding down Ctrl key and dragging it to the property in the header file
My question is this: can I do this without Ctrl-drag? And if so, how?
More specifically - it's annoying to have to put both my header file and storyboard on screen at the same time, and it seems there should be a way to make this connection without doing so.
I also understand that I can manually place the view by creating it inside my controller's viewDidLoad function, but I'd really like to use the interface builder to simplify / visualize things.
Edit: Is the answer to my question affected whether I use storyboards or xib/nib files? (I'd switch to use the one where it works)
you should be able to right click the element, and drag the "referencing outlet" item to the view's "File's Owner" in interface builder. There, it will give you a list of all available IBOutlets (matching the object's type).
In addition to Dima's answer, you can just as well use the Connection inspector in the Utilities pane
I have been struggling quite a bit with this problem and I can't seem to figure it out by myself.
This is the situation:
I want to have a custom Nib-based view, with its own ViewController. I then want to add this view to a window. Therefore the window should contain my custom view.
So I go about and create a very simple example like this:
In Xcode 4 I create a new blank document-based Cocoa application
I create a new Cocoa Class which should extend from NSViewController (which causes the nib to be created along with the .h and .m file. The name of the created .h, .m und .xib file is FaceViewController for testing purposes it should only display text for now.
I open the NSViewController.xib in InterfaceBuilder and add a multi-line text component and place it in the custom view, which is already in the xib file. I make the text span the whole view.
In MyDocument.xib I also add a Custom View place holder, which should be replaced with my custom FaceView.
From this starting point on, everything I tried to include the created View + ViewController on my MyDocument.xib failed and the area where my text should be shown remains empty (just like the background of the underlying window.
So my question really is what I need to do, so that my FaceView gets loaded into the Custom View which I placed on MyDocument.xib. Here are some things which are unclear to me:
The custom View extends from NSView so I wanted to change this to my FaceView but the view does not exist as a class but is defined in InterfaceBuilder in the xib, do I need to set this to anything other than NSView?
Do I have to alloc, init the FaceViewController in code or is it enough to drag it into either of my two .xibs?
Can I use InterfaceBuilder to place my FaceView or do I have to do this programmatically?
I really thought that creating a custom view like this would be a piece of cake but it turned out quite the opposite so far, so any help would be greatly appreciated.
You can create your FaceViewController either by adding one to the MyDocument.xib or by creating it with alloc, init.
To place your FaceView you'll have to do it programmatically, you can use
[customView addSubview:[FaceViewController view]];
of if you want to replace the view
[customView replaceSubview:oldView with:[FaceViewController view]];
I just created a new Xcode project. In the AppControl class Header file I have the following objects defined (and some other ones, too):
IBOutlet NSImageView *inputImageView;
IBOutlet NSImageView *outputImageView;
IBOutlet NSTextField *myNoiseLevel;
IBOutlet CGFloat *mySharpness;
After putting the basic code into the .h and .m files, I then went into Interface Builder and created my UI. I was able to bind the two NSImageView controls in IB to the corresponding NSImageView objects listed above. And I was able to bind a couple of other objects/controls, also. But I am NOT able to bind the last two items listed (myNoiseLevel and mySharpness) to the NSSlider controls I have on the application main window. I'm not sure why. I know this kind of thing is probably hard to diagnose, because it is not "strictly code related," but if there is something "tricky" about binding sliders please let me know what the main "suspects" are that I should check.
This is my first attempt to use a slider control through IB. I have a book (Cocoa programming for Mac OS X, 3rd ed., by A. Hillegass) that I am using to learn about the basic way to do this stuff. And he has a slider example in there. But his slider example is "continuous" and it uses key path binding. I think this is overkill for what I want/need to do -- I just want to pull the value from the slider when another button is pushed (no need for "continuous" update). So I am trying to directly bind the "outlets" listed when I right-click on my App Control object (one for each of those items shown above), to the slider controls on my window. But when I cntl-drag from the AppControl outlet up to the corresponding slider, the slider will not "accept" the arrow I'm dragging.
Does this make sense? Any idea what I'm doing wrong and/or what I need to do to make the binding work? I have tried saving / building / closing & reopening IB and Xcode -- all to make sure IB has the latest version of everything. Still no luck, though.
One last thing ... What I really need are CGFloat numbers, from the slider. Can I simply declare the Outlet as CGFloat type ... or do I need to define it as NSTextField (or something else), and then convert it to Float in my program? You can see in the IBOutlets I pasted above, that I was trying different data types for the outlets (trying to see if my defining them as CGFloat was somehow preventing the bindings).
Make the outlet an NSSlider*. You should then be able to connect to it. When you need the value (eg, in response to the button press you mention) call [yourSliderOutletName doubleValue].
More generally: an IBOutlet is an ivar that can be filled in with a pointer to the actual object awoken from a NIB file. As such, it needs to be of an appropriate type to hold that pointer -- the object's actual class, or one of its superclasses or protocols, or (least informatively) id. You can't just arbitrarily connect an object to any old variable, like your CGFloat. There's no implicit conversion -- how is the system supposed to know what you want?