If you add something to the xib file in an xcode project, you can in fact make them generate little snippets in your code for things like event handlers.
what isn't generate however is some code that actually creates the object, assigns it to a viewport, initialises it etc. My question is, where is this code? is it hidden in the xib file?
and also, if I wanted to do all this myself programatically, what would it look like and where would i put it, for example in the open gl template xcode comes with?
I don't know where the code is but it's abstracted so you don't have to deal with it. You would put it in a ViewController file if you were to do it in code.
You would need something like;
CGRect viewRect = CGRectMake(0, 0, 100, 100);
UIView* myView = [[UIView alloc] initWithFrame:viewRect];
The following link explains how to deal with views in code.
http://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/ViewPG_iPhoneOS/CreatingViews/CreatingViews.html
Interface Builder/Xcode doesn't generate code for the interface. Each xib contains the interface in serialized form (currently this is an xml like file, but note that this can change at any time! Also its converted to byte data file during compilation). At runtime a parser will read the file and create all the elements, hook everything up using KVC and then you have your interface.
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Today I'm writing my first "Hello World" application for iOS. And I wondered how can I manipulate .xib files programmatically similar to Android XML layout files or XAML? I also want Interface Builder dynamically display changes. For example I have a .xib file "LoginPageView.xib", where I have buttons and other controls which I added via Interface Builder constructor, then I connect this .xib to the private class extension of "LoginPageViewController" in .m file. And now I want to add a new button programmatically: UIButton *button = [[UIButton alloc] initWithCGRect:...]; or I want to change button's background and so on. The only way I know is to implement it in viewDidLoad method but if I do this my changes will display only when program run and I want Interface Builder dynamically display these changes before compiling. So the question is there some way in Xcode IDE to implement this and instructions how to do this?
The short answer is no, this is not possible. The long answer is that you could possibly implement such a thing by reverse engineering the .xib file format (which is XML), and figuring out how to write it yourself. It would be far more trouble than it is worth.
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.
Closed 11 years ago.
I have an iphone app ready and approved by the app store. Now I want to create different themes for my app. Can someone please help me out, with info/links/steps on how to create themes for my app?
I want to create a Metal theme for the Boys and a Pink theme for the Girls. Again by theme I mean, the whole app(features and functionality) is gonna stay the same, but depending on who the user is(boy or girl), he/she can choose the theme they wish to see. And when the theme changes, only the images/Background/music will change according to the applied theme.
Thanks a lot!
This is quite difficult as apps don't have the equivalent of a css stylesheet.
First you need to work out what parts of the app you want to skin, and when you want to allow the user to swap skins.
I'm going to assume that you want to change images and font colours, and that it's okay if the user has to relaunch the app to change the skin (that will make things simpler for now).
Create a plist containing all your skinnable images and colours. The plist will be a dictionary with sensible, theme neutral key names for the images and colours (e.g. don't have a colour called "red", call it "primaryHeadingColor"). Images will be file names, and colours can be hex strings, e.g. FF0000 for red.
You'll have one plist for each theme.
Create a new class called ThemeManager and make it a singleton by adding the following method:
+ (ThemeManager *)sharedManager
{
static ThemeManager *sharedManager = nil;
if (sharedManager == nil)
{
sharedManager = [[ThemeManager alloc] init];
}
return sharedManager;
}
The ThemeManager class will have an NSDictionary property called "styles", and in the init method you will load the theme into your styles dictionary like this:
- (id)init
{
if ((self = [super init]))
{
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *themeName = [defaults objectForKey:#"theme"] ?: #"default";
NSString *path = [[NSBundle mainBundle] pathForResource:themeName ofType:#"plist"];
self.styles = [NSDictionary dictionaryWithContentsOfFile:path];
}
return self;
}
(Note: some people don't like doing a lot of work inside an init method. I've never found it to be an issue, but if you prefer, create a separate method to load the themes dictionary and call it from your app's setup code).
Notice how I'm getting the name for the theme plist from user defaults. That means the user can select a theme in your preferences and save it and the app will load that theme next time it is launched. I've put in a default theme name of "default" if no theme is selected, so make sure you have a default.plist theme file (or change the #"default" in the code to whatever your default theme plist is actually called).
Now that you've loaded your theme you need to use it; I'm assuming your app has various images and text labels. If you're loading and laying those out in code then this part is easy. If you are doing it in nibs then it's a bit trickier but I'll explain how to handle that later.
Now normally you would load an image by saying:
UIImage *image = [UIImage imageNamed:#"myImage.png"];
But if you want that image to be themable, you'll now need to load it by saying
NSDictionary *styles = [ThemeManager sharedManager].styles;
NSString *imageName = [styles objectForKey:#"myImageKey"];
UIImage *image = [UIImage imageNamed:imageName];
That will look in your theme file for the themed image that matches the key "myImageKey" and will load it. Depending on which theme file you've loaded you'll get a different style.
You'll be using those three lines a lot so you may want to wrap them up in a function. A great idea would be to create a category on UIImage that declares a method called something like:
+ (UIImage *)themeImageNamed:(NSString *)key;
Then to use it you can just replace any calls to [UIImage imageNamed:#"foo.png"]; with [UIImage themeImageNamed:#"foo"]; where foo is now the theme key instead of the actual image name.
Okay, so that's it for theming your images. To theme your label colours, suppose you're currently setting your label colours by saying:
someLabel.color = [UIColor redColor];
You would now replace that with:
NSDictionary *styles = [ThemeManager sharedManager].styles;
NSString *labelColor = [styles objectForKey:#"myLabelColor"];
someLabel.color = [UIColor colorWithHexString:labelColor];
Now you may have noticed that UIColor doesn't have a method "colorWithHexString:" - you'll have to add that using a category. You can Google for "UIColor with hex string" solutions to find code to do that, or I've written a handy category that does that and a bit more here: https://github.com/nicklockwood/ColorUtils
If you've been paying attention you'll also be thinking that instead of writing those three lines over and over, why not add a method to UIColor called:
+ (UIColor *)themeColorNamed:(NSString *)key;
Just like we did with UIImage? Great idea!
So that's it. Now you can theme any image or label in your app. You could use the same trick to set the font name, or any number of other potentially themable visual properties.
There's just one tiny thing we've forgotten...
If you've built most of your views as nibs (and I see no reason why you wouldn't) then these techniques aren't going to work because your image names and font colours are buried inside impenetrable nib data and aren't being set in your source code.
There are a few approaches to solve this:
1) You could make duplicate themed copies of your nibs and then put the nib names in your theme plist and load them from your theme manager. That's not too bad, just implement the nibName method of your view controllers like this:
- (NSString *)nibName
{
NSDictionary *styles = [ThemeManager sharedManager].styles;
return [styles objectForKey:NSStringFromClass([self class])];
}
Notice my neat trick of using the class name of the view controller as the key - that will save you some typing because you can just make a base ThemeViewController with that method and have all your themable view controllers inherit from it.
This approach does mean maintaining multiple copies of each nib though, which is a maintenance nightmare if you need to change any screens later.
2) You could make IBOutlets for all of the imageViews and labels in your nibs, then set their images and colors in code in your viewDidLoad method. That's probably the most cumbersome approach, but at least you don't have duplicate nibs to maintain (this is essentially the same problem as localising nibs btw, and pretty much the same solution options).
3) You could create a custom subclass of UILabel called ThemeLabel that automatically sets the font color using the code above when the label is instantiated, then use those ThemeLabels in your nib files instead of regular UILabels by setting the class of the label to ThemeLabel in Interface Builder. Unfortunately if you have more than one font or font colour, you'll need to create a different UILabel subclass for each different style.
Or you could be devious and use something like the view tag or accessibilityLabel property as the style dictionary key so that you can have a single ThemeLabel class and set the accessibility label in Interface Builder to select the style.
The same trick could work for ImageViews - create a UIImageView subclass called ThemeImageView that, in the awakeFromNib method replaces the image with a theme image based on the tag or accessibilityLabel property.
Personally I like option 3 best because it saves on coding. Another advantage of option 3 is that if you wanted to be able to swap themes at runtime, you could implement a mechanism where your theme manager reloads the theme dictionary, then broadcasts an NSNotification to all the ThemeLabels and ThemeImageViews telling them to redraw themselves. That would probably only take about an extra 15 lines of code.
Anyway, there you have a complete iOS app theming solution. You're welcome!
UPDATE:
As of iOS 5, it's now possible to set custom attributes by keyPath in Interface Builder, meaning that it's no longer necessary to create a view subclass for each themable property, or abuse the tag or accessibilityLabel for selecting styles. Just give your UILabel or UIImageView subclass a string property to indicate which theme key it should use from the plist, and then set that value in IB.
UPDATE 2:
As of iOS 6, there is now a limited skinning system built into iOS that allows you to use a property called the UIAppearance proxy to skin all instances of a given control class at once (there's a good tutorial about the UIAppearance APIs here). It's worth checking if this is sufficient for your skinning needs, but if not, the solution I outlined above still works well, and can be used instead, or in combination with UIAppearance.
So here is what my interface looks like at the moment:
Here is what I have changed it to in Interface Builder:
This is what is shown after I run it in Xcode:
Obviously the two programs are not communicating - if someone could point me in the right direction it would be great.
Thanks heaps!
If stuff isn't in sync, try cleaning your build. Product>Clean should do the trick.
The programs communicate through the NIB/XIB files. Make sure you have saved your changes from Interface Builder before rebuilding in XCode (this does not happen automatically). Also double check that the file Interface Builder is editing is the exact same file (not a copy) of the one in your XCode project.
Hope this helps.
This happens if you rename a nib but forget to change name of nib name passed in to a ViewController in its initWithNibName: bundle initialiser.
For example. If I have a nib named ViewOne.xib which I'm passing in to a ViewController like this:
ExampleViewController *exampleViewController = [[ExampleViewController alloc] initWithNibName:#"ViewOne" bundle:nil];
And I change the name of the nib to ViewTwo, Xcode isn't smart enough to amend this reference in the initialiser, so now a xib that noi longer exists is being passed in to the ViewController. For reasons that I cannot fathom, despite the fact there is no longer a nib called ViewOne.xib, Xcode maintains some sort of ghost of the file and you won't get an error because of the missing nib. Cleaning and deleting derived data did not get rid of this ghost reference, at least in my case.
The fix is easy - just amend the nib name in the initialiser to your new name:
ExampleViewController *exampleViewController = [[ExampleViewController alloc] initWithNibName:#"ViewTwo" bundle:nil];
I'm having an issue with creating new windows in Cocoa.
Hypothetically speaking, let's say I have "WindowA" and has a button called "myButton".
When you click on "myButton", it runs this code in the following class file:
-(void)openFile2:(id)sender
{
myNextWindow = [[TestWindowController alloc] initWithWindowNibName:#"MainMenu"];
NSString *testString = #"foo";
[myNextWindow showWindow:self];
[myNextWindow setButtonText:testString];
}
The code in a nutshell makes a duplicate "WindowA" and shows it. As you can see, this code also runs a method called 'setButtonText', which is this:
- (void)setButtonText:(NSString *)passedText
{
[myButton setTitle:passedText];
}
The problem is that when I call this method locally, in the original window - the button text changes (e.g., [self setButtonText:testString]) it works. However, it does not work in the newly created window (e.g., [myNextWindow setButtonText:testString];)
When I debug the newly created window, step by step, the 'myButton' value it gives is 0x0. Do I have to manually assign controllers/delegates to the new window? I think the 'myButton' in the code isn't associated to the 'myButton' in the newly created window.
How would I fix this problem?
The first problem is that you are loading the MainMenu NIB/XIB repeatedly. That will do Very Bad Things -- the MainMenu should only be loaded once at application startup.
You want to break out any UI that needs to be loaded repeatedly into a separate NIB/XIB file (the same way a document based application has a MainMenu.xib and Document.xib files).
To properly do this, you need to understand the concept of "File's Owner" and how to leverage it properly. Note that there is also overlap with window controllers and understanding those, if you want to use them, will be helpful.
I have a table that I created within xcode so there is no nib file in this case. I want to make my table into the 'Grouped' style but im not sure how.
I think it has somthing to do with the method below, the problem is Im not really sure how to call it, I do understand how methods work I'm just not too sure on where to start with this one:
- (id)initWithFrame:(CGRect)frame style:(UITableViewStyle)UITableViewStyleGrouped
So could someone tell me how to call it? The problem is that its not a method I wrote its a built in one so I could put that line into my header file but how would I use it in my implementation file?
Thanks guys,
It sounds like you need to get a better understanding of how objective-c works. What you have given us is not a method, but a method declaration. In your controllers viewDidLoad:, you would do something like:
table = [[UITableView alloc] initWithFrame:self.view.frame style:UITableViewStyleGrouped];