I have a UIViewController with an xib and using Interface Builder I've added a child UIView.
Within the child UIView, when I click on an object within that view, I want to be able to alter the title of the whole window.
Now I'd normally do that setting
self.title = #"hi";
on the parent UIViewController. But is there any way I can access the parent title from within the child?
I've tried
self.superview.title = #"i";
self.parentViewController.title = #"hi";
but neither work.
Any help much appreciated
thanks
self.superview.title = #"i"; evaluates to an object of type UIView, and UIView has no title property. UIViewControllers have a parentViewController property but UIViews don't.
So the fundamental problem is that you're not properly separating your controller and your view classes. What you'd normally do is make the view you want to catch taps on a subclass of UIControl (which things like UIButton already are, but if it's a custom UIView subclass then you can just change it into a UIControl subclass since UIControl is itself a subclass of UIView), then in your controller add something like:
- (void)viewDidLoad
{
[super viewDidLoad];
// we'll want to know if the view we care about is tapped;
// we've probably set up an IBOutlet to it but any way of
// getting to it is fine
[interestingView
addTarget:self
action:#selector(viewTapped:)
forControlEvents:UIControlEventTouchDown];
// UIButtons use UIControlEventTouchUpInside rather than
// touch down if wired up in the interface builder. Pick
// one based on the sort of interaction you want
}
// so now this is exactly like an IBAction
- (void)viewTapped:(id)sender
{
self.title = #"My new title";
}
So you explicitly don't invest the view with any knowledge about its position within the view hierarchy or how your view controllers intend to act. You just tell it to give you a shout out if it receives a user interaction.
Related
Am new to Mac apps, and am writing one simple app which has a common layout for different sections of the app. Its basically an image with one or two buttons(titles keep varying) in all sections.
So I thought of creating a CustomNSView with one Image Well and two rounded buttons in a new Nib file and in a separate class file (MyCustomView, which is a subclass of NSView) it would load this Nib in initWithframe method. So now when ever I drag drop a custom view and set its class to MyCustomView I get the Image and two buttons instantly without any additional code. But now how would I control these buttons(outlets/actionms) in other View Controllers ? The same view will be used every where so I cannot set files owner in nib to the view controller ?
Is it right in doing so ? Is there any way to create a custom view which would delegate all button actions to which ever view controller its included in ?
You can write your custom delegate. Though using that you can send messages from one object to another
Here's how I would do it. I wouldn't create a CustomNSView, I would create a CustomViewController (with its xib file included). On that CustomViewController, I would design the two buttons and setup CustomViewController.h like so.
#property (nonatomic, weak) id delegate; // Create a delegate to send call back actions
-(IBAction)buttonOneFromCustomVCClicked:(id)sender;
-(IBAction)buttonTwoFromCustomVCClicked:(id)sender;
CustomViewController.m like so.
-(void)buttonOneFromCustomVCClicked:(id)sender {
if ([self.delegate respondsToSelector:#selector(buttonOneFromCustomVCClicked:)]) {
[self.delegate buttonOneFromCustomVCClicked:sender];
}
}
-(void)buttonTwoFromCustomVCClicked:(id)sender {
if ([self.delegate respondsToSelector:#selector(buttonTwoFromCustomVCClicked:)]) {
[self.delegate buttonTwoFromCustomVCClicked:sender];
}
}
In interface builder of your customViewController, link up both button's SentAction event to the two methods (they should be displayed in file's owner).
Then in your otherClass in which you want to load the generic custom view, instantiate the generic view controller like so.
#import "customViewController.h"
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
customViewController *newCustomViewController = [[ViewController alloc] initWithNibName:#"customViewController" bundle:nil];
[newCustomViewController setDelegate:self];
self.backGroundView = [newCustomViewController view]; // Assuming **backGroundView** is an image view on your background that will display the newly instantiated view
}
-(void)buttonOneFromCustomVCClicked:(id)sender {
// Code for when button one is clicked
}
-(void)buttonTwoFromCustomVCClicked:(id)sender {
// Code for when button two is clicked
}
I'd like to set up a custom NSView in Interface-Builder, but I don't get it to work for OSX.
In my ViewController's .xib, I added a custom view and set the Class to MyCustomView. I created MyCustomView.h, MyCustomView.m and MyCustomView.xib.
In MyCustomView.xib, I set the Class to MyCustomView as well. In MyCustomView.m, - (void)awakeFromNib is called, but - (id)initWithCoder:(NSCoder *)aDecoder and - (id) awakeAfterUsingCoder:(NSCoder*)aDecoder aren't.
What I'd like to achieve is that in my ViewController, the view I added is "filled" with the view I set up in MyCustomView.xib. What's the best way to do that?
EDIT: I don't think I was clear enough...
I've got my ViewController containing a Custom View called MyCustomView.
This view should be of type MyCustomView, where
MyCustomView.h
MyCustomView.m
MyCustomView.xib
exists. I already set the File's Owner of MyCustomView.xib to MyCustomView and I already set the CustomView in my ViewController to MyCustomView - but it doesn't work.
If I do it with
- (void)awakeFromNib {
NSString* nibName = NSStringFromClass([self class]);
NSArray* topLevelObjects;
[[NSBundle mainBundle] loadNibNamed:nibName
owner:nil
topLevelObjects:&topLevelObjects];
NSView* view = topLevelObjects[0];
[view setFrame:[self bounds]];
[self addSubview:view];
}
I only get a view of type NSView, not MyCustomView... Is there no easy way to tell the ViewController.xib that it's a MyCustomView?
EDIT 2: I uploaded a simple project
At https://dl.dropboxusercontent.com/u/119600/Testproject.zip you find a simple project with the MyCustomView (not in a ViewController but in the window.xib) - but it doesn't show the button which is in MyCustomView.xib. I'd like to achieve exactly that - what's the simplest, best way?
EDIT - apologies, my existing answer failed to take into account the need to connect outlets and actions. This way should do it...
Given the files...
MyCustomView.h
MyCustomView.m
MyCustomView.xib
In MyCustomView.h
declare IBOutlets for your interface elements. You need at least one, to hold a pointer to the top-level view in the xib file
#property (nonatomic, strong) IBOutlet NSView *view;
In MyCustomView.xib
ensure that there is only one top-level view
set file's owner class to MyCustomView in the Identity Inspector
ensure that the top-level view is set to the default NSView class.
now you can connect IBOutlets declared in MyCustomView.h to interface objects in the xib file. At very least you need to connect up the top-level view to your view outlet.
In MyCustomView.m:
- (id)initWithFrame:(NSRect)frame
{
NSString* nibName = NSStringFromClass([self class]);
self = [super initWithFrame:frame];
if (self) {
if ([[NSBundle mainBundle] loadNibNamed:nibName
owner:self
topLevelObjects:nil]) {
[self.view setFrame:[self bounds]];
[self addSubview:self.view];
[self.myCustomButton setTitle:#"test success"];
}
}
return self;
}
In your window's xib file, add a custom NSView and change it's class to MyCustomView.
in OSX prior to 10.8 the method loadNibNamed was a class method - use it instead if you need backwards compatibility, but it is deprecated now:
[NSBundle loadNibNamed:#"NibView" owner:self]
Note that MyCustomView.xib's view is NOT MyCustomView's view, but the sole subview of it's view (this is similar to the way a tableViewCell possesses a single contentView).
In the project sample you have posted, you need to make the following changes:
in MyCustomView.h
. add an NSView property
in MyCustomView.xib:
. change the top-level view from MyCustomView custom class to NSView (the default)
. set the File's Owner to MyCustomView.
. connect IBOutlets from File's owner's view and myCustomButton to interface view and button
. for testing make the view a lot smaller and push the button up to the top right (you won't see it in your window as it is here)
in MyCustomView.m:
. replace all of your implementation code with the initWithFrame method here
In order to load a custom subclass of a view or a control (or any other class that can be used in Interface Builder for that matter), you need to add the base version (NSView in your case, and as you have done), then select that object in the window and go to the Identity Inspector (Cmd-Opt 3).
Instead of the pre-defined value for Class (NSView, in your case), type in the name of your custom subclass. Voilà!
A small detail related to the IB UX is that you'll probably have to move the focus from the input field in order for that change to be registered when you build and run the app.
I'm new to Xcode and objective c. I want to create a button (probably a UIBarButtonItem, for a navigation bar) with a particular appearance, which I will use repeatedly in different views. I've searched at length but can't figure out how.
Would it be appropriate to subclass UIBarButtonItem? I tried to do that, but I was quickly in over my head. Once I create the .h and .m files as a subclass of UIBarButtonItem, do I then have to instantiate a UIBarButtonItem? Do those files not automatically create a button object for me (imported from the parent class), which I can refer to as self? It seems like it would be weird to instantiate a button within its own subclass.
One thing I want to do is add the line,
button.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
but I'm at a loss as to how to create reusable button with that property.
Even if that is completely the wrong approach to creating a reusable custom button, I clearly need to improve my understanding of objects, so explanation of my misunderstandings would be much appreciated!
Please?
You can do this without subclassing - by making a category (a preferred way of doing things in Objective-C). With a category you can provide custom methods for an object without having to subclass it. You can't (easily) provide custom properties, but in your case this is not relevant.
Using a Category
This is how your category header file could look:
// UIButton+StyledButton.h
#import <UIKit/UIKit.h>
#interface UIButton (StyledButton)
- (void) styleButton;
#end
Then in the implementation file:
//
// UIButton+StyledButton.m
//
#import "UIButton+StyledButton.h"
#implementation UIButton (StyledButton)
- (void) styleButton {
//style your button properties here
self.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
}
('self' refers to the button object, which also acquires the custom methods you write in the category.)
To use it, #import "UIButton+StyledButton.h" then you can do this sort of thing...
on viewDidLoad {
[super viewDidLoad];
UIButton* myButton = [[UIButton alloc] initWithFrame:myFrame];
[myButton styleButton];
}
Using a Subclass
The subclassed equivalent would look something like this:
The header file...
// MyCustomButton.h
#import <UIKit/UIKit.h>
#interface MyCustomButton : UIButton
- (id)initWithCoder:(NSCoder *)coder;
- (id)initWithFrame:(CGRect)frame;
#end
The implementation file...
// MyCustomButton.m
#import "MyCustomButton.h"
#implementation MyCustomButton
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self styleButton];
}
return self;
}
- (id)initWithCoder:(NSCoder *)coder
{
self = [super initWithCoder:coder];
if (self) {
[self styleButton];
}
return self;
}
- (void) styleButton {
//style your button properties here
self.titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
}
You provide two init methods - initWithFrame is the method to call when alloc/initing the object in code; initWithCoder is the init method called by the system if loading the object from a storyboard or xib.
To create one of your custom buttons in code, you alloc/init as you would any other object:
MyCustomButton* button = [[MyCustomButton alloc] initWithFrame:buttonFrame];
You wouldn't also alloc/init the superclass instance, this is done by the initWithFrame: method in the subclass when it calls [super initWithFrame:frame]. self refers to your custom subclass instance, but that includes all of the (public) properties and methods from it's superclass - unless you have implemented overrides in the subclass.
To use your subclassed button in a storyboard/xib, just drag out a regular button then set it's type to your custom button class in the Identity Inspector. The initWithCoder method is called automatically when the button is loaded from the storyboard/xib into a view.
update
From your comments, you seem to harbour a few confusions still, so here are some highly compressed de-obfuscating notes...
Keep away from subclassing UINavigationController unless you really know what you are doing. It's rarely necessary.
The buttons on a navController's interface are properties of it's contained viewControllers. Look up the navigationItem property of UIViewController (similarly - in the case of a UIToolbar - the View Controller has a toolbarItems property). This allows Navigation Controllers to be context-aware.
The 'viewDidLoad' in my example is assumed to be in a regular UIViewController. My example is also a category on the regular UIBUtton which has no formal relationship with UIBarButtonItem.
Try getting a UIButton category to work with a regular ViewController first before experimenting with UIBarButtonItem (which does not inherit from UIButton).
UIBarbuttonItem has no initWithFrame, because the thing that organises the bar (UINavigationBar or UIToolbar) - in this case a Navigation Controller - is responsible for it's ultimate size and positioning. The viewController governs the relative order of barButtonItems, and whether they appear on the left or the right, and the content and (some aspects of) it's appearance, but the rest is up to the NavController.
I'm using an NSCollectionView to display various objects. The whole things works rather well, except for one annoying thing. I cannot figure out how to access the various controls on the view used to represent each object in the collection.
Here's the setup:
I have dragged an NSCollectionView into my view in IB.
I made a custom subclass of NSCollectionViewItem. Mapped my class in IB.
I made a custom subclass of NSBox to act as the view for each object in the collection. Also mapped this class in IB and connected it to the view property of my NSCollectionViewItem subclass.
I made all the bindings in IB to display the correct information for each object.
The view:
The resulting collection view:
Reasoning that that my subclass of NSCollectionViewItem is basically a controller for each view in the collection, I made referencing outlets of the various controls in the view in my controller subclass:
#interface SourceCollectionViewItem : NSCollectionViewItem
#property (weak) IBOutlet NSTextField *nameTextField;
#property (weak) IBOutlet NSTextField *typeTextField;
#property (weak) IBOutlet RSLabelView *labelView;
#property (weak) IBOutlet NSButton *viewButton;
#end
When I inspect any instance of SourceCollectionViewItem in the debugger, all the properties show up as nil despite the fact that I can actually see them on my screen and that everything is displayed as it should be.
My setup was inspired by Apple's sample app IconCollection.
I am obviously missing something. What?
EDIT: I found various posts hinting at a similar issue:
CocoaBuilder.com and this question on SO.
EDIT: Just to be complete: this post deals with the subject as well and delivers a solution based on a combination of the options mentioned in the accepted answer.
Outlets are set during nib loading, and only the prototype item is loaded from nib and has its outlets assigned. All other ViewItems and their Views are cloned from the prototype, in that case outlets are just instance variables that are never initialized.
Here are the options I could come up with:
Override newItemForRepresentedObject: of collection view and reload nib instead of cloning the prototype. But this will probably hurt the performance greatly.
Override copyWithZone of collection view item and assign outlets manually using viewWithTag: to find them.
Give up and try to provide data via bindings only.
I found that overriding NSCollectionViewItem's -setRepresentedObject: could also be a good choice, as it is called on the new Item when all IBOutlet seem to be ready. After the call to super you can do whatever is needed:
- (void)setRepresentedObject:(id)representedObject
{
if (representedObject) {
[super setRepresentedObject:representedObject];
[self.anOutlet bind:#"property" toObject:self.representedObject withKeyPath:#"representeProperty" options:nil];
}
}
I used this method to bind a custom property of an interface object. The check is there to avoid useless calls, when the representedObject is not yet ready. The project uses a separate xib for the ViewItem, as explained in the links in the original edits.
Great question. Like #hamstergene suggests, you can use copyWithZone, it will be much more efficient compared to newItemForRepresentedObject. However viewWithTag is not always an option, first, because not everything can be tagged (easily), and, second, using tag for this purpose is a little wrong. Here's a cool approach with performance in mind, in Swift.
import AppKit
class MyViewController: NSCollectionItemView
{
// Here you are cloning the original item loaded from the storyboard, which has
// outlets available, but as you've seen the default implementation doesn't take
// care of them. Each view has a unique identifiers, which you can use to find it
// in sublayers. What's really cool about this, is that you don't need to assign
// any tags or do anything else while having advantage of better performance using
// cached nib object.
override func copyWithZone(zone: NSZone) -> AnyObject {
let copy: NSCollectionItemView = super.copyWithZone(zone) as! NSCollectionItemView
let oldView: RecordingView = self.view as! MyView
let newView: RecordingView = copy.view as! MyView
newView.foo = newView.viewWithIdentifier(oldView.foo.identifier!) as! NSTextfield
newView.bar = newView.viewWithIdentifier(oldView.bar.identifier!) as! NSImageView
return copy
}
}
#IBDesignable class MyView: View
{
// Custom collection view item view. Lets assume inside of it you have two subviews which you want
// to access in your code.
#IBOutlet weak var foo: NSTextfield!
#IBOutlet weak var bar: NSImageView!
}
extension NSView
{
// Similar to viewWithTag, finds views with the given identifier.
func viewWithIdentifier(identifier: String) -> NSView? {
for subview in self.subviews {
if subview.identifier == identifier {
return subview
} else if subview.subviews.count > 0, let subview: NSView = subview.viewWithIdentifier(identifier) {
return subview
}
}
return nil
}
}
Since UIViewController navigationItem outlets are deprecated (yes, I'm a bit behind), what is the correct idiom specifying the elements of a UINavigationItem?
I've seen several approaches suggested, but none are entirely clear to me:
"Embed the navigation item in the view controller" in the view controller's XIB.
Initialize the navigation item's properties in code, with from-scratch values.
Create an outlet for the navigation controller in the view controller, wire up a navigation item in the view controller's XIB, and use its properties to initialize the (actual) navigation item's properties in code.
It isn't clear to me how to "embed" the navigation item (simply adding it as a child of the view controller in IB has no effect); and it isn't clear to me which of these approaches is better, or, for that matter, where (in what method) to do 2 or 3.
1) If controller is created in XIB you can drop UINavigationItem on it and tweak this item - it will work. For example when you're defining UINavigationControler in XIB you can put some controller inside as root view controller. So you can have UINavigationItem for this controller in XIB.
2) If controller loads it's view from XIB (it was created by alloc and then init or initWithNibName:bundle:) it's presented in XIB only as File's Owner which doesn't support UINavigationItem in it. In this case you should configure navigation item in code (I do it in viewDidLoad usually). There is no need to create it, it's already there in navigtionItem property of your controller
self.navigationItem.title = #"Price List";
Maybe it's possible to make outlet for navigation item but I wouldn't recommend this. Apple declared such outlet obsolete for a reason. I remember discussing this with co-worker one day, but I forgot what it was (it was obvious then).
On our project we have a requirement to make UI be as customizable from IB as possible.
So, I add UINavigationItem to xib, configure it, link it as outlet to my custom UIViewController subclass, and then copy all properties at runtime with method added to UIViewController using category:
- (void)setNavigationItemPropertiesFromOtherItem:(UINavigationItem *)navItem
{
// WORKAROUND: we can't link UINavigationItem to UIViewController from IB, and navigationItem property in UIViewController is readonly
self.navigationItem.title = navItem.title;
self.navigationItem.prompt = navItem.prompt;
self.navigationItem.hidesBackButton = navItem.hidesBackButton;
if (navItem.backBarButtonItem != nil)
{
self.navigationItem.backBarButtonItem = navItem.backBarButtonItem;
}
if (navItem.leftBarButtonItem != nil)
{
self.navigationItem.leftBarButtonItem = navItem.leftBarButtonItem;
}
if (navItem.rightBarButtonItem != nil)
{
self.navigationItem.rightBarButtonItem = navItem.rightBarButtonItem;
}
if (navItem.titleView != nil)
{
self.navigationItem.titleView = navItem.titleView;
}
}
This workaround also allows to link bar button items to UINavigationItem using IB.