I'm looking into a project that would upload custom NSBundles that include a NSViewController. In my main program I've got this code to deal with the bundle after it's been loaded...
id principalClass = [loadedBundle principalClass];
id instance = [[principalClass alloc] init];
[localLabel setStringValue:[instance name]];
NSView *incomingView = [[instance viewController] view];
[localView addSubview:incomingView];
[localView display];
And the principal classes init method in the bundle looks like this...
-(id) init {
if(self = [super init]){
name = #"My Plugin";
viewController = [[ViewController alloc] initWithNibName:#"View" bundle:nil];
}
return self;
}
View.nib is a nib located in the bundles project. But whenever I load the bundle I get this error...
2010-05-27 09:11:18.423 PluginLoader[45032:a0f] unable to find nib named: View in bundle path: (null)
2010-05-27 09:11:18.424 PluginLoader[45032:a0f] -[NSViewController loadView] could not load the "View" nib.
I know I've got everything wired up because the line [label setStringValue:[instance name]]; sets the label text correctly. Plus, if I take all of the clases in the bundle and load them into my main applications project everything works as expect. Any thoughts on how I can correctly reference "View" in my bundle?
Thanks!
In the init method, you shouldn't pass nil to the bundle parameter. According to the UIViewController documentation, passing nil will look up the NIB file in the main bundle (the application's one), which is not what you want.
You can workaround, by using a specialized initializer like this:
- (id) initWithBundle:(NSBundle *)bundle {
if(self = [super init]){
name = #"My Plugin";
viewController = [[ViewController alloc] initWithNibName:#"View" bundle:bundle];
}
return self;
}
And use it as follow:
Class principalClass = [loadedBundle principalClass];
id instance = [[principalClass alloc] initWithBundle:loadedBundle];
"View.xib is a nib"? Either it is a xib or it is a nib. A xib is not a nib. xib files can only be used in the interface builder, in deployment applications they must be transformed to nib files. That is what ibtool is doing. Xcode does not simply copy your xib files, it runs them through ibtool that converts them to nib files that are then placed into the Resources folder.
Related
I am trying to create a custom NSViewController and just log something out in viewDidLoad. In iOS, this is very trivial and works fine. However, when I setup a contentViewController on NSWindow (which i assume is similar to RootViewController in iOS?) it attempt to load it from a nib.
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
self.ABViewController = [[ABViewController alloc] init];
self.window.contentViewController = self.ABViewController;
}
2016-06-28 09:15:42.186 TestApp[32103:33742217] -[NSNib _initWithNibNamed:bundle:options:] could not load the nibName: ABViewController in bundle (null).
What assumptions am I missing about how Cocoa is different from iOS that prevent me from simply setting up a viewController?
NSViewController doesn't have the same behavior as UIViewController, in that it won't automatically know to look for a nib file with the same name as itself. In other words, it won't automatically know to look for the ABViewController.nib file.
The simplest way to fix this is just override the nibName method in ABViewController:
#implementation ABViewController
- (NSString *)nibName {
return NSStringFromClass([self class]);
}
#end
Note that using NSStringFromClass() is usually better than trying to hard code the string, as this way will survive refactoring.
You can then call [[ABViewController alloc] init]; like before and NSViewController's default init method will get the nib name from your overridden nibName method.
It looks like your program wan't find the file where the view's are defined. You need to do something like this for storyboards:
UIStoryboard *sboard = [UIStoryboard storyboardWithName:#"StoryboardFileName"
bundle:NSBundle.mainBundle()];
SecondViewController *vc1 = [sboard instantiateInitialViewController];
I am having a weird error with NSViewController where if I allocate a view using the viewcontroller's regular init message, the view created is not my view, but when using the default NIB name, it does work.
Specifically, this code works all the time. It creates the view defined in the nib file, and displays it in the parentView.
+ (void)createTransparentViewCenteredInView:(NSView*)parentView withText:(NSString*)text duration:(NSTimeInterval)duration {
TransparentAccessoryViewController* controller = [[TransparentAccessoryViewController alloc] initWithNibName:#"TransparentAccessoryViewController" bundle:nil];
NSLog(#"%#", [controller.view class]); // Returns "TransparentAccessoryView" -- CORRECT
[parentView addSubview:controller.view];
}
However, the following code works SOME of the time (which is weird in that it doesn't always fail). With some parentViews, it works perfectly fine, and with others, it doesn't. The parent views are just random custom NSViews.
+ (void)createTransparentViewCenteredInView:(NSView*)parentView withText:(NSString*)text duration:(NSTimeInterval)duration {
TransparentAccessoryViewController* controller = [TransparentAccessoryViewController new];
NSLog(#"%#", [controller.view class]); // Returns "NSSplitView" -- INCORRECT
[parentView addSubview:controller.view];
}
The errors that comes up are as follows (I have no idea why it is bringing up an NSTableView, as I don't have an NSTableView here at all. Also, it is weird that it complains about an NSTableView when the type it prints is an NSSplitView):
2013-04-07 21:33:12.384 Could not connect the action refresh: to
target of class TransparentAccessoryViewController
2013-04-07 21:33:12.384 Could not connect the action remove: to target
of class TransparentAccessoryViewController
2013-04-07 21:33:12.385 * Illegal NSTableView data source
(). Must implement
numberOfRowsInTableView: and tableView:objectValueForTableColumn:row:
The NIB file defines a custom subclassed NSView, called TransparentAccessoryView, and hooks this up to the File Owner's view property, standard stuff (all I did was change the custom class name to TransparentAccessoryView). I added an NSLog's to see what was going on, and for some reason, in the second case, the view class type is incorrect and thinks it is an NSSplitView for some reason. The ViewController class is as follows:
#implementation TransparentAccessoryViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Initialization code here.
}
return self;
}
- (void)awakeFromNib {
self.textField.stringValue = #"";
}
+ (void)createTransparentViewCenteredInView:(NSView*)parentView withText:(NSString*)text duration:(NSTimeInterval)duration {
TransparentAccessoryViewController* controller = [[TransparentAccessoryViewController alloc] initWithNibName:#"TransparentAccessoryViewController" bundle:nil];
NSLog(#"%#", [controller.view class]);
[parentView addSubview:controller.view];
}
#end
I thought that the default init message triggers the viewcontroller to load the NIB named after the viewcontroller, which seems to be the case some of the time as the second version of my code works in certain conditions.
Does anyone know why this behavior is occurring at all?
From the docs:
If you pass in a nil for nibNameOrNil then nibName will return nil and
loadView will throw an exception; in this case you must invoke
setView: before view is invoked, or override loadView.
Therefore, if you're initializing a NSViewController with -init, you should call -setView: to set the view controller's view, or override -loadView. In the latter case, you could certainly implement the UIViewController-like behavior that you're probably expecting -- if nibNameOrNil is nil, try to load a nib that has the same name as the class.
I think that when you call init on a NSViewController, you're assuming that the implementation of init for NSViewController searches for a nib with the same name as the view controller and uses it. However, this is undocumented API or at least I can't seem to find any documentation supporting that assumption. The link you posted on your comments doesn't cite any documentation either and even reiterates that this is undocumented and that Apple could change this implementation at any point.
I think to assure that your code works in future versions of the SDK (and since it is already creating undesired behavior), you should not rely on this assumption. To achieve the same outcome simply override init and initWithNibName:bundle: in such a way as explained by this post:
#implementation MyCustomViewController
// This is now the designated initializer
- (id)init
{
NSString *nibName = #"MyCustomViewController";
NSBundle *bundle = nil;
self = [super initWithNibName:nibName bundle:bundle];
if (self) {
...
}
return self;
}
- (id)initWithNibName:(NSString *)nibName bundle:(NSBundle *)bundle
{
// Disregard parameters - nib name is an implementation detail
return [self init];
}
I have a UIViewController with some controllers and some views. Two of these views (Grid Cell) are other nibs. I've got outlets from the Grid Cells to File's Owner, but they aren't loaded automatically.
So I try to override GridCell.m's initWithCoder.
This starts an infinite loop.
I know it's possible to just override initWithFrame and add the subview from code, but this is not what I want. I want to be able to move the view around in Interface Builder and have Xcode initialize the view with the right frame.
How do I go about achieving this?
EDIT 1
I'm trying to get it working with the help of Alexander. This is how I've now got it set up:
MainView has UIView with a Custom class set as GridCell. It got an outlet in the MainView/File's Owner.
Removed all init-code from GridCell.m and set up an outlet to my custom class
The MainView don't still display the GridCell though. There's no error, just a lonely, empty space where the red switch should be. What am I doing wrong?
I'm very close to just doing this programmatically. I would love to learn how to this with nibs though.
Loading the nib causes initWithCoder to be called again, so you only want to do so if the subclass currently doesn't have any subviews.
-(id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
if (self.subviews.count == 0) {
UINib *nib = [UINib nibWithNibName:NSStringFromClass([self class]) bundle:nil];
UIView *subview = [[nib instantiateWithOwner:self options:nil] objectAtIndex:0];
subview.frame = self.bounds;
[self addSubview:subview];
}
}
return self;
}
Loading a nib will cause the corresponding owner in a
-(id) initWithCoder:(NSCoder *) coder;
call
Therefore your coude in this method:
self = [[[NSBundle mainBundle] loadNibNamed: #"GridCell"
owner: self
options: nil] objectAtIndex:0];
will cause again a call of the initWithCoder method. That's because you try to load the nib again. If you define a custom UIView and create a nib file to lay out its subviews you can't just add a UIView to another nib file, change the class name in IB to your custom class and expect the nib loading system to figure it out.
What you could do is the following:
Your custom view's nib file needs to have the 'File's owner' class set to your custom view class and you need to have an outlet in your custom class called 'toplevelSubView' connected to a view in your custom view nib file that is acting as a container for all the subviews. Add additional outlets to your view class and connect up the subviews to 'File's owner' (your custom UIView). (See https://stackoverflow.com/a/7589220/925622)
EDIT
Okay, to answer your edited question I would do the following:
Go to the nib file where you want to include the custom view with it's nib file layouting it.
Do not make it to the custom view (GridCell) itself, instead make a view which will contain your grid cell (gridCellContainer for example, but it should be a UIView)
Customize the initWithFrame method within your custom view like you did in initWithCoder:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"GridCell" owner:self options:nil];
self = [nib objectAtIndex:0];
self.frame = frame;
}
return self;
}
And then, in the viewController which is the fileOwner for the view where you want to include your custom view (the one with the gridCellContainer view) do this in viewDidLoad e.g.
//...
GridCell *gridCell = [[GridCell alloc] initWithFrame:self.viewGridCellContainer.bounds];
[self.viewGridCellContainer addSubview:gridCell];
Now eveything should work as you expected
The File's owner will not get a call to
-(id) initWithCoder:(NSCoder *) coder;
when loading a xib.
However, every view defined in that xib will get a call to
-(id) initWithCoder:(NSCoder *) coder;
when loading a xib.
If you have a subclass of a UIView (i.e. GridCell) defined in a xib and also try to load that same xib in your subclass's initWithCoder, you will end up with an infinite loop. However, I can't see what will the use case be.
Usually you design your UIView's subclass (i.e. GridCell) in one xib, then use that subclass in a view controller’s xib for example.
Also, can't see a use case where your custom view will have a subview in it's initWithCoder, i.e.
-(id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
if (self.subviews.count == 0) {
UINib *nib = [UINib nibWithNibName:NSStringFromClass([self class]) bundle:nil];
UIView *subview = [[nib instantiateWithOwner:self options:nil] objectAtIndex:0];
subview.frame = self.bounds;
[self addSubview:subview];
}
}
return self;
}
Unless you want to be able to override its view hierarchy on demand in some other xib. Which IMO assumes an external dependency (i.e. a hierarchy defined in another xib) and kinda defeats the purpose of having a reusable UIView in the first place.
Bare in mind that when loading a xib, passing an instance as the File's owner, will have all of its IBOutlet(s) set. In that case, you would be replacing self (i.e. GridCell) with whatever the root view in that GridCell.xib is, losing all IBOutlet connections in the process.
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:#"GridCell" owner:self options:nil];
self = [nib objectAtIndex:0];
self.frame = frame;
}
return self;
}
There is a more detailed post on "How to implement a reusable UIView." that goes into a bit more detail as well and hopefully clears things up.
loadNibNamed:: will call initWithCoder:
Why don't you follow this pattern?
-(id)initWithCoder:(NSCoder *)coder
{
if (self = [super initWithcoder:coder]) {
// do stuff here ...
}
return self;
}
Does [super initWithcoder:coder] do things that you want to avoid?
I had the same issue when I'm trying to override initWithsomething method, we need
-(id)initWithsomething:(Something *)something
{
if (self = [super initWithsomething:something]) {
// do stuff here ...
}
return self;
}
instead
-(id)initWithsomething:(Something *)something
{
if (self = [super init]) {
// do stuff here ...
}
return self;
}
I have an iOS application for which I want to create a ViewController programmatically.
I started an empty XCode project and modified the main method so it looks like this
int main(int argc, char *argv[])
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
int retVal = UIApplicationMain(argc, argv, nil, #"MyAppDelegate_iPad");
[pool release];
return retVal;
}
The app is a Universal Application, MyAppDelegate_iPad is a subclass of MyAppDelegate, which is a subclass of NSObject <UIApplicationDelegate>.
My problem is that the applicationDidFinishLoading method I've overridden in MyAppDelegate_iPad is never called (break point on the first line never hits). The method looks like this
-(void) applicationDidFinishLaunching:(UIApplication *)application {
window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
if(!window)
{
[self release];
return;
}
window.backgroundColor = [UIColor whiteColor];
rootController = [[MyViewController alloc] init];
[window addSubview:rootController.view];
[window makeKeyAndVisible];
[window layoutSubviews];
}
I removed the line to link to a nib file from my plist file (I used to get the default "My Universal app on iPad" white screen) and now all that is displayed is a black screen. applicationDidFinishLoading is still not being called.
Am I doing something wrong? How should I properly create my AppDelegate instance?
There’s a main nib file that bootstraps your application. This nib file is referenced in the Info.plist file under the NSMainNibFile key and should contain an object that corresponds to your application delegate class (setting the Class attribute in Interface Builder). This application delegate object is referenced by the delegate outlet on the file’s owner placeholder.
So if I understand things correctly, the application loader loads the main nib file, setting itself as the nib owner. Its delegate property gets set to a fresh instance of your application delegate class, and so the loader knows where to dispatch the various application lifecycle event callbacks.
There’s an awesome blog post about Cocoa application startup on Cocoa with Love.
If you are making universal you don't need two different app delegate classes. see this link (my answer), it may be help you to make universal app.
I'm trying to lay out some images in code using addSubview, and they are not showing up.
I created a class (myUIView) that subclasses UIView, and then changed the class of the nib file in IB to be myUIView.
Then I put in the following code, but am still getting a blank grey screen.
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// Initialization code
[self setupSubviews];
}
return self;
}
- (void)setupSubviews
{
self.backgroundColor = [UIColor blackColor];
UIImageView *black = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"black.png"]];
black.center = self.center;
black.opaque = YES;
[self addSubview:black];
[black release];
}
yes, just implement initWithCoder.
initWithFrame is called when a UIView is created dynamically, from code.
a view that is loaded from a .nib file is always instantiated using initWithCoder, the coder takes care of reading the settings from the .nib file
i took the habit to do the initialization in a separate method, implementing both initWithCode and initWithFrame (and my own initialization methods when required)
try implementing initWithCoder: sometimes I've had trouble with IB and initWithFrame:
or at least add a logging call to see if your init method is executed